NAVAL SPACE

2-2 • Encourage state, local and private sector investment in, and use of, space technologies; and • Promote international cooperation to further U.S. domestic, national security, and foreign policies. The United States is committed to the exploration and use of space by all nations for peaceful purposes and for the benefit of all humanity. "Peaceful purposes" allows defense and intelligence-related activities in pursuit of national security and other goals. The United States rejects all claims to sovereignty by any nation over outer space or celestial bodies or any portion thereof, and rejects any limitations on the fundamental right of sovereign nations to acquire data from space. The United States considers the space systems of any nation to be national property with the right of passage through and operations in space without interference. Purposeful interference with space systems is viewed as an infringement on sovereign rights. The National Science and Technology Council (NSTC) is the principal forum for resolving issues related to a national space policy. As appropriate, the NSTC and National Security Council (NSC) will co-chair the policy processes. National Space Policy specifically directs the national security space sector (composed primarily of the Secretary of Defense (SecDef) and the Director of Central Intelligence (DCI)), to conduct space activities necessary for national security by: • Providing support for the United States’ inherent right -of self-defense and our defense commitments to allies and friends; • Deterring, warning, and if necessary, defending against enemy space attack; • Assuring that hostile forces cannot prevent our own use of space; • Countering, if necessary, space systems and services used for hostile purposes; • Enhancing operations of U.S. and allied forces; • Ensuring our ability to conduct military and intelligence space-related activities; • Satisfying military and intelligence requirements during peace and crises as well as through all levels of conflict; and • Supporting the activities of national policy makers, the intelligence community, the National Command Authorities, combatant commanders and military services, other federal officials, and continuity of government operations. Further, the policy directs a closer coordination between the Department of Defense (DoD) and intelligence community activities related to space policy.

2-3 Within the national security sector, specific DoD guidelines include the directive to maintain the capability to execute the mission areas of space support, force enhancement, space control and force application. Space Co ntrol activities are necessary to ensure freedom of action in space, thus supporting all space activities, and if directed, DoD space control capabilities will be employed to deny such freedom of action to adversaries. These defense capabilities may be enhanced by diplomatic, legal or military measures to preclude an adversary’s hostile use of space systems and services. The U.S. will maintain and modernize space surveillance and associated battle management command, control, communications, computers, and intelligence to effectively detect, track, categorize, monitor, and characterize threats to U.S. and friendly space systems and contribute to the protection of U.S. military activities. DoD will continue to serve as the launch agent for both the defense and intelligence sectors, and maintain the capability to evolve and support those space transportation systems, infrastructure, and support activities necessary to meet national security objectives.DoD will be the lead agency for improvement and evolution of the current expendable launch vehicle fleet, to include technology development. DoD will pursue integrated satellite control and continue to enhance the robustness of its satellite control capability, and where appropriate, foster the integration and interoperability of satellite control for all governmental space activities. The SecDef, in concert with the DCI, and for the purposes of supporting operational military forces, may propose modifications or augmentations to intelligence space systems as necessary. The DoD may develop and operate space systems to support military operations in the event that intelligence space systems cannot provide the necessary intelligence support. The United States will pursue a ballistic missile defense program to provide for: future enhanced theater missile defense; a national missile defense deployment readiness program as a hedge against the emergence of a long-range ballistic missile threat to the United States; and an advanced technology program to provide options for improvements to planned and deployed defenses. Specific guidance for the intelligence portion of the national security sector includes the timely provision of information and data to support: foreign, defense and economic policies; military operations; diplomatic activities; indications and warning; crises management; and treaty verification, and to conduct research and development activities related -to these functions. The DCI shall continue to develop and apply advance technologies that respond to changes in the threat environment and support national intelligence priorities. The DCI shall work closely with the SecDef to improve the intelligence space sector’s ability to support military operations worldwide.

2-4 The lead agency for research and development in civil space activities is the National Aeronautics and Space Administration (NASA). NASA, in coordination with other departments and agencies, will focus research and development efforts in space science to enhance knowledge of the solar system, the universe, and fundamental natural and physical sciences; Earth observation to better understand global change and the effect of natural and human influences on the environment; human space flight to conduct scientific, commercial and exploration activities; and space technologies and applications in support of U.S. Government needs and our economic competitiveness. Activities include: development and operation of the International Space Station; development of next-generation reusable launch systems; research activities and programs to support a robotic presence on the surface of Mars; and the development of innovative space technologies, and smaller and more capable spacecraft. Also within the civil space sector, the Department of Commerce (DOC), through the National Oceanographic and Atmospheric Administration (NOAA), has the lead responsibility for managing Federal space-based civil operational Earth-observations necessary to meet civil requirements. The Department of the Interior (DoI), through the U,.S. Geological Survey (USGS) will maintain a national archives of land remote sensing data and other surface data as appropriate, making the data available to U.S. Government and other users. The fundamental goal of the U.S. commercial space sector is to support and enhance U.S. economic competitiveness in space activities while protecting U.S. national security and foreign policy interests. Expanding U.S. commercial space activities will generate economic benefits for the Nation and provide the U.S. Government with an increasing range of space goods and services. U.S. Government agencies shall purchase commercially available space goods and services to the fullest extent feasible and shall not conduct activities with commercial applications that preclude or deter commercial space activities except for reasons of national security. The United States will pursue its commercial space objectives without direct Federal subsidies. Commercial Sector space activities shall be supervised or regulated only to the extent required by law, national security, international obligations and public safety. MILITARY SPACE ORGANIZATIONS The DoD Space Policy implements the National Security Space Policy. The primary DoD goal in space is to provide operational capabilities to ensure that the United States can meet national security objectives. Support of these objectives involves using space as a medium from which to conduct and support military missions.

2-5 Each of the armed services is assigned respon sibilities to organize, train, equip and provide forces for either land, maritime or air warfare. Over the past four decades, the services have relied more and more on space assets to conduct or support their assigned missions. During the 1980s, each service consolidated space operations under its own space command. In 1985, the JCS established the USSPACECOM as a unified command to, control U.S. military space assets and to coordinate across service boundaries. Once established, USSPACECOM was assigned operational command (OPCOM) of the service space commands, now considered component commands. The DoD organization for space operations is depicted in Figure 2-1. SAC FORSCOM SPECIFIED COMMANDS AIR FORCE SPACE COMMAND NAVAL SPACE COMMAND ARMY SPACE COMMAND UNITED STATES SPACE COMMAND USTRANSCOM USLANTCOM USPACOM USEUCOM USCENTCOM USSOCOM USSOUTHCOM UNIFIED COMMANDS JOINT CHIEFS OF STAFF SECRETARY OF DEFENSE PRESIDENT CMDR-IN-CHIEF Figure 2-1. Military space organizations−operational chain of command. Department of the Air Force In addition to the shared responsibilities to provide forces for the strategic defense of the U.S. and coordination with the other services for space operations, the Department of the Air Force is specifically assigned the missions of acquiring and operating launch vehicles; developing, producing, and deploying space systems for warning and surveillance of nuclear attack; and providing orbital operations support for DoD missions. The Air Force performs these missions for the benefit of all the services. The Air Force also uses space systems for communications, navigation, surveillance, and environmental monitoring to accomplish its own primary mission of maintaining air supremacy in support of national objectives. Historically, the Air Force has been the principal provider of space systems for DoD, and remains uniquely postured for that role. The Air Force offers a career path in space systems. Career paths are available in several space-related operations, engineering, and staff fields for both officer and enlisted personnel. With these career space personnel, the Air Force has established an infrastructure representing approximately 90 percent of DoD’s space experienced personnel and 80 percent of the DoD space budget.

2-6 Current Air Force initiatives include developing increased launch capacity to ensure unimpeded access to space, anti-satellite command and control capabilities to ensure that we can deny an adversary use of his space systems, a space-based wide area surveillance system to increase surveillance capability for defense of the United States, and a survivable satellite command and control system to provide uninterrupted space operations. UNITED STATES SPACE COMMAND On September 23, 1985, the United States Space Command (USSPACECOM) was activated to consolidate all military space efforts under the direction of one commander-in-chief (CINC) directly responsible to the President through the Secretary of Defense and Chairman, Joint Chiefs of Staff. USSPACECOM is a unified command of the DoD and is headquartered at Peterson Air Force Base, Colorado. . Personnel from the Army, Marine Corps, Navy and Air Force staff the command. USSPACECOM oversees three service component commands: Army Space and Missile Defense Command, Naval Space Command, and Air Force Space Command. USSPACECOM provides joint employment of military forces and operational support to other unified combatant commands. The command performs these functions through four primary missions: space support, force enhancement, space control, and force application. Space Support: Space support operations include launch and on-orbit satellite command and control operations. Space support is provided by Army, Naval and Air Force Space Commands. The U.S. has two primary launch sites; located at Cape Canaveral Air Force Station (CCAFS), FL, and Vandenberg AFB, CA. Air Force Space Command (AFSPC) operates the launch wings at each base and is engaged in a major program to restore and modernize launch facilities. AFSPC launches warning, navigation and communications satellites from Cape Canaveral into low or synchronous orbits. Once a satellite is in orbit, a worldwide network of ground stations controls it. Scheduling is done by AFSPC at Shriever AFB, CO, and Onizuka Air Station (AS), CA. NAVSPACECOM controls the Fleet Satellite (FLTSAT) and UHF Follow-On (UFO) communications satellites. The U.S. Army Space and Missile Defense Command (SMDC) operates the Defense Satellite Communications Systems’ (DSCS) payloads supporting worldwide combat needs. Force Enhancement: Space systems provide direct support to land, sea, and air forces. To meet this need, USSPACECOM has control-of a fleet of satellites that provide ballistic missile warning, communications, weather and navigation, and positioning support. U.S. forces also employ commercial communications satellites, civil weather satellites, and civil multi- spectral imagery satellites.

2-7 Defense Support Program (DSP) satellites provide warning data o n ballistic missile launches. FLTSAT, DSCS, UFO and Air Force Satellite Communications System (AFSATCOM) provide satellite communications support. The Defense Meteorological Satellite Program (DMSP) and civil-meteorological satellites provide weather data. The Global Positioning System (GPS) satellites provide navigation and positioning. U.S. LANDSAT, IKONOS and French SPOT satellites provide multi-spectral imagery on the commercial market. During Operations "Desert Shield" and "Desert- Storm," space assets met the needs of U.S. land, sea and air forces; frequently providing capabilities and support not envisioned when the systems were on the drawing boards. For example, the alerting system that warned of SCUD attacks was based on warning provided by DSP satellites, originally designed to warn of intercontinental ballistic missile (ICBM) attack. Ground forces that initially deployed to Desert Shield had access to the United States’ most effective means of navigation, the GPS. Thousands of commercial GPS receivers were purchased to meet the demand of GPS navigation and positioning data. Deployed forces received weather data broadcast by satellites and used maps produced from space-borne platforms. Satellite communication was the backbone for long haul and intra-theater connectivity for Desert Shield and Desert Storm, with over 90% of communications into and out of the theater carried over communication satellites. Space Control: Space control is essential to the success of future United States land/sea/air military operations. Assured access to, and unimpeded operation in space, and the denial to an enemy of the same, are the key tenets of space control operations. The three pillars of space control are surveillance, protection, and negation. The USSPACECOM worldwide Space Surveillance Network (SSN) is tasked to detect, track, identify, and catalog all man-made space objects to ensure space operations are conducted without interference. The USSPACECOM Space Control Center (SCC) in Cheyenne Mountain provides warning to United States space system operators to protect their satellites from potentially hostile situations or dangerous natural events. Disrupting, degrading, denying or destroying space-based support to hostile military forces are the basic principles of negation. The United States has no operational anti-satellite (ASAT) weapon system. However, research and development into ASAT technology is continuing. An operational ASAT would deter threats to U.S. space systems, enabling U.S. to negate hostile space-related forces and ensuring the right of self-defense. Force Application: Force application will be performed through the planned acquisition of ballistic missile defense systems.

2-8 The Missile Defense Act of 1991, as amended by Congressional language in 1992, directs the DoD to provide protection of the U.S., forward deployed U.S. forces, and allies from limited ballistic missile strikes. Ballistic missile defense systems are divided into theater defense systems to counter short, medium and intermediate range ballistic missiles, and U.S. defense systems to counter ICBMs. USSPACECOM will provide space-based ballistic missile support (warning, surveillance, cueing, etc.) to theater commanders for theater missile defense (TMD) and to the North American Aerospace Defense Command (NORAD) for the protection of the North American Continent against ICBM threats. Space Surveillance Space surveillance is a critical part of USSPACECOM’s mission. Involves detecting, tracking, cataloging and identifying man-made objects orbiting Earth, e.g. active/inactive satellites, spent rocket bodies or fragmentation. Space surveillance accomplishes the following: • Predicts when and where a decaying satellite will re-enter the Earth’s atmosphere; • Charts the present position of space objects and plots anticipated orbital paths; • Detects new man-made objects in space; • Produces a running catalog of man-made space objects; • Determines which country owns a re-entering space object; and • Informs NASA if objects may interfere with the Space Shuttle. The command accomplishes these tasks through its worldwide network of Space Surveillance Network (SSN) radar and optical sensors. Space Surveillance Network (SSN) The SSN has been tracking space objects since 1957 when the USSR opened the space age with the launch of SPUTNIK I. Since then, the SSN has tracked and cataloged more than 23,000 space objects. The SSN currently tracks about 10,000 objects. The space objects now orbiting Earth range from satellites weighing several tons to pieces of spent rocket bodies weighing only 10 pounds. About 7% of the space objects are operational satellites; the rest are debris. The SSN tracks space objects which are 10 centimeters in diameter (baseball size) or larger. The SSN uses a "predictive" technique to track space objects; i.e., it spot- checks them rather than tracking them continually. This technique is used because of SSN limitations (number of sensor, geographic distribution, capability, and availability). The SSN consists of the types of sensors shown in Table 2-1.

