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AmericaSpace

For a nation that explores
August 24th, 2013

 

'Crankin' APUs': Mission 51I and NASA's 'Can-Do' Spirit

By Ben Evans

 

In a triumphant ending to a triumphant space salvage, James "Ox" van Hoften strikes a Charles Atlas pose on the end of the shuttle's RMS mechanical arm, seemingly hoisting the world on his shoulders. Photo Credit: NASA

When Space Shuttle Discovery touched down in Florida on 19 April 1985—suffering seized brakes and enduring a burst tire in the process—she left some unfinished business in low-Earth orbit. A few days earlier, her crew deployed an important U.S. Navy communications satellite, called Leasat-3, whose antenna had stubbornly refused to unfurl and whose perigee kick motor had failed to ignite. Despite sterling efforts to fashion a makeshift "flyswatter" and send two astronauts on a fruitless contingency EVA, the satellite lingered in an orbit far lower than its intended 22,600 miles. Within days of the incident, NASA's bulletproof attitude led to the first mutterings of a shuttle mission to recover, repair, and reboost Leasat. The flight, designated "Mission 51I," succeeded spectacularly and amply demonstrated the reusable orbiter's myriad capabilities.

For James "Ox" van Hoften, however, it did not begin with much excitement. When the crew—Commander Joe Engle, Pilot Dick Covey, and Mission Specialists Jim Buchli, Mike Lounge, and Bill Fisher—were named in November 1983, they were slated to deploy a Tracking and Data Relay Satellite, and, later, as the shuttle manifest writhed and contorted over the following year, they ended up training to retrieve a NASA payload known as the Long Duration Exposure Facility. In the meantime, Buchli was named to another mission and van Hoften took his place on 51I. "Stale, pale, and male," was Lounge's summary of the crew and its cargo, "but we had a great time."

Lounge and van Hoften shared similar backgrounds. They had both served as reservists in the Air National Guard after periods of active military duty, and one night in April 1985, whilst training for 51I, they were on alert status at Ellington Field in Houston. Midway through their duty, the two men heard about the Leasat fault and started swapping ideas about how to resolve it. They even roped in Engle for his opinion. "Back then," van Hoften said, "there was a much more can-do spirit at NASA and everyone felt like, hey, you can do anything." Armed with the relevant data on Leasat—its size, mass properties, angular momentum, and so forth—the men sat down with Engle and Covey, with a few pieces of paper and some push-button calculator watches, to hash out a plan.

Their first idea, to bring the satellite back to Earth, quickly became unrealistic, since it was filled with volatile hydrazine fuel. At length, the plan crystallised into a complex affair, whereby Leasat would be recovered and redeployed into space using the shuttle's Canadian-built Remote Manipulator System (RMS) arm. A method was devised to bypass the satellite's faulty deploy switch and provide power to the electrical buses from the batteries using external test ports, and NASA management was sufficiently enthused to send the astronauts to Hughes Aerospace—the prime contractor of Leasat—in Los Angeles. In the auditorium, despite a bout of laryngitis which left him hoarse, van Hoften outlined the plan to around a thousand engineers and managers.

As 51I's ambitious space salvage operation took shape, one thing was certain: the mission would be EVA-intensive and RMS-intensive. Pictured on Discovery's middeck with one of the space suits, astronaut Bill Fisher would perform delicate electrical work on the crippled Leasat-3. Photo Credit: NASA

After van Hoften's speech came the questions:

"Can we stop the rotation of the spacecraft?"

"Oh, yeah," replied the astronaut. "It's only going to take … ", and he demonstrated, "this much force to the stop the rotation. That's not an issue."

"Did anybody think that we could have a person stop the rotation?"

"Well," van Hoften replied, with a twinkle in his eye, "here's me!"

He sketched himself next to Leasat and reminded the gathered engineers that a few months earlier, in November 1984, "Little Joe" Allen had managed to grab the errant Palapa-B2 communications satellite. It should be equally possible for the much larger van Hoften to grab the much larger Leasat. In all seriousness, though, van Hoften had already performed two EVAs to retrieve and repair NASA's Solar Max observatory, and he knew his own capabilities and those of the RMS.

