The shuttle Discovery and its crew of six returned safely home, rejuvenating
a space program that until now had been vexed by the same chronic foam problem
that brought down Columbia three years ago.
The crew of the space
shuttle Discovery on Mission STS-121, ( From L-R) Michael Fossum, Lisa
Nowak, Commander Steven Lindsey, Stephanie Wilson, Pilot Mark Kelly and
Piers Sellers, who was born in England, stand in front of the shuttle
after Discovery landed at the Kennedy Space Center in Cape Canaveral,
Florida July 17, 2006. One crewmember, Germany's Thomas Reiter, remained
on the International Space Station.[Reuters] |
Within hours of the smooth touchdown Monday, NASA was already looking ahead
to the next shuttle launch in just six weeks and, with it, the long-awaited
return to construction work on the half-finished space station.
"It's a good day," NASA Administrator Michael Griffin said. "It's an awfully
good day."
Discovery's commander, Steven Lindsey, who took a walk around the shuttle
after landing, said he had never seen one look so clean and undamaged after a
spaceflight. It was a striking achievement for a launch that was challenged by
some within NASA who wanted more improvements to protect the spacecraft from
flyaway foam insulation.
Lindsey noted that both of the mission's major objectives were accomplished:
completing tests of the shuttle and its redesigned fuel tank, which now carries
less foam, and readying NASA to resume space station construction, left hanging
after the Columbia tragedy which killed seven astronauts.
"We're ready to go assemble station," Lindsey said in the shorthand typical
of NASA engineers. "And we're ready to start flying shuttles on a more regular
basis."
All around the Johnson Space Center in Houston, home to Mission Control,
posters advertised the homecoming ceremony that was set for the astronauts on
Tuesday. "We're BAAAACK!" the signs shouted in big red letters.
The smooth landing left NASA officials jubilant, after conquering the
potentially deadly threat of foam chunks breaking off the external fuel tank
during launch _ still a problem, but not a serious one on this mission.
The largest piece of foam that came off Discovery's tank during the July 4
liftoff was barely bigger than a sheet of legal paper and weighed less than an
ounce. Like all of the handful of notable foam chunks that peeled away, it came
off late enough in the launch to pose no danger to the spaceship.
During the same shuttle's launch last summer, a 1-pound (450 grams) chunk of
foam tore away at a crucial moment. Even though it missed Discovery, it stunned
and embarrassed NASA, and forced a one-year grounding of the shuttle fleet, on
top of what already had been a 2{-year standdown. The piece of foam that ripped
Columbia's left wing weighed 1{ pounds (680 grams).
Outsiders gave NASA high marks Monday.
"What's important is that they changed their approaches to spaceflight
considerably; it was an organizational test," said American University public
policy professor Howard McCurdy, who has written several books about NASA
management. "I don't give many A's. They're clearly back to where they want to
be. A B-plus."
Columbia accident investigator John Logsdon, director of George Washington
University's Space Policy Institute, said Discovery's latest mission was carried
out "with the kind of laser-like attention and vigilance" that was missing
before the 2003 disaster.
NASA still does not know why so much foam insulation is falling off the tank
late in the launch when it poses no threat, but the just-completed flight will
be "tremendously important" in providing clues, said Bill Gerstenmaier, space
operations chief.
An especially vulnerable area of the tank will be redesigned, hopefully by
next year.
"This is as good a mission as we've ever flown," Griffin said. "But we're not
going to get overconfident. We're going to keep looking at the data and we're
going to make our decisions based on the data just the way that we did on this
flight."
