Directory of U.S. Military Rockets and Missiles
Appendix 3: Space Vehicles
ASB-11
SSB-10
 
Copyright © 2003-2008 Jos Heyman
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Orbital Sciences ASB-11 Pegasus

Orbital Sciences Corp. and Hercules Aerospace developed the Pegasus winged launch vehicle for small payloads. The vehicle is propelled by three solid fuelled stages and is air-launched by a Tristar launch aircraft, except for the initial flights which were air-launched from a B-52. The Pegasus carries the military designation ASB-11A which probably only applies to military launches.

The basic Pegasus vehicle has a small delta shaped wing with a span of 6.70 m attached to its first stage and the entire vehicle has a length of 15.50 m. The payload bay has a length of 1.83 m and a diameter of 1.22 m. It has a capability to place a 375 kg payload into low-Earth orbit. Some references include the launch aircraft as an additional stage.

Stage Length Diameter Engine Fuel Thrust
18.90 m1.22 m1 Alliant Techs. Orion 50Ssolid 484,926 N
22.70 m1.22 m1 Alliant Techs. Orion 50solid 118,203 N
32.10 m1.22 m1 Alliant Techs. Orion 38solid 34,569 N

Specifications for Pegasus


Photo: Orbital Sciences
Pegasus underneath Stargazer


The Pegasus XL is an improved version with increased propellant and a length of 17.60 m. It has a capability to place a 443 kg payload into low-Earth orbit.

Stage Length Diameter Engine Fuel Thrust
18.90 m1.22 m1 Alliant Techs. Orion 50SXLsolid 589,028 N
22.70 m1.22 m1 Alliant Techs. Orion 50XLsolid 153,508 N
32.10 m1.22 m1 Alliant Techs. Orion 38solid 34,569 N

Specifications for Pegasus XL


Photo: Author's collection
Stargazer launch aircraft


The first flight of the Pegasus was on 5 April 1990 and there had been nine flights with the last one on 7 June 2000. The first flight of the Pegasus XL was on 9 March 1996, after two failures on 27 June 1994 and 22 June 1995. Up to 31 December 2007 there had been 28 flights.

At one stage consideration was given to adding two turbojet engines which would assist the vehicle to achieve orbital speed and altitude faster. The two turbojets would have been jettisoned at an altitude of 30 km. This development did not proceed.


Back to Directory of U.S. Military Rockets and Missiles, Appendix 3




Last Updated: 18 January 2008