From 1970, a Grumman Alternate Space Shuttle design that utilizes the S-IC booster from the Saturn V. Quite a number of Space Shuttle concepts called for the S-IC to be used as a first stage booster, as an expendable stage, a partially reusable or fully reusable stage. Shown here, the basic S-IC would be expendable. However, a second option would be to use a modified S-IC where the outer four engines would drop off during ascent and would be recovered. This is the same concept that Boeing proposed for the S-ID stage (see the October 2008 issue of the AIAA-Houston “Horizons” newsletter for more on the S-ID).
The use of a S-IC – stock or modified for partial recovery – would have presented a number of advantages, not least being that the existing Saturn launch facilities could be used. The S-IC would have provided adequate launch performance; the use of recoverable engines would have lowered cost and increased performance. However, the S-IC production line had been shut down for some time, and restarting it would have proven not only politically dubious (restating the S-IC would have led to questions about restarting the rest of the Saturn/Apollo line), but also expensive.
Slightly more on this is HERE.
