Raumfahrt - 30 Jahre seit dem Jungfernflug des Space-Shuttle Discovery


Thirty years ago, today (30 August 1984), the Shuttle Discovery—which would become, in time, the most-flown member of NASA’s fleet of orbiters—embarked on her maiden space voyage, launching from Pad 39A at the Kennedy Space Center (KSC). Aboard Discovery were Commander Hank Hartsfield, Pilot Mike Coats, Mission Specialists Mike Mullane, Steve Hawley, and Judy Resnik, and Payload Specialist Charlie Walker. During their six days in space, they became the first shuttle crew to deploy as many as three commercial satellites, they extended an experimental solar array “wing,” and they became forever known to history as “The Icebusters.” However, as described in a previous AmericaSpace history article, the 41D mission had already experienced more than its fair share of excitement, before Discovery even departed the launch pad.
Two months earlier, on 26 June, the six astronauts had been strapped into their seats aboard the orbiter and had counted down to T-4 seconds. The shuttle’s three main engines ignited, but were rapidly shut down in the shuttle program’s first Redundant Set Launch Sequencer (RSLS) abort. It had been a harrowing experience, which Mullane later described eloquently to the NASA oral historian. “After a launch abort,” he said, “you could take a gun and point it right at somebody’s forehead and they’re not even going to blink, because they don’t have any adrenaline left in them; it’s all been used up.” Discovery’s launch was postponed to accommodate engine repairs and the 41D payload manifest shifted to feature the Telstar-3C, Syncom 4-2, and SBS-4 communications satellites—all mounted atop Payload Assist Module (PAM)-D upper stages—and the OAST-1 solar sail from NASA’s Office of Aeronautics and Space Technology. Tipping the scales at 41,180 pounds (18,680 kg), the 41D payload was the heaviest ever carried by the shuttle at that time.
Hank Hartsfield (bottom center), surrounded by his STS-41D crewmates on the maiden voyage of Discovery in August 1984. Photo Credit: NASA
The crew returned to the pad on 29 August 1984 for their next launch attempt. For Charlie Walker—a McDonnell Douglas engineer, flying under a commercial contract to operate an experimental electrophoresis machine—it was his 36th birthday, but it was not to be a lucky omen. The launch was scrubbed when a timing discrepancy was noted between the flight software and Discovery’s Master Events Controller (MEC). This was particularly unnerving. Tests had shown that, under worst-case timing conditions, MEC might be unable to process certain critical events commands, such as separation of the Solid Rocket Boosters (SRBs) or the External Tank. “There was something like a one-in-thirty chance that the primary software wouldn’t separate the [SRBs],” Steve Hawley recalled in his NASA oral history, “if it didn’t get around to issuing the command to the master events controller to send the command to separate the solids.” If the solids failed to separate properly, the crew would be dead. If the External Tank failed to separate properly, the crew would be dead. It was that straightforward.
An ominous cloud of smoke billows away from Pad 39A in the seconds after a problematic Main Engine Start on 26 June 1984. Photo Credit: NASA
The crew assembled for a debriefing later that afternoon. The problem was already known—in his memoir, Riding Rockets, Mullane mentioned that it had been a topic of discussion among the astronauts as long ago as April 1984—and it was decided to effect a software “patch.” This was put in place by engineers overnight, and the countdown was recycled for another launch attempt at 8:35 a.m. EDT on the 30th. Despite a problem with the Ground Launch Sequencer (GLS), which forced an extended hold at T-9 minutes, events ran smoothly … until a pair of private pilots accidentally strayed into the closed airspace of KSC. A hold was called whilst the pilots were shooed away, but for the crew of 41D, who had already sat through two uncomfortable countdowns, plus a harrowing pad abort, there was a black mood. (Shoot the f****r down was the general opinion, according to Mullane, whilst Walker recalled some decidedly “colorful” language, aimed specifically at the pilot’s parentage!) “After nearly a seven-minute delay,” wrote Mullane, “its pilot pulled his head out of his ass and flew off. We all wished him engine failure.”
Five minutes to go. Mike Coats flipped the APU switches, and the three Auxiliary Power Units hummed to life.
