PUBLIC INTEREST REPORT WINTER 2011 The Anti- Satellite Capability of the Phased Adaptive Approach Missile Defense System — BY LAURA GREGO In early 2008, President Bush tasked U.S. based missile defense system. After a few days done so since 1982.2 This unofficial morato- Strategic Command with Operation Burnt of waiting out rough seas, on February 20, the rium had been recently broken by China in Frost: “mitigating” the threat posed by a non- U.S. Navy Ticonderoga-class cruiser Lake Erie 2007, when it destroyed its own aging responsive intelligence satellite that was soon launched an SM-3 missile which intercepted weather satellite at 800 km altitude. The Bush to re-enter the Earth’s atmosphere. USA-193 the USA-193 satellite. administration had withdrawn from the Anti- had been launched into orbit just over a year While framed as a public safety measure, Ballistic Missile Treaty in 2002 and expressed earlier, and its fate was sealed after the Na- some observers expressed skepticism that this interest in a range of new military uses for tional Reconnaissance Office was unable to risk was the real or entire motivation for the space, including space-based weapons and establish control over the satellite after launch. exercise. The interception, at an altitude of anti-satellite weapons. Just a week before Op- While the imminent re-entry of a satellite was 240 kilometers (km), vividly demonstrated eration Burnt Frost was carried out, China not in itself at all remarkable—70 tons of the ASAT capability of the U.S. Aegis sea- and Russia had circulated to the Conference space debris and scores of large objects drop based missile defense system. The intercept on Disarmament a draft treaty that would out of orbit each year without any casualty required only modification of the system ban putting weapons in space and using force and without any operations mounted in re- software,1 and could have been done from any against satellites.3 The United States re- sponse—administration officials expressed of the 5 cruisers or 16 destroyers equipped sponded with little interest, saying that there concern that leftover hydrazine fuel aboard with the Aegis system at the time (two de- was no need for arms control in space.4 the satellite might survive re-entry and hurt stroyers were slated to be backups to the USS Operation Burnt Frost, in turn, is impor- someone on the ground. Lake Erie). tant context for the announcement eighteen On February 14, 2008, General James The context is important. This was the months later of the Obama administration’s Cartwright announced the United States first time the United States had deliberately new plans for European missile defense, the would destroy the satellite using the Aegis sea- destroyed a satellite since 1985; Russia hadn’t Phased Adaptive Approach (PAA). 1 FEDERATION OF AMERICAN SCIENTISTS WWW.FAS.ORG PUBLIC INTEREST REPORT WINTER 2011 This new PAA plan replaced the maneuver (“divert capability”). Both Block I and the recently shuttered Airborne Laser, George W. Bush administrations’ plan that interceptors have a reported burnout velocity of also have intrinsic anti-satellite capability.9 aimed to protect European allies from 3.0-3.5 km/s. The Block IIA will have longer The GMD interceptors could reach nearly missile threats in the Middle East using range and a seeker with better discrimination any satellite in low earth orbit (LEO). powerful ground-based interceptors in and more divert capability. The Block IIA inter- The SM-3 is designed to intercept Poland and a radar in the Czech Republic. ceptors are expected to burnout at a velocity 45- warheads in the midcourse phase of flight, PAA would rely on and substantially ex- 50percent faster than the Block I missiles, so in when they are above the atmosphere. The pand and improve the Aegis missile de- the range of 4.5 to 5.5 km/s.5 The Block IIB kill vehicle carries its own fuel for maneu- vering as well as an infrared sensor. The fense system used in Operation Burnt interceptor is still in the conceptual stage, but is sensor is intended to guide the interceptor Frost and demonstrated to have anti- meant to engage intercontinental-range ballistic toward an object and allow it to home in satellite capability. missiles and to have yet higher propulsion. It on and destroy the target by direct impact, may be land-based only. or “kinetic kill.” The Phased Adaptive The plan is to make all versions of the SM-3 Because midcourse missile defense Approach to European missile able to be launched from the launch systems are intended to destroy ballistic tubes on the Aegis ships. Missile Defense missile warheads, which travel at speeds Also important is the development of more and altitudes comparable to those of satel- sensors and the capability of the Aegis ships and The PAA