Ambitious, breathtaking but somewhat antiquated, the Space Shuttle gave us triumph and tragedy. It reached its apogee as the United States became the world’s foremost superpower, and went out of commission as the country was suffering a financial meltdown.
The first Shuttle launch of the Columbia took place on April 12, 1981. It was 20 years to the day since Russia’s Yuri Gargarin became the first man in space.
The final Shuttle mission was completed when Atlantis touched down at Kennedy Space Center in Florida on July 21, 2011. Total missions count is 135, the combined number of orbits is 20952, covering 537,114,016 miles, and the program cost $196 billion (at 2011 estimates, adjusted for inflation).
Plans for the Shuttle were considered even before Neil Armstrong made his small step onto the Moon’s surface. President Richard Nixon gave the go-ahead for a re-usable system with a view to creating a space station. Once the X-24B experimental vehicle proved an aircraft could reach altitude (X24-B reached 74300ft in ’73) and make an unpowered landing, the US Space Shuttle program was on track.
It was the most complex vehicle ever built, with more than 2.5 million parts and 230 miles of cable. Most of us know the Shuttle (the Orbiter) piggybacks a huge, external tank of liquid oxygen and liquid hydrogen. These fuel the Shuttle’s three main engines, but its the solid fuel boosters on either side of the tank that provide 83% of thrust at liftoff and for the next two minutes as 4.5 million pounds achieve a maximum velocity of 17500mph.
To establish a low orbit, most of the acceleration has to be horizontal, but the initial vertical acceleration takes it out of sight. During this part of the flight, the Orbiter is upside-down. That’s deliberate. It’s more aerodynamically efficient and allows the crew to see the ground for orientation.
Every Orbiter was made in Palmdale, CA by Rockwell International. The first was originally called the Constitution, but a postal campaign from some dedicated Star Trek fans succeeded in changing it to Enterprise.
Some cast members of the TV show attended the unveiling but ironically, Enterprise never left our atmosphere. It was only ever released from a 747 to execute glide and landing tests.
The Orbiter with the longest service record was Discovery, which logged a year in space. After every mission, all main engines had to be removed and refurbished before being reused.
Although it was one of the earliest machines to feature fly-by-wire system for its thrusters, the digital power (on the early models, at least) was almost laughable by today’s standards. Four IBM computers had 424KB of memory each, but were upgraded in 1990 to 1MB each. They ran the same software (written in HAL/S, a high-level language) but because it was theoretically possible all four might freeze, a fifth computer was added as a backup, running software developed separately.
Tragedy came on January 28, 1986, when Challenger blew up 73sec after lift-off (Endeavor was assembled from spare parts to replace Challenger). And on February 1, 2003, Columbia disintegrated during re-entry; it was never replaced.
There were technical issues behind both accidents, but NASA’s bureaucracy was also at fault. Engineers’ warnings on the Challenger’s O-rings, and requests for Columbia’s astronauts to inspect damage caused during the launch, were ignored by NASA managers.
The surviving Orbiters are now museum pieces. Discovery is at the Smithsonian; Enterprise at the Intrepid Sea, Air and Space Museum in NYC; Endeavor returned to its home state at the California Science Center in Los Angeles; and Atlantis will go on display at the Kennedy Space Center’s Visitor Complex.
The Shuttle leaves a rich legacy. It’s put many satellites into orbit that contribute to our GPS navigation systems and cellphone networks. It was also responsible for countless inspiring images of Earth taken from the cockpit or from spacewalking astronauts. Crews also deployed (and repaired) the Hubble telescope, one of mankind’s most incredible creations, which has provided us with visions of distant galaxies and the ability to peer millions of years back in time.