With help from SGI technology, NASA is ready to send America back into space.
Hugging the torso of the Space Shuttle Discovery is a billboard-sized image of the American flag. Beside it are two words that read, simply, "United States."
But to thousands of scientists, engineers, and administrators at NASA, the 114th Shuttle flight can be embodied in a somewhat more personal motto: "We're back."
Such is the sentiment these days as NASA prepares for its first Shuttle flight in more than two years. The
long road to launching STS-114 may have begun with tragedy—namely, the loss of the Space Shuttle Columbia
and its crew on Feb. 1, 2003—but it has been paved by a torrent of hard-won innovation. A significant
number of those advances have come with the help of advanced technologies from SGI.
Safety first...and last
While Discovery's 12-day mission will include a visit to the International Space Station, its most crucial directive is to ensure the safe return of its crew. The Columbia Accident Investigation Board (CAIB), in a report published in the summer of 2003, diagnosed the root cause of the disaster and prescribed fixes that NASA had to implement before any Shuttle returned to space.
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| On Columbia, the External Tank's bipod fittings were insulated with foam
ramps. Foam from one of these ramps broke off and struck the Orbiter's wing, eventually leading to the
Shuttle accident. For STS-114, NASA redesigned the bipod fittings with electric heaters, thus eliminating
the need for foam insulation. |
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Columbia's fate was sealed just 82 seconds into the flight, when a small piece of lightweight insulation
foam broke off from the external fuel tank and slammed into the leading edge of the Shuttle's wing. The foam
punched a hole into a critical area of the wing's Reinforced Carbon Carbon (RCC) leading edge—a problem
that went undetected until after Columbia reentered the Earth's atmosphere 16 days later. Hurtling back from
space at more than 17,000 miles an hour, Columbia, like every Shuttle before it, was wrapped in searing heat
as friction rapidly slowed its descent. As always, temperatures on the wing's leading edges reached 3,000
degrees Fahrenheit. But because the foam debris had pierced the RCC shield during ascent, the terrific heat
of reentry tunneled through the Orbiter's outer skin and into the vehicle itself. In moments, Columbia and
the seven astronauts it carried were gone.
Since the CAIB report, NASA centers throughout the country are collaborating as "One NASA" on a series of exhaustive tests, analyses and simulations to ensure that what happened to Columbia will not occur again. Widespread collaboration is key to the agency's Return to Flight initiative, NASA scientists say, because each change in the Shuttle's design triggers further testing, verifications and other redesigns. They must ensure that modifications do not result in new safety hazards.
A new generation of advanced computing technology, much of it from SGI, is a major "work horse" supporting Return to Flight efforts. At five NASA centers, SGI supercomputers, visualization systems and storage solutions provide NASA scientists with needed resources to respond to the technological and process challenges to making STS-114 the safest Shuttle mission of all.
Chain of analysis
Outfitting Discovery for Return to Flight involves an interwoven chain of analyses that transcended geographic and NASA
administrative boundaries. NASA engineers have improved dozens of design features of the entire Shuttle
system—comprised of two Solid Rocket Boosters, the huge External Tank and the Orbiter itself—that will launch from
Kennedy Space Center, Florida.
In many cases, NASA relied on SGI technology to help deliver the right answers. For example, SGI technical solutions helped
engineers at several NASA centers design and test a new method for thermally insulating the parts of the Shuttle's External
Tank (ET) that protrude from its otherwise smooth surface. It was one of these protruding parts - a bipod fitting that
attaches the Orbiter to the massive External Tank—from which a roughly 1½-pound piece of foam broke off and struck
Columbia's left wing at more than 500 miles per hour. Taller than the Statue of Liberty, the ET is filled with
super-chilled fuel. Insulating the ET with foam prevents ice from forming on its surface—ice that can disengage and
strike the Orbiter.
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Image credits:
Lockheed Martin/NASA Michoud
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