Two minutes. The astronauts were instructed to close their visors.
One minute. “Eyes on the instruments,” Hartsfield told his crew.
Thirty-one seconds: Go for Autosequence Start. Discovery’s on-board General Purpose Computers (GPCs) assumed primary control of the countdown.
Ten seconds: Go for main engine start …
Six seconds: For the second time in two months, the orbiter’s engines roared to life. This time, all three did so crisply and to perfection. The manifold pressures shot up on the data tapes in front of Coats’ eyes. They had three good engines, all running at full power.
“ … three, two, one … we have SRB ignition … and we have liftoff! Liftoff of Mission 41D, the first flight of the orbiter Discovery … and the shuttle has cleared the tower … ”
Many astronauts have described the immense power of Main Engine Start, but if anyone was uncertain as to precisely what was happening, T-zero changed that uncertainty forever, and there was no doubt that Discovery was heading out of town in a hurry. From his perch on the middeck, Walker glanced to the left and could see the steel structure of the launch pad tower move visibly as the engines shook the 41D stack in a phenomenon known as “the twang,” then a cacophony of noise—he estimated 170 decibels in the cabin—from the crackle of the SRBs. Within a fraction of a second, the tower was gone, to be replaced by daylight as Discovery climbed away from Earth and began her GPC-controlled “roll program” to establish herself on the proper flight azimuth for a 28.5-degree orbit.
Discovery powers towards orbit on the morning of 30 August 1984, 30 years ago today. Photo Credit: NASA
Walker was instantaneously pushed “down” into his seat, and he had the feeling that he was in some sort of pickup truck, rumbling down a gravel country road at high speed. As Discovery accelerated faster and faster, he could see the sugar-cube-like Vehicle Assembly Building (VAB), then the marshy KSC landscape, then the countryside of central Florida, and finally the whole state and the offshore Keys. After the roll program maneuver had been completed, the window seat enjoyed by Walker and Judy Resnik was facing due south, offering them glorious views of the entire southeastern portion of the United States. Every second, it seemed, the world was falling farther and farther away from them. Separation of the SRBs, a little more than two minutes into the climb, was accompanied by a loud bang, a bright flash, and an acknowledgement from the flight deck that residual “gunk” from the boosters had deposited itself on the forward windows.
The view was somewhat different for the four men on the flight deck, who had six wrap-around windows at the front and two overhead windows, just behind Mullane and Hawley, to behold the controlled explosion that was occurring all around them. “After the boosters separated,” Mullane told the NASA oral historian, “I craned my neck back, because the rocket’s still going into orbit upside down.” He was rewarded with his first glimpse of Earth from extreme high altitude—not quite the edge of space, yet, but around 30 miles (50 km)—and could only describe it as “breathtaking.” With the SRBs gone, the remaining six minutes of the ride to orbit was, in the words of both Walker and Mullane, “glass-smooth,” with scarcely any vibration and very little noise, apart from the ventilation fans, the crackling of the intercom, and the astronauts’ own breathing. Mullane described the transition from the harsh rattling of the boosters to flying solely on the liquid-fueled main engines as “just dead quiet.” Eighty percent of the thrusting was gone, and the astronauts suddenly felt lighter in their seats. Outside, the blue sky turned to black and the curvature of the horizon became more obvious. By Main Engine Cutoff (MECO), at eight and a half minutes after launch, Hawley felt like he was sitting through another run in the simulator … with the exception that no anomalies had arisen.
In fact, the majority of their training had been devoted to ascent contingencies. Now, after “all the things you trained for in the sim,” he told the oral historian, “ninety percent of your training is now irrelevant!” With the onset of weightlessness, the astronauts saw and felt things never before experienced: a mosquito, which accidentally found its way into the cabin, struggled to acclimatize to its new environment, whilst screws, nuts, and washers drifted out from various nooks and crannies.
