Altair (rocket stage)
The Altair was a solid-fuel rocket with a fiberglass casing, initially developed for use as the third stage of Vanguard rockets in 1959. It was manufactured by Allegany Ballistics Laboratory as the X-248. It was also sometimes called the Burner 1.
Altair
The X-248 was one of two third-stage designs used during Project Vanguard. Early launches used a stage developed by the Grand Central Rocket Company, but the last used the X-248 which enabled the Vanguard to launch more massive payload.The X-248 was used as the second stage of some early Thor flights. These vehicles were designated "Thor-Burner".
Altairs were used as the third stage of early Delta rockets.
The fourth stage of the Scout-X rocket used the "Altair-1A" stage, powered by a X-248A engine.