These would be pad-launched from a vertical position. #The larger winged vehicle would be called the "Booster", while the smaller winged vehicle would be called the "Orbiter". The Booster would carry the Orbiter to an altitude of about 50 miles. The Orbiter would then separate and fire its own engines to reach orbit. After separation, the Booster would turn and descend through the atmosphere for a landing near the launch site. The Orbiter would return for a landing upon the end of its space mission. The Booster would, in essence, be a fuel tank with wings. In this two-stage concept, both the Booster and Orbiter would require cockpits, hardware and instrumentation to facilitate landings. Both were designed to carry internal turbo-fan engines which would produce controlled flight during landing operations. Each vehicle would carry its own fuel tanks. As originally described by NASA in 1970, this two-stage Space Shuttle would be able to carry a 25,000-pound payload to a maximum 300-mile circular orbit. As we now know, this early two-stage concept does not resemble the Space Shuttles which were built. This was due to the economic realities facing NASA in the early 1970's. In a time of general recession, it was clear that NASA could not afford to build a fleet of complicated two-stage Space Shuttles along with a space station at the same time. Matters were further complicated in 1971 as NASA debated with the U.S. Air Force regarding shared use of the Space Shuttle fleet. Military funding for the Space Shuttle program was vital if NASA hoped to build the vehicle at all. But the U.S. Air Force specified a total payload capability of 65,000 pounds for Space Shuttles capable of carrying large, sophisticated military satellites into orbit. This figure was nearly three times more than NASA had originally planned. These major factors led to a dramatic redesign of the Space Shuttle and the proposed space station.
