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Wright, David, Laura Grego et al. Physics of Space Security. Washington, D.C.: Union of Concerned Scientists, May 2005. [ 5 quotes ]

Evidence Related to this Citation

Planned Missile Defense Systems have an Inherent ASAT capability
 
Missile defense systems designed to intercept long-range ballistic missile outside the atmosphere during the midcourse of their trajectory have significant ASAT capabilities against satellites in low earth orbits. These satellites orbit at altitudes similar to the altitude at which the defense is designed to intercept missiles. Unlike the case of an attacking missile, the trajectory and appearance of the satellite would be known in advance and the future trajectory would be predictable. Moreover, even highly controlled intercept tests of the defense against ballistic missile targets would provide confidence that the system would work against satellites, since the information provided to the defense about the missile target in these tests is comparable to what would be available in advance about satellite targets Using interceptors against a satellite rather than against a missile warhead is also easier in that the attacker could take multiple shots at the satellite if the initial attack was not successful. ( More ... )
Wright, David, Laura Grego et al. Physics of Space Security. Washington, D.C.: Union of Concerned Scientists, May 2005. [ 5 quotes ] [ page 10-11 ]
Space-Basing Offers Several Advantages over Air-Breathing Systems
 
Satellite-based sensors can see much larger areas of the Earth than sensors closer to the Earth can see. This allows large-scale simultaneous observation of the Earth's surface and atmosphere, and communication between and simultaneous broadcast to large parts of the Earth. Because the atmosphere blocks transmission of many types of electromagnetic waves, some kinds of astronomical observations can only be made from space. Moreover, space is much better suited to some types of operations than to others. Electromagnetic signals (light and radio waves) can be transmitted over large distances almost instantaneously and with very little energy cost. Space therefore favors activities that entail sending and receiving electromagnetic signals over activities that involve transporting large amounts of mass from the Earth into space or that involve significant maneuvering in space, which can require a large mass of propellant. As a result, the applications for which space basing is uniquely well suited include:

  • large-scale environmental monitoring of, for example, atmospheric
    behavior, climate change, and deforestation

  • large-scale weather monitoring for weather forecasting astronomy

  • global communication, broadcast, and data transfer

  • highly accurate navigation and position determination reconnaissance on a global or large-scale basis

  • detection on a global basis of missile launches, to provide early warning of attacks and information about the missile testing programs of nations


Some of these tasks could, as discussed later, be accomplished by ground- and air-based alternatives, if urgently needed, albeit on a regional rather than global basis. ( More ... )
Wright, David, Laura Grego et al. Physics of Space Security. Washington, D.C.: Union of Concerned Scientists, May 2005. [ 5 quotes ] [ page 6-7 ]
"Bodyguard" Satellites Won't Reduce Satellite Vulnerability
 
Deploying defensive "bodyguard" satellites to protect other satellites against ASAT attacks cannot provide confidence in the survivability of those satellites. Doing so will therefore not preclude the need to take into account the vulnerability of satellite systems and to have backup systems for any essential military capability the satellites provide. As discussed above, satellites are vulnerable to many types of attack and defending them is inherently difficult. Equally important, nations will not be able to rely on bodyguard satellites to protect their satellites from direct attack or interference by a determined adversary, because the limited amount of real-world testing that would be feasible would provide little confidence in the capability of the bodyguards. ( More ... )
Wright, David, Laura Grego et al. Physics of Space Security. Washington, D.C.: Union of Concerned Scientists, May 2005. [ 5 quotes ] [ page 9 ]
Force-Projection Space Weapons would be 10 Times more Expensive than Comparable Conventional Systems
 
Deploying a space-based system would be tens of times more expensive than deploying a comparable system using ballistic missiles. This is a consequence of the fact that any satellite system with prompt global coverage would require numerous satellites to ensure that at least one is in the right place at all times. The exact number of satellites will depend on the altitude of the orbit and the reach of each weapon, but tens of satellites would be required for prompt attack of one target. For example, the constellation considered in Section 9, which could attack any point on the Earth within about 30 minutes, would require nearly 100 satellites. If the promptness requirement was relaxed to a 45-minute response time, roughly 50 satellites would still be required. ( More ... )
Wright, David, Laura Grego et al. Physics of Space Security. Washington, D.C.: Union of Concerned Scientists, May 2005. [ 5 quotes ] [ page 9 ]
Space-Based Force-Projection Weapons less Reliable than Ground-Based Options
 
Unlike ground-based weapons, space-based weapons that have been launched must remain operational without either routine or emergency maintenance. As a consequence, space-based weapons would be less reliable and an attacker would have less confidence in using them for an attack than ground-based missiles. If a space-based weapon in the proper position for an attack failed, other satellites in the constellation could be used in its place but could not meet the same promptness criterion, because they would take time to move into position. ( More ... )
Wright, David, Laura Grego et al. Physics of Space Security. Washington, D.C.: Union of Concerned Scientists, May 2005. [ 5 quotes ] [ page 8 ]