F-15 ASAT
Last revised March 3, 2000
In the late 1970s, even before the advent of the Strategic Defense Initiative (SDI), an anti-satellite (ASAT) mission evolved for the F-15 Eagle.
The goal of ASAT weapons is the neutralization of enemy military satellites in the event of war, particularly low-orbiting reconnaissance, ELINT, and ocean surveillance satellites. The Soviets had their own antisatellite program in which a killer satellite would rendezvous with the target satellite and explode. The American equivalent involved the arming of an F-15 Eagle with a missile which would be launched against an orbiting satellite from a zoom climb at an altitude of 80,000 feet.
In 1979, a contract was issued to Vought for an air-launched low Earth-orbit antisatellite vehicle. The Vought ASM-135A that emerged was a two-stage rocket, with a first stage derived from the AGM-69 SRAM-A and a second stage derived from the Altair III rocket. The ASM-135A weighed about 2700 pounds at launch and was 18 feet long. The payload of the ASM-135A consisted of a miniature kinetic kill vehicle which used an infrared seeker to home in on the target satellite, destroying it by impact. No explosive warhead was to be needed.
F-15A 76-0086 was modified for trials with the Vought ASM-135A. The ASM-135A was carried on the centerline station of the F-15. The aircraft had to be specially wired to accommodate the ASM-135A missile, and had to be provided with backup battery, microprocessor, and datalink for midcourse guidance.
Beginning in the early 1980s, captive flights were made with the missile in place, the aircraft zoom climbing to altitudes as high as 80,000 feet. The first actual launch of an ASM-135A from an F-15 took place in January 1984, the missile being aimed at a predetermined point in space. Subsequently, three launches of the ASM-135A were made against celestial infrared sources.
The first and only ASM-135A launch against an actual target satellite took place on September 13, 1985, when F-15A 77-0084 of the 6512th Test Squadron stationed at Edwards AFB took off from Vandenberg AFB and zoom-climbed up to 80,000 feet and then launched the ASAT against the Solwind P78-1, a gamma ray spectroscopy satellite that had been launched in February of 1979. Both the first and second stages fired successfully, and the miniature kinetic kill vehicle separated and homed in on the satellite, destroying it upon impact.
The test was a success in that it demonstrated that the basic concept was feasible. However, it enraged arms control advocates, who saw the test as a violation of a joint US/Soviet treaty forbidding the development and testing of antisatellite weapons. Solar scientists were not happy about the test either, since although the Solwind P78-1 that was killed had officially completed its mission, it was still sending back useful data.
Initial plans were made to modify twenty F-15As for the antisatellite mission and to assign them to the 48th TFS at Langley AFB in Virginia and the 318th TFS at McChord AFB in Washington. These squadrons had each received three or four F-15A/B airframes which had been rewired for ASAT operations. However, Congress was unwilling to permit any further testing of the system, and the ASAT program was officially terminated in 1988.