The view from orbit was astounding. “Your eye can pick up a lot more than any camera can,” said Mullane, “and it was just so glorious to see the horizon of Earth, the blackness of space, the blue of the oceans, the white of the clouds.” For Walker, the euphoria of reaching space was arrested by Resnik, who gave him a high-five and then told him to stay in his seat until the rest of the crew had completed their final checks. It reminded Walker that although Resnik, Coats, Mullane, and Hawley were also rookies, they were professional astronauts; they had been around since 1978 and although he had important research to do on 41D, he was effectively a passenger.
Judy Resnik became America’s second woman in space on Mission 41D. Photo Credit: NASA, courtesy of Joachim Becker/
Although he did not remember any outright belligerence from other members of the astronaut office, it was made clear to Walker that he was not fully “one of them.” Years later, he would express astonishment at how a combination of luck and good timing had put him in the right place at the right time. He had joined McDonnell Douglas in December 1977 as a test engineer on the shuttle’s Orbital Maneuvering System (OMS), part of a subcontract from Rockwell International. Within a year, he became one of the first members of the company’s space manufacturing team and eventually rose to the post of chief test engineer for the Electrophoresis Operations in Space (EOS) project. “Electrophoresis … is really applied to a pretty basic process, as it’s been used in laboratories around the world for the past hundred years,” Walker told the oral historian, “in which a compound, like a gel or a liquid that has an electrical conductive nature to it … is exposed to an electric field. Within an electric field, they will all move as a group toward the attracting electrical pole and they’ll move at different rates, so if you expose, within a sample, that sample to an electric field for a period of time, when you shut the field off, you’ll have groups of compounds all separated from one another.” In précis, electrophoresis encompassed the purification of individually obtained groups from an original mixture.
Already, several shuttle flights had carried the Continuous Flow Electrophoresis System (CFES) apparatus in the middeck and demonstrated that these separation processes could be accomplished with far greater precision in the microgravity environment; moreover, with increased emphasis on the purification of hormones and enzymes, useful for the treatment of various diseases, McDonnell Douglas anticipated a vast new opportunity to open in the pharmaceutical industry. When the electrophoresis project was first proposed to NASA, the intent was to fly on the Spacelab-3 mission, but as that flight was pushed further and further back on the shuttle manifest, it was decided to fly a middeck version instead. “The investment of private capital,” explained Walker, “could not stand that kind of uncertainty and neither could our pharmaceutical investment partners.” By 1983, agreement had been reached for six proof-of-concept missions, followed by two flights of a large production plant, to be mounted in the payload bay.
On 29 June 1983, Walker was assigned as the first “industry” payload specialist, flying on Hartsfield’s crew, specifically to operate an upgraded version of the CFES hardware. It was not his first brush with the space program. He had long harbored an interest in aviation and had worked toward gaining his private pilot’s license in the early 1970s, but admitted to being “a poor student and I couldn’t afford to fly.” Still, he applied for NASA’s 1978 astronaut intake and it was this experience which guided him whilst at McDonnell Douglas. He failed to make the cut as a pilot or a mission specialist, but knew that plans were afoot for payload specialists to be hired from universities, research institutions … and from within industry. “I obviously don’t work for a university,” he said. “I’m not a PhD in any one specialty, so maybe the industrial part.”
Years later, Walker would admit that, when all was said and done, he was basically very lucky to be selected. “I found the company and the project that—at the time—was virtually the only thing in this country in the aerospace arena that was being proposed to NASA from the private side that looked like it was really going to produce something of real benefit to the country and to the commercial side of our economy, that could be done in space, and managed to get into an early key position with that project.” It was McDonnell Douglas’ EOS Program Director, Jim Rose, who suggested Walker’s inclusion on a shuttle crew in the summer of 1982, and the request was passed up through the chain of command to NASA Headquarters in Washington, D.C., as a “special case.”
Although CFES had flown previously on the shuttle, the version on 41D had been upgraded to support continuous operations for around 100 hours, adding further weight to the request for a dedicated payload specialist. Interestingly, the first word of Walker’s selection came not from George Abbey, the head of the Flight Crew Operations Directorate (FCOD), or from Jim Rose, or even NASA’s head of the Office of Space Flight … but from an Aviation Week journalist, who had talked to a source in Washington. A few days later, it was confirmed. McDonnell Douglas would pay NASA $40,000 for each of Walker’s flights; a trivial sum, by any standards. “If you could get that today,” he told the oral historian, “you’d be booked up!”