2-9 Table 2-1. Space Surveillance Network (SSN) Sensors Mechanical Tracking Radar Large dish antenna radar that are mechanically rotated in azimuth and raised in elevation to locate and track an object. Detection Fan Radar Older technology. Area search radar systems that monitor large sections of space. Stationary objects are detected as they pass through the search area. Phased Array Radar Newer technology. Area search radar can simultaneously monitor sections of space and track multiple objects as they orbit overhead. They have no moving parts to limit the speed of the radar scan; the radar energy is steered electronically. Ground-Based Electro-Optical Deep Space Surveillance System (GEODSS) Consists of three telescope sensors linked to video cameras. The video cameras feed their space pictures into a nearby computer which drives a display scope. The image is transposed into electrical impulses and recorded on magnetic tape—the same process used by video cameras. The image can be recorded and analyzed in real-time. Combined, these types of sensors make 30,000 to 50,000 satellite observations each day. This enormous amount of data comes from SSN sites such as NAVSPACECOM, Maui, HI, Eglin AFB, FL, Thule, Greenland, and Diego Garcia, in the Indian Ocean. The data is transmitted to USSPACECOM’s SCC via satellite, ground wire, microwave and telephone. The SCC in Cheyenne Mountain is the terminus for the SSN’s abundant and steady flow of information. The SCC houses large, powerful computers to process SSN information and accomplish the space surveillance missions. NAVSPACECOM provides the site and processing capability for the Alternate SCC (ASCC) located at Naval Space Command, Dahlgren, VA. The ASCC would take over all operations in the event the SCC could not function. This capability is exercised weekly. Air Force Space Command AFSPC is the Air Force component of USSPACECOM. The mission of AFSPC is to defend the United States through the control and exploitation of space. As such, the command is also responsible for organizing, training, equipping, and administering Air Force units in support of USSPACECOM’s missions. Air Force Space Command (AFSPC) is headquartered at Peterson Air Force Base in Colorado Springs, Colorado. The command was established in 1982 as an Air Force major command to bring space systems operation and planning on a par with other Air Force missions, such as tactical and strategic air supremacy. As a major-command, AFSPC organizes, trains, equips, sustains and operates assigned Air Force space, surveillance and missile warning systems. Specifically, the command:

2-10 • Operates military space systems - weather, communications, navigational and missile warning satellites; • Operates ground-based radar and missile warning satellites to provide ballistic missile warning for North America; • Operates the national launch centers and ranges to provide military, civil and commercial access to space; • Operates worldwide surveillance radar to provide continuous information on the location of satellites and space debris in orbit; • Operates the nation’s intercontinental ballistic missile (ICBM) force. AFSPC operates a host of different organizations to accomplish these objectives. These subordinate units are located around the world, operating from remote sites, stations, and bases. AFSPC personnel and units are organized into several wings. 14 th Air Force. The 14th Air Force located at Vandenberg AFB, California plans and executes operations for space support, force enhancement and space control. It also serves as the operational component of AFSPACECOM by providing the day-to-day operators and managers of AFSPC’s space forces. 14 th Air Force is also responsible for AFSPC’s operational planning and employment in wartime and during major worldwide exercises and contingencies. The 14 th Air Force consists of subordinate units as discussed in the following paragraphs. 21st Space Wing. The 21st Space Wing is located at Peterson AFB, Colorado. Operates a network of dedicated missile warning sensors. These sensors provide Integrated Tactical Warning and Attack Assessment (ITW/AA) of sea and land-launched ballistic missile attacks against the continental United States and Canada. Resources include the Defense Support Program (DSP); a space based early warning system, phased-array radar and mechanical radar. The Wing provides day-to-day management, training and evaluation for the personnel at the missile warning, intelligence and communications units assigned to it. Included in this worldwide network of sensors are the PAVE PAWS SLBM warning system radar at Cape Cod AFS, Massachusetts and Beale AFB, California. Ballistic Missile Early Warning Systems (BMEWS) are located at Thule AB, Greenland, Clear AFS, Alaska and Fylingdale’s Moor in the United Kingdom (U.K.). DSP ground stations are located in Colorado, Europe and Australia. 30 th Space Wing. The 30 th Space Wing is located at Vandenberg AFB, California and operates the Western Test Range. The Wing is responsible for launching and tracking expendable space boosters and conducting ICBM test launches from the West Coast of the U.S. The Delta II, Titan II and IV and a variety of other expendable boosters used for placing satellites into a variety of orbits, to include near-polar, are currently launched from the range.

2-11 45th Space Wing. The 45th Space Wing is located at Patrick AFB, Florida. It provides space launch and tracking facilities, safety procedures and test data to a wide variety of users. The Wing launches a variety of expendable vehicles to include the Delta II, Atlas II and Titan IV. It also provides support to the Space Shuttle program, operates Cape Canaveral AFS, and the Eastern Test Range. Additional responsibilities include launch operation and management of DoD space programs, and launch and tracking facilities for NASA, foreign governments, the European Space Agency and commercial customers. 50 th Space Wing. The 50 th Space Wing, located at Shriever AFB, Colorado, provides command and control of operational DoD spacecraft and management for the worldwide Air Force Satellite Control Network (AFSCN). The AFSCN is a network of eight satellite tracking stations linked by sophisticated communications equipment. The eight Remote Tracking Stations (RTS’s) are: Vandenberg RTS, CA; Hawaii RTS, HI; Colorado RTS, CO; New Hampshire RTS, NH; Thule RTS, Greenland; Oakhanger RTS, UK; Guam Tracking Station, Guam; and the Diego Garcia Tracking Station, British Indian Ocean Territory. The AFSCN supports more than 110 DoD satellites by allowing satellite operators at Onizuka AS and Shriever AFB to communicate with and control the satellites for which they are responsible. Before an orbiting satellite passes over an RTS, the RTS equipment is configured for the specific satellite, pointed toward the satellite, and tested to ensure system readiness. Actual pass support begins with the acquisition of a satellite signal. Typical pass sequence activities include transmitter turn-on, health check, mission data readout, automatic sequence programming, satellite reconfiguration, and transmitter turn off. Recorded data is analyzed after the satellite passes. Typical satellite passes, including preparation, average 30 minutes to an hour depending on the satellites’ orbit and the functions being performed. Low-Earth orbiting satellites are in view of the tracking stations for 15 minutes or less. The 750 th Space Group (750 SG) is a component of the 50th Space Wing and is located at Onizuka AFS, California. This organization is responsible for operations, maintenance and logistics support for the common user resources of the AFSCN. The Group monitors, maintains and updates the status of the AFSCN resources and provides the status of configurations and readiness of controlled resources to multiple users and command centers. Two Resource Control Complexes belonging to the 750 SG are the 21 st Satellite Operations Squadron (SOPS) at Onizuka AS and the 22nd SOPS at Shriever AFB. These organizations give the network dual node capability, insuring continual support for on-orbit satellites. They are responsible for scheduling the use of tracking stations for satellite operators at Onizuka AS and Shriever AFB. This capability enables them to make contact with the satellites through the tracking stations to accomplish the functions of command and control. Due to the Base Realignment and Closure List, AFSPC operations at Onizuka AS will be transferred to Shriever AFB. This move is expected to be completed by the year 2001. The SOPS’s under the 50 th Space Wing at Shriever AFB perform tracking, telemetry and command functions for orbiting spacecraft. They are compatible with the SOPS located at

2-12 Onizka AS and provide support to the Defense Meteorological satellite Program (DMSP), DSP, Navstar Global Positioning System (GPS), Defense Satellite Communications System (DSCS), NATO III, and the UHF Follow-On (UFO), MILSTAR and the technology for Autonomous Operational Survivability (TAOS) experimental satellite. Also located at Shriever AFB are the GPS Master Control Station (GPS MCS) operated by the 2 nd SOPS; the MILSTAR Master Control Center operated by the 4th SOPS; and the 5oth Space Wing Command Post. Co-located on Shriever AFB are the dual AFSCN terminals, the Colorado Tracking Station of the AFSCN and a GPS monitor station. The 50th Space Wing subordinate units include the 1st through 7th SOPS: 1st SOPS , located at Shriever AFB provides routine, consolidated command and control support for three different systems: DSP, GPS, TAOS and other assigned Research and Development (R&D) spacecraft. The 1 st SOPS operates and maintains 24-hour AFSCN command and control capability for the GPS and DSP systems. The squadron also operates and maintains R&D space systems that possess potential residual capabilities to support military operations. Early orbit operations performed by the 1 st SOPS include satellite activation, initial checkout and transfer to mission orbit. The squadron plans and executes Tracking, Telemetry and Commanding (TT&C) functions for GPS and DSP satellites to maintain spacecraft state-of- health, sustain on-orbit operations and accomplish mission tasking. They also support satellite end of-life testing and conduct satellite disposal operations for GPS and DSP satellite. The 1 st SOPS maintains DSP spacecraft positional data to 200 meters and distributes this data to a host of worldwide users. The squadron maintains the capacity to support at least six contacts for each DSP satellite per day. When required, the squadron can relocate operations within 48 hours to their back-up node at Onizuka AS to perform limited command and control to sustain on-orbit operations of assigned GPS and DSP satellites. 2 nd Sops, located at Shriever AFB, provides command and control for the nominal GPS constellation of 24 satellites. GPS provides worldwide precision navigation service for U.S. and allied military forces as well as civilian users. The 2 nd SOPS operates and maintains the GPS Master Control Station (MCS) and a dedicated network of monitor stations and ground antennas to control and monitor the satellite constellation. The monitor stations passively track the navigation signals on all the satellites. Information is processed at the MCS and is used to update the satellites’ navigation messages. The MCS then sends updated navigation information to the GPS satellites through ground antennas. Ground Antennas are also used to transmit commands to satellites and to receive the satellites’ state of health (SOH) telemetry. 3 rd SOPS is also located at Shriever AFB and conducts both launch and on-orbit operations for military communications satellites for the DoD and Air Force Space Command. The 3rd SOPS conducts launch and on-orbit operations for DoD communications satellites,

2-13 which include the DSCS III, and MILSTAR. These satellites relay communications for the Defense Information Systems Agency (DISA). These organizations manage and maintain all primary peacetime and wartime communications links for the National Command Authority (NCA), theater commanders and all strategic and tactical forces worldwide. The 3 rd SOPS also has the AF Satellite Communications (AFSATCOM) mission. AFSATCOM provides reliable, enduring, worldwide command and control communications to users based on a priority system outlined by the Joint Chiefs of Staff (JCS). Operational crews at the 3 rd SOPS are responsible for providing telemetry analysis and tracking data for orbit determination and commanding of on-board subsystems for the DSCS III program. In addition, they are responsible for launch and early orbit operations for the Navy’s UHF F/O spacecraft, a replacement for the Fleet Satellite (FLTSAT) Communications system. The 3 rd SOPS also shares operational control of MILSTAP, a next generation communications satellite program, with the 4th SOPS. The 3 rd SOPS was primarily responsible for the launch and emergency operations, but all operational control of MILSTAR has been turned over to the 4th SOPS. As the 3rd SOPS has been gaining control of new satellite systems, it has been working to focus its operations on these newest generation satellites. As a result, the operational mission for NATO III and DSCS II was transferred to 5 th SOPS at Onizuka AS. Control of the aging FLTSAT constellation was surrendered to the Navy at Pt. Mugu, California, in June of 1996. 4th SOPS is located at Shriever AFB and is responsible for overall command and control of the MILSTAR satellite constellation. The 4th SOPS is responsible for ensuring that the MILSTAR system provides survivable, enduring, essential command and control communications through all levels of conflict for the NCA and warfighting Commanders-in- Chief worldwide. The 4 th SOPS operates the MILSTAR system, executing communications management, satellite command and control, and ground segment maintenance for the MILSTAR constellation of satellites. MILSTAR is the most advanced military communications satellite system to date. The multi-satellite constellation links command authorities to high priority U.S. forces via MILSTAR terminals on aircraft, ships, submarines, trucks and ground sites through encrypted voice, data, teletype or facsimile communications. 5th SOPS, located at Onizuka AS, is responsible for planning and conducting launch and on-orbit support for a wide spectrum of DoD, allied and commercial space systems to include Inertial Upper Stage (IUS) missions which are used to transfer satellites from Low Earth Orbits to geosynchronous or interplanetary trajectories. The squadron also provides tracking and telemetry support on every Space Shuttle mission, and commercial customers. The 5 th SOPS has two primary responsibilities. The first is the launch and early orbit support for all DSCS III satellites. The second is the on-orbit command and control of the DSCS II communications satellites. Additionally, the 5 th SOPS provides tracking, telemetry, and commanding support for the National Oceanic Atmospheric Administration (NOAA), the Geostationary Operational Environmental Satellite (GOES) and the Total Ozone Mapping Spectrometer-Earth Probe (TOMS-EP) satellites.