Hughes' president was so impressed that he took van Hoften to one side and immediately called NASA Administrator James Beggs to invest $5 million in the Leasat salvage effort. When the go-ahead finally came from NASA management, Engle, Covey, and Shuttle Program Mnaager Glynn Lunney were at the home of 51I Lead Flight Director Jay Greene. The four men promptly drained a bottle of Old Overholt, Greene's favourite whisky. "We drank that bottle," Covey related in his oral history, "celebrating the fact that we had hoodwinked the whole system into letting us think that we could go do this. It would not happen today!"

The official crew patch for the astronauts of Mission 51I: Commander Joe Engle, Pilot Dick Covey, and Mission Specialists Mike Lounge, James "Ox" van Hoften, and Bill Fisher. Image Credit: NASA

Despite the seat-of-the-pants approach to the salvage effort, as the crew plunged into training, there were many aspects for which they could not effectively prepare. Instead, they had to hone their skills, rather than specific tasks, because there were no assurances for how well or badly the mission would go. The Solar Max repair had been choreographed down to the finest detail, but Leasat was different: by their own admission, the astronauts were "winging it."

At one stage, it seemed likely that Joe Engle might launch on his 53rd birthday, as launch slipped into the third week of August 1985. The first attempt on the 24th was scrubbed due to local rain showers; although there were no thunderstorms in the area, the conditions were sufficiently poor to violate Launch Commit Criteria. Discovery had only a couple of days available in which to achieve her rendezvous "window" with Leasat, and launch was quickly recycled for the 25th. That attempt also came to nothing when a failure in the shuttle's backup flight software was experienced. A two-day delay pushed the next attempt past Engle's birthday and on to the 27th. (To celebrate, the astronauts unstowed his birthday cake from a middeck locker and presented it to him.)

Dick Covey was not alone in his frustration. "I can't believe we scrubbed for those two little showers out there," he remarked. "Anybody with half a lick of sense would have said: Let's go. This could be a lot worse." However, Chief Astronaut John Young told them bluntly that they could not make calls on the weather, as their knowledge was limited to the view from inside the orbiter. They should focus on the mission, he said, and leave others to worry about the weather.

The morning of the third launch attempt, 27 August, was even more dismal, and the astronauts were clad in yellow raincoats over their flight suits as the Kennedy Space Center suffered a torrential downpour. After being strapped into their seats, Lounge and van Hoften—certain that the weather was too appalling for NASA to give the green light to go—released their harnesses and took a nap. From his perch on the right-hand side of the cabin, Covey was amazed as they moved smoothly and crisply through the built-in holds and was even more amazed when he was given the go-ahead to start Discovery's Auxiliary Power Units (APUs), with five minutes to go in the countdown. As he flipped the switches, he could see sprinkles of rain on the forward windows. "The reason," Joe Engle explained, "was that they had one more day delay before they had to de-tank and that would have been two more days and the weather forecast was not good for the next day, anyway."

Downstairs, on the middeck, the hum of the APUs startled Bill Fisher.

"What's that noise?"

"We're crankin' APUs," came the response from the pilots. "Let's go."

"Yeah, sure. We're not going anywhere today. Why are you starting APUs?"

"Damn it, Fisher, we're going! We're going to launch! Get back in your seat and get strapped in."

The final seconds progressed, as the NASA commentator reeled off the milestones and Discovery's internal systems rumbled to life, in harmony, it seemed, with the rumble of the inclement weather.

"And we have a Go for autosequence start," came the call at T-31 seconds, as Discovery's flight computers assumed primary command of vehicle critical functions. "T-15, 14, 13, 12, 11, 10, nine … we have a Go for Main Engine Start … " as Discovery's three liquid-fueled powerplants flared to life in the gloom of a pre-dawn darkness, " … four, three, two, one … ignition … and LIFTOFF … Liftoff of the 51I and the commercial deploy and repair mission … and it has cleared the tower!"

On the cusp of daybreak, Mission 51I spreads its wings on 27 August 1985, kicking off one of the most dramatic shuttle flights in history. Photo Credit: NASA 

Launch occurred on the very cusp of daybreak, at 6:58 a.m. EDT, with the shuttle's engines and the twin Solid Rocket Boosters blazing brilliantly as the 20th mission of the reusable fleet spread its wings and took flight.