Training was quite different from the pilots and mission specialists, of course, and it was made quite clear to Walker that he was not a NASA employee, nor a civil servant, but remained attached to his parent company. He did not undertake any survival training, but was given a few T-38 flights by Hartsfield to prepare him physiologically and psychologically for high-performance flight, and he participated in integrated simulations with the rest of the crew in Houston. “I knew what systems did,” he explained, “like the electrical systems [and] environmental systems. I knew the computer interfaces.” Walker wanted to integrate himself into the crew more thoroughly, to “feel” part of the team, but found opposition from NASA leadership; indeed, he was even barred from participating in the more mundane activities, such as executing waste water dumps in orbit. He did, however, participate in a number of NASA medical experiments and wore sensors for heart and blood pressure measurements during ascent.
In Walker’s mind, 41D was probably going to be his only mission and he had nothing to lose by volunteering to provide a few points of medical data along the way. Little could anyone have foreseen that Walker—an engineer who had not even reached the interview stage for the 1978 astronaut selection, whose flying experience was less than a hundred hours and whose academic credentials rose no higher than a bachelor’s degree—would actually fly more missions, and more often, than any other astronaut during this period of shuttle operations in the pre-Challenger era.
Thirty years ago, this week, the Shuttle Discovery—which would become, in time, the most-flown member of NASA’s fleet of orbiters—embarked on her maiden space voyage, launching from Pad 39A at the Kennedy Space Center (KSC) on 30 August 1984. Aboard Discovery were Commander Hank Hartsfield, Pilot Mike Coats, Mission Specialists Mike Mullane, Steve Hawley, and Judy Resnik, and Payload Specialist Charlie Walker. During their six days in space, they became the first shuttle crew to deploy as many as three commercial satellites, they extended an experimental solar array “wing,” and they became forever known to history as “The Icebusters.” However, as described in yesterday’s AmericaSpace history article, the 41D mission had already experienced more than its fair share of excitement, before Discovery even departed the launch pad.
Less than eight hours after launch, at 4:40 p.m. EDT, the first communications satellite, SBS-4 for Satellite Business Systems, was sent spinning out of Discovery’s payload bay; the wrist camera on the Remote Manipulator System (RMS) mechanical arm captured the successful 87-second firing of its Payload Assist Module (PAM)-D booster. Early on Day Two, however, a quite different satellite—the U.S. Navy’s Syncom 4-2—was deployed, in a quite different way. Instead of sitting “vertically” in the payload bay, it lay horizontally, and was spring-ejected in a manner not dissimilar to a frisbee. Since NASA’s fee to its customers was proportional to how much length a satellite occupied in the payload bay, the Syncoms were deliberately designed as full-width, stubby drums. This enabled them to precisely fit the width of the bay and minimized their length. In shape, they took the form of 3,100-pound (1,400-kg) cylinders and were designed to provide worldwide, high-priority communications between ships, aircraft, submarines, and land-based stations for the U.S. armed forces, as well as the Presidential Command Network. Syncom was also known by another name—“Leasat”—because its services were “leased” by the U.S. Navy from prime contractor Hughes.
Syncom 4-1, the first of new series, was assigned to 41D, originally scheduled for June 1984, whilst Syncom 4-2 was due to launch aboard Mission 41F in August. By the time of 41D’s on-pad abort, the 41F payload—which also included SBS-4 and Telstar-3C—was in the final stages of processing for its early August launch. In the wake of the abort, NASA considered it more straightforward to switch the entire 41F commercial payload onto 41D, and reschedule Syncom 4-1 for launch later in the year. Consequently, the second Syncom 4 entered orbit ahead of the first. The Syncom 4-2 deployment came at 9:16 a.m. EDT on 31 August and occurred perfectly; the satellite departed the bay at a velocity of 2.3 feet per second (0.7 meters per second), spinning at a couple of revolutions per minute. Very soon, it was in the process of executing the required maneuvers to insert itself into geostationary transfer orbit.
