Thirty years ago, today (on 5 October 1984), history was made when Shuttle Challenger rocketed into orbit on Mission 41G, an ambitious science and technology flight. On-board was the largest crew ever launched—a seven-strong team, commanded by veteran shuttle flier Bob Crippen—which included the first U.S. woman to embark on a second spaceflight, the first U.S. female spacewalker, Canada’s first man in space, and the first Australian-born astronaut. During their eight days aloft, the crew of 41G deployed a large Earth resources satellite—as described in yesterday’s AmericaSpace history article—and imaged the Home Planet with powerful synthetic aperture radar, as well as embarking on a risky EVA to rehearse techniques for the on-orbit fueling of future spacecraft.
The spacewalk began at 11:38 a.m. EST on 11 October, six days into the mission, when astronauts Dave Leestma and Kathy Sullivan pushed open the outer hatch of Challenger’s airlock and entered the floodlit payload bay. Leestma later told journalist Henry S.F. Cooper, Jr., for the latter’s 1987 book Before Liftoff, that venturing outside the shuttle on an EVA was like moving from a desk in a large room to a desk in the middle of a prairie. Both astronauts needed about 30 minutes to acclimatize to their surroundings. The first thing Leestma noticed was that his heart rate shot up as soon as he saw Earth.
After his return home, one of the doctors pulled him to one side with his electrocardiogram results, which proudly included a sharp spike at one stage. “This,” they told him, “is when you came out the hatch.”
Leestma grinned. “Yeah, no kidding!”
As explained in yesterday’s article, the main task for the EVA was a series of transfers of 175 pounds (80 kg) of highly toxic hydrazine between two tanks, part of the Orbital Refueling System (ORS). On future missions, NASA hoped to repair and refuel the Landsat-4 and Gamma Ray Observatory (GRO) with shuttle spacewalkers and 41G provided “real-world” experience of the techniques they might someday use. Small quantities of hydrazine were remotely transferred between the two ORS tanks on 6 October, controlled from Challenger’s aft flight deck, without incident, but the real test involved the astronauts. Leestma and Sullivan worked to modify the piping with a ball valve, leak-tested it, and transferred 110 pounds (50 kg) through the fuel lines.
Stopping periodically to allow Sullivan to photo-document his work, Leestma completed the task in one, 90-minute orbit of Earth. The task closely mirrored the planned GRO refueling operation. This observatory was scheduled to be launched by the shuttle in May 1988, loaded with almost 4,000 pounds (1,800 kg) of hydrazine, and equipped with a standardized refueling coupling. Refueling GRO promised to be one of the first instances that a fully functional satellites would be refilled with propellant in space. Contracts to develop the refueling coupling were awarded by NASA in December 1984, for delivery by March 1986, and it was envisaged that future missions might even replenish high-pressure helium and nitrogen and even cryogens. The loss of Challenger in January 1986, however, and the subsequent investigation put paid to these plans.
With this hazardous portion of the spacewalk over, Leestma and Sullivan’s next task was to ensure that Challenger’s Ku-band antenna could be retracted and stowed for re-entry. To do this, they had to move it by hand, such that a “pin,” activated from the aft flight deck, engaged to lock it in place; if they could accomplish this, they would leave the dish open so it could continue relaying data from the Earth-watching instruments. If, on the other hand, they could not engage all of the locking pins, they were to manually close, deactivate, and latch the antenna. Obviously, for the sake of maximum data return from the Shuttle Imaging Radar (SIR)-B, it was hoped that the second option could be averted. Moreover, if the antenna could not be retracted at all, the crew would be forced to jettison it overboard in order to close the payload bay doors for re-entry. That, said Leestma, was equally unthinkable. “The Ku-band assembly and digital avionics was worth $1 million,” he said, “so it would have been a very big loss to the program if we had to jettison it.”
The repair involved not only the spacewalkers, but also their colleagues inside the cabin. In fact, because of her role in the effort, 41G mission specialist Sally Ride “missed” watching most of the 3.5-hour EVA. After she and Challenger’s pilot, Jon McBride, had unplugged the wire to the antenna’s electrical motors on 6 October, they also disabled a mechanism that drove the pins to “lock” the alpha and beta gimbal axes into place. Early on the day of the spacewalk, they rigged a “jump wire” which would allow them to reconnect power to the pins, though not the motors. Unfortunately, both plugs in the jump wire were “female” and they had to quickly rig up a new, 36-pin “adaptor.” As Ride labored in the middeck, Leestma manually moved the Ku-band in one axis, then the other, while Sullivan radioed her crewmates when the pins were correctly lined up with the holes they were meant to slot into. Crippen, meanwhile, told Ride when to plug in the two ends of the jumper. Working the current in pulses—plugging and unplugging the cable, such that the pins were “hammered” into position—the attempt succeeded.
Difficulties with SIR-B’s data gathering, though, continued and involved the link with the geostationary Tracking and Data Relay Satellite (TDRS)-1. “Now, that caused us problems, orbiter-wise,” admitted Leestma, “because to use the Ku-band, which the SIR-B required, we had to reorient Challenger so the antenna was pointed towards TDRS-1 and make the orbiter rotate. We’d take data and then do data ‘dumps’ and point the orbiter at the TDRS; then we’d go back and do data ‘writes’, rather than being able to take data the whole time and point the antenna and dump it. The SIR-B scientists didn’t get all the data that they wanted, but the mission was not a loss and they got almost everything.”
