Autor Wątek: [AmericaSpace] Dale Gardner, MMU Spacewalker, Dies Aged 65  (Przeczytany 180 razy)

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Dale Gardner, MMU Spacewalker, Dies Aged 65
By Ben Evans, on February 21st, 2014

Joe Allen (right, with red stripes on the legs of his suit) and Dale Gardner celebrate their success with a 'For Sale' sign, displayed high above Westar and Earth. The triumphant Mission 51A would cement the Shuttle's credentials as infallible...but it was an infallibility which would usher in a mistaken sense of complacency. The Shuttle, though capable of performing to near-perfection, was an imperfect machine. Photo Credit: NASA

Joe Allen (right, with red stripes on the legs of his suit) and Dale Gardner celebrate their success with a “For Sale” sign, displayed high above Westar and Earth. The triumphant Mission 51A would cement the shuttle’s credentials as infallible … but it was an infallibility which would usher in a mistaken sense of complacency. The shuttle, though capable of performing to near-perfection, was an imperfect machine. Photo Credit: NASA

Dale Gardner, a member of NASA’s first group of shuttle astronauts and one of only six men to fly the Manned Maneuvering Unit (MMU) jet-propelled backpack on a spacewalk, died Wednesday, 19 February, reportedly following a sudden brain aneurysm. He was 65. Gardner flew aboard STS-8 in August-September 1983, which featured the shuttle program’s first nocturnal launch and landing, and aboard STS-51A in November 1984, which dramatically retrieved the errant Palapa-B2 and Westar-6 communications satellites and returned them to Earth for refurbishment and resale.

Dale Allen Gardner was born in Fairmont, Minn., on 8 November 1948. He began to over-achieve from a very young age, graduating as valedictorian—the highest-ranking academic member of his class—from Savanna Community High School in Savanna, Ill., in 1966. Gardner next entered the University of Illinois at Urbana-Champaign to study engineering physics, and upon receipt of his bachelor’s degree in 1970 he entered active duty with the U.S. Navy. As an ensign at the Aviation Officer Candidate School in Pensacola, Fla., he soon established his credentials as the most promising naval officer in his class and graduated from basic officer training with the highest academic average ever achieved in the history of his VT-10 squadron.

Gardner then moved to the Naval Technical Training Center in Glynco, Ga., from which he emerged as a Distinguished Naval Graduate and earned his flight officer’s wings in May 1971. For the next two years, he was detailed to the Naval Air Test Center in Patuxent River, Md., working in the weapons systems test division, conducting initial development of the new F-14 Tomcat fighter. He later participated in two cruises to the Western Pacific and Indian Oceans aboard the U.S.S. Enterprise, flying the Tomcat, and in December 1976 he joined Test and Evaluation Squadron Four at Naval Air Station Point Mugu, Calif. Over the next 12 months, he was actively involved in the operational testing of advanced fighters for the Navy. It was whilst at Point Mugu that he spotted NASA’s call for shuttle astronaut candidates, and in November 1977 he found himself among 23 finalists invited to the Johnson Space Center (JSC) in Houston, Texas, for screening.

The STS-8 crew, launched in August 1983, which included Dale Gardner (second from left) on his first flight. Photo Credit: NASA

That group of finalists was actually the ninth and second-to-last group to be interviewed by NASA, ahead of the selection of the first team of shuttle astronauts in January 1978. Interestingly, in addition to Gardner it included John Fabian, Norm Thagard, and Guy Bluford. “From what I later learned,” Bluford told the NASA oral historian, years later, “there were more astronaut candidates selected from that group than from any other astronaut finalist group.” Indeed, with Fabian, Thagard, Bluford, and Gardner selected in January 1978, two others from that ninth group of finalists—Bill Fisher and Bob Springer—were picked for the very next astronaut intake, two years later. Another interesting point was that four of the astronauts selected in January 1978 had been aboard the U.S.S. Enterprise when they spotted NASA’s call for applicants. In addition to Gardner himself, Rick Hauck was project test pilot for the carrier acceptance trials of the F-14, and he and two other aviators, Robert “Hoot” Gibson and John “J.O.” Creighton, also tendered their applications.