The SBS-4 satellite, atop its PAM-D upper stage, is released from Discovery’s payload bay. Photo Credit: NASA, courtesy of Joachim Becker/
What did not work quite so well was the IMAX motion-picture camera, which had previously flown on shuttle mission 41C and would fly again on 41G and whose footage subsequently formed the basis of the 1985 movie “The Dream is Alive.” Operation of this large and unwieldy camera was Mike Coats’ responsibility, and one of its earliest uses was to film the deployment of Syncom 4-2. Unfortunately, during this time, in the words of the official NASA mission report, it “jammed.” The background to what caused this jam has been explained with some color by Mike Mullane and Steve Hawley. As Syncom left the bay, Hank Hartsfield was filming the deployment when, all of a sudden, its belt-driven magazine sucked up a shank of Resnik’s black hair, which weightlessness had liberated into flowing tresses. The IMAX ground to a stop, blowing the circuit breaker in the process. Eventually, with scissors, they freed Resnik’s hair and Coats took the camera down to the middeck to repair it. When the time came for Hartsfield to report the incident to Mission Control, Resnik gave him a threatening stare and he respected her embarrassment, telling the ground simply that IMAX had jammed and Coats was working to fix it.
IMAX did have a belt guard but, as Hawley told the NASA oral historian, “for whatever reason we decided we didn’t need to fly it. I don’t know if we were trying to save weight, but we decided we didn’t need this belt guard.” Coats worked for several hours, methodically removing shreds of Resnik’s hair from the camera, and for a time it seemed unlikely that IMAX would work. At length, he restored it to operation and it was used for a variety of tasks, including the deployment of the experimental OAST-1 solar array, provided by NASA’s Office of Aeronautics and Space Technology. It was an amazing machine. “The thing pulled so much film, so fast,” recalled Hawley, “and it’s [so] big that, in zero-G, it will actually torque you like a gyroscope! To use it, you really have to be affixed to something, because it will rotate you!”
Following the Syncom 4-2 deployment, the third and final satellite, Telstar-3C, was sent spinning out of the payload bay at 9:25 a.m. EDT on 1 September. Like SBS-4 and most previous PAM-D payloads, it was a cylindrical, spin-stabilized satellite, coated with solar cells for electrical power. For Steve Hawley, it was also particularly memorable, because its purpose-built ground station lay at a place called Hawley in eastern Pennsylvania. In his oral history, he admitted that he had previously never heard of the place, “but it’s spelled the same way. After the flight, I got to go to Hawley, Penn.!”
With three satellites successfully deployed and on their way to geostationary orbit, the final days of 41D were to be spent on their other payloads, most notably OAST-1, which was primarily Judy Resnik’s responsibility. Its hardware sat atop a Mission Peculiar Experiment Support Structure (MPESS) and consisted of a number of experiments. Of these, the most notable was the solar array, which, when unfurled, projected 103 feet (31.5 meters) “above” Discovery’s payload bay—taller than a 10-story building. Although it was not designed to generate electricity, the intent was to demonstrate the structural dynamics of a large array, placing it under different levels of stress, including thruster firings, to understand its behavior. The primary structure was Kapton and the array comprised 84 panels, which folded out, accordion-like, on an epoxy-fibreglass mast from a 5-foot-high (1.5-meter) canister on the MPESS.
Hank Hartsfield works with the IMAX camera on Discovery’s middeck. Photo Credit: NASA
After full deployment, the array had a triangular cross-section, longitudinally stabilized by short guide wires between interconnecting battens. On Day Three, soon after the Telstar deployment, Resnik began the first part of the experiment, extending the array to 70 percent open. To do this, a “nut” with internal threads rotated at the top of the storage canister, causing the rollers to move up through the threads and allowing the longerons to straighten and the guide wires to keep the structure rigid. The initial phase of mast extension unlatched the containment box lid, gradually unfolding the solar array blankets. In the first test, when the array reached the 70-percent-open position, a tension bar was deployed to pull the unfurled section “flat.” It was at this stage that the first series of structural dynamics tests were conducted, and the following day, 2 September, the array was extended to its full height.
