The ASM-135 ASAT is an air-launched anti-satellite multistage missile that was developed by Ling-Temco-Vought’s LTV Aerospace division. The ASM-135 was carried exclusively by United States Air Force (USAF) F-15 Eagle fighter aircraft.
On December 21st, 1982, an F-15A was used to perform the first captive carry ASM-135 test flight from the Air Force Flight Test Center, Edwards AFB, California in the United States.
On August 20th, 1985, President Reagan authorized a test against a satellite. The test was delayed to provide notice to the United States Congress. The target was the Solwind P78-1, an orbiting solar observatory that was launched on February 24th, 1979.
On September 13th, 1985, Maj. Wilbert D. “Doug” Pearson, flying the “Celestial Eagle” F-15A 76-0084 launched an ASM-135 ASAT about 320 kilometres (200 mi) west of Vandenberg Air Force Base and destroyed the Solwind P78-1 satellite flying at an altitude of 555 kilometres (345 mi). Prior to the launch, the F-15 – flying at Mach 1.22 – executed a 3.8 g0 (37 m/s2) zoom climb at an angle of 65 degrees. The ASM-135 ASAT was automatically launched at 11,600 metres (38,100 ft) while the F-15 was flying at Mach 0.934 (992.2 km/h; 616.5 mph). The 14 kilograms (30 lb) MHV collided with the 910 kilograms (2,000 lb) Solwind P78-1 satellite at closing velocity of 24,000 kilometres per hour (15,000 mph; 6.7 km/s).
NASA learned of U.S. Air Force plans for the Solwind ASAT test in July 1985. NASA modeled the effects of the test. This model determined that debris produced would still be in orbit in the 1990s. It would force NASA to enhance debris shielding for its planned space station.
Earlier the U.S. Air Force and NASA had worked together to develop a Scout-launched target vehicle for ASAT experiments. NASA advised the U.S. Air Force on how to conduct the ASAT test to avoid producing long-lived debris. However, congressional restrictions on ASAT tests intervened.
In order to complete an ASAT test before an expected Congressional ban took effect (as it did in October 1985), the DoD chose to use the existing Solwind astrophysics satellite as a target.
NASA worked with the DoD to monitor the effects of the tests using two orbital debris telescopes and a reentry radar deployed to Alaska.
NASA assumed the torn metal would be bright. Surprisingly, the Solwind pieces turned out to appear so dark as to be almost undetectable. Only two pieces were seen. NASA Scientists theorized that the unexpected Solwind darkening was due to carbonization of organic compounds in the target satellite; that is, when the kinetic energy of the projectile became heat energy on impact, the plastics inside Solwind vaporized and condensed on the metal pieces as soot.
NASA used U.S. Air Force infrared telescopes to show that the pieces were warm with heat absorbed from the Sun. This added weight to the contention that they were dark with soot and not reflective. The pieces decayed quickly from orbit, implying a large area-to-mass ratio. According to NASA, as of January 1998, 8 of 285 trackable pieces remained in orbit. The last piece of debris, COSPAR 1979-017GX, SATCAT 16564, deorbited May 9th, 2004, according to SATCAT.
Look for Hobby Master’s rendition of the Celestial Eagle sometime in October.