Selected as one of the “Thirty-Five New Guys” (TFNG) in January 1978, Gardner thus formed part of the largest astronaut group ever chosen by NASA at that time. In the following years, he worked as project manager for the shuttle’s flight software and served as a support crew member for Columbia’s final test mission, STS-4, in the summer of 1982. By the time this mission took place, he had already been assigned as a mission specialist on STS-8, becoming one of the first of his class to draw a flight assignment. This came as no surprise to fellow astronaut Joe Allen, who glowingly described Gardner in his 1986 book, Entering Space, as “a premier Navy test engineer.”

STS-8, the third flight of the orbiter Challenger, was originally intended to deploy NASA’s second Tracking and Data Relay Satellite (TDRS-B), but this payload was removed from the manifest when the TDRS-A mission in April 1983 suffered problems with its Air Force-built Inertial Upper Stage (IUS) booster. Consequently, in addition to India’s Insat-1B communications satellite, STS-8 was assigned the Payload Flight Test Article (PFTA), a giant dumb-bell to evaluate the performance and handling characteristics of the shuttle’s Remote Manipulator System (RMS) mechanical arm. As a member of the five-man crew, Gardner had prime responsibility for both the Insat-1B deployment and for the RMS activities, which he performed admirably.

“Dan, how do the engines look?” As Gardner worried, Challenger roared into the history books on the morning of 30 August 1983. Photo Credit: NASA

The mission made history as the first shuttle to launch and land in darkness … and this caused some consternation for Gardner as Challenger climbed into orbit under the power of her three main engines. Sitting on the flight deck, he could see through the overhead windows an apparent “fluttering” of the engines’ exhaust and, from his experience during training, such behavior tended to precede an explosion. Every so often, he asked STS-8 pilot Dan Brandenstein how the engines were performing, to which Brandenstein replied from his data tapes that all was well. “As you get higher in altitude,” Brandenstein later told the NASA oral historian, “and from the perspective Dale had, the flames from the engines seemed to be fluttering. You just have a different perspective as you get higher. The air pressure goes way down and you get into a vacuum, so basically what holds your flame real tight is the atmospheric pressure factors. When you get outside atmospheric pressure, they expand and flutter a little bit more.”

For the six days of STS-8, media attention focused overwhelmingly on the presence of Guy Bluford—NASA’s first African-American astronaut—on the crew, but the mission proved an enormous success. Within weeks of landing, Gardner was assigned to another crew, commanded by Rick Hauck, with launch planned in August 1984. Little could he have foreseen how dramatically that mission would morph into what it became. In February 1984, the crew of STS-41B deployed the Palapa-B2 and Westar-6 communications satellites, but the attached Payload Assist Module (PAM)-D boosters failed to fire correctly and left them stranded in low-Earth orbit. In the bulletproof days of the pre-Challenger era, a plan was formulated to execute a shuttle retrieval mission, using the Manned Maneuvering Unit (MMU) jet-propelled backpack, to bring them back to Earth for refurbishment.

A day later than planned, Discovery springs away from Pad 39A on 8 November 1984—Dale Gardner’s 36th birthday—to begin one of the most spectacular and successful shuttle missions of all time. Photo Credit: NASA

By March, it seemed that Hauck’s crew would draw the plum mission. “I think there were a number of things that worked in our favour,” Hauck continued. “One was just the timing of our mission. I had flown proximity operations on STS-7. Clearly, proximity operations would be necessary to do this mission.” Then, the following month, the STS-41C crew demonstrated in spectacular fashion that it was indeed possible to retrieve a satellite from orbit and bring it into the payload bay for repairs. However, Hauck’s crew would not be repairing the satellites, but salvaging them and returning them to Earth. The MMU with its Trunnion Pin Attachment Device (TPAD) could be used to accomplish this feat, but some sort of mechanism would also be needed to snare the satellites.