“Surprisingly,” recalled Hank Hartsfield, “once the thing is deployed, it’s fairly rigid. In fact, one of the big experiments we did was to turn off the control systems on the orbiter and let it get really stable and then fire the thrusters and … measure how the array oscillated.” The array turned out to be much “stiffer” than engineers had anticipated, and by the time Hartsfield and Coats prepared for the second set of thruster firings, which were intended to increase the motions, the array had almost stopped moving completely. On a couple of occasions, Steve Hawley was given the chance to perform the firings. “Some of it required inputting jet firings simultaneously in different directions,” he told the oral historian, “so that was where I got to play. Mike Coats was primarily responsible for making the input, but some of the times when we had to make a yaw and a pitch or roll simultaneously, it’s easier for two guys to do that.”
The array had only a few transducer cells for test purposes, but, had it been operational, a structure of its size would have been capable of generating up to 12 kilowatts of electrical power. For the 41D crew, the size of the array was one of its most impressive features. “At sunrise or sunset,” remembered Hawley, “the first thing that either the last bit of sunlight or the first bit of sunlight would hit was the solar array and it would make it almost look like it was lighting up with its own source of internal illumination. Everything else would be dark and the solar array would be glowing gold.”
“Glowing gold,” the OAST-1 solar sail rises prominently from the payload bay during Mission 41D. Photo Credit: NASA
Also spectacular, although for different reasons, was another “structure” which extended not from Discovery’s payload bay … but from a nozzle normally use to dump the crew’s urine overboard. Early on 1 September, unusual temperature data from one of these dumps suggested that a large icicle had formed around the nozzle on the exterior of the vehicle. “Heaters on the exit nozzle are supposed to ensure the fluid separates cleanly,” Mike Mullane wrote in his 2006 memoir, Riding Rockets, “and does not freeze to it.” Mission Control suspected that an icicle might have formed, but since the exit point of the waste nozzle was located on the port side of the middeck, it was impossible to view it with anything other than the camera on the RMS.
Hank Hartsfield duly used the arm to take a look and, lo and behold, there was an icicle, measuring three-quarters of a metre in length and about 12 inches (30 cm) wide. If left to its own devices, the icicle might break off during re-entry, potentially damaging the critical thermal protection system. Ice from dump nozzles had caused damage to Mission 41B during re-entry. Initial attempts to dislodge it focused on using the Reaction Control System (RCS) thrusters were unsuccessful. On the 2nd, Discovery’s cabin pressure was reduced, preparatory to a contingency EVA by Mullane and Hawley the following day. Mullane was thrilled, but Hawley was cautious; the location of the icicle—just aft of the middeck entry hatch—was virtually inaccessible to a spacewalker.
Still, the EVA remained an option and as the crew prepared for bed that evening, they reckoned that it was the only solution. Just before bedding down, fellow astronaut Jerry Ross, the Capcom in Mission Control, told them of a sudden change. There would be no EVA, but they would be asked to dislodge the icicle with the tip of the RMS. Although Hartsfield was not the primary operator of the mechanical arm, he insisted on doing the job. If anyone dinged a brand-new orbiter on its maiden voyage, it had to be the commander’s responsibility. Fellow astronaut Sally Ride had worked a procedure in the simulator and she read the instructions up to them. Hawley felt that it was a good plan. Mullane, on the other hand, was upset to have lost his chance to do a spacewalk.
The icicle drifts away from Discovery, after being successfully detached by the RMS. Photo Credit: NASA
Yet the option of knocking the icicle free with the RMS was itself fraught with difficulty … and danger. “One of the rules in those days,” said Hawley, “was you’re not allowed to operate the arm in a place where you can’t see what it’s doing. I was supposed to go down to the side hatch window and watch as best I could, while Henry drove the arm to knock the ice off. He would move it through a pre-determined trajectory and, if he did it properly, they knew from the ground simulations that it would hit the ice.”
