Mission 51C remains the shortest “operational” mission ever undertaken by the Space Shuttle. The flight lasted just over three days. Video Credit: NASA/Matthew Travis/YouTube
When Commander Ken Mattingly, Pilot Loren Shriver and Mission Specialists Ellison Onizuka and Jim Buchli were named as the crew of STS-10 in October 1982, they confidently expected to fly Challenger in September 1983 on the first classified shuttle mission for the Department of Defense. It would put the shuttle’s advertised capability as a “truck” for the United States’ largest and most sensitive national security assets to the ultimate test. They were later joined by an Air Force Manned Spaceflight Engineer (MSE) named Gary Payton, who would serve as Payload Specialist.
Unfortunately, the mission quickly ran into problems when the Inertial Upper Stage (IUS) booster, built by Boeing for the Air Force, failed to properly insert the first Tracking and Data Relay Satellite (TDRS) into orbit in April 1983. Mattingly’s mission was manifested to use the same type of booster. His flight hung in limbo whilst an investigation panel pored over the engineering data and made recommendations. Boeing, meanwhile, spent a year correcting the problems and recertifying the IUS. By November 1983, Mattingly’s flight was redesignated Mission 41E and rescheduled for July 1984, but within months it succumbed again to extensive delay. When NASA issued an updated shuttle manifest in May 1984, it had vanished entirely and Mattingly and his men were reassigned to Mission 51C, still on shuttle Challenger and now set for December 1984. “That,” said Loren Shriver, with an air of understatement, “is when we started to learn that the numerical sequence of the numbers of the missions didn’t mean a lot.”
For a time, Shriver wondered if he would ever fly, but unlike other shuttle missions at the time, in which payloads were interchangeable, they were a Department of Defense crew. “You were kind of linked to it, as long as there some thought that it was going to happen, and it never did completely go away,” he remembered. “It just went kind of inactive for a while, then came back as 51C.” Shriver was unsurprised that the crew were all active-duty military men. “I think NASA believed that it didn’t have to do that,” he said, “but I think it also believed that things would probably go a lot smoother if they did.”
Flying a classified mission posed its own problems for Mattingly. Within NASA, he had become familiar with the practice of sharing information, particularly about the shuttle. With a Department of Defense payload, the crew could not publicly discuss the particulars of their flight, and the exact details were made available to only a handful of engineers, technicians and Air Force managers. “I had some apprehension,” Mattingly said, “about could we keep the exchange of information timely and clear in this small community when everybody around us is telling anything they want and we’re keeping these secrets. Security was the challenge of the mission.”
Cipher locks were placed on training materials, “but then you had to give the code to a thousand people, so you could go to work!” They were given a classified meeting room in the astronaut office, a classified safe for their documents…and a classified phone, with an unlisted number. In the entire span of their training time together, the phone rang just once. It was a sales call, asking Mattingly if he wanted to buy a new long-distance service…
The ridiculous levels of secrecy became even more laughable at other times, particularly when the astronauts were obliged to “disguise” the places where they were doing their training. They would file T-38 flight plans to Denver, Colo., then file new ones to the San Francisco Bay area, then rent a car to reach their military destination at Sunnyvale, Calif. They were asked to do their mission training during the daytime and at night, to keep the launch time secret from prying eyes, or anyone who could be bothered to put two and two together, but all this furore never convinced Mattingly that anyone really cared. On one occasion, their office secretary booked motel rooms for them—“secretly”, of course—but the four astronauts, crammed into a decrepit old rental car, with Ellison Onizuka at the wheel, had a surprise when they arrived. Jim Buchli spotted it first.
“Stop here,” he said. “Now, let’s go over this one more time. We made extra stops to make sure that we wouldn’t come here directly…and they can’t trace our flight plan. We didn’t tell our families. We didn’t tell anyone where we were. And we can’t tell anyone who we’re visiting. Look at that.” Four sets of eyes peered over toward their “secret” motel and beheld an enormous banner, emblazoned with the legend: WELCOME, 51C ASTRONAUTS. “How’s that for security?” chuckled Mattingly.
When Challenger returned from her previous flight in October 1984, she was scheduled to be relaunched on 8 December for Mission 51C, but inspections revealed that almost 5,000 of the delicate thermal protection tiles had become de-bonded during re-entry. One tile, located in the vicinity of the left-hand wing chine, had completely separated from the airframe and, although not a catastrophic problem in itself, revealed a far more worrying issue. A vulcanizer material, known as “screed”, used to smooth metal surfaces under tile bonding materials, had softened to such an extent that its “holding” qualities were impaired. Subsequent investigation revealed that repeated injections of a tile waterproofing agent called “sylazane”, coupled with the effects of six high-temperature re-entries, had caused degradation in the bonding material. By the time Challenger flew her next mission, the use of sylazane had been scrapped. In the interim she was reassigned to Mission 51E, scheduled for launch in March 1985, and 51C switched to Discovery with a launch date in late January 1985. Years later, Loren Shriver did not remember any significant mission impact, other than the six-week launch delay from switching orbiters.
Fortunately, Shriver’s family and most of his wife’s relatives were from Iowa, which was sufficiently distant for many to be unable to make the journey to Florida. Privately, Shriver and his crewmates worried that their inability to discuss the mission openly might compromise their preparedness and the thoroughness of their training. It must have been an unusual sight to behold the 51C stack, sitting on Pad 39A, with only a select number of military and NASA personnel knowing precisely when the launch would take place; in fact, the media had been told to expect liftoff within a three-hour “block” of time, sometime between 1 p.m. and 4 p.m. EST on 23 January 1985. Freezing weather conditions kept Discovery on the ground that afternoon, but the situation seemed to have improved marginally by the following day.
For the spectators at the Kennedy Space Center (KSC), the famous countdown clock, which normally ticks away the final minutes and seconds, showed a blank face, and all communications between launch controllers and the flight crew were kept quiet.
Then, at 2:41 p.m. EST, the blackout suddenly ended with a statement from the launch commentator: “…T-9 minutes and counting. The launch events are now being controlled by the ground launch sequencer…”
The spectators braced for the first shuttle launch of 1985.