\<COLOUR 1> LIFT-OFF THRUST: \<COLOUR 0> About 50 tonnes
\<COLOUR 1> NO OF STAGES: \<COLOUR 0> 3 or 4
\<COLOUR 1> PROPELLANTS: \<COLOUR 0> First three stages, solid; fourth stage, hydrazine
\<COLOUR 1> TYPICAL PAYLOAD: \<COLOUR 0> Small satellites into low Earth orbit
\<COLOUR 1> LAUNCH SITE: \<COLOUR 0> Dropped from B-52 at height of about 12,500 metres
\<COLOUR 1> COUNTRY: \<COLOUR 0> USA
\<COLOUR 1> COMMENTS: \<COLOUR 0> First air-launched satellite system; first orbital flight on April 5, 1990; two satellites carried, NASA's Pegsat and US Navy's USA 55.