Thor Able

Introduced in 1958, Thor Able was the first variant of the Thor Intermediate Range Ballistic Missile (IRBM) to be used as a space launch vehicle. Originally designed to support testing of military and civilian high-speed re-entry vehicles, Thor Able was modified to carry small payloads into space. Commercial Thor-based rockets were renamed Delta in 1960, so Thor Able represents the first generation of the Delta rocket family. Indeed, the modern Delta II and Delta III were direct descendants of the Thor Able.

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