2-14 6th SOPS is located at Shriever AFB, and is responsible for back-up command and control of the Defense Meteorological Satellite Program (DMSP). In May 1994, President Clinton directed the convergence of the DMSP program with NOAA’s Polar-Orbiting Environmental Satellite (POES) program. The POES program currently provides weather data to civilian and military users. Primary DMSP operations have been relocated to Suitland, Maryland, NOAA’s satellite control center. 7 th SOPS is located at Shriever AFB and is the first Air Force Reserve unit assigned to AFSPC. The mission of this squadron is to augment the SOPS’s of the 50 th Space wing. These activities include responding to satellite emergencies, launch and early orbit, day-to-day routine operations and satellite end of-life disposal for the GPS and Defense Support Program (DSP) satellites. Future plans call for expanding the mission to include support for other programs. 20 th Air Force. AFSPC has delegated the day-to-day management of our ICBM forces to the 20th Air Force, headquartered at F.E. Warren AFB, Cheyenne, WY. Its mission focuses on deterring conflict with ICBM’s that provide a quick-reacting, inertially guided, highly survivable component to America’s nuclear Triad. Missiles are dispersed in hardened silos to protect against attack and are connected to an underground launch control center through a system of hardened cables. Launch crews, consisting of two officers, perform round-the-clock alert in a launch control center. A variety of communications systems provide the NCA with highly reliable, virtually instantaneous direct contact with each launch crew. Should command capability be lost between the launch control center and remote missile launch facilities, specially-configured EC-135 airborne launch control center aircraft automatically assume command and control of the isolated missile or missiles. Fully qualified airborne missile combat crews aboard airborne launch control center aircraft wouldexecute the NCA orders. The 20 th Air Force units include: the 90th Missile Wing, F.E. Warren AFB, WY.; the 91st Missile Group, Minot AFB, ND; and the 341st Missile Wing, Malmstrom AFB, MT SPACE Warfare Center. The Space Warfare Center (SWC), at Shriever AFB, supports the warfighter through operational testing and tactics development for space-related systems. By working with the theater commanders, the SWC personnel are able to integrate space systems into exercises and war plans. They also develop concepts and prototypes to employ emerging technologies for advanced space systems and missions. For example, among its initiatives is Project Hook−a combination of GPS navigation and survival radios designed to improve search and rescue operations for downed pilots. Project Hook essentially takes the "search" out of "search and rescue" by pinpointing the location of the pilot on the ground and relaying it via "burst transmission" to a Search and Rescue Center. The Multi-Source Tactical System (MSTS), another SWC initiative, provides a six-layered picture of the operational theater for the aircrews. It combines tactical, intelligence and digital mapping information with real-time Airborne Warning and Control System (AWACS) information to upgrade flight crews en route to their targets or drop zones. Overall, there are more than 30 initiatives currently underway in the SWC to improve the tactical use of space by warfighters. The SWC is also

2-15 developing space models and simulations for inclusion in war gaming centers around the world for all the services. They are developing, through their deployable Forward Space Support in Theater (FAST) teams, operational plans for theater commanders that provide access to space assets and training in their use. Finally, the center is developing courses to teach space operators how to wage war so they can better understand and plan for space support to warfighting missions. Air Force Space Battlelab. The Air Force Space Battlelab at Shriever AFB, CO, is responsible for developing and testing innovative military space concepts. Because the pace of technology and innovation is faster than the current resource constrained planning, programming, and budgeting process can accommodate, the Battlelab creates an environment where innovative concepts can be harvested and rapidly evaluated, leading to more responsive fielding of proven concepts. The objective of the Battlelab is to provide proven operations and logistics concepts, which can be assimilated into Air Force organizational, doctrinal, training, and/or acquisition efforts. Table 2-2 summarizes all major AFSPC units. Table 2-2. Air Force Space Command (AFSPC) Major Units UNIT BASE WEAPON SYSTEM/ ACTIVITY 14th Air Force Vandenberg AFB, CA Provides day-to-day management of AFSPC space forces 21st Space Wing Peterson AFB, CO Missile Warning Operations 721st Space Group Cheyenne Mountain AS, CO Communications Maintenance Support 30th Space Wing Vandenburg AFB, CA DoD, civil, and commercial spacelift 45th Space Wing Patrick AFB, FL DoD, civil and commercial spacelift 50th Space Wing Shriever AFB, CO Satellite Operations and AFSCN 750th Space Group Onizuka AS, CA AFSCN operations 20th Air Force F.E. Warren AFB, WY Manages ICBM force 90th Space Wing F.E. Warren AFB, WY 150 Minuteman-III and 50 Peacekeeper ICBMs 91st Space Wing Minot AFB, ND 150 Minuteman-III ICBMs 341st Space Wing Malmstrom AFB, MT 200 Minuteman-III ICBMs Space Warfare Center Shriever AFB, CO Tactics for Space Systems Air Force Battlelab Shriever AFB, CO Space applications R&D 20th Space Surveillance Squadron Eglin AFB, FL Space Surveillance and Missile Warning 2nd Space Warning Squadron Buckley ANGB, CO Missile Warning 5th Space Warning Squadron Woomera AS, AUS Missile Warning 6th Space Warning Squadron Cape Cod AS, MA Missile Warning 7th Space Warning Squadron Beale AFB, CA Missile Warning 1st Satellite Operations Squadron (SOPS) Shriever AFB, CO Command and control for DSP, GPS, and TAOS 2nd SOPS Shriever AFB, CO NAVSTAR GPS 3rd SOPS Shriever AFB, CO DSCS 4th SOPS Shreiver AFB, CO MILSTAR 5th SOPS Onizuka AS, CA NATO IV/SKYNET 6th SOPS Shriever AFB, CO DMSP back-up Command and Control 7th SOPS Shriever AFB, CO AF Reserve Unit

2-16 North American Aerospace Defense Command (NORAD) President Franklin Delano Roosevelt and Canadian Prime Minister Mackenzie King issued the "Ogdensburg Declaration" in August 1940. It voiced the concept of joint defense. At war’s end, collective security for continental defense remained of vital interest to both nations. In February 1947, Ottawa and Washington announced the principles of future military cooperation that included consultation on air defense issues. On August 1, 1957, the U.S. Secretary of Defense and the Canadian Minister of National Defence put the plans into action. It was then that they announced a binational agreement for a system of centralized operational control of air defense forces under an integrated command located in Colorado Springs. The agreement signed by the two governments on May 12, 1958, set NORAD as the first and only successful binational command. In the agreement between the United States and Canada, NORAD provides a framework for cooperative defense planning and operations between both governments for the defense of North America. After its establishment, the new binational command started working on a secure and safe home from which to operate. To increase the chances for survival, the center was moved in the mid-‘60s from an above-ground and vulnerable building in Colorado Springs to the granite-shielded security of Cheyenne Mountain, then about seven miles south of the city. NORAD is responsible to the heads of both governments for surveillance and control of the airspace of Canada and the United States; warning and assessment of an aerospace attack on North America; and, providing an appropriate response should deterrence fail. Surveillance: For control of its North American airspace, NORAD maintains an extensive radar network throughout the U.S. and Canada. Additionally, the Commander in Chief (who is also the Commander of U.S. and Air Force Space Commands) has access to a wide array of space-borne sensors. These sensors are capable of detecting and tracking missile launches from anywhere in the world, and surveillance and monitoring aircraft suspected of smuggling illegal drugs into North America. Warning and Assessment: To accomplish its warning and assessment role, NORAD maintains an Integrated Tactical Warning/Attack Assessment (ITW/AA) system. With information from the ground-based and space-based sensors, CINCNORAD can provide timely, reliable, and unambiguous warning of any attack against North America. In 1994, NORAD detected and analyzed over 200 missile launches worldwide, and, with the proliferation of ballistic missile technology, that number is expected increase dramatically in the future.

2-17 Response: NORAD’s response capability is provided by a network of alert fighters along the periphery of North America. U.S. F-15s, and F-16s and Canadian F-18s stand ready to intercept and if necessary to engage any air breathing threat to the continent. The NORAD/United States Space Command Collocated Command Center The heart of the Cheyenne Mountain AFB, underground complex is the NORAD/USSPACECOM Command Center. Within the center, the NORAD/USSPACECOM CINC and battle staff receives immediate warning and surveillance information from a worldwide system of ground and space-based sensors. Computers in the center translate and display the information on maps of North America and the world to give the battle staff a realistic picture of current situations. With its communications "hot" lines, the command center staff can contact the Pentagon or White House, U.S. Strategic Command, Canadian Forces Headquarters in Ottawa, other aerospace defense system command posts, and major military centers around the world. USSPACECOM supports the NORAD mission by manning the missile warning, space control, communications and intelligence centers. Department of the Navy The Department of the Navy, like the other service departments, is responsible for providing forces for the strategic defense of the United States. Is charged with coordinating with the others to develop doctrines, procedures, and equipment for space operations. The Navy is specifically assigned responsibility for sea-based launch and space support missions. Additionally, the Navy is assigned missions such as maritime reconnaissance, antisubmarine warfare and mine warfare that may have unique applications for space systems. The Navy is the primary tactical user of space systems support services, and virtually every ship in the fleet and every unit of the fleet Marine force is equipped to receive this information. Over 85% of all satellite signal intelligence output provided to our military forces is used by the Navy and Marine Corps. Because of this strong reliance on space systems, the Navy has exerted significant influence in development and operation of space systems in the 1980s and early 1990s. Rather than relying on space systems support from the Air Force, the Navy is now competing with other services for both development and operation of the systems upon which it relies. It is reasonable to expect this trend to continue throughout the present decade. NAVY SPACE SYSTEMS DIVISION. Within the Office of the Chief of Naval Operations (CNO), the Director of Space, Information Warfare, Command and Control (SIWC2) (N6) is assigned responsibility for centralized coordination of policy, planning, and integration for Navy command, control and communications; space exploitation; space defense matters; reconnaissance; ocean surveillance; and communications security. N6 sponsors Navy communications systems for command and control, space communications systems, navigation and environmental sensing systems, and support equipment.

2-18 The Navy Space Systems Division is responsible for developing a composite program for the Navy’s use of space systems to perform surveillance, communications, navigation, command and control, environmental sensing, targeting, and warning. N63 is the principal point of contact within the Navy for command and control space matters, including policy and planning for space exploitation and the defense of space systems. This office also ensures that Navy space systems meet the needs of the operational commanders, including joint commands, and represents the Department of the Navy (DON) on interdepartmental, DoD, and national committees related to space systems. The staff of the Director, Navy Space Systems, assesses future satellite and space system concepts and applications as they relate to the overall Navy command and control plan. They also validate requirements for space systems; coordinate with the OPNAV warfare and platform sponsors to ensure that space systems are responsive to operational requirements; maintain liaison with the other services and federal agencies for space system utilization; and identify training needs related to space systems support. The division also sponsors NAVSPACECOM initiatives within OPNAV. Space and Naval Warfare Systems Command. The Space and Naval Warfare Systems Command (SPAWAR), San Diego, Ca., provides material, acquisition and life-cycle support to the Navy and Marine Corps for space systems; command, control, communications, and intelligence (C 3I) systems; and surveillance. SPAWAR also develops force warfighting architecture and requirements integration, including space applications, for the Department of the Navy. It also manages Navy Research and Development Centers. The command was established in 1966 as the Naval Electronic Systems Command (NAVELEX) under the Chief of Naval Material. The Naval Material Command was disestablished in 1985 and NAVELEX became the Space and Naval Warfare Systems Command. With the reorganization, the Department of the Navy placed new emphasis on space systems and undersea warfare programs. As the manager of the Navy Research and Development Centers, SPAWAR controls seven Navy laboratories, four university laboratories, and eight engineering centers. Including the systems command staff, SPAWAR comprises nearly 30,000 military and civilian personnel. NAVAL SPACE COMMAND. The Naval Space Command (NAVSPACECOM) is headquartered at Dahlgren, Virginia. The command was established in 1983 to strengthen operational control of naval space systems and provide a focal point for operational naval space matters. The commissioning of NAVSPACECOM culminated a series of initiatives to consolidate the Navy’s extensive space efforts. Other initiatives in the early 1980s included formation of the Navy Space Systems Division on the staff of the Chief of Naval Operations; establishment of annual Naval Space Symposiums to examine Navy and Marine Corps roles and activities in space; development of the Space Operations and Space Systems Engineering

2-19 curricula at the Naval Postgraduate School; and the assignment of a flag officer as Director, Navy Space Project Office to manage Navy space acquisition efforts. NAVSPACECOM is the naval component of USSPACECOM. As such, the command is responsible for organizing, training, equipping, and administering Navy and Marine Corps forces in support of USSPACECOM missions. NAVSPACECOM provides the Navy and Marine Corps perspective in planning for DOD space system support to maritime and amphibious operations; ensures integration of Navy requirements in USSPACECOM operating plans; responds to USCINCSPACE-directed tasking; commands assigned forces; and conducts planning for DOD space operations in support of naval strategic and tactical missions. Efforts to fulfill this mission encompass operations, space intelligence, awareness and education, and future planning. NAVSPACECOM maintains a constant surveillance of space and provides satellite data as directed by the Chief of Naval operations and higher authority to fulfill Navy and national requirements; supports the U.S. Space Command as a dedicated sensor in the worldwide Space Surveillance Network (SSN); provides satellite observations, elements, and look angles to the Space Control Center (SCC); functions as the Alternate Space Control Center (ASCC) that serves as the backup for the SCC; manages the Navy space- based communications systems, including the Fleet Satellite (FLTSAT) Communications System, LEASAT and the UHF Follow-On (UFO); the Naval Space Surveillance System; the Relocatable Over-The-Horizon Radar (ROTHR) System; and participates in the development and operation of other communications, navigation, and surveillance systems. Space intelligence involves assessing the threat to the space systems upon which our forces rely, using our own space systems to identify air and surface threats. In addition to supporting education and training programs throughout the fleet, the command sponsors a Chair in the Space Operations curriculum at the Naval Postgraduate School as well as a Space Chair in the Aeronautical Engineering curriculum at the U.S. Naval Academy. Finally, NAVSPACECOM determines operational requirements for space and space support systems, and also tracks applicable technology development on behalf of the CNO. NAVSPACECOM is comprised of the headquarters command and two subordinate commands: the Naval Satellite Operations Center (NAVSOC) and the Fleet Surveillance Support Command (FSSC). A Rear Admiral (0-7) with extensive operational experience commands NAVSPACECOM. The Deputy Commander is a Marine Colonel (0-6), who provides a Marine Corps perspective on the utilization of space assets. A Technical Director, a senior civilian, who provides extensive experience in space system operations and development, assists both. The remaining staff is organized into functional divisions for management support (N1), intelligence (N2), operations (N3), logistics (N4), planning (N5), information systems (N6), and training (N7).

