Skybolt (XGAM-87A, later XAGM-48A) was an air-launched ballistic missile, consisting of two solid fueled stages built by Douglas Aircraft Co. It was developed based on the experience with the Bold Orion (WS-199B) an High Virgo (WS-199C) experimental air launched ballistic missiles.
Skybolt was powered by two Aerojet General manufactured solid rocket motors. The missile had a length of 11.66 m and a diameter of 0.89 m. The fin span was 1.68 m. The two rocket stages of the 5000 kg missile propelled the warhead to a speed of 15300 km/h, which gave it a range of up to 1850 km.
Unpowered drop tests began in January 1961. Flight tests of powered and guided Skybolt prototypes began in April 1962. The flights originated from Eglin, Florida with the Atlantic Missile Range used as drop zone. The first five tests were all failures. The only fully successful Skybolt flight occurred on 19 December 1962, but on that same day the whole program was cancelled and the production of the operational GAM-87A missiles was stopped.
The operational Skybolt missiles would have carried a General Electric Mk.7 reentry vehicle with a W-59 nuclear warhead. Planes intended to carry the Skybolt were the US B-52H and B-70 and the british Vulcan B.2 bombers.
|Version||Aircraft||Stage 1||Stage 2|
|Skybolt (XGAM-87A / XAGM-48A)||B-52H||XM-80||XM-81|
No. TNo. Vehicle Date LS Payload
1 1 Skybolt 19.04.1962 * F Egl / B-52G R&D 2 2 Skybolt 29.06.1962 * F Egl / B-52G R&D 3 3 Skybolt 13.09.1962 * F Egl / B-52G R&D 4 4 Skybolt 25.09.1962 * F Egl / B-52G R&D 5 5 Skybolt 28.11.1962 * F Egl / B-52G R&D 6 6 Skybolt 22.12.1962 * Egl / B-52G R&D Failures: 1: stage 2 failed to ignite 2: stage 1 failed to ignite 3: veered off course, range safety destruct at T+58 sec 4: stage 2 premature thrust termination 5: out of control after 4 sec Launch sites: Egl = Eglin AFB, Florida, USA