Hartsfield’s jab at the ice was successful and, within minutes, Mullane was able to photograph the spear-like icicle drifting away. With “Ghostbusters” having arrived in cinemas in June 1984, the 41D crew earned themselves a new moniker: Icebusters. Although the icicle was gone, its presence had caused another problem. “We were told we could not use the urinal for the rest of the mission,” Mullane wrote, “for fear another ice ball could jeopardize us.” They would still be able to use the shuttle’s toilet for “solid wastes,” but were forced to use “Apollo-style” plastic bags for liquids; Mission Control told them that there was sufficient remaining volume in the waste water tank for about three man-days’ worth of urine, meaning that Resnik could use it, if needed. However, she was keen to hold onto her feminist sensitivities, it seems, and elected to use the plastic bags. At length, the pragmatic gentleman in Hank Hartsfield came to the fore: “Judy … had a hard time with the bag,” he told the oral historian. “I said, ‘I don’t care what the ground says. You use the bathroom. The rest of us will do the bag trick.’”
Another problem quickly arose. In microgravity, fluids do not readily remain at the bottom of bags, but begin floating around, and it became clear that the astronauts would need to put something in place to soak up the urine. They stuffed dirty towels, underwear and socks into the urine bags to act as an impromptu absorbent. As the bags gradually filled up the waste tanks under the middeck floor, the unsanitary environment was distinctly unpleasant. Randy Stone, the flight director at the Johnson Space Center (JSC) in Houston, Texas, asked his superiors for permission to tell the crew to reconfigure one of their water tanks into a waste tank. “It was easy to do,” Hartsfield recalled, “just a quick plumbing thing … but there was a big concern about turning the orbiter around. They had the idea that if they converted a water tank to a waste tank, it would add another week to the [processing] flow at the Cape to get [Discovery] ready to go again.” Stone’s request to senior management was rejected, twice. Years later, Hartsfield would wonder whether he ought to have requested a private medical conference and enforced a decision. After the flight, he spoke to several engineers and managers, who offered their apologies; ironically, replumbing a water tank into a waste tank would not have affected Discovery’s processing schedule at all.
Offering two quite different perspectives of Discovery’s return to Earth on 5 September were Charlie Walker, seated in the darkened middeck, and Steve Hawley, riding in the flight engineer’s seat and facing into the forward flight deck windows. “There’s a bright kind of plasma plume that seems to form above the orbiter during re-entry,” Hawley recalled, “and it comes in through the overhead windows. You get this soft kind of pink, whitish, orangish glow that develops and encircles the orbiter.” Mike Mullane remembered seeing ribbon-like vortices of white-hot plasma streaming past the overhead windows. Downstairs, Walker used a small water container to convince his eyes that gravity was steadily establishing its grasp on the descending orbiter. He found that, at first, he could let go of the container and it would remain weightless.
After a while, when he began to sense the onset of gravity, he tried again and saw it drift down to the floor. A third attempt later in the descent would see it fall faster. “I played this little game over the next five minutes or so,” he recalled. “I’d catch it before it hit the ground and put it back up in the air and it seems like after about three or four minutes of that, it was dropping so fast, I couldn’t catch it before it hit the floor and went skittering away somewhere!” The noise outside intensified as they slowed below the speed of sound, although the touchdown at Edwards Air Force Base at 6:38:54 a.m. PDT (9:38:54 a.m. EDT) was perfect and smooth. After two months of delays and a hair-raising pad abort, the shuttle was back in business.
It had also begun a remarkable, 27-year career for Discovery herself. By the time of her final mission and retirement in 2011, she would have accomplished no fewer than 39 flights, launched 31 satellites—including the Hubble Space Telescope (HST)—spent a cumulative time of almost 366 days in orbit, ferried 252 unique crew members beyond the sensible atmosphere, traveled 148.2 million miles (238.5 million km), and rendezvoused and docked once with Russia’s Mir space station and on 13 occasions with the International Space Station (ISS). Her many voyages included three Return to Flight (RTF) missions (one in the aftermath of the Challenger disaster and two in the aftermath of the Columbia disaster), and Discovery was the first shuttle to launch a Russian cosmonaut, a woman pilot, a serving politician, an Arab,a Frenchman, a Canadian woman, a Spaniard, and former Mercury astronaut John Glenn.
Discovery sits on the runway at Edwards after her maiden voyage. Photo Credit: NASA
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