2-20 NAVSPACECOM manages the use of existing satellites and space support systems by the Navy and Marine Corps, and assists in the development of future space systems to meet the projected needs of the fleet. A significant current initiative involves managing the FLTSAT Extra High Frequency (EHF) Package (FEP) program. FEP modules have been added to FLTSAT 7 and 8 (the last two FLTSAT spacecraft) to provide a space-based test bed for EHF technology and the development of EHF communications terminals for the MILSTAR satellite communications program. Other initiatives include the development and deployment of the Joint Tactical Ground Station (JTAGS) for the enhanced capability to detect tactically significant targets using the Defense Support Program (DSP) satellites; provides multi- and hyper-spectral imagery (MSI) from LANDSAT IKONOA and SPOT Earth resources spacecraft to assist naval forces with exercise and strike planning, provide updated maps and charts, and enhance intelligence and surveillance capabilities; assessing the global space threat, prioritizing enemy space assets, and providing targeting data for the proposed kinetic energy anti-satellite system; the development and operation of tactical satellites (TACSATS) to provide theater-level communication, tactical surveillance, and environmental monitoring; demonstration of a recoverable sea-launched booster (SEALAR); the application of military man-in-space (MMIS) to naval operations; and development of the Space-Based Wide Area Surveillance (SBWAS) system. The Navy is also assisting other services in developing plans and programs for Ballistic Missile Defense (BMD), a personal computer-based Multi-spectral Imagery (MSI) workstation, and a standardized satellite command and control system. NAVSPACECOM operates a unique space sensor as part of the SSN. A network of field stations produces a fence of electromagnetic energy approximately 5,000 nautical miles long, extending across the continental United States and portions of the Atlantic and Pacific Oceans. In the north-south direction, the fence is approximately 2 miles wide and can detect objects at a height of 15,000 nautical miles. Together, NAVSPACECOM’s nine field stations comprise one of the largest antenna systems in the world. With a total length of over 15 miles, each antenna site incorporates 150 miles of transmission lines, 10,000 feet of steel posts, and 18,000 dipoles. NAVSPACECOM’s six receiver sites receive the transmitted energy reflected from satellites as they pass through the fence. Each receiver site has individual antennas spaced at precise intervals. The longest antenna at each site is known as the alert antenna, because it is more sensitive and can detect a signal before the remaining antennas. It then electronically alerts the system controller to the presence of a target so that the receiver may be tuned to the precise frequency of the reflected energy from the satellite. Two receiver sites, Elephant Butte and Hawkinsville, are known as high-altitude sites. Their antenna arrays have higher gain and their electronics are configured to make them more sensitive to the reflected energy from higher altitudes.

2-21 The receiver sites collect over 1 million satellite detections, or observations, each month. This data is transmitted to NAVSPACECOM headquarters over conditioned telephone lines and upon arrival, is ready for processing within seconds of fence penetration. The lines of sight from each station are then calculated and used to pinpoint the object in space. Satellite identification is made by matching the observed fence crossings with the predicted position. These observations are used to update the database of orbital elements at headquarters and generate new fence crossing predictions. The computers can also use these orbital elements to generate a wide variety of data products for use by USSPACECOM, the fleet and other military and scientific agencies. NAVSPACECOM staffs a command center 24 hours a day, 7 days a week, to maintain operations of the network. Command center personnel monitor launches, maneuvers, and breakups of both foreign and domestic satellites. An up-to-date catalog of all objects in space is maintained by NAVSPACECOM. This catalog, which serves as a direct backup to the space object catalog kept by USSPACECOM, contained nearly 10,000 objects in 1998. In recent years it has grown steadily at a rate of approximately 8% per year. In addition, a small group of analysts is dedicated to the evaluation of unusual satellite on-orbit activity. These analysts maintain an accurate database on all foreign launches and provide observations and conclusions about satellite orbital behavior using tailored databases and information from other NAVSPACECOM analysts as well as the Space Surveillance Network. NAVAL SATELLITE OPERATIONS CENTER. The NAVSOC, formerly called the Navy Astronautics Group (NAG), provides telemetry, tracking and control (TT&C) for experimental spacecraft, and recently provided TT&C for GEOSAT, an oceanographic and geodetic survey satellite. Additionally, NAVSOC can remotely operate the two Fleet Satellite Extremely High Frequency Package (FEP) Operations Centers ( FEPOCs), located in Maine and Massachusetts, to coordinate testing of FEP communications systems and related terminals. The NAG was commissioned in April 1962 to provide an accurate, all-weather positioning capability to naval forces operating around the world via TRANSIT satellites. During TRANSIT operations from 1965 to 1998, the TRANSIT/NAVASTROGRU system maintained 99.86% reliability. Recognizing the transition from a research and development facility in its early years to an operational satellite control center, the command’s title was changed in June 1990 to the Naval Satellite Operations Center (NAVSOC). The name change reflects a growing commitment by the Department of the Navy to better exploit space systems in support of our operational forces. The mission of the NAVSOC is to maintain and operate satellite systems (including spacecraft and ground-based components and subsystems) to fulfill naval and national requirements. It is the only Navy organization that performs all space-related functions, including satellite launch support, orbit insertion and adjustments, satellite commanding and

2-22 system monitoring, network scheduling, and providing technical assistance with new satellite system developments and concepts. NAVSOC headquarters is located at Point Mugu, California. Personnel in the Satellite Operations Control Center at the headquarters schedule and monitor all operations for assigned satellites, evaluate telemetry, and compute precise satellite orbit trajectories. Four Tracking and Satellite Contact Facilities communicate with the satellites to provide tracking and control, the operation of which is discussed in detail in Chapter 7 of this manual. The command has also established a detachment in Colorado Springs, Colorado, to serve as an on-sight representative to Air Force Space Command, provide technical expertise, and oversee Air Force Satellite Control Network operations of the Fleet Satellite Communications System. The TRANSIT navigation system was phased out when the NAVSTAR Global Positioning System (GPS) became fully operational in the mid-1990s. It has been proposed that NAVSOC provide TT&C for the Submarine Laser Communications satellite system, the Fleet Satellite follow-on program, and the Space-Based Wide Area Surveillance program, all under development. NAVSOC is also developing sea-based, mobile TT&C systems to provide survivable satellite command and control, and participates in locating sources of radio frequency interference (RFI). NAVAL RESEARCH LABORATORY.The Naval Research Laboratory (NRL) is the Navy’s principal in-house research laboratory for the physical and engineering sciences. Established under the command of the Chief of Naval Research, NRL is responsible for conducting a broad-based, multidisciplinary program of scientific research and advanced technological development of new and improved materials, equipment, techniques, systems, and related operational procedures for the Navy. The Laboratory conducts exploratory and advanced development programs in response to identified and anticipated Navy needs. It is the lead agency responsible for the development of space technology for the Navy. NRL has been responsible for both satellite technology and specific satellite programs. The Laboratory directed the development and operation of "Vanguard"; satellite computer and memory systems; satellite-based experiments; technology and the test bed for the Global Positioning System; and, most recently, the Low-Power Atmospheric Compensation Experiment (LACE) satellite for the Strategic Defense Initiative (SDI or “Star Wars”) program. The Laboratory occupies approximately 130 acres on the Potomac River in Washington, D.C. The Chesapeake Bay Detachment in Chesapeake Beach, MD, and the Underwater Sound Reference Detachment in Orlando, FL, are NRL’s major remote facilities. The Laboratory also maintains 12 other remote facilities in the District of Columbia, Maryland, Virginia, Florida and Alabama.

2-23 The mission of the Laboratory is carried out by four science and technology directorates supported by the Executive Directorate and the Business Operations Directorate. NAVAL COMPUTER AND TELECOMMUNICATIONS COMMAND. The Naval Computer and Telecommunications Command (NAVCOMTELCOM) is a shore activity under the direct command of CNO. The command was established in 1967 as the Naval Communications Command, reorganized in 1973 as the Naval Telecommunications Command, and merged with the Naval Data Automation Command in 1990 to form NAVCOMTELCOM. The command is responsible for operating and maintaining the Naval Telecommunications System (NTS), a network of equipment and subsystems that provide telecommunications and data processing for the operation, command and control, and administration of the Navy. NAVCOMTELCOM exercises configuration control of the Naval Telecommunications System (NTS); serves as the operations and maintenance manager of elements of the Defense Communications System assigned to the Navy; supports Fleet Commanders in Chief in assuring the adequacy, effectiveness, and responsiveness of operational telecommunications; and provides technical support for non-tactical data processing systems that interact with common user communications networks, and publishes communications security (COMSEC) and COMSEC Material System (CMS) policy. NAVCOMTELCOM manages the NTS and commands its major shore elements, which include four Naval Computer and Telecommunications Area Master Stations (NCTAMS), Naval Computer and Telecommunications Stations (NCTS), Naval Communication Units, Naval Communication Detachments, Naval Telecommunications Centers, Antisubmarine Warfare Support Communications Centers, special communications sites, the Naval Telecommunications Automation Support Center, the Naval Telecommunications Systems Integration Center, and the Naval Electromagnetic Spectrum Center. The NCTAMS provide up link of Navy messages, weather broadcasts, and the distribution of tactical surveillance intelligence for the fleet broadcast portion of the FLTSATCOM system. NAVCOMTELCOM also manages the interfaces between the International Maritime Satellite (INMARSAT) system and the NTS for Military Sealift Command operations. U.S. Marine Corps The Marine Corps uses space to achieve enhanced command and control capabilities. Marines use the space assets of other organizations to provide space-based combat support to amphibious forces. This is accomplished by placing a few Marines in select billets to leverage external assets as much as possible, and by purchasing the necessary ground stations and equipment to use existing and proposed systems. The Marines typically do not organize to

2-24 provide space support, but rather, provide support organized along functional areas, some of which use space systems to accomplish their mission. Typically, Marines interface with the following organizations to obtain their required space support: U.S. Space Command. Several Marines with the Military Occupational Specialty (MOS) 9666 are located at USSPACECOM, providing joint support to CINCSPACE. Naval Space Command. Marines are an integral part of the NSC staff. Both active and reserve Marines work on matters of interest to both naval services, including doctrinal issues, operations access to space systems, and space systems acquisition. One U.S. Marine Reserve unit is associated with NSC. Army Space Command. Marine reservists have supported ARSPACE in the past, particularly in the area of multi-spectral imaging. COMMANDANT OF THE MARINE CORPS (CMC). The Commandant works through his staff at Headquarters, Marine Corps, to direct policy and budgetary actions affecting space- related systems. Graduates of the Naval Postgraduate School, Space Operations Curriculum, who have the 9666 secondary MOS work at CMC, Code PL8. CMC is a focal point for coordination of Marine Corps space policy. Access for Tactical Exploitation of National Capabilities (TENCAP) is obtained via Marine Corps headquarters, as well as the Naval Space Command. Department of the Army In addition to the shared responsibilities of providing forces for the strategic defense of the U.S. and coordinating with the other services for space operations, the Department of the Army is responsible for exploiting space activities that contribute to the successful execution of Army missions. Although not assigned sole responsibility for their development, the Army is particularly interested in systems related to mapping, charting, and geodesy. Like the other services, the Army uses space systems for communications, navigation, surveillance, and environmental monitoring to accomplish its primary mission of air/land combat operations in support of national objectives. The Army has been active in space activities since late 1940s. Early efforts included the development of boosters, launch vehicles, and satellites, including America’s first satellite, "Explorer" I. Today, like the other services, the Army is capitalizing on space systems to provide increased capability to air and ground forces. Future Army requirements will place increased emphasis on deployment of light, mobile forces assisted by space systems. The Army Space Policy states that:

2-25 "Successful implementation…will require development of a pool of Army space expertise and judicious planning, to include development of concepts, requirements, and a long-term management strategy. Army plans and evolving space architecture must capitalize on national and joint programs, preserving options to support initiatives that fulfill Army requirements. Implementation of this policy demands a visionary outlook to exploit fully evolving space capabilities.” Like the Navy, the Army has recently begun to exert more influence in the development of space systems, and is competing with other services for space programs. Under the direction of the Deputy Chief of Staff for Operations (DCSOPS) at Headquarters Department of the Army, the Army is developing plans and operating concepts for Strategic Defense System elements that include ground-based radar, surveillance and tracking systems, and ballistic missile defense and anti-satellite weapons systems. U.S. ARMY SPACE AND MISSILE DEFENSE COMMAND (SMDC). The Army Space and Strategic Defense Command (SSDC) was created in 1992 to unite key Army space organizations under a Lieutenant General. This command was a combination of two former Army commands, the Army Space Command (ARSPACE), located in Colorado Springs and the Strategic Defense Command in Huntsville, Alabama. Since 1992, the Army Space Program Office (ASPO), which runs the Army TENCAP program; and the Army Space Technology Program, which guides Army R&D activities, have joined SMDC. In October 1997, Army SSDC was renamed Army Space and Missile Defense Command (SMDC). The headquarters for SMDC, in Arlington, Virginia, reports directly to the Army’s Deputy Chief of Staff for Operations (DCSOPS). Mission U.S. Army SMDC activities in Huntsville trace their lineage to Werner von Braun and the Redstone Arsenal space activities of the 1950s. Today, SMDC maintains a place within DoD as a superior research facility supporting not only Army initiatives, but the Ballistic Missile Defense Organization, the Advanced Research Program Agency (ARPA) and a myriad of other DoD research and applications initiatives. SMDC at Huntsville is organized into two main centers: the Missile Defense and Battlefield Integration Center supporting modeling and simulation activities; and the Missile Defense and Space Technology Center focusing on space and strategic defense-oriented research and development. Primary functions of SMDC include: • Operation of the Advanced Research Center (ARC), a government-owned, contractor-operated research center for ballistic missile defense activities. ARC is a

2-26 part of the National Testbed and works with the Joint National Test Facility (JNTF) at Shriever AFB. • Operation and maintenance (O&M) of the High Energy Laser System Test Facility (HELSTF) at White Sands Missile Range, New Mexico. • Development of technologies associated with Army space capabilities. SMDC Organizations U.S. Army Space Command (USARSPACE). The Army Space Command (ARSPACE) was created in 1988 and functioned as the Army component command to USSPACECOM. ARSPACE was re-designed as the U.S. Army Space Command (USARSPACE) in 1994 to differentiate the original ARSPACE in Colorado from the headquarters in Virginia. Beginning with DESERT SHIELD/DESERT STORM and continuing through activities in Haiti and Bosnia, ARSPACE has established a presence within the Army as an important provider of space capabilities. ARSPACE routinely trains with units and may provide contingency support. ARSPACE also provides equipment and expertise during major training exercises. ARSPACE continues to focus heavily on tactical, operational, and strategic applications as demonstrated by the following list of missions and functions managed by ARSPACE: • Theater Missile Defense Tactical Operations Center (TMDTOC) • Joint Tactical Ground Station (JTAGS) • Army Space Support Teams (ARSST) • Army Space Exploitation Demonstration Program (ASEDP) • Payload management of the Defense Satellite Communications System (DSCS) • Western Test Range and Space Surveillance Operations at Kwajalein Atoll USARSPACE supports the Army by assuring access to the nation’s space resources as well as planning for future space systems. By executing control of DSCS payloads through its subordinate elements, USARSPACE provides the warfighter with assured access to satellite communications to support command, control and communications needs. USARSPACE delivers relevant space capabilities to tactical Army units and deploys Army Space Support Teams to major units during crisis and exercises. These teams deliver equipment and expertise to empower tactical forces with satellite-based communications, weather, positioning, mapping and intelligence capabilities. USARSPACE supports tactical missile defense by operating warning and command systems in a ground theater of operations. The JTAGS and the Army Tactical Missile Defense