It is interesting to view launches from this era, particularly the images from within Mission Control, and understand the "Go" fever associated with each event. "It turned out we launched right through the eye of a hurricane," van Hoften told the historian. "It coalesced into a hurricane and then we spent the whole time looking down at this major hurricane, going around wiping out Florida." He was referring to what became Hurricane Elena, which originated as a gigantic tropical wave off the coast of East Africa on 23 August and progressed weakly westwards, running parallel to northern Cuba, becoming a tropical storm on the 28th and a hurricane on the 29th. From orbit, the crew would take several stunning images of the hurricane, which expanded across the entire Gulf of Mexico and whose winds reached a peak of more than 100 mph on 1 September, yet steadily weakened as it headed north and finally made landfall in Biloxi, Miss. In its few days of mayhem, Elena wreaked $1.2 billion of damage, but, miraculously, caused no direct fatalities.

From the flight engineer's seat, Mike Lounge had crafted himself a small Mylar "mirror" and fixed it to the back of his checklist, hoping to watch the reflected launch through the overhead window, just over his left shoulder. "If you hold this mirror, right in your lap," he said, "you get this great view as the orbiter lifts up and rolls. You're looking through that window right down at the pad and this huge billow of smoke and flame … and the pad gets smaller and smaller." There was little time to be a spectator, of course, as Lounge paged through his checklist, mentally ticking off each of the major milestones: Negative return, Single-engine TAL, and the call which had caused his predecessors, the crew of Mission 51F, great anxiety: Abort to Orbit. After what seemed like an age, the moment of main engine shutdown occurred and the sensation of weightlessness was felt through a gentle rising against the straps and the quirkiness of the checklist, floating, in front of his eyes. That comical sight was arrested very soon by a sight of unimaginable grandeur: Africa, looming large and spectacular in Discovery's windows.

They were in orbit.

Ahead of them lay three satellite deployments … and then Leasat.

 

 

Copyright © 2013 AmericaSpace - All Rights Reserved

 

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AmericaSpace

For a nation that explores
August 25th, 2013

'If Something Happens': Mission 51I and the End of an Era

By Ben Evans

 

The sheer size of the 15,000-pound Leasat-3 satellite is illustrated in this view of James "Ox" van Hoften manhandling it into space on Mission 51I. Photo Credit: NASA

For Dick Covey, the pilot of Mission 51I, the instant that Space Shuttle Discovery broke the shackles of Earth on the cusp of daybreak on 27 August 1985 had been a long time coming. In fact, he was the last of his 35-strong astronaut class, chosen seven years earlier, to reach space. "I got that distinction," he told the NASA oral historian, "and that was hard to take." At the time of his assignment to Mission 51I in November 1983, Covey knew that he would not fly until at least the end of the following year. "At the time, I didn't realise I was going to be the very last one," he said, "but I knew I was going to be somewhere down there."

For Discovery's astronauts, their first day in orbit turned out to be particularly busy, because they were the first shuttle mission to perform two satellite deployments in those first few hours in orbit. Originally, the first satellite, the American Satellite Company's ASC-1, was to be deployed nine and a half hours after launch, followed by Australia's Aussat-1 exactly a day into the mission and Leasat-4 early on 29 August.

However, a little more than two hours after launch, Aussat's Pacman-like sunshield was commanded open to perform routine health checks … and the port-side clamshell door only partially unfurled. "It was believed," read NASA's post-flight mission report for 51I, "that the clamshell structure had been deformed and was believed to be binding on the omni antenna bracket, located on the top of the Aussat." Mission Specialist Mike Lounge would later blame himself, and a last-minute change to the flight plan, for how this deformation to the sunshield happened. A couple of weeks before launch, he had been assigned the task to activate a payload bay camera to inspect the sunshield. "I did that," he explained, "then I commanded the sunshield open and I had failed to stow the camera. If it had been Day Two, instead of Day One, I would have been more aware of it. On Day One, you're just kind of overwhelmed and you're just down doing the steps … but that was an example of why you don't change things at the last minute and why you don't do things you haven't simulated—because we'd never simulated that."

