Patriot, PAC-3, was developed and tested—a complete redesign of the PAC-2 deployed during the war, including a totally new missile. The improved guidance, radar and missile performance improves the probability of kill over the earlier PAC-2. During Operation Iraqi Freedom, Patriot batteries engaged 100% of enemy TBM's within their engagement territory. Of these engagements, 8 of them were verified as kills by multiple independent sensors; the remaining was listed as a probable kill due to lack of independent verification. Patriot was involved in three friendly fire incidents: two incidents of Patriot shootings at coalition aircraft and one of U.S. aircraft shooting at a Patriot battery. A new version of the Hawk missile was tested during the early to mid-1990s and by the end of 1998 the majority of US Marine Corps Hawk systems were modified to support basic theater anti-ballistic missile capabilities. The MIM-23 Hawk missile is not operational in U.S. service since 2002, but is used by many other countries. Soon after the Gulf War, the Aegis Combat System was expanded to include ABM capabilities. The Standard missile system was also enhanced and tested for ballistic missile interception. During the late 1990s, SM-2 block IVA missiles were tested in a theater ballistic missile defense function. Standard Missile 3 (SM-3) systems have also been tested for an ABM role. In 2008, an SM-3 missile launched from the , successfully intercepted a non-functioning satellite. Brilliant Pebbles concept Approved for acquisition by the Pentagon during 1991 but never realized, Brilliant Pebbles was a proposed space-based anti-ballistic system that was meant to avoid some of the problems of the earlier SDI concepts. Rather than use sophisticated large laser battle stations and nuclear-pumped X-ray laser satellites, Brilliant Pebbles consisted of a thousand very small, intelligent orbiting satellites with kinetic warheads. The system relied on improvements of computer technology, avoided problems with overly centralized command and control and risky, expensive development of large, complicated space defense satellites. It promised to be much less expensive to develop and have less technical development risk. The name Brilliant Pebbles comes from the small size of the satellite interceptors and great computational power enabling more autonomous targeting. Rather than rely exclusively on ground-based control, the many small interceptors would cooperatively communicate among themselves and target a large swarm of ICBM warheads in space or in the late boost phase. Development was discontinued later in favor of a limited ground-based