The Speed Of Dark

The Space Shuttle Challenger disaster

On January 28th 1986, Christa McAuliffe completed 73 seconds of her mission aboard the Challenger Space Shuttle after winning a NASA competition to become the first teacher in space. She perished along with the rest of the seven member crew when the orbiter exploded over the ocean leaving horrified observers staring in disbelief at plumes of smoke streaking across the sky. Several crew members were still alive after the initial break-up of the craft (their emergency oxygen packs had been activated), but the colossal impact of the capsule hitting the ocean meant survival was out of the question.

The launch had originally been scheduled for January 25th to tie in with President Reagan’s State of the Union speech on the 28th. Reagan had intended to set up a communication link with the Challenger, so that he could speak to McAuliffe and the other astronauts during the address. However, the weather had intervened and the launch had been pushed back to the 27th. Then a malfunctioning sensor in the hatch door led to a further postponement.

Challenger’s maiden flight had taken place on April 4 1983, and nine missions had been completed before it was lined up for the launch of the Teacher in Space Project (TISP), an initiative designed to inspire students and fuel interest in mathematics, science and space exploration. As McAuliffe was the first civilian to fly aboard the shuttle, the TISP launch generated an exceptional amount of national interest. So millions of people in schools, homes and offices watched in wonder, and then horror, as the tragedy unfolded live on television.

There were, of course, many vested interests involved in the ensuing investigation and NASA and the White House led the scramble for a damage-limitation “cover-up” strategy. The Rogers Commission was charged with investigating the disaster. It was chaired by William Rogers and included Richard Feynman, who had won a Nobel Prize in Physics and had been involved in the development of the A-bomb. Their task was rendered more difficult owing to the incredible complexity of the shuttle and the towering reputations of some of the people (and organisations) involved.

Eventually, the cause of the accident entered the public domain. Abnormally low temperatures at the launch site had resulted in the failure of one of the rubber O-ring joints which connected the segments of the rockets. Fuel had escaped from the joint causing a rupture of the external fuel tank.

What was not made clear for quite some time was that NASA managers had known about the potentially catastrophic flaw in the O-rings since 1977, but had failed to address it properly. A company called Morton Thiokol had been awarded the contract for the shuttle’s solid rocket boosters in late 1973. During the procurement process, this company had scored third out of four in technical competency, but it had succeeeded as the lowest cost vendor. They had been able to undercut their competitors by shipping the boosters to NASA by rail. This meant the design had been constrained by what could fit on a rail freight car. Hence the multi-sectional rocket booster, and hence the O-rings.

According to Richard C. Cook, Resource Analyst for NASA’s Comptroller’s Office: “There were a lot of people in the NASA bureaucracy, including engineers at headquarters, engineers at Commercial Space Flight Center in Huntsville, Alabama, and the engineers with the Solid Rocket Booster contractor, Morton Thiokol, out in Utah, who all knew that the O-Rings were extremely hazardous and that they had a potential for causing a catastrophe.” His warnings were ignored.

Cook believed one of the main underlying causes of the disaster was the militarisation of the manned space programme. The NASA/Shuttle programmes were transferred to the Defense Department and plans were drawn up for the deployment of military, scientific and commercial satellites from the shuttle payload bays. “NASA had a tremendous investment of prestige, of money, of national security in the Space Shuttle program,” Cook explained, “because it was being portrayed as the exclusive launch system for all requirements that the United States had for space flight. Everything was going to be put on the Shuttle, from national security missions to satellite launches to commercial launches to economic-related experiments to getting ready to put up a space station. I mean, they put everything they had into the Space Shuttle, and so there was tremendous pressure to keep the schedule going and to keep the Space Shuttle flying.”

During the Rogers Commission investigation, it transpired that NASA officials, under pressure from the White House, disregarded warnings from Morton Thiokol engineers about the dangers posed by the freezing temperatures. On the morning of the launch, eighteen-inch long icicles had formed on the shuttle. Despite this, the commission concluded that “no one person was to blame.” Feynman, the maverick outsider who had ripped aside red tape to uncover the true cause, dissented with the majority opinion and insisted his comments be added as an appendix to the official report. He blamed the disaster on “engineers and managers who were not communicating effectively.” At one point, during a press conference, Feynman famously illustrated the failure of the O-ring rubber material by putting a small piece inside a glass of iced water. When the cameras focused on him, he turned to Larry Mulloy, the former chief of the solid rocket booster programme, and explained: “I took this stuff that I got out of your seal and I put it in ice water, and I discovered that when you put some pressure on it for a while and then undo it, it doesn’t stretch back. It stays the same dimension. In other words, for a few seconds at least and more seconds than that, there is no resilience in this particular material when it is at a temperature of 32 degrees. I believe that has some significance to our problem.”