The Space Shuttle was retired before my three-year-old was born, but he still happily pulls out his metal replica whenever we’re talking about space exploration. Without any official SpaceX or even Soyuz toys to be had, this isn’t terribly surprising that the space shuttle is surviving in our memories and imaginations. When explaining that the recent ExoMars mission didn’t involve a spaceship like his toy Shuttle, my son was slightly sad and offended. “Why don’t they use them anymore?”
Despite looking a bit like an airplane, the Space Shuttle was originally billed as a utilitarian “space truck” (which was apparently the most exciting phrase my son has ever heard.) Embracing the “shuttle” concept, designers hoped that the spacecraft would be blasting off once a month, with five vehicles providing relatively simple and affordable flights to low Earth orbit. Things didn’t work out quite as planned, but the Shuttles did prove to be able cargo vessels, carrying many of the components that would be assembled into the International Space Station (ISS). They also helped launch scientific instruments like the Hubble Space Telescope, and then later returning to space for that telescope’s repairs. In that sense, the Shuttles were successful.
Of course, the Shuttle program also had a number of huge problems in its 30 years tenure. In 1986, the Challenger exploded due to a gas leak in one of the booster rockets just after takeoff, killing the seven-astronaut crew. Disaster struck again 17 years later, when the Columbia disintegrated upon reentering the atmosphere, also killing all seven astronauts aboard. These accidents were a grave blow to the program, not only for the loss of life, but also as they exposed some overall weaknesses in the Shuttle program. Insulating foam implicated in the Columbia disaster was observed coming loose during other missions, raising safety concerns about multiple missions’ landings.
On the less dire side of things, the Shuttles were facing problems that simply came with age. After 30 years, even supplying parts for what was supposed to be an affordable spacecraft was becoming increasingly difficult and expensive. Some parts were so customized, only one manufacturer was available to make them. Others were outdated in just about every other context, but because they were part of the 1970s-era design, they were still required for the Shuttle to operate. The cost analysis of certifying new designs and parts started bumping up against the costs of increasingly difficult logistics, with neither option looking like a clear win. By 2008, the program had a minimum cost of $4 billion a year, making it cheaper to pay Roscosmos $54 million for seats on their Soyuz missions and have money to develop other programs. Originally scheduled to retire in 2010, the Shuttle program ended in 2011 with the July 21st return of the Atlantis, having safely delivered equipment to the ISS.
Awaiting an heir
At this point, the remaining Shuttles are on display at various museums around the country, still waiting to be replaced by the next American spacecraft. Some of their parts have found their way into other projects, and they’ve inspired at least one knock-off that never really went into use, but they clearly have a symbolic place in many people’s minds as what a crewed spacecraft should look like. Hopefully the upcoming Dragon capsules and Space Launch System rockets make for some cool toys in the near future, because my living room could certain use more spaceships scattered about.
Source: Q&A: Why space shuttle fleet is retiring, what's next by Seth Borenstein, USA Today