2-27 Elements focus land components efforts to protect friendly forces, intercept hostile missiles and counterstrike enemy launch systems. USARSPACE advances Intelligence Preparation of the Battlefield (IPB) by delivering terrain and weather imagery from commercial and military satellite-derived information is efficiently exploited in command and control systems. USARSPACE is currently involved in the design of future satellites to include Space Based Infrared System (SBIRS), DSCS Follow-On, GPS Block 2F and MILSTAR. Army Space Program Office (ASPO). The U.S. Army Space Program Office (ASPO), located in Alexandria, Virginia provides the Army’s principle interface to the National Intelligence community. ASPO has the Army’s charter to field, train and maintain a limited number of Tactical Exploitation of National Capabilities (TENCAP) systems to Army tactical organizations. At this time, ASPO nominally falls under SMDC for administrative and command and control purposes while retaining funding ties directly to the Department of the Army. Other Space Support Organizations Army Training and Doctrine Command (TRADOC). HQ TRADOC at Ft. Monroe, Virginia is the home of the Army’s "Space Command and Control Warfare Directorate," which focuses Army requirements for space capabilities into formal statements of need. These are then subsequently passed to material developers for acquisition or development. The Army regards requirements as either short-term or long-term, roughly corresponding to the time frame of support. Short-term, or operational requirements, are strictly the responsibility of specific operational commands. For instance, requirements for a tactical communications capability requested by an infantry brigade, may be acted upon by the appropriate element of ARSPACE. ARSPACE would then validate the requirement, establish the means to support the request then dispatch a team or system to address the need. Requirements for long term items such as changes to doctrine or training are passed through the training and Doctrine Command from TRADOC schools and centers. This is where functional experts attempt to express future Army needs in a formal requirements definition process. An example would be the estimation by the Signal School that a capability would be needed in the year 2000 to support the warfight tactics and technologies of a future tactical application. The Space and C2 Directorate at TRADOC formally receives such requirements for space from Space Action Officers. Action officers are located in many of the Army’s doctrine and training centers and schools and examine the requirements in lieu of other cross-function requirements.

2-28 TRADOC Battle Labs have been in existence since 1966 and serve as rapid prototyping and evaluation centers for various battlefield functions. The labs have demonstrated steadily increasing appetites for space systems or information derived from space systems. Communications Engineering Command (CECOM) . Although the SMDC provides some material development capabilities, the Army’s CECOM at Ft. Monmouth, New Jersey provides communications oriented material developed under the Space and Terrestrial Communications Directorate and the Program Manager for Satellite Communications (PM SATCOM). Army Corps of Engineers (COE). The Army Corps of Engineers has been extremely active in the exploitation of space systems. Mainly, their work has been from applications or disciplines represented in the Topographic Engineering Center (TEC), Ft. Belvoir, Virginia, which has preformed limited fielding of space systems in conjunction with ASPO. The Program Manager for Combat Terrain Information Systems (PM CTIS) resides at TEC, and is responsible for the fielding and training of many systems. For example, the Multi Spectral Imager Processor (MSIP), which is now being fielded throughout the Army Topographic Engineering community. This is a result of joint TEC, TRADOC and ARSPACE initiatives to demonstrate the utility of space systems to Army tactical forces. CIVIL SPACE ORGANIZATIONS Prior to the Soviet’s launch of SPUTNIK I on 4 October 1957, the United States did not have a civil space program. The success of SPUTNIK I, followed closely by SPUTNIK II, galvanized the nation’s leadership to recognize the potential strategic and international implications of the use of space. The Navy was given the task of developing and launching the United States’ first Earth- orbiting satellite. The Army, under the leadership of the noted German rocket scientist, Dr. Werner von Braun, modified a ballistic missile to launch our first satellite, EXPLORER II, in January 1958. After several spectacular launch attempt failures, the Navy succeeded in launching the Project Vanguard satellite on 17 March 1958 from a new, Navy built facility at Cape Canaveral, Florida. NATIONAL AERONAUTICS AND SPACE ADMINISTRATION . Following the success of the Navy’s "Vanguard" satellite, the National Aeronautics and Space Act of 1958 was quickly enacted. The first National Space policy declared that "...it is the policy of the United States that activities in space should be devoted to peaceful purposes for the benefit of all mankind." In making this declaration, Congress created a new independent agency, the National Aeronautics and Space Administration (NASA). NASA’s charter stated that the agency would be responsible for providing direction and control over all U.S. space activities "...except those activities peculiar to or primarily associated with the development of weapons systems, military operations, or the defense of the United States."

2-29 The new space agency absorbed an existing independent agency, the National Advisory Committee on Aeronautics (NACA), originally chartered in 1915 to advance aeronautical technology. NACA became the "aeronautics" part of NASA. The transfer of approximately 200 Navy scientists and engineers from the Naval Research Laboratory, and a number of U.S. Army personnel all of whom had previous experience with launching spacecraft formed the “space” portion of NASA. NASA HEADQUARTERS. NASA fulfills the responsibilities of the agency’s statutory charter through the operation of five major space flight centers, four major research centers, and seven field installations all under the command and control of NASA Headquarters in Washington, D.C. NASA’s responsibilities are described by the functions of the six principal program offices within NASA Headquarters and are discussed in the following chapter. The Office of Aeronautics and Space Technology (OAST) is responsible for advanced development programs in aeronautics and space technology. The Office of Space Science and Applications (OSSA) is responsible for NASA’s research and development activities in astrophysics, planetary exploration, Earth environmental observation, materials processing, communications and data processing systems, and flight of the manned, reusable SPACELAB module carried aboard the Space Shuttle. The Office of Space Operations (OSO) is responsible for providing trajectory tracking and communications to all NASA spaceflight programs. The OSO manages an integrated worldwide network of tracking and communications facilities including the Deep Space Network (DSN), the Spaceflight Tracking and Data Network (STDN), and the Tracking and Data Relay Satellite System (TDRSS). The Office of Space Station has full program responsibility for the development of the manned, Earth-orbiting Space Station, Freedom. The Office of Commercial Programs is responsible for ensuring that NASA- developed technology with commercial applications is made promptly available for use by private sector enterprise. The Office of Space Flight (OSF) is responsible for the management and operations of the manned Space Shuttle Program (SSP), all U.S. civil unmanned launch vehicle operations, and development of NASA spaceflight centers, including the Johnson Space Center, Marshall Space Flight Center, Goddard Space Flight Center, and the Kennedy Space Center. JOHNSON SPACE CENTER. Johnson Space Center (JSC )located in Houston, Texas, is NASA’s principle center for the research, design, development, and test of manned spacecraft systems to include the International Space Station. It was established as the Manned

2-30 Spacecraft Center in 1961 with the move of the Space Task Group from the NASA Langley Research Center in Virginia.JSC’s Mission Control Center has been NASA’s command and control center for all manned spaceflight missions since the flight of Gemini 4 in June 1965. The center was renamed following the death of President Lyndon B. Johnson, a strong supporter of the nation’s manned space program. JSC plays a key role in the Space Shuttle program, including responsibility for the development of the Orbiter spacecraft, payload integration, and overall Shuttle integration. JSC is also responsible for the selection and training of astronauts, flight crew and flight controller training, Shuttle flight control, and control of experiments and payloads on board the Orbiter. JSC also operates the White Sands Test Facility (WSTF) located on the Army’s White Sands Missile Range near Las Cruces, New Mexico, in support of the Space Shuttle Propulsion System development. Nearby is the White Sands Space Harbor, an alternative- landing site for the returning Orbiter. Shuttle pilots practice landing approaches at WSSH using specifically modified shuttle training aircraft. KENNEDY SPACE CENTER. The nation’s first space launch on 24 July 1950 used a modified version of a captured World War II V-2 rocket. The V-2 attained an altitude of 10 mile’s from the launch facility that was simply known as "Cape Canaveral." Renamed after the death of President John Fitzgerald Kennedy, the 140,000-acre Kennedy Space Center (KSC) is the primary NASA center for the integration, test, and launch of all of the nation’s manned spacecraft and the majority of unmanned expendable launch vehicles. Manned launches from "the Cape" include the Mercury, Gemini, Apollo, Apollo-Soyuz, and Space Shuttle programs, and the world’s first space station, Skylab. KSC has full responsibility for all ground processing of the Space Shuttle including pre- flight assembly and checkout, launch, and landing recovery operations. KSC provides a full ground support team to the NASA Ames-Dryden Flight Research Center for support of Orbiter landings and subsequent ferry flight of the Orbiter back to KSC atop a NASA 747 Shuttle carrier aircraft. KSC is designated as the secondary landing site for the Orbiter. In addition to manned space launches, KSC has been the launch site for many unmanned satellites, including all U.S. government communications satellites, geosynchronous weather satellites, and interplanetary probes such as Pioneer, Viking, and Voyager. Under an agreement with the U.S. Air Force, NASA shares many of the expendable launch vehicle and support facilities including the 10,000-mile-long Eastern Test Range headquartered at the adjacent Cape Canaveral Air Force Station (CCAFS). Boosters launched from CCAFS include the Atlas, Delta, Titan, and many early developmental rockets. KSC personnel also support high inclination NASA launches from the Western Test Range at Vandenberg Air Force Base, California.

2-31 MARSHALL SPACE FLIGHT CENTER . The Marshall Space Flight Center (MSFC) was the home of the German rocket scientist Dr. Werner von Braun and his team of engineers. Located on the Army’s Redstone Arsenal, MSFC’s primary responsibility is for the development of large spacecraft propulsion systems and launch vehicles. The "Apollo" Saturn V moon rocket, "Saturn" 1B, and other major launch vehicles were developed by MSFC engineers. In support of the Space Shuttle program, MSFC has principal responsibility for the development and production of the reusable solid rocket boosters, the external tank, and the reusable main engines. MSFC is also the focal point for NASA, in cooperation with the European Space Agency (ESA), for the design and operation of the modular reusable SPACELAB laboratory carried aboard the Orbiter, as well as many of the experiments carried aboard SPACELAB. MSFC also had systems engineering and integration responsibility for the Hubble Space Telescope. GODDARD SPACE FLIGHT CENTER. Named for American rocket pioneer, Dr. Robert H. Goddard, the Goddard Space Flight Center (GSFC) is responsible for the development and operations of unmanned earth-orbiting spacecraft, and serves as the center of NASA’s worldwide spaceflight tracking and communications networks. In addition, GSFC serves as the program manager for the NASA expendable launch vehicle program. Some of GSFC’s major spacecraft projects include: • Solar Maximum Mission satellite (Solar Max); • Cosmic Background Explorer (COBE); • Gamma Ray Observatory (GRO); • Upper Atmospheric Research Satellite (UARS); • TIROs series NIMBUS satellites; and • LANDSAT (formally Earth resources technology) satellite series. GSFC is also responsible for operating and servicing the Hubble Space Telescope throughout its 15-year mission. As the hub of NASA’s space tracking and communications networks supporting the Space Shuttle and other space systems, GSFC is responsible for the management and operation of the Spaceflight Tracking and Data Network, the Tracking and Data Relay Satellite Systems, and the NASA Communications Network (NASCOM). GSFC manages several NASA field installations including Wallops Flight Facility, the Space Telescope Science Institute, and the National Scientific Balloon Facility. The Wallops Flight Facility (WFF) on Wallops Island, Virginia (formerly Chincoteague Naval Air Station), is one of the oldest and busiest flight test ranges in the world. Averaging over 300 launches per year, the WFF launches experiments to study the upper atmosphere and

2-32 space environment on vehicles ranging in size from small meteorological rockets to the four- stage Scout with orbital capability. The Association of Universities operates the Space Telescope Science Institute (STScI), located at the Johns Hopkins University in Baltimore, M.D., for NASA for Research in Astronomy. The STSCI is responsible for processing, analyzing, and displaying astronomical data transmitted from the Earth-orbiting Hubble Space Telescope. The National Scientific Balloon Facility located near Palestine, Texas is responsible for launch and recovery support of high altitude scientific balloon-borne experiments. STENNIS SPACE CENTER. NASA’s smallest center, the Stennis Space Center (SSC), is the agency’s primary center for the static test firing of large rocket engines. SSC construction started in October 1961 in preparation for full scale testing and flight acceptance test firing of the first (S-lC) and second (S-IIC) stages of the Saturn V launch vehicle. The test stands constructed to hold the Saturn S-lC stage remain today as the tallest structures in the State of Mississippi. Since 1975, SSC has used the former "Apollo" test stands for the static test firing and flight acceptance firing of the Space Shuttle Main Engines. SSC isalso NASA’s lead center for advance development of remote sensing and multi-spectral technology for Earth resources applications. Several Navy facilities are co-located at the SSC, including the Naval Oceanography Command, the Naval Oceanographic Office, the Naval Oceanic and Atmospheric Research Laboratory, and the Institute for Naval Oceanography. JET PROPULSION LABORATORY. Operated for NASA by the California Institute of Technology, the Jet Propulsion Laboratory’s (JPL) primary space-related responsibilities include the planetary exploration of the Earth and solar system with unmanned, automated scientific space probes, and the design and operation of the global Deep Space Tracking Network. Some of JPL’s major missions include the "Ranger" and "Surveyor" lunar mapping missions, which paved the way for a manned lunar landing, the Mariner missions to Mars, Venus, and Mercury, the "Viking" Mars Observers and Landers, the "Voyager" missions to the outer planets, the "Galileo" mission to study Jupiter, and the Magellan radar mapping mission to Venus. JPL is also noted for development of digital image processing and computer enhancement techniques for analysis of remotely sensed data. LANGLEY RESEARCH CENTER. As one of the original NACA research facilities,Langley Research Center (LaRC) is NASA’s oldest center. LaRC’s principal responsibility is basic research in aeronautics and space technology. LaRC was the home of the original "Mercury" astronauts and the Space Task Group before the construction of the JSC in Houston. Using more than 40 wind tunnels, LaRC explores the full range of flight from general aviation and transport type aircraft, to hypersonic vehicles potentially capable of direct ascent to Earth orbit. Among LaRC developed Space Shuttle experiments is the Long Duration