system’s much smaller SM-3 lites, such defense systems also have ASAT sites to perform “launch on remote,” the ability interceptors are to be based primarily at sea capabilities. In fact, while the technologies to launch on the cue from a sensor not on the on Aegis ships converted to the purpose as being developed for long-range missile ship. This will allow the interceptors to launch defenses might not prove very effective well as some land-based “Aegis ashore” from a greater range. This capability was first against ballistic missiles—for example, sites. It is meant to be flexible and address introduced to the Aegis system after Operation because of countermeasure problems in- emerging ballistic missile threats from the Burnt Frost and will now become standard. herent in midcourse missile defense—they Middle East over the coming decade. It could be far more effective against satel- will be improved incrementally, in four Missile Defenses as ASAT Weapons lites. phases. The current generation of the SM- In many ways, attacking satellites is an 3 missiles, Block 1, will eventually be aug- easier task than defending against ballistic mented with longer-range, more sophisti- While Operation Burnt Frost was the first time the United States used a missile defense system missiles. Satellites travel in repeated, pre- cated missiles. More ships would be outfit- to destroy an orbiting satellite, the United States dictable orbits that ground facilities can ted with new missiles and new and im- has for years had some intrinsic ASAT capability accurately determine by tracking them. An proved sensors added. Land-based sites in its existing missile defense programs. Both the attacker would have time to plan an attack would be added starting in 2015. Aegis BMD and Terminal High Altitude Area against a satellite, could choose the time of Currently, only the Block IA variant Defense (THAAD) missile defense systems the attack in advance, and would be able to of the SM-3 missile is deployed. The Block were considered during the preparation of Op- take as many shots as necessary to destroy IB interceptors, currently under testing eration Burnt Frost,7 although THAAD, like it whereas advance notice of a ballistic and development, are based on the same 3- the SM-3 Block 1 systems, would be useful only missile attack is unlikely. In addition, an stage booster missile as the Block IA mis- against the lowest altitude satellites. interceptor attacking a satellite would not sile, but the Block IB kill vehicle will have The U.S. Ground Based Midcourse (GMD) have to contend with the same counter- sensors that can image the target at two missile defense system with a total of 30 de- measure10 problems that a midcourse mis- ployed interceptors in Alaska and California8 wavelengths and increased capability to sile defense system would face. 2 FEDERATION OF AMERICAN SCIENTISTS WWW.FAS.ORG PUBLIC INTEREST REPORT WINTER 2011 Countermeasures can severely limit the below the inclination angle) twice a day. Since the vast majority of LEO satellites (see Fig- ability of a midcourse missile defense to de- an attacker could choose the timing and ge- ure 2).11 Interceptors with burnout speeds at fend against ballistic missiles: warheads and ometry, the attack can be mounted when the the high range of estimates for the SM-3 IIA lightweight decoys move on the same trajec- satellite is overhead and the missile defense (5.5 km/s) would be able to reach any satel- tories in the vacuum of space, and the inter- interceptor may therefore use its velocity to lite in LEO, as would GMD interceptors. ceptor’s onboard sensor or ground-based reach the highest altitude possible rather than radars would be unable to distinguish these to reach out laterally. A rough estimation of PAA as a Strategic ASAT decoys from the warhead. An attacker can the maximum altitude an interceptor can Weapons System release numerous decoys along with the war- reach may be calculated by setting the kinetic head in order to confuse the missile defenses energy of the interceptor at burnout (when While the United States has long had ASAT or exhaust them by forcing them to intercept the missile ceases powered flight) to the po- capability in its missile defense systems, the all the decoys along with the warheads. tential energy at the given altitude. PAA system as conceived is ASAT capability Operation Burnt Frost showed that The current Aegis interceptors SM-3 IA/ on a much different scale. The enormous SM-3 interceptors can successfully intercept IB can reach only the relatively few satellites in potential size of the capability is new. While satellites if they can be reached. LEO satel- orbits with perigees at or below 600 km alti- the projected inventory of Block II SM-3 lites are generally in highly inclined or nearly tude.