Mike Mullane - Riding Rockets

At just ten missions per year the shuttle was driving the system to its knees. The message was the same everywhere: “I need more people. I need more equipment. I need more spare parts.” But NASA didn’t have the money to buy these things. While commercial customers offset a portion of the expense, the cash flow was nowhere close to making the shuttle the pay-as-you-go enterprise promised years earlier to Congress. Significant taxpayer money was needed to underwrite the program, and those funds were fixed in the budget. The launch rate had to be doubled with the funds available. The end result was that more was being demanded of the existing manpower and equipment to achieve a higher flight rate. Everybody had a story about how this was overwhelming the various NASA teams. I recall being with an MCC controller when his boss brought in more work for him. The controller objected, “I haven’t had a day off in six weeks. My wife and kids don’t know who I am.” The supervisor was sympathetic but had no other option. “We’re all in the same boat. I don’t have anybody else. You’ve got to do it.” I could see it in both of their faces. They were exhausted, totally burned out. And they weren’t the exception. In many areas NASA only had a first string. There was no “bench” to call on for substitutes. One of our STS-41D prelaunch hangar tests of Discovery had been botched for that reason. The first string had been supporting the pad checkout of the shuttle being readied for the next launch, so the contractor had scraped together a team for us from God-only-knew-where. One of the technicians had apparently been called from home because he arrived in the cockpit with the smell of alcohol on his breath. It was an outrageous violation and Hank Hartsfield confronted the man’s supervisor about it. He apologized for the intoxicated worker as well as for the entire test debacle, adding, “I don’t have enough people to cover everything.”

The story was no different for the engineers at the SRB Thiokol factory in Utah. The pressure to keep flying was hammering them even while they were struggling with a major anomaly. The O-ring problem first seen on STS-2 had not gone away. In fact, it had gotten worse. Beginning with STS-41B, launched in February 1984, and up to Challenger, only three missions did not have O-ring problems. The other fifteen flights of this period returned SRBs with eroded O-rings. Astonishingly, in nine of these fifteen flights, the engineers had recorded “blow-by,” in which heat had not only eroded the primary O-rings but, for very brief moments, had gotten past those rings. On STS-51C, the blow-by had been exceptionally significant. That mission had launched in January 1985, after the stack had waited on the pad through a bitterly cold night. Engineers suspected that cold had reduced the flexibility of the rubberized O-rings, which, in turn, had allowed a more significant primary O-ring leak, resulting in a more significant blow-by. But in all cases none of the observed erosion equaled what had been recorded on STS-2’s damaged O-ring, and that mission had been fine. In effect the STS-2 experience had become the yardstick against which all following O-ring damage was being measured. If the damage was less (and it always was), then it was okay to continue flights. In what would later be defined as “normalization of deviance” in The Challenger Launch Decision by Diane Vaughan, the NASA and contractor team responsible for the SRBs had gotten away with flying a flawed design for so long they had lost sight of its deadly significance. The O-ring deviance had been normalized into their judgment processes.

There were a handful of individuals who resisted this normalization of deviance phenomenon. Thiokol engineer Roger Boisjoly was one. In a July 31, 1985, memo to a company vice president, Boisjoly expressed his concern about continuing shuttle flights with the SRB O-ring anomaly. He concluded the memo with this prophetic sentence: “It is my honest and very real fear that if we do not take immediate action to dedicate a team to solve the problem with the field joint [a reference to the O-ring] having the number one priority, then we stand in jeopardy of losing a flight along with all the launch pad facilities.” Boisjoly feared a catastrophic failure at booster ignition that would not only destroy the shuttle and kill her crew, but would also destroy the launchpad.

Another engineer, Arnold Thompson, wrote to a Thiokol project engineer on August 22, 1985: “The O-ring seal problem has lately become acute.”

An October 1, 1985, interoffice Thiokol memo contained this plea: “HELP! The seal task force is constantly being delayed by every possible means.” In his last paragraph, the memo’s author, R. V. Ebeling, obliquely highlights the major problem of the operational STS…not enough people. “The allegiance to the O-ring investigation task force is very limited to a group of engineers numbering 8–10. Our assigned people in manufacturing and quality have the desire, but are encumbered with other significant work.” He finished his memo with the warning, “This is a red flag.”

Another indication of the crushing workload being borne by the Thiokol engineers is found in an October 4, 1985, activity report by Roger Boisjoly. “I for one resent working at full capacity all week long and then being required to support activity on the weekend…” The operational shuttle program was devouring people.

Astronauts remained ignorant of the O-ring bullet aimed at our hearts. It was never on the agenda of any Monday meeting. None of the memos being circulated at Thiokol made it to our desks. But there were other things happening in the Golden Age of which we were aware—terrifying near misses.

On April 19, 1985, as Discovery landed from STS-51D at KSC, the brake on the inboard right-side wheel locked on, resulting in severe brake damage and the blowout of the tire. Unlike large aircraft, which have engine trust-reversers to aid in stopping the machine, the shuttle is completely dependent on brakes…and it lands 100 miles per hour faster than airplanes of comparable size. (A deployable drag chute was added in 1992.) When a shuttle touches down, it is a hundred tons of rocket, including several tons of extremely dangerous hypergolic fuel, hurling down the runway at 225 miles per hour. While the shuttle runways at KSC and Edwards AFB, at 3 miles in length, are sufficiently long for stopping, they are only 300 feet wide. A perfectly landed shuttle is only 150 feet from an edge, an eye blink in time at those speeds. It was a minor miracle that Discovery didn’t experience directional control problems as a result of the blown tire and careen off the runway.

STS-51F experienced the second engine-start pad abort of the shuttle program. While not really a near miss, pad aborts have the potential to become dangerous. Afterward, I watched that crew put on their Right Stuff, no-big-deal faces for the press, just as we had done following our 41D pad abort. Astronauts are great actors.

STS-51F also became the first shuttle mission to perform an ascent abort when Challenger ’s center SSME shut down nearly three minutes early. It was later determined that the malfunction was due to two faulty engine temperature sensors. There had been nothing wrong with the engine. With only two SSMEs, the crew was forced into an Abort to Orbit (ATO). Fortunately, this was the safest of aborts. The shuttle had been high enough and fast enough at the time of the engine failure to limp into a safe orbit on its two remaining engines. Had the engine failure occurred earlier, the crew would have faced a much more risky 15,000-mile-per-hour, thirty-minute TAL to a landing at Zaragoza, Spain.

Having experienced both an engine-start abort and a powered-flight abort, the 51F crew had gone through ten lifetimes of heartbeats. After they returned, astronauts joked that a cocked, loaded gun pointed between the eyes of any of them would not have elicited the slightest fear response. The mission had desiccated their adrenal glands.