New Launch Dates For STS-114, STS-121
NASA won't get its wish
to return its remaining space fleet to service next Spring. Working
under a promise to abide by recommendations of the
Columbia Accident Investigation Board (CAIB) and beset by
new maintenance issues, the fleet will remain grounded until at
least next September.
The first and second flights, now scheduled for September and
November, will be considered test missions. Astronauts will
demonstrate their ability to spot and repair potentially fatal
problems while they're still in orbit. They'll first have to
design, then attach an extension to the shuttle's robot arm. That
will allow them to inspect the entire spacecraft for damage while
they're still in orbit. Work on that project just started and isn't
expected to be complete until about a year from now.
Per the CAIB recommendations, NASA scientists and engineers will
also have to design and test a "band-aid" to repair damage to
shuttle heat tiles. The reinforced "carbon-carbon" tiles on
Columbia were damaged during its last, fatal launch. That
damage and a puncture in the space plane's left wing caused the
shuttle to disintegrate as Columbia re-entered the
atmosphere on February 1st. All seven astronauts, including
Israel's first-ever man in space, were killed in the disaster.
They'll also have to
demonstrate the effectiveness of repairs to problems new and old.
Corrosion has been found under the nose caps of both
Discovery and Endeavour. Tests beneath
Atlantis's nose cap were recently discovered to have been
incomplete. A new inspection on Atlantis could take the shuttle out
of service for almost a year. Atlantis was tentatively
scheduled to be the first shuttle to return to flight. But, because
of the nose cap corrosion issue, astronauts may indeed have to find
another ride. That leaves Discovery as the only other
option right now. It just came out of the shop, where it underwent
modifications and repairs. Endeavour is still up on blocks.
The launches of STS-114 and STS-121 will be limited by daylight
so that a phalanx of cameras -- some of them high-definition -- can
capture any potential damage to the shuttle from a multitude of
angles. That limits the days on which a shuttle can launch with
hopes of meeting up with the International Space Station. Greg
Oliver, chief of ascent/descent at the Johnson Space Center,
explained last month: "For all rendezvous missions, the earth
rotates the launch pad under the ISS orbital place once per
day."
Still, space experts are a bit surprised at the ambitious
back-to-back launches. One source told ABC News, "It's gutsy. They
are biting off a lot trying to launch two shuttles back to
back."
Speaking to reporters on Friday, NASA's associate administrator
for space flight, Bill Readdy, said, "This is going to be a long,
uphill climb back to 'return to flight. But I'll also guarantee you
that we're getting an awful lot smarter about this and we're going
to come back stronger and safer as a result. We're going to be very
much driven by milestones and by the content that we have to
accomplish here."