The crew was advised to uncradle the Remote Manipulator System (RMS) and push the sunshield door open, but unfortunately the Canadian-built mechanical arm was suffering its own problems: a failure of its elbow joint meant that Lounge had to command it in a "single-joint" mode. "Instead of some co-ordinated motion," he said, it was "a little awkward and took a while." Commander Joe Engle remembered Lounge having the incredibly difficult and intricate job of manually operating electrical switches, selecting each RMS joint in turn, then moving them one at a time to position the arm correctly. "That became a concern," Engle reflected in his NASA oral history, "as to how much that was going to slow us down in the grapple and the capture and then the redeployment of the failed [Leasat] that we were going to go repair."

The American Satellite Company's ASC-1 communications satellite spins out of Discovery's payload bay, early in the 51I mission. Note the Pacman-like jaws of the satellite's protective sunshield. Photo Credit: NASA

The RMS was uncradled from the port-side sill and, at 11:15 a.m. EDT, Lounge successfully pushed Aussat's clamshell door fully open. Due to fears of imposing excessive thermal stress on both Aussat and its attached booster, NASA decided not to wait until Day Two to deploy it. Under the supervision of Mission Specialist Bill Fisher, Aussat-1 was duly released at 1:33 p.m. EDT on the descending node of Discovery's fifth orbit, whilst ASC-1's deployment was delayed by a couple of hours from the seventh to the eighth orbit. It was sent spinning out of the payload bay by Lounge at 6:07 p.m. "We scrambled to get that done," remembered Dick Covey, "so we could get that one that didn't have the protection done, plus the one that we had already planned on. It made for a very, very busy first day for a bunch of new guys up there!" The third payload, Leasat-4, was deployed under the supervision of Mission Specialist James "Ox" van Hoften at 6:48 a.m. EDT on 29 August.

Unlike its ill-fated predecessor, Leasat-3, launched in April 1985, the omni-directional antenna unfolded without incident, the spacecraft spun-up without incident, and its integral perigee kick motor ignited without incident, transferring it perfectly into geosynchronous orbit. Testing got underway on 4 September, but trouble was in store, for Leasat-4 suffered a failure of a transmission cable between its UHF multiplexer and transmitter and ground controllers lost contact with it. Nothing could be done to save it, since it was far beyond the reach of even the shuttle.

When Dick Covey was named to fly at Joe Engle's side on 51I, it was an excitement and an honour, for Engle's experience spanned several decades and encompassed not only the shuttle, but the Apollo lunar module and the X-15. More than that, however, he was delighted when Engle assigned the rookie the task of performing the rendezvous with the failed Leasat-3. This was completed in spectacular fashion on 31 August. Early in training, they agreed that Covey would perform the "phasing" manoeuvres and precise Reaction Control System (RCS) thruster firings to approach to about 1,000 feet, whereupon Engle would take over and manoeuvre to position the fully-suited van Hoften, his feet secured in a restraint on the end of the RMS, close enough to the satellite to manually grapple it. "When he had completed the rendezvous manoeuvre and had stabilised," said Engle, "I looked up and kind of expected to see [Leasat] somewhere in the field of view in the window, but he had flown that rendezvous and perfectly nailed it, so the satellite was right … in the centre of the [crosshairs]."

His feet secured in a portable restraint, Bill Fisher is photographed by crewmate James "Ox" van Hoften during the Leasat-3 salvage effort. Note the open external airlock hatch, leading into the payload bay. Photo Credit: NASA

In addition to serving as the primary RMS operator, Mike Lounge was responsible for helping van Hoften and Fisher into their space suits and into the airlock. It was then time for him to head up to the flight deck, whilst the two spacewalkers ventured outside for an excursion that would last seven hours and 20 minutes. Van Hoften installed a foot restraint on the end of the arm and secured himself. By his own admission, the biggest challenge was that "I had to go literally up there and get hold of this thing, somehow, until we could get hold of it and get the arm on it, because I had to attach a [capture] bar to it … It was every bit as tricky as I thought it would be." The massive Leasat, which weighed over 15,000 pounds, was rotating very slowly. He fell behind schedule when the capture bar refused to fit, but he persevered. The situation was hampered by a lack of continuous communication with Mission Control, since in 1985 the full network of Tracking and Data Relay Satellites had yet to be established, and Lounge found that the RMS difficulties meant he had to be very deliberate with each motion.