2-33 Exposure Facility (LDEF), which was designed to determine the long-term effects of the space environment on typical spacecraft materials. LEWIS RESEARCH CENTER. Lewis Research Center ( LeRC) is NASA’s lead center for research and development of advance technologies in aircraft air-breathing propulsion, space propulsion, space power generation, and satellite communication systems. LeRC has investigated many exotic forms of space propulsion including nuclear and electric rocket systems. LeRC was responsible for the development of the "Atlas" expendable launch vehicle and Centaur upper stage, and maintains technical management of both programs. AMES RESEARCH CENTER . Named after Joseph F. Ames, the NACA’s chairman for 12 years, Ames Research Center (ARC) was established in 940 as a major aeronautical research laboratory. Located on Moffett Field Naval Air Station, CA, ARC has played significant roles in the development of military and civil aviation programs. As NASA’s lead center for helicopter research, ARC also uses very large wind tunnels to conduct full-scale aircraft testing. ARC space exploration efforts continue to make history in step with the civil program’s progress. The "Pioneer" series of unmanned probes, managed by ARC, were the first spacecraft to visit Jupiter, Saturn, and Venus. As the world’s oldest operating spacecraft, "Pioneers" 10 and 11 are now the farthest man-made objects from Earth, as they continue their journey outbound from the solar system. ARC maintained contact with these historic spacecraft through the year 2000. ARC also operates the Ames-Dryden Flight Research Facility (DFRC) at Edwards Air Force Base, CA. Specializing in flight research programs, Dryden has tested many major research aircraft, including the X-1, D-558, X-3, X-4, X-5, XB-70, and the X-15, which was piloted to world speed and altitude records of 4,500 mph and 350,000 feet. DFRC also plays a significant role in Space Shuttle operations. As the primary, end-of-mission landing site, DFRC was the location of the early series of approach and landing tests where the Orbiter ENTERPRISE was flown off the top of the NASA 747 shuttle carrier aircraft and glided to safe landings on the dry Edwards lake bed. Major NASA facilities are shown in Figure 2-2 and are briefly described in the accompanying table.

2-34 Figure 2-2. Major NASA facilities.

2-35 1. NASA Headquarters, Washington DC, is responsible for management and direction of all agency programs; 2. NASA Johnson Space Center, Houston Texas, is responsible for all Space Shuttle operations, design and testing of manned spacecraft, and selection and training of astronauts; 3. NASA White Sands Test Facility, White Sands, New Mexico, a JSC field installation, is responsible for Space Shuttle propulsion testing, materials testing for space flight, and secondary landing sight for the Orbiters; 4. NASA Kennedy Space Center, Cape Canaveral, Florida, is responsible for assembly, pre- flight testing, launch, and landing recovery of the Space Shuttle; 5. NASA Marshall Space Flight Center, Huntsville, Alabama, is responsible for Space Shuttle Main Engines, External Tank, Solid rocket Booster, and Spacelab; 6. NASA Michoud Assembly Facility, East New Orleans, Louisiana, a MSFC field installation, is responsible for manufacture and assembly of the Space Shuttle External Tank; 7. NASA Slidell Computer Complex, Slidell, Louisiana, is responsible for computer services for the Michoud Assembly Facility; 8. NASA Stennis Space Center, Bay St. Louis, Mississippi, is responsible for testing of Space Shuttle main engines and remote sensing/multi-spectral imaging technology development; 9. NASA Goddard Space Flight Center, Greenbelt, Maryland is responsible for Earth-orbiting scientific satellites and the space tracking and communication networks; 10. Wallops Flight Facility, Wallops Island, Virginia, a GSFC field installation, is responsible for launching small rockets with scientific payloads; 11. Space Telescope Science Institute, Baltimore, Maryland, a GSFC field installation, is responsible for processing, analysis and display of Hubble Space Telescope astronomy data; 12. NASA National Scientific Balloon Facility, Palestine, Texas, a GSFC field installation, is responsible for launch and recovery support of high-altitude scientific balloon experiments; 13. NASA Jet Propulsion Laboratory, Pasadena, California, is responsible for unmanned automated space probes to explore-the solar system; 14. NASA Langley Research Center, Hampton, Virginia, is responsible for research in advance aeronautics and space technology; 15. NASA Lewis Research Center, Cleveland, Ohio, is responsible for research and development of advanced aircraft and spacecraft propulsion systems, space power systems, and satellite communications; 16. NASA Ames Research Center, Moffett Field, California, is responsible for advanced research in aeronautical and space technology; 17. NASA Ames-Dryden Flight Research Facility, Edwards Air Force Base, California, a field installation of ARC, is responsible for flight test of new aircraft and spacecraft and primary end-of-mission landing site for the Orbiters.

2-36 NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION (NOAA) A component of the US Department of Commerce, the National Oceanic and Atmospheric Administration (NOAA), is responsible for conducting research and gathering environmental data about the oceans, atmosphere, space, and the sun. The agency then applies this information to products and services that benefit all Americans. The NOAA line organizations that use space-derived environmental data include: • National Weather Service; • National Marine Fisheries Service; • National Ocean Survey; • Office of Oceanic and Atmospheric Research; and • National Environmental Satellite, Data and Information Service. SUMMARY For over four decades, the United States has led the world in the exploration and use of space. Our achievements in space have inspired a generation of Americans as well as the rest of the world. We maintain this leadership role by supporting a strong,-stable, and balanced national space program that serves our goals in national security, foreign policy, economic growth, environmental stewardship, and scientific and technical excellence. Access to and use of space is central for preserving peace and protecting U.S. national security as well as civil and commercial interests. The U.S. military is committed to fulfilling national security objectives by integrating fully and effectively, the tremendous force enhancement potential of space-related assets into our national war-fighting capabilities. If the vast world of space systems is fully understood and effectively applied, space operations can have an impact on mission planning and execution, saving friendly lives and increasing weapon effectiveness.

3-1 CHAPTER 3 THE SPACE ENVIRONMENT INTRODUCTION Knowledge of the space environment provides the understanding necessary to tactically optimize space assets. The space environment is hostile; there are continuous processes occurring in space that can alter the characteristics and change the performance of various space systems. In some cases, space weather events increase vulnerability to the loss of critical satellite functions or even entire systems. Increasing dependence on space-based systems to meet Naval operational objectives makes it imperative to have an understanding of the space environment. In this chapter, we will review the different phenomena of the space environment known to impact humans as well as satellites. Additionally, we will look at satellite design guidelines and procedures that reduce these effects. THE SUN The sun has the biggest effect on the space environment. Fueled by nuclear fusion, the sun combines or “fuses” 600 million tons of hydrogen each second. Two by-products of the fusion process that impact space systems are: • Electromagnetic radiation • Electrically charged particles. ELECTROMAGNETIC RADIATION Electromagnetic radiation is energy radiated from the sun over the entire electromagnetic spectrum. Basically, it is an oscillating force field transmitted through space in the form of a transverse wave. The majority of this energy is characterized by visible light and heat which have minimal impact on space systems. However, substantial amounts of electromagnetic radiation have the potential to adversely impact radar, communications, and space systems when they are enhanced and intensified by solar-geophysical phenomena or events. For example, the electrically charged particles of primary interest in the space environment are electrons and protons. These particles stream continuously from the sun to form what is called a “Solar Wind” (See Figure 3-1).

4-2 The Chinese had a working calendar at least as early as the fourteenth century B.C. They also maintained accurate records of comets, meteor showers, meteorites, and other phenomena. Egyptian astronomers were able to roughly predict the flooding of the Nile River each year near the time when the star Sirius could be seen rising in the dawn sky just before the sun. The Bronze age people in Northwestern Europe built many monuments such as Stonehenge, which was certainly used as a crude calendar. One of the earliest known attempts to describe the location of the planets, Sun, Moon, and their motions with respect to each other was by Pythagoras. He assumed that the Earth was stationary at the center of a system comprised of the seven known moving objects visible to the unaided eye−the Sun, Moon, Mercury, Venus, Mars, Jupiter, and Saturn. Pythagoras theorized that all revolved about the Earth in complex spherical orbits. This was known as the geocentric theory. Aristotle (384-322 B.C.), one of the most famous of Greek philosophers, understood such phenomena as the phases of the Moon and eclipses. Aristotle considered the theory that the apparent daily motion of the sky could be explained by a hypothesis of the rotation of either the Earth or of the celestial sphere. Perhaps most importantly though, Aristotle considered the possibility that the Earth revolves around the Sun, instead of the more popular idea that the Earth was the center of the universe. Aristarchus of Samos (310-230 B.C.), another famous Greek astronomer, was the first to profess a belief in the heliocentric theory−that the Earth moves about the Sun. He also believed that the stars must be extremely distant to account for the fact that their apparent positions in the sky remain the same all year long. However, because Aristarchus’ ideas were too revolutionary, they were rejected, and the geocentric theory continued to be accepted for centuries. About A.D. 140, Claudius Ptolemy amplified the geocentric theory by developing an elaborate geometrical representation of the solar system, which predicted the apparent motion of the planets with considerable accuracy. According to his theory, the planets revolve about imaginary planets, which in turn revolve around the Earth. Ptolemy’s hypothesis, with some later modifications, was accepted as absolute authority throughout the Middle Ages. MODERN ASTRONOMY It was not until some 1800 years after Aristarchus had first proposed the heliocentric theory, that a Polish monk named Nicolaus Copernicus (1473-1543) published a book in defense of the heliocentric system. Copernicus postulated that the Earth was one of the six (then known) planets that revolve around the Sun. Starting nearest the Sun, he ordered the planets Mercury, Venus, Earth, Mars, Jupiter, and Saturn. He further deduced that the closer a planet is to the Sun, the greater its orbital speed. Thus, the retrograde (or, backward) motion of Mars, Jupiter, and Saturn was easily explained. He also calculated the approximate scale of the

4-3 solar system. Contrary to what has been a popular belief, Copernicus did not prove that the Earth revolves about the Sun. A Danish astronomer, Tycho Brahe (1546-1601), established an astronomical observatory in 1576, where for 20 years he carried out the most complete and accurate astronomical observations made up to that time. In 1600 Brahe was joined by a young German mathematician named Johannes Kepler (1571-1630). Brahe put Kepler, an early convert to the heliocentric theory, to work on finding a satisfactory theory of planetary motion. LAWS OF MOTION Kepler’s most detailed study was of Mars, for which Brahe’s observational data was the most extensive. For 10 years he attempted to fit combinations of circular motion to the observed motion of Mars. Finally, Kepler tried to represent the orbit of Mars with an oval and soon discovered that the orbit could be fitted by a curve known as an ellipse. KEPLER’S LAWS OF PLANETARY MOTION Kepler found that Mars has an orbit that is an ellipse, with the Sun at one focus (the other focus of the ellipse is empty, an unoccupied point in space). Kepler generalized that what is true for Mars must be true for the other planets as well. This generalization has become known as Kepler’s First Law of Planetary Motion. Kepler’s First Law of Planetary Motion (Law of Ellipses) Each planet moves in an elliptical orbit with the Sun a t one focus and the other focus empty. This law also applies to man-made objects orbiting the Earth (i.e., satellites). The orbit of each satellite is an ellipse with the center of the Earth at one focus and the other focus unoccupied. This law simply implies that the purpose of the occupied focus (i.e., the Earth) is to provide gravitational attraction to the satellite to keep the satellite in its elliptical orbit (see Figure 4-1). Figure 4-1. Kepler’s 1st Law applied to an Earth satellite.

4-4 Kepler’s Second Law of Planetary Motion (Law of Areas) The line joining a planet to the Sun sweeps over equal areas in equal time intervals. As applied to an Earth-orbiting satellite, the line joining it to the Earth sweeps over equal areas in equal periods of time (see Figure 4-2). This law implies that the speed of a satellite changes depending on its distance from its gravitational attraction source, the center of the Earth. A satellite’s speed is greatest at the point in the orbit closest to the Earth, and is slowest at the point farthest from the Earth. If a satellite is traveling in a circular orbit, then the speed of the satellite is constant. Figure 4-2. Kepler’s 2nd Law. It is important to understand that the orbit followed by a satellite is not dependent on its mass. A large, heavy satellite could be in the same orbit with a small, light satellite with each sweeping out equal areas in equal periods of time. Kepler’s Third Law of Planetary Motion (Law of Harmonics) For any planet, the square of its period of revolution about the Sun is directly proportional to the cube of its mean distance from the Sun. When applied to earth satellites, this

4-5 law explains that the farther a satellite is from the Earth, the longer it will take to complete its orbit, the greater the distance it will travel, and the slower its average speed.

4-6 This law is expressed as follows: p2/d3 = K where p is the period d is the distance K is a constant with the same value for all satellites GALILEO GALILEI An Italian mathematician, Galileo Galilei (1564-1642), contributed greatly to the understanding of the behavior of objects at rest or in motion. In addition to being the first person to develop and use a telescope, he accumulated a great deal of evidence in support of the heliocentric theory. In 1632, he published the "Dialogue of the Two Great World Systems," which examined all arguments for and against the heliocentric theory. NEWTON’S LAWS OF MOTION AND UNIVERSAL GRAVITATION While declaring his three laws of planetary motion, Kepler deduced that a force from the Sun pulled on the planets, but he did not determine the mathematical nature of this force. Galileo discovered some of the basic laws governing the behavior of physical objects. Sir Isaac Newton (1643-1727), regarded as the father of classical mechanics, drew upon the work of both Kepler and Galileo to formulate the Law of Universal Gravitation and the three Laws of Motion. While Kepler’s laws provided a conceptual model of orbital motion, Newton’s laws provided the foundation for the mathematical description of orbits and why a satellite remains in orbit. Newton’s First Law of Motion (Law of Inertia) A body in motion will keep moving at the same speed and in the same direction unless acted upon by an external force. This explains why a satellite moves in a curved path around the Earth, because the Earth’s gravitational pull acts as an external force on it. Newton’s Second Law of Motion (Law of Momentum) If the sum of forces acting on an object is not zero, the object will have an acceleration proportional to the magnitude and in the direction of the net force. This provides some of the explanation for changes in a satellite’s orbit due to external forces other than the Earth’s gravity, and the need to adjust a satellite’s orbit.

