Space Transportation System
proposed post-Apollo system of reusable crewed space vehicles
The Space Transportation System (STS), also known internally to NASA as the Integrated Program Plan (IPP), was a proposed system of reusable crewed space vehicles envisioned in 1969 to support extended operations beyond the Apollo program (NASA appropriated the name for its Space Shuttle program, the only component of the proposal to survive Congressional funding approval). The purpose of the system was two-fold: to reduce the cost of spaceflight by replacing the existing method of launching capsules on expendable rockets with reusable spacecraft; and to support ambitious follow-on programs including permanent orbiting space stations around Earth and the Moon, and a human landing mission to Mars.
In February 1969, President Richard Nixon appointed a Space Task Group headed by Vice President Spiro Agnew to recommend human space projects beyond Apollo. The group responded in September with the outline of the STS, and three different program levels of effort culminating with a human Mars landing by 1983 at the earliest, and by the end of the twentieth century at the latest. The system's major components consisted of:
A permanent space station module designed for 6 to 12 occupants, in a 270-nautical-mile (500 km) low Earth orbit, and as a permanent lunar orbit station. Modules could be combined in Earth orbit to create a 50 to 100 person permanent station.
A chemically fueled Earth-to-orbit shuttle.
A chemically fueled space tug to move crew and equipment between Earth orbits as high as geosynchronous orbit, which could be adapted as a lunar orbit-to-surface shuttle.
A nuclear-powered shuttle or ferry using the NERVA engine, to move crew, spacecraft and supplies between low Earth orbit and lunar orbit, geosynchronous orbit, or to other planets in the solar system. A crew module derived from the space station module would be used to send humans to the Moon or Mars.
This brief starts where responsible research should: with the source description of “Space Transportation System” as proposed post-Apollo system of reusable crewed space vehicles. Everything that follows is an evidence route, not borrowed authority.
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The citation trail is more important than the brevity of the summary: it shows where individual claims can be examined in context. The source revision retrieved here is dated Apr 27, 2026. The linked authority identifier is Q10480840. None of the 1 selected statements returned an explicit reference. The first chronological checks are 1969 and 1983.
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This entry incorporates text from “Space Transportation System” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.