Eventually, after the installation of the capture bar, Lounge was able to manoeuvre van Hoften and Leasat toward fellow spacewalker Bill Fisher in the payload bay, who fitted a second "handling" mechanism. Van Hoften then attached an RMS grapple fixture. The two men safed the satellite with grounding plugs, then fitted a bypass cable harness to work around the faulty deploy switch. Leasat-3's batteries had not frozen and the repair showed its first sign of success when the omni-directional antenna popped open. For Fisher, a physician with a background in emergency medicine, it represented something totally new: microsurgery on perhaps the biggest patient he had even worked upon.

Van Hoften has described his relationship with Fisher—an astronaut since May 1980 and the husband of Anna Fisher—as not nearly as good as George "Pinky" Nelson, with whom he had done two EVAs to repair Solar Max. "Bill's very competent," he admitted in his NASA oral history, "but he was obsessed with strength. He had gone out and done lots and lots of bodybuilding before we went on this. For some reason, he thought this was important in a spacewalk and I kept telling him that it wasn't." As Fisher built mass and muscle, van Hoften even worried that he might outgrow his finely-sized space suit.

For Joe Engle (front left), James "Ox" van Hoften (back left), and Bill Fisher (back right), 51I would be their final space mission. For the other two crew members, Mike Lounge (centre) and Dick Covey (front right), their next voyage together would be aboard Discovery's very next flight … but after the destruction of Challenger, the shuttle as a vehicle would have changed beyond recognition. Photo Credit: NASA

The second EVA, which occurred on 1 September and lasted four and a half hours, involved the two men installing an instrumented cover over Leasat's apogee kick motor nozzle and arming it. The enormous size of the satellite almost caused it to collide with the orbiter—the spacewalkers could not see each other from their positions on opposing sides of the payload bay—and van Hoften resolved that, "if something happens and I'm about to lose it," he would give it "a heck of a push and bail out!" At length, they managed to control its motions and van Hoften manually spun it up to three revolutions per minute and released it. The satellite went on to perform its manoeuvres just as planned.

With the successful deployment of Leasat-3, the mission had effectively completed its objectives. From time to time, over the next day or so, the sounds of Willie Nelson echoed through Discovery, thanks to Mike Lounge's penchant for country music. On 3 September the astronauts prepared for their return to Earth. Re-entry was mostly in darkness, as Discovery headed across the slumbering Pacific toward the California coastline and, further inland, deep in the Mojave Desert toward Edwards Air Force Base.

From the flight engineer's seat, Lounge took a handful of photographs of the dazzling plasma wake trailing behind the shuttle, and Dick Covey remembered that it "crawled," like fiery fingers, along the bottom of his window. "Then, as you get into the thickest, hottest regions," he continued, it turned "into this complete sheath of white over the windows." Touchdown on Runway 23 at 6:16 a.m. PDT (9:16 a.m. EDT) concluded a mission of just over seven days. Rising from his seat, Lounge felt heavy—he could feel his weight and it required conscious effort to keep his head up—and he remembered that walking and taking corners was awkward, tentative even, at first. It did not last. Just as he had adapted to weightlessness, within a day Lounge was once more adapted to life on Earth.

Mission 51I had been spectacularly successful, but would represent the last shuttle spectacular of its kind in the pre-Challenger era. Only one other commercial satellite salvage operation would be performed, on the maiden voyage of Endeavour in May 1992, a mission which one senior NASA manager described harking back to "the good ol' days." Some observers have looked back on those days long ago as times of foolhardiness, in which a mistaken sense of being bulletproof prevailed and a protective hand of God forever sheltered the shuttle and her astronauts. Others have regarded them for what they were: a spectacular demonstration of human beings accomplishing tasks of profound complexity, against all the odds. Yet the loss of Challenger, just a few months after Mission 51I, provided a healthy dose of the reality that space exploration carried extreme risk. When Dick Covey and Mike Lounge next flew into orbit together, in September 1988, the "picnic" atmosphere of launch parties would be gone, friends would have been lost, a sense of innocence destroyed, and the shuttle would never be the same again.

 

Copyright © 2013 AmericaSpace - All Rights Reserved

 

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