A 1977 concept drawing for a space station. Known as the Spider concept, this station was designed to use Space Shuttle hardware. A solar array was to be unwound from the exhausted main fuel tank. The structure could then be formed and assembled in one operation. The main engine tank would then be used as a space operations control center, a Shuttle astronaut crew habitat, and a space operations focal point for missions to the Moon and Mars.
When I was growing up in the 80s, I never really understood just how recently space exploration had been pioneered. A mere 20 years had passed since a single Soviet man became the first human being to journey into space. On the day of the 20th Anniversary, 12th April 1981, the first spaceflight of a reusable spacecraft began. It seems hard to believe that so much happened in such a short time.
Before the space shuttle, the accepted method of getting things into space involved a multi-stage rocket. Each stage has its own rocket engines and when expended, would be released from the rest of the “stack”, allowing the now-uncovered next stage to fire. This method was used for everything; even the lunar lander was a two-stage vehicle, one stage each was used for descent and take-off.
And yet, as early as the mid-sixties, designs were being discussed for a reusable spacecraft, something that didn’t jettison and irreversibly damage the majority of its useful components. Several methods were investigated.
In 1972, the space shuttle was greenlit for development in a statement from President Richard Nixon.
“This system will center on a space vehicle that can shuttle repeatedly from Earth to orbit and back. It will revolutionize transportation into near space, by routinizing it. It will take the astronomical costs out of astronautics. In short, it will go a long way toward delivering the rich benefits of practical space utilization and the valuable spinoffs from space efforts into the daily lives of Americans and all people.”
It was to play a vital role in helping achieve America’s goals in space: making space travel easier, cheaper, safer and more productive. As well as delivering satellites and equipment into orbit, it would ferry scientists and their experiments into a microgravity environment, and allow study of the effects of long-duration space travel on crews and equipment.
Two years later, construction of the first of the space shuttles, referred to as “orbiters”, began. OV-101 (“Oribiter Vehicle”-101), called “Enterprise”, rolled out to some considerable fanfare in 1976, and began the first test flights in early 1977.
NASA began by putting it on the back of what was to become the Shuttle Carrier Aircraft (SCA), the primary means of moving the orbiter fleet around the country. After making sure that the combination could fly as expected, NASA began a series of five flights where the shuttle disconnected from the SCA and glided to a runway landing.
These tests proved that the unpowered return of the shuttle worked in practice. Other “fitting” tests had Enterprise on a launch pad, with external tank and boosters in place. All that was left to do was modify Enterprise for space travel.
It didn’t happen. The many design tweaks that crept in during the tests meant that refitting Enterprise to go into space would have cost more than building a new one.
On March 25th 1979, Columbia arrived at Kennedy Space Centre, and combined with the rest of the “launch stack”.
This consists of the shuttle itself, which carries the crew and mission payload (experiments, or occasionally a satellite). The biggest part of the stack is the external tank. This is just an enormous fuel tank for the shuttle’s main engines. The fuel in this tank is expended just 8.5 minutes after launch, when it is jettisoned. This is the only part of the launch stack that isn’t re-used.
The remaining part is the the two Solid Rocket Boosters (SRBs). Unlike the shuttle engines, these are basically fireworks. Once ignited, they burn until they are empty of fuel, and are jettisoned. They can’t be switched off, and so are only ignited at T-0. Once they’re on, the shuttle is committed to launching.
On 12th April 1981, Columbia blasted into orbit on the first full test flight of the space shuttle programme.
Next update: STS-1 and Columbia.
(Edit: Fix for accuracy: Columbia was not made from a test article. My bad!)