One morning, Dale Gardner arrived at work in a state of excitement. He had been awake all night, he told them, thinking about possible salvage methods. Years later, Hauck could not be sure if it was Gardner, alone, or in conjunction with the EVA equipment team, who came up with the idea, but the consensus was to create a probe-like “stinger”—a six-foot-long (1.8-meter) Apogee Kick Motor Capture Device (ACD) —mounted onto the arms of the MMU . “The astronaut could then fly the stinger into the satellite’s rocket nozzle,” wrote crewmate Joe Allen in Entering Space. “Once inside, he could release a lever that would allow toggle fingers to expand, much like opening an umbrella inside a chimney. A hand-driven crank would shorten the length of the stinger and pull the satellite against a padded ring at the stinger’s base. The satellite would be held securely and the astronaut could then use the MMU’s thrusters to stop its tumbling and hold it while the [RMS] grabbed a grapple fixture on the stinger.”

It seemed fairly straightforward, but for one thing: Only the nozzle “end” of the satellites could be clamped into the payload bay for the return to Earth; therefore, some other technique would have to be employed to temporarily “hold” Palapa and Westar—each valued at $100 million by their insurance underwriters—whilst the stringer was detached and a cradling adaptor fitted. NASA’s solution was for an aluminum A-frame (properly termed the “Antenna Bridge Structure”) to be placed over the delicate antenna at the “top” of each satellite. “Next, the arm would take hold of a grappling pin on the A-frame,” concluded Allen, “keeping the satellite motionless while two astronauts manually fitted the adaptor at the nozzle end.” With the adaptor in place, the RMS would lower the satellite into position in the bay and the spacewalkers would finally remove the A-frame. It was a brilliant plan, which, if it were executed to perfection, would cement the shuttle’s credentials and demonstrate its capabilities in space.

Equipped with a stinger mechanism on the arms of his MMU, Dale Gardner carefully approaches Westar-6 for retrieval. Photo Credit: NASA

Indeed, it was a brilliant plan, but a plan which Hauck considered had no guarantee of success. The story of its success on STS-51A in November 1984 has been described in two AmericaSpace history articles, which may be accessed here and here, and saw Gardner and Allen perform two spectacular EVAs, utilizing the MMU backpacks to capture both Palapa and Westar and anchor them into the payload bay of shuttle Discovery. In Entering Space, Allen paid tribute to Gardner’s diligence and persistence, working alone to manually tighten nine bolts to secure Palapa into its cradle. The next day, on the second spacewalk, Gardner flew the MMU out to Westar, grappled it with the TPAD and brought it back to Discovery for positioning in the payload bay. To celebrate their triumph, Gardner famously untaped and displayed a sign, emblazoned with the legend, For Sale.

The success of STS-51A cemented the shuttle’s credentials, but marked the final mission of the MMU. In January 1985, Gardner was assigned to STS-62A, which would have been the first launch from Vandenberg Air Force Base, Calif., to deploy the Teal Ruby experimental infrared imaging satellite. At the time of the Challenger tragedy, its launch was anticipated sometime in mid-July 1986. However, Gardner’s NASA career ended in October 1986, when he returned to active Navy duty. For two years, he served as deputy chief of the Space Control Operations Division in Cheyenne Mountain Air Force Base in Colorado Springs, Colo., and was promoted to captain in June 1989. He retired from the Navy a year later to join TRW as a program manager in the Space and Defense Sector. In 2003, he joined the National Renewable Energy Laboratory in Golden, Colo., and over the next decade worked on research and development of biofuels, fuel cells, and advanced transportation. Divorced, and with two children, Gardner accrued 14 days in space, across his two shuttle missions, and more than 12 hours of EVA time in two spacewalks.