4-7 Newton’s Third Law of Motion (Law of Action & Reaction) For every action, there is an equal and opposite reaction. This law explains how a satellite gets into orbit. Newton’s Law of Universal Gravitation Any two objects in the universe attract each other with a force directly proportional to the product of their masses, and inversely proportional to the square of the distance between them. Mathematically, this law is expressed as follows: F = G*(m 1*m2)/d2 where F is the force acting between the bodies G is the universal constant of gravitation m is the mass of a body, and d is the distance between the bodies Simply stated, the more massive the objects, or the closer they are together, the greater the gravitational pull between them. ORBITAL PARAMETERS To better understand the operational application of satellites, you should become familiar with the fundamental terms and relationships associated with satellite orbits. ORBITAL INSERTION To illustrate how a satellite is placed into orbit, refer to Figure 4-3. Imagine someone standing atop a tall mountain and throwing a ball horizontally. Not considering atmospheric friction, the Earth’s rotation, or any other force except gravity, the path of the ball will curve downward due to gravity and it will strike the Earth (Path A). Now, if that person fires a gun horizontally, the bullet will obviously go farther than the ball, but it will still be pulled down to the Earth (Path B). However, if a projectile is fired horizontally at a very high speed, approximately 17,500 miles per hour, the curvature of its path due to gravity will match the curvature of the Earth below it. The projectile will then continue to "fall" around the Earth just as fast as the Earth curves away from the projectile, and become an Earth-orbiting satellite (Path C).

4-8 Figure 4-3. Orbital insertion. For an object to achieve orbit, sufficient energy must be provided so that the path does not intersect the surface of the Earth. However, the object cannot be given too much energy or it will escape the effects of the Earth’s gravity. The following three conditions are required to place an object in orbit: • The object must be put above most of the Earth’s atmosphere (approximately 60 miles high) to negate the effects of atmospheric friction • The object must be imparted with a speed of approximately 17,500 miles per hour within about 200 miles of the Earth’s surface • The object’s speed must be in a direction parallel to the surface of the Earth. POSSIBLE SATELLITE ORBITS Suppose that an object is boosted to an altitude of approximately 200 miles above the Earth’s surface, then turned so that it is horizontal to the Earth, and finally provided with a forward horizontal motion. The object will enter into an orbit the size and shape of which depends on the exact direction and speed of the object at "burnout" (when thrusting terminates). If the object is moving horizontally to the earth, the possible types of orbits it can enter are depicted in Figure 4-4.

4-9 Figure 4-4. Possible satellite orbits. If the object’s burnout velocity is slightly greater than that required for a perfect circular orbit, the resulting orbit will be elliptical with the center of the Earth at one focus. The point farthest from the center of the Earth will be the point of burnout. If the burnout velocity is substantially below the circular-orbit velocity requirement, the object will strike the Earth’s surface. If the burnout velocity is just slightly below the circular-orbit velocity, the object may barely clear the Earth’s surface, but atmospheric drag would soon cause it to slow down below the required orbital velocity and it will strike the Earth. If the burnout velocity is exactly the circular-orbit velocity requirement, a circular orbit results (in practical situations, this is nearly impossible to achieve). Burnout velocities equal to or greater than the escape velocity from the Earth’s gravitational field result in parabolic or hyperbolic orbital paths. At these velocities, satellites will escape the gravitational pull of the Earth and never return. ORBITAL TERMS AND ELEMENTS When an object’s burnout velocity results in an elliptical orbit, a point on the orbit farthest from the center of the Earth is referred to as apogee (apogee – “away”). The point closest to the center of the Earth will be halfway around the orbit and is called perigee (see Figure 4-5). Apogee and perigee are always 1/2 revolution apart. For a circular orbit, apogee and perigee altitude are equal.

4-10 Figure 4-5. Orbital parameters. Orbital Elements Six parameters, often referred to as the "orbital element set," establish the size, shape, and orientation of an orbit in space as well as the location of a satellite in its orbit. These parameters, some of which are depicted in Figure 4-6, are as follows: • Semi-major axis • Eccentricity • Inclination • Right ascension of the ascending node • Argument of perigee • Time

4-11 Figure 4-6. Orbital elements. The semi-major axis is simply o ne-half the diameter of an ellipse. The length of the semi-major axis is used to define the size of an orbit. From this, the orbital period (the time it takes a satellite to complete one orbital revolution) can be calculated. Eccentricity defines the shape of an ellipse. For all ellipses, the value of eccentricity lies between zero and one. The larger the value, the more elliptical the orbit. Circular orbits have an eccentricity equal to zero. A satellite orbit with an eccentricity equal to or greater than one will escape the Earth’s gravitational field (parabolic or hyperbolic orbit). The semi-major axis and the eccentricity of the orbit are determined before launch to design the orbit for that particular satellite’s mission. Inclination is used to orient the orbital plane with respect to the Earth. It is the angular measurement made at the ascending node (the point at which a satellite crosses the equatorial plane going from south to north) from the equatorial plane to the orbital plane (see Figure 4-6). Inclination orients the orbital plane to the equatorial plane, and determines the northernmost and

4-12 southernmost latitudes covered by the satellite’s ground track. Inclination also defines another manner in which orbits are described: • Prograde: inclination > 0° but < 90° • Retrograde: inclination > 90° but < 180° • Polar: inclination equal to 90° • Equatorial: inclination equal to 0 ° or 180° The final element used to define the size and shape of the orbit and the orbital plane is Right Ascension of the Ascending Node. This is the angular measurement in the equatorial plane from the Vernal Equinox (that point determined by a line extending from the center of the Sun through the center of the Earth to the celestial equator at the start of spring) eastward to the ascending node. The remaining two orbital elements are used to position the orbital plane. The Argument of Perigee orients the orbit within the orbital plane. It is the angular measurement from the ascending node along the orbital path to the point of perigee. Once the perigee point has been determined, the point of apogee is 180° away. Finally, to determine where a satellite is in its orbit at a specific time, Epoch Time or True Anomaly is used. Epoch Time is an arbitrary time used as a starting point. Normally, the time when a satellite is at the ascending node is used as epoch time. True Anomaly is the angular measurement from the point of perigee along the orbital path to the location of the satellite at the epoch time. Although period is not categorized as an orbital element, it is very useful in satellite operations. Typically, the period of a satellite is the time it takes to travel from one ascending node point to the following ascending node point (referred to as the "nodal period"). The minimum period a satellite can have and still be in a stable, non-decaying orbit is approximately 87.5 minutes. If there is any less time, the object will eventually reenter the Earth’s atmosphere. REFERENCE SYSTEMS Since observational data for a satellite may be derived by any one of a wide variety of types and locations of sensors, an understanding of the common reference systems used is essential. Each reference system is designed for a particular use, fulfilling at least one of the following purposes: • to locate a specific object in space

4-13 • to discriminate between two or more objects in space • to describe motion of an object in space. Reference systems may be classified into two basic types, either inertial or non-inertial. An inertial reference system is one in which direction does not change with time. It is used in locating the position of a satellite to establish the orbital plane and the satellite’s orbit within that plane. A non-inertial reference system does change direction with time. The four reference systems typically used in space operations are summarized in Table 4-1 below: Table 4-1. Summary of Common Reference Systems COORDINATE SYSTEM ORIGIN USED TO LOCATE Geographic (Non-Inertial) Earth Center Earth Radius Tracking Station Topocentric (Non-Inertial) Tracking Station Slant Range Locate satellite Ref: Tracking Station Geocentric (Inertial) Earth Center Geocentric Radius Locate satellite in space Orbit (Inertial) Earth Center Celestial Radius Locate satellite in its orbit LAUNCH AND ORBITAL MANEUVERING Many factors enter into the mission planning and subsequent design of a satellite. One of the most restrictive facets of this planning is the launch environment (i.e., booster, launch site, launch "window"). LAUNCH AZIMUTH AND INCLINATION Launch azimuth is the direction from the launch site in which a booster is launched. The relationship between the location of the launch site and the launch azimuth to the resulting inclination of a satellite’s initial orbit is very specific. The minimum orbital inclination of a satellite is equal to the latitude of the launch site, and is achieved with a launch azimuth of due East. For launches with any azimuth other than due East, the orbital inclination will always be greater than the latitude of the launch site. Practically speaking, a satellite launched on an azimuth between 0° and 180 ° will have an inclination between 0° and 90 °, or a prograde orbit. Satellites launched on azimuths between 180° and 360° will have inclinations between 90° and 180°, or a retrograde orbit.

4-14 Most U.S. launches take place from one of two complexes: Kennedy Space Center, Cape Canaveral, Florida, or Vandenberg Air Force Base in California. If a satellite is launched with the Space Shuttle from Kennedy Space Center (which is located at a latitude of 28.5° North) on a due East azimuth, its orbital inclination will be 28.5° and the limits of its ground track will be between 28.5° North and 28.5° South latitude. Therefore, the limits of the ground track equal the launch inclination. Launch Site Limitations Many safety factors must be considered when launching from a particular site. Of course, one of the safety considerations is not to launch over populated areas. Consequently, there are limitations to the launch azimuths from each site. Because of safety considerations, the maximum practical inclination from a Kennedy Space Center launch is 57°. However, after an initial orbit is established, the inclination of an orbit can be changed by out-of-plane maneuvers (described later in this section), but this is costly in terms of on-orbit propellant. To obtain an orbit with an inclination greater than 57°, U.S. satellites are launched from Vandenberg AFB, CA. A significant advantage of launching from Vandenberg is the capability to economically achieve polar orbits, with ground tracks covering all latitudes from the North Pole to the South Pole. Another limitation induced by the location of a launch site is the affect of the Earth’s rotational velocity. The speed of the Earth changes with latitude, ranging from zero mph at the poles to about 1037 mph at the equator. Since the Earth rotates from West to East, all points on its surface have an eastward velocity, with the greatest eastward velocity occurring at the equator. The farther a launch site is from the equator, the less the Earth’s rotational velocity imparts energy to the booster. This results in requiring more fuel to get a satellite into orbit, or a tradeoff with the satellite’s payload weight to conserve on-orbit fuel. Launching from an equatorial site offers a significant advantage, and is an important consideration since many satellites operate in low-inclination orbits. Launch Window Satellite launches take place within a specified time interval referred to as the "launch window." Some of the factors affecting the launch window are: • Launch and orbit lighting conditions • Sun angles • Payload orbit requirements • Satellite system phasing

4-15 • Tracking and communications requirements • Collision avoidance with other space objects. During the winter months, the available launch window for lighting conditions alone can be as little as 3 hours per day. When combined with other factors, launch windows become very constrained. ORBITAL MANEUVERING It is rare that a satellite is launched directly into its final orbit. A satellite will typically need to change its orbit at least once to be able to perform its mission. For example, the Space Shuttle may deploy a communications satellite designed for placement in a geosynchronous orbit. The Shuttle itself cannot reach geosynchronous altitude, so a small booster attached to the satellite has to be pointed in the proper direction at the right time and place, and thrusted for a precise length of time. Then, once it gets to geosynchronous altitude, it will have to thrust again to stay in its desired orbit. Mission Considerations After a satellite has been on orbit for a period of time, it is often necessary to change its orbit by thrusting. Firing a spacecraft’s thrusters results in a Delta "V"−a change in the satellite’s velocity. The amount of fuel used during a burn depends on the desired velocity change and the mass of the satellite. Since the amount of fuel carried is limited, fuel consumption is one of the primary considerations in satellite mission planning, and is critical to mission life. On orbit, a satellite can thrust in any direction. Thrusting along the flight path, forward or backward, is the most common. Forward thrusting increases a satellite’s velocity and is known as a "prograde burn." With prograde burns, the orbital path of the satellite will be raised at all points except the burn point. Thrusting opposite to the direction of the orbit, which slows a satellite down, is called a "retrograde burn." For retrograde burns, the orbit will be lowered at all points except the burn point. Maneuvers Most maneuvers may be performed any place in the orbit; however, there are certain points that minimize energy requirements for a particular type of maneuver: • The most economical method for obtaining a change in orbital period is by applying thrust at perigee or apogee

4-16 • The most economical place to perform an inclination change is at either the ascending or descending node

• The most economical place to perform a change in right ascension of the ascending node is at either of the tw o midway points between the ascending and descending nodes

• The change in inclination or right ascension is easiest if it is performed at apogee

• The most economical place to perform a maneuver to change perigee height is at apogee.

In-Plane Maneuvers

When a satellite needs to change its altitude, period, or eccen tricity, additional energy is required. This energy requirement is true whether or not the element's value is being increased or decreased. The type of tran sfer used to meet this energy requirement depends on the satellite's mission, and the amount of fuel available.

The most energy efficient in-plane ma neuver is known as the Hohmann Transfer (see Figure 4-7). The Hohmann Transfer is a two-impulse maneuver between two co- planar orbits.

Courtesy of Damon, Thomas D. (2001) Introduction to Space: The Science of Spaceflight, Third Edition. Krieger Publishing Company. Figure 4-7. Hohmann transfer.

In accomplishing a Hohmann Transfer, two applications of thrust are required. Each thrust changes the speed of the satellite and places it in a new orbit. If an increase in altitude is

4-17 desired, the point of departure becomes the perigee of the tran sfer orbit and the point of injection into the higher circular orbit becomes the apogee of the transfer orbit. The use of the Hohmann Transfer minimizes the velocity change required, with the advantage of using minimum fuel. The disadvantage of the H ohmann Transfer is th at it takes longer than most other transfers. The Hohmann Transfer is used extensively with interplanetary satellites, because it does not require a large maneuver engine or fuel tanks.

