The Air Force was mildly interested but demanded a much larger vehicle, far larger than the original concepts, which NASA accepted since it was also beneficial to their own plans. This led to an effort to interest the US Air Force in using the shuttle for their missions as well. When funding for the program came into question, there were concerns that the project might be canceled. By 1970 the shuttle had been selected as the one major project for the short-term post-Apollo time frame. The shuttle project rose to the top, largely due to tireless campaigning by its supporters.
Three were eventually presented to Vice President Agnew in 1969. As each of these projects fought for funding, the NASA budget was at the same time being severely constrained. Numerous offerings from a variety of commercial companies were also offered but generally fell by the wayside as each NASA lab pushed for its own version.Īll of this was taking place in the midst of other NASA teams proposing a wide variety of post-Apollo missions, a number of which would cost as much as Apollo or more. An attempt to re-simplify was made in the form of the DC-3, designed by Maxime Faget, who had designed the Mercury capsule among other vehicles. This was a two-stage system with delta-winged spacecraft, and generally complex. One was designed by engineers at the Manned Spaceflight Center, and championed especially by George Mueller. The primary intended use of the Space Shuttle was supporting the future space station, ferrying a minimum crew of four and about 20,000 pounds (9,100 kg) of cargo, and able to be rapidly turned around for future flights.
The early studies were denoted "Phase A", and in June 1970, "Phase B", which were more detailed and specific. Before the Apollo 11 Moon landing in 1969, NASA began studies of Space Shuttle designs as early as October 1968.