Space Shuttle-C

Shuttle-C would have used the external tank, solid rocket boosters, and SSME engines familiar from the shuttle, but without a crewed orbiter. The aim was to use existing production and operating infrastructure for heavy payloads without crew risk.

NASA developed several variants of the concept, particularly for heavy payloads and future space stations. It did not receive funding and never entered production; its studies remain a record of the search for heavy lift before SLS.