Another way to accomplish an altitude change is referred to as the Fast Transfer (see Figure 4-8). This transfer is most useful when time is a critical factor. In the Fast Transfer, the transfer orbit crosses the final orbit at an angle. The burn is performed in two increments but requires substantially more fuel than the Hohmann Transfer. It is, however, the quickest way to get to the final required orbit. The Fast Transfer is typically used by surveillance satellites to reposition over new target areas.

Courtesy of Damon, Thomas D. (2001) Introduction to Space: The Science of Spaceflight, Third Edition. Krieger Publishing Company. Figure 4-8. Fast transfer.

Out-of-Plane Maneuvers

To change inclination or right ascension, an out-of-plane maneuver is required. The inclination maneuver changes only inclination and maintains right ascension. This plane change requires one burn at either the ascending node or descending node of the original orbit. The amount of inclination change depends on the length of the burn.

The right ascension maneuver changes only right ascension without changing inclination. This plane change requires one burn anywhere in the original orbit except at the ascending or

4-18 descending nodes. The maximum effect is achieved when the burn is performed midway between the nodes. ORBIT TYPES AND APPLICATIONS The laws of nature force the orbits of all satellites to lie in planes that pass through the center of the Earth. A satellite’s ground track is formed by the intersection of the surface of the Earth and a line between the Earth’s center and the satellite. As the satellite moves in its orbit, this intersection traces out a path on the ground below it. GROUND TRACK If the Earth did not rotate, a satellite would retrace the same ground on each revolution (see Figure 4-9). Notice that the maximum latitude North and South of the equator over which the satellite passes is equal to the satellite’s inclination. Figure 4-9. Example of ground track (non-rotating Earth). The orbital plane of a satellite remains fixed in space as the Earth rotates under it. The effect of this rotation is to displace the ground track westward on each successive revolution of the satellite by the number of degrees the Earth turns during one orbital period (see Figure 4-

4-19 10). This is referred to as nodal regression. The resulting ground tracks provide operators with an indication of the position of their satellite in accomplishing its mission.

4-20 Figure 4-10. -Example of ground track (rotating Earth). As mentioned above, a satellite in either a circular or an elliptical orbit will trace out a path over the Earth between the limits of latitude as determined by the inclination angle. A satellite in a circular orbit will spend equal amounts of time North and South of the equator. However, a satellite in an elliptical orbit will remain North or South of the equator for unequal periods of time. Only satellites that are in circular orbits travel along their ground track at a constant velocity. When an orbit is inclined to the equator, the component of satellite velocity in the direction due East or due West varies continuously throughout the orbit. More specifically, a satellite in a nearly circular orbit moves slower in an easterly or westerly direction at the equator and faster when it is at its most northerly or southerly points. The relative speeds of satellites in elliptical orbits vary even more. FIELD OF VIEW The field of view of a satellite is defined as the area of the Earth’s surface that is in view from the satellite at any given time. Satellites in high orbits have greater fields of view than those in lower orbits. For example, a satellite at an altitude of 800 nmi has a circular field of view with a diameter of about 4,100 nmi. A satellite at 200 nmi has a circular field of view with a diameter of about 2,000 nmi.

4-21 TYPES OF ORBITS The various types of orbits are the result of different satellite missions, and the desire for satellites to perform their missions over different areas of the Earth’s surface (i.e., have different ground tracks). Low Earth Orbit A satellite is considered to be in a low earth orbit (LEO) at altitudes between approximately 150 and 800 miles above the Earth’s surface. At an altitude of approximately 150 miles, a satellite’s period will be about 90 minutes. The Space Shuttle and some scientific satellites are typically placed in low inclination, low earth circular orbits. Polar Orbit In contrast to a low inclination orbit and its latitude limitations, a polar orbit passes over the entire surface of the Earth. A polar orbit has an inclination of 90° and is usually circular (see Figure 4-11). Due to the ability to pass over the entire surface of the earth throughout the course of several days, the polar orbit is used extensively by imagery satellites. Figure 4-11. Polar orbit. Geosynchronous Orbit A satellite placed in orbit with an average altitude of approximately 19,300 nautical miles ( nm) will have an average angular velocity exactly equal to that of the Earth’s. Stated more simply, the satellite would have a period approximately equal to one day. This means that it would take as long for the satellite to complete one revolution around the Earth, as it takes for the earth to rotate once about its axis. Such an orbit is called a geosynchronous orbit.

4-22 If a geosynchronous orbit with an inclination of 0° were perfectly circular, the satellite would appear to remain stationary in space above the same point on the Earth’s surface. This is referred to as a geostationary orbit (see Figure 4-12).This orbit is predominantly used by relay satellites to provide a continuous communications capability among ground stations within their very broad field of view. Some surveillance and warning satellites also use the geostationary orbit. The geostationary field of view is constant, covering nearly one-third of the Earth’s surface with latitude limitations of approximately 70° North and South of the equator. Effective satellite communications from a geostationary orbit is not possible at either pole. Figure 4-12. Field of View from a Geostationary Orbit. Elliptical Orbit To obtain satellite communications capability in the northern or southern latitudes, a highly eccentric elliptical orbit, commonly referred to as a Molniya orbit is used (see Figure 4-

4-23 13). The Molniya orbit has an apogee nearly equivalent to the geosynchronous altitude and an inclination of approximately 63° to 64°. A satellite in this type of highly eccentric elliptical orbit slows down at apogee in the Northern Hemisphere (providing longer duration over its greatest field of view) and whips through perigee (smallest field of view) in the Southern Hemisphere. This provides communications in the Northern Hemisphere for nearly 75 percent of the satellite’s orbital period. If the apogee/perigee points were shifted 180°, this orbit would cover the Southern Hemisphere. Figure 4-13. Molniya orbit. Semi-Synchronous Orbit An average orbit with an altitude of approximately 10,800 nmi results in a period of about 12 hours and is referred to as a semi-synchronous orbit. The purpose of placing satellites in this type of orbit is to allow a user to receive signals from more than one satellite at any time. Navigation and certain kinds of area communications (Molniya) satellites use the semi- synchronous orbit. Sun-synchronous Orbit The sun-synchronous orbit takes advantage of the precession of the orbital plane caused by the Earth not being a perfect sphere. All sun-synchronous orbits are highly inclined (normally with inclinations between 95° and 105 °) retrograde orbits that precess eastward around the Earth’s polar axis at the rate on one revolution per year. Since the Earth-Sun line also revolves eastward at the rate of one revolution per year, the orbital plane will maintain a

4-24 constant orientation relative to the Earth-Sun line (see Figure 4-14). If the satellite’s orbital period is then synchronized with the rotation of the Earth, it will pass over the same point on the Earth’s surface at the same local time at a regular interval. Figure 4-14. Sun-synchronous orbit. A sun-synchronous satellite ensures that a constant sun angle and uniform lighting exists for the same field of view from revolution to revolution. For certain mission requirements, a noon/midnight sun-synchronous orbit can be selected that would provide good photography for about one-half of every revolution. Most meteorological and earth resources LEO satellites are placed in sun-synchronous orbits, imaging the entire Earth on a regular schedule. ORBITAL PERTURBATIONS AND DECAY There are other forces besides the Earth’s gravity (referred to as perturbations) which act on an orbiting satellite. Although much smaller, these other forces are of sufficient magnitude to cause orbital decay, and result in significant changes in a satellite’s ground track over time if not recognized and corrected for periodically. Changes in a satellite’s ground track can result in reduced mission effectiveness. To neutralize the effects of natural perturbations, a satellite may perform "station-keeping" thruster burns.

4-25 ORBITAL PERTURBATIONS The Earth is not a perfect sphere. The North Pole region is more pointed than the flatter South Pole region, and a bulge exists at the equator. This bulge, referred to as the Earth’s oblateness, causes the equator to be slightly elliptical. Earth’s Asymmetry These asymmetrical conditions have an influence on the orbital parameters of satellites in low-and-medium- altitude orbits. One effect of the Earth’s asymmetry is positive, in that the nodal regression of an orbit can be timed to make an orbit sun-synchronous without using precious fuel to maneuver for that purpose. Atmospheric Drag The Earth’s atmosphere does not suddenly end, it gradually tapers off into interplanetary space. Generally speaking, atmospheric drag circularizes and decreases the apogee of a low earth orbit. Any drag caused by air resistance can normally be disregarded above 300 nmi. Occasionally, however, a period of extreme solar activity may occur that will heat the atmosphere and cause it to expand. Third Body Effects Newton’s Law of Universal Gravitation indicates that there is a force of attraction (gravity) between all objects and bodies in the universe. The gravitational pull of "third bodies" such as the Moon and the Sun can affect the orbits of geosynchronous and deep space satellites. Radiation As discussed previously, the Sun is continually expelling matter in the form of ionized gas. The particles in this gas (mostly electrons and protons) that penetrate interplanetary space move with high velocities. These particles, commonly referred to as the solar wind, exert a pressure on satellites, particularly those with large area-to-mass ratios. This pressure induces a restraining force on satellites, and is only present on the daylight (or, windward) side of the Earth. This causes irregular perturbations of a satellite’s orbit. Electrons and protons can become trapped when encountering the Earth’s magnetic field. They oscillate back and forth along the lines of magnetic force, and since the magnetic field completely encircles the Earth, the trapped particles completely encircle the Earth. This region of trapped particles, mentioned earlier in Chapter 3, is known as the Van Allen Radiation Belt.

4-26 The belt has an inner and outer portion. The inner Van Allen belt starts at an altitude of approximately 250 to 750 miles, depending on the latitude. It extends to about 6,200 miles where it begins to overlap the outer belt. This inner belt extends from 45° North latitude to about 45° South latitude. The outer Van Allen belt begins around 6,200 miles and extends to an altitude that varies from 37,000 to 52,000 miles. The upper boundary is dependent on the activity of the Sun. Electromagnetic Forces The Earth’s magnetic field extends far into space. As a satellite orbits the Earth, it is traveling through this magnetic field. The electronic components of a satellite also produce a magnetic field that consequently reacts with the Earth’s magnetic field. Additionally, the ions and electrons in the Earth’s magnetic field collide with the satellite, causing a negative charge on the satellite’s surface. The negative charge is larger on the day-side of an orbit than on the night side. The interaction of these induced fields with the Earth’s magnetic field causes a magnetic drag to act on a satellite. This drag can cause charging or torquing of a satellite. ORBITAL DECAY AND DEORBIT For satellites that pass close to the Earth (low orbit or highly elliptical orbits), we can arrange for the satellite to re-enter, or let it re-enter by itself. Deliberate re-entry of a satellite with the purpose of recovering the vehicle intact is deorbiting. We usually do this to recover something of value: people, experiments, film, or the vehicle itself. The natural process of spacecraft (or any debris: rocket body, payload, or piece) eventually re-entering Earth’s atmosphere is decay. In some situations the satellites are in such stable orbits that natural perturbations won’t do the disposal job for us. In these situations, we plan to remove the satellite from the desirable orbit. To return a satellite to Earth (or low Earth orbit), it would take just as much energy as it did to place it in orbit. Obviously it is impractical to return old satellites to Earth from a high orbit. We usually just boost the satellite into a slightly higher orbit to get it out of the way, and there it will sit for thousands of years to come. SUMMARY The overall purpose of understanding the principles of orbital mechanics is to recognize the elements that affect the design and planning of a satellite’s mission. Many mission planning factors and constraints, such as on-orbit fuel, satellite weight, and launch site considerations, were mentioned in this chapter. However, one factor essential to the planning of a satellite’s mission remains to be discussed, and that is the selection of a satellite booster, or launch vehicle.

5-1 CHAPTER 5 LAUNCH AND RECOVERY SYSTEMS INTRODUCTION This chapter provides an overview of the systems and operations associated with the launch and recovery of spacecraft. The discussion includes a description of the U.S. launch and orbit transfer vehicles used to place payloads into orbit, an overview of launch and recovery operations, a description of the three major U.S. launch sites, a summary of the major ground processing activities that contribute to a successful launch and recovery, and a look at some future launch systems. It should be noted that the information contained in this chapter represents only a snapshot of the current U.S. launch vehicle inventory. As you might expect when dealing with a dynamic industry, this inventory will change as technologies emerge, evolve, and are replaced or removed. BACKGROUND During the early years of the space program, both the National Aeronautics and Space Administration (NASA) and the Department of Defense ( DoD) developed launch vehicles to satisfy their own specific requirements. Consequently, there has been a wide variety of launch vehicles used to support the space program. DoD developed the Atlas, Delta, and Titan series of launch vehicles from ballistic missile technology. Meanwhile, NASA developed the Scout and Saturn. Used to send Apollo crews to the Moon, both are now out of production. All these launch vehicles, which can only be used once, are called expendable launch vehicles (ELVs) and each has a different capability to put satellites in orbit. From the least to the most capable in terms of lift, they are Pegasus, Taurus, Delta, Atlas, and Titan. The Pegasus is a recent addition to the inventory of expendable launchers and is aircraft-launched. The Taurus is a ground-launched, mobile vehicle. Currently, there is no one vehicle that can launch all satellites into all the orbits required for the various missions. NASA and DoD select the vehicle best suited for their particular mission based on the size, weight, and desired orbit of the payload. In 1972, President Nixon approved NASA’s plan to create a reusable launch vehicle called the Space Shuttle, and directed that it become the primary U.S. launch vehicle, replacing all ELVs except the Scout. This made both NASA and DoD dependent on a single launch vehicle for access to space but, in theory, the resulting high launch rate for the Shuttle would significantly reduce the cost per flight. The Shuttle was first launched in 1981, and was declared operational in 1982. The phase-out of ELVs began. However, in 1984, concerned about having “assured access to space,” DoD successfully argued that it needed a “complimentary” ELV as a backup to the Shuttle and initiated what became known as the “Titan IV Program.” Production lines for the Delta and Atlas launch vehicles were closed down in anticipation that only the Shuttle and Titan IVs would be used by the end of the 1980s.