Prior to returning inside Challenger’s airlock at 3:05 p.m. EST, Sullivan took a long look at SIR-B, in an attempt to discover why it had been so difficult to automatically latch it into position. It looked, Henry S.F. Cooper wrote later, “like an over-stuffed sandwich”; its thermal insulation having billowed in space to make it “thicker” than it should have been. This pure white blanket had thus frustrated previous efforts to close it. “The insulation is billowing enough,” she told her crewmates, “to interfere with a single motor closing and you don’t need to miss by much to keep the latch from shutting.”
In the astronauts’ minds, the real deal had been the successful completion of the ORS tests, but to the media, back on Earth, Sullivan’s achievement as the first U.S. female spacewalker had seized headlines. Speaking to Cooper afterwards, she would admit that she could not care less that the Soviets had cynically beaten her to it by sending their own woman cosmonaut, Svetlana Savitskaya, on an EVA in July 1984, but admired her counterpart’s credentials and abilities. Like Sally Ride, she considered herself an astronaut first, and a female astronaut a distant second.
One aspect which did rankle was that Leestma was “EV1”, the chief spacewalker, with Sullivan as “EV2,” despite being more junior to her in the Astronaut Office. “I’m a class senior to Dave,” she told the NASA oral historian in May 2007. “I’ve been in the program longer than Dave. I’ve worked in the suits more than Dave. I worked this payload longer than Dave did and I’m number two to him on the spacewalk. That’s really bad optics.” Intuitively, Sullivan knew Bob Crippen had faith in her abilities, but she was still perplexed that an organization in which “class rank matters” and “the senior class guy leads” was apparently changing its position. The EV1/EV2 debate was not lost on the media, either, and several awkward questions were directed at both Sullivan and Crippen during this period. “Don’t be asking me to answer this,” Sullivan told Crippen, paraphrased from her oral history, “because I don’t see any particularly good reason I’m not EV1, but it’s your call.”
Privately, both Sullivan and McBride felt that the primary focus, at least in the eyes of the media and possibly NASA’s senior management, was the fact that this would be Sally Ride’s second mission. “In the early press stuff, it was very much slanted that way,” she recalled. “Sally was still right in the bull’s-eye of all the media interest. The flight was announced … about five or six months after her first landing, so there’s still a flood of interest surrounding her.” No one seemed interested in Sullivan, only Ride. Sullivan even went so far as to have a new name tag made for her flight suit, reading Sally, but with a bar through it. “Evidently, what I am is not Sally,” she reasoned. “Can’t help that. Sally was less than thrilled with that line of teasing.”
Years later, Sullivan found it amusing that so much attention was given to the precise duration of her EVA; since Savitskaya had beaten her to it, there were some within NASA who wanted the 41G spacewalk to last a few minutes longer. In Sullivan’s mind, such matters were absurd. “The EVA flight team was actually watching the duration clock very carefully,” she said, “and was very mindful of where we were relative to Svetlana’s time … I think our duration was 3:29 and hers was 3:34, so it was a five- or six-minute difference, and in the wrong direction, as far as they were concerned. That was the melodrama around the spacewalk and spacewalking records.”
Challenger’s mission, meanwhile, at just over eight days, was the longest she would ever achieve in her short life. After checking her preparedness for re-entry and successfully stowing the troubled Ku-band antenna, the Orbital Maneuvering System (OMS) engines were fired at 11:30 a.m. EST on 13 October 1984, beginning a hypersonic dive toward the Kennedy Space Center (KSC), Fla. Touchdown was perfect on the Shuttle Landing Facility (SLF) Runway 33 at 12:26:38 p.m. EST, with the orbiter rolling 10,000 feet (3,000 meters) to a halt. For Crippen and Ride, it was also a personal achievement. “All the previous entries,” Crippen noted in his oral history, “because we were landing at Edwards … came in pretty much over the Pacific, so you weren’t flying over land that much. This one, we started up in Canada and pretty much came across the centre of the United States, headed for the peninsula of Florida, and it was a nice, clear day across all the states and you could see everything.”
At one stage, taking a quick peek out of his left window, he could see Jacksonville, Fla., whilst still flying over the Kansas-Missouri region! The peninsula of Florida was exceptionally clear. “I often joke that they’ve got a 15,000-foot runway,” at the swamp-fringed Cape, “but they built this moat around it and filled it full of alligators to give you an incentive to stay on the runway!”
Crippen’s triumphant landfall in Florida was not entirely without blemishes. Astronaut Dave Hilmers, sitting at the Capcom’s console in Mission Control, jovially radioed congratulations on finally making it to the East Coast. However, he alerted them that, judging from Crippen’s track record for making successful Florida landings, their “Welcome Home” case of beer had been delivered to Edwards Air Force Base, Calif., by mistake. …
This is part of a series of history articles, which will appear each weekend, barring any major news stories. Next week’s article will focus on the 25th anniversary of STS-34, which launched the Galileo spacecraft on a historic voyage to Jupiter.