NASA’s Greatest Failure: the Space Shuttle Program

Elizabeth Heywood

London, United Kingdom

The program's restricted budget meant design trade-offs—swapping safety for cost benefits (Photo Credit: Space)

In 1969, Apollo 11 put a man on the moon—but not without repercussions. As the 70s rolled around, NASA’s financial freedom diminished. After the costly Gemini and Apollo programs, NASA needed a new one that was cheap but that would still give them a way to transport crew and cargo into space for future missions.

The program officially began on January 5, 1972 with the goal of being able to utilize reusable components and a flight plan whereby the space shuttle should reenter the atmosphere and fly back to earth. NASA began designs in 1968, and, in 1975, designs were ready.

NASA originally aimed for there to be a rocket launch every month, but it soon became clear that this was unattainable, leading to some accusing NASA of developing ‘go-fever.’ The space shuttle program had a considerably lower budget than previous programs—mostly due to NASA’s aim to make the program reusable and cost-efficient. The Office of Management and Budget, in an effort to moderate NASA’s planning for a ‘cadillac of space shuttles,’ severely limited their budget and asserted that there was no possibility of budget increases during the next five years.

This restricted budget meant design trade-offs—swapping safety for cost benefits. For example, weight had been a big issue, as the weight of the orbiter would put a strain on the shuttle’s propulsion system. So, two escape rockets on the orbiter were scrapped, leaving the astronauts locked in the launch vehicle after lift-off. And, in another effort to economize, NASA cut spending on safety testing and other development work for the shuttle components.

NASA’s troubles did not end there. Not only were cost estimates off in the beginning, but they rose in unpredictable ways. Inflation had its effect. The true launching cost turned out to be 20 times greater than the original estimate. There was also a thrust shortfall that restricted the payload, so each launch would bring in less income than initially predicted. NASA’s hope that businesses would pay them to bring satellites into space was crushed when the European space agency organized Arianespace—a commercial satellite launch consortium—which successfully began competing with NASA. NASA lost business, and yet again, the cost rose.

The Challenger mission ‘STS-51-L’ was originally scheduled for January 22, 1986. It was one of the most exciting missions to date of the program. Dubbed the ‘teacher in space’ mission, hundreds of schoolchildren were excited to watch Christa McAuliffe, the payload specialist, teach elementary school children from space.

Despite the mounting anticipation, there were already obstacles in the way. The previous Columbia launch had to be delayed, leading to the postponement of the Challenger mission seven times over a 25-day period until January 28. This meant that NASA was already reluctant to delay the launch any further. But, worse, at 1:00 pm on January 27, NASA personnel at Cape Canaveral became concerned about the cold temperatures at the launch pad. Temperatures were predicted to be around -5ºC in the early hours of launch day. Engineers were hastily told to investigate any problems that this may cause.

What was found was that the cold may affect the resilience of O-rings used in the solid rocket boosters to create seals. But the O-rings had never been tested in temperatures as cold as the ones that were predicted for January 28, so they couldn’t know for sure. There was also ice on the launch pad, causing concern that the acoustics at ignition would create ice debris that would ricochet, possibly hitting the Orbiter, but again, with no clear evidence, they went ahead with the mission.

At 11:38 am the following morning, Challenger lifted off the earth. As the shuttle ascended, one of the seals on a booster rocket opened enough to allow a plume of exhaust to leak out. Hot gases bathed the hull of the cold external tank full of liquid oxygen and hydrogen until the tank ruptured. Challenger was lost 73 seconds after take-off as a fireball erupted and the shuttle disappeared into a huge cloud of smoke.

The ensuing investigation, called the Rogers Commission Report, discovered that the cold did affect O-ring resilience, as the engineers had correctly predicted. The O-rings held the sections of the side booster together. The cold caused the rings to harden to such an extent that they would not be able to seal the joints against the hot gases created at ignition––increasing the amount of erosion. If both the primary and secondary O-rings of a section failed, it would lead to hot exhaust gas shooting out the side of the Solid Rocket Booster, which would lead to catastrophe.

NASA engineers had actually known about the O-ring problems long in advance. On numerous flights before Challenger, especially those during cold temperatures, the primary O-ring had failed and allowed propellant to blow by. But, the secondary O-ring had prevented the propellant from escaping the booster. After they first noticed this, they tested the O-rings and believed they understood what had happened. However, the engineers noticed it kept on happening. Rather than stalling the program to redesign the joint, NASA waived the requirements governing O-ring safety, accepting the risk of this known anomaly.

The disaster resulted in a 32-month hiatus in the Space Shuttle program and, ultimately, the failure of the program. When it resumed, NASA’s ‘go-fever’ had long since disappeared. The space shuttle lives on in our memory as the most complicated flying machine to ever grace our skies, but also a symbol of our desire to reach the stars, often eclipsing the safety of the astronauts themselves.