On April 12, 1981, coincidentally exactly twenty years after Yuri Gagarin became the first man to orbit the Earth in Vostok 1, the United States launched one of the most ambitious and risky manned space flights ever attempted. The flight of Space Shuttle Orbiter Columbia on its first mission, STS-1, would be the first time a manned spacecraft was launched with a crew on its first flight. (All earlier spacecraft were tested in unmanned flights before putting a crew at risk.) It would also be the first manned spacecraft to be powered by solid rocket boosters which, once lit, could not be shut down but had to be allowed to burn out. In addition, it would be the first flight test of the new Space Shuttle Main Engines, the most advanced and high performance rocket engines ever built, which had a record of exploding when tested on the ground. The shuttle would be the first space vehicle to fly back from space using wings and control surfaces to steer to a pinpoint landing. Instead of a one-shot ablative heat shield, the shuttle was covered by fragile silica tiles and reinforced carbon-carbon composite to protect its aluminium structure from reentry heating which, without thermal protection, would melt it in seconds. When returning to Earth, the shuttle would have to maneuver in a hypersonic flight regime in which no vehicle had ever flown before, then transition to supersonic and finally subsonic flight before landing. The crew would not control the shuttle directly, but fly it through redundant flight control computers which had never been tested in flight. Although the orbiter was equipped with ejection seats for the first four test flights, they could only be used in a small part of the flight envelope: for most of the mission everything simply had to work correctly for the ship and crew to return safely. Main engine start—ignition of the solid rocket boosters—and liftoff!
Even before the goal of landing on the Moon had been accomplished, it was apparent to NASA management that no national consensus existed to continue funding a manned space program at the level of Apollo. Indeed, in 1966, NASA’s budget reached a peak which, as a fraction of the federal budget, has never been equalled. The Saturn V rocket was ideal for lunar landing missions, but expended each mission, was so expensive to build and operate as to be unaffordable for suggested follow-on missions. After building fifteen Saturn V flight vehicles, only thirteen of which ever flew, Saturn V production was curtailed. With the realisation that the “cost is no object” days of Apollo were at an end, NASA turned its priorities to reducing the cost of space flight, and returned to a concept envisioned by Wernher von Braun in the 1950s: a reusable space ship.More