This
story was updated at 12:51 p.m. EDT.
CAPE CANAVERAL,
Fla. - Astronauts aboard the space shuttle Atlantis inspected their
spacecraft's vital heat shield for damage Tuesday while en route to the Hubble
Space Telescope to perform one last service call.
The
spaceflyers used an inspection pole tipped with laser sensors and cameras to
seek out any dings in the heat-resistant panels lining the spacecraft's wing
edges and nose.
The
shuttle's heat shield health will be a key concern for NASA throughout the
risky mission to overhaul
Hubble. The space agency has put the shuttle Endeavour on standby to fly a
rescue
mission to retrieve the Atlantis astronauts if their spacecraft is damaged
beyond repair.
Atlantis
and its crew of seven astronauts launched toward Hubble on Monday to begin
NASA's fifth and final mission to the 19-year-old
space telescope. After the successful liftoff, NASA technicians were surprised
to find damage at the launch pad from the fiery blast of the shuttle's rocket
engines, agency officials said.
Atlantis is
due to arrive at Hubble on Wednesday and is about 8,000 miles (12,874 km) and
closing on the telescope. The astronauts plan to perform five consecutive
spacewalks to add two new cameras, repair two other instruments never designed
to be repaired in space and perform other maintenance.
Shuttle
looks good
Some pieces
of debris were spotted falling from the shuttle's external tank and boosters during
launch, but none of the pieces appeared to cause any damage, NASA officials
said.
"They're
very minor from what we could observe," NASA's space operations chief Bill
Gerstenmaier said after launch.
NASA has
kept a close watch on shuttle heat shield health since 2003, when a piece of
fuel tank foam struck the Columbia orbiter's wing and led to its destruction
and the loss of seven astronauts. Now, astronauts inspect their shuttle heat
shield twice on every mission.
Today,
Atlantis commander Scott Altman and his crew conducted extended version of heat
shield scans used on missions bound for the International Space Station. The
scan is one of two to make sure Atlantis is not damaged by launch debris or
space junk.
The area
around Hubble's 350-mile (563-km) orbit is littered with space trash, giving
Atlantis a slightly higher chance of being struck by debris or micrometeorites,
NASA officials have said. But the risk is still within NASA's acceptable
limits, they added.
Back on
Earth, NASA technicians are evaluating the damage to Atlantis' launch pad caused
when the shuttle blasted off Monday. The damage was spotted in the pad's flame
trench, which funnels rocket engine exhaust away from a shuttle during liftoff.
Some
nitrogen and pressure lines were damaged, as well as a 25-square-foot section
of the heat-resistant coating that covers the bricks beneath the launch pad,
NASA spokesperson Allard Beutel told SPACE.com. The damage is less
severe than that seen during a launch last year, and can be repaired in time
for NASA's next mission in June, he added.
Marathon
inspection
Today's
shuttle survey will take nearly 10 hours to complete - about twice as long as
normal - because the Atlantis crew must inspect the thousands of black,
heat-resistant tiles covering the spacecraft's underbelly. On missions to the
space station, the same area is covered in photographs taken by astronauts
inside the orbiting laboratory while the shuttle performs an orbital back flip
nearby.
"What we've
added for this flight is a belly tile survey," said shuttle flight director Tony
Ceccacci, adding that Atlantis astronauts will go nearly nine hours without a
break to cram the extended survey into an already tight schedule. "Usually, in
a station flight, you break that up with a meal, we don't have that luxury with
the timeline."
Atlantis
astronauts used the shuttle's robotic arm to inspect the outside of the crew
cabin and cargo bay. To see the hard-to-reach spots on Atlantis' belly,
astronauts will reach under the spacecraft with the 50-foot (15-meter)
inspection pole, which double's the length of the shuttle's robotic arm.
Mission
specialist Megan McArthur, Atlantis' robotic
arm expert, will lead the inspection work, but the long job will be shared
among the entire crew. The chore, she said, is not too different than those
used on station-bound shuttle missions, just longer.
"They're very
similar, so it's a very well understood operation," McArthur said.
SPACE.com
is providing continuous coverage of NASA's last mission to the Hubble Space
Telescope with senior editor Tariq Malik at Cape Canaveral and reporter Clara
Moskowitz in New York. Click
here for mission updates and SPACE.com's live NASA TV video feed.
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