CAPE CANAVERAL, Fla. - Astronauts aboard NASA's space shuttle Atlantis once more
scanned their spacecraft's heat shield Monday, this time in search of any signs
of strikes by micrometeorites
or orbital debris (MMOD).
STS-115
shuttle pilot Chris Ferguson wielded Atlantis' 100-foot (30-meter) assembly
of a robotic arm and sensor-laden inspection boom to hunt for potential damage
along the shuttle's wing leading edges and nose cap, areas that see the highest
temperatures during reentry.
"If you look at the cumulative risks
we take in flight, MMOD risks is not insignificant," Phil Engelhauf, NASA's chief of the flight directors office, said Sunday of the micrometeorite
and orbital debris hazard to space shuttles in flight. "[But] it is not at the
highest end of the scale."
Atlantis' heat shield has already
been cleared
for reentry based on studies of imagery taken during its
Sept. 9 launch, a similar Flight
Day 2 inspection, and a photographic survey taken by astronauts
aboard the International
Space Station (ISS) prior to the shuttle's Sept. 11
docking.
Paul Dye, NASA's lead shuttle flight
director for Atlantis' STS-115
mission, said Saturday that anytime a spacecraft flies in orbit, there is a
risk it could be struck by natural or man-made orbital debris.
"It is a small risk," Dye said.
"We've taken very few hits. We take the occasional hit, and it's something we
think that, since we have the time, it's prudent to go take a look at."
Atlantis mission specialists Daniel
Burbank and Steven
MacLean are aiding Ferguson's
heat shield scan - known as a late inspection - which was first performed on
NASA's STS-121
shuttle flight aboard Discovery in July.
During that flight, astronauts
actually began
the late inspection while still docked at the ISS, but the crew - and
mission controllers - found
that the task ran long because of additional procedures and clearance
issues associated with using a 100-foot (30-foot) robotic arm combination in
close proximity with the ISS.
"It wound up taking quite a bit
longer to run the procedure because they had to take a lot more care and kind
of depart from the rehearsed procedures," Engelhauf said of the STS-121
late inspection, adding that shifting the scan to post-undocking for
STS-115 was an easy trade on crew time and energy. "We think it'll go faster,
it'll be less stressful for the crew and just makes it easier all around."
Atlantis' STS-115 mission has
delivered a $372
million, 17.5-ton pair of trusses and new solar
arrays to the ISS in NASA's first dedicated space station construction
flight since the 2003 Columbia
accident. The shuttle undocked
from the orbital laboratory early Sunday after jump starting what NASA expects
to be four
more years of ISS construction.
NASA roused Atlantis' crew today
with John Denver's "Rocky Mountain High," a song chosen for STS-115
mission specialist Joseph Tanner by his wife Martha.
"So good morning, Houston," Tanner said. "And we just flew over
Colorado
yesterday. It was beautiful [and] looked like a great place to live. And thank
you, Martha. The next few years are gonna be pretty
exciting."
Water dump interruption
Atlantis' heat shield inspection was
paused intermittently as the STS-115 crew eyed a glitch with the orbiter's
waste water dump system.
Earlier today, shuttle
commander Brent Jett reported seeing a sort of burping action from an
exterior nozzle that vents waste and extra water overboard, NASA commentator
Kelly Humphries said.
The glitch was not expected to pose
a great concern for Atlantis, though mission controllers want to ensure the extra
water did not freeze into ice along the nozzle area and pose a debris hazard
later in the shuttle's flight, he added.
After more troubleshooting work by
flight controllers on Earth and the STS-115 crew - which included clearing out
the pump nozzle of any water using air - the matter was resolved.
"We're going to continue to monitor
the [temperatures] to make sure that no ice forms," NASA astronaut Megan
McArthur, serving as spacecraft communicator, told Jett.
Meanwhile, STS-115
mission specialists Heidemarie Stefanyshyn-Piper
worked with Jett and others to ready Atlantis for its Sept. 20 landing.
12 people on orbit
While Atlantis headed for a waypoint
about 70 nautical (129 kilometers) behind the ISS - where its crew will await
analysis of today's heat shield inspection - the shuttle's orbital neighborhood
got a bit more crowded.
At 12:09 a.m. EDT (0409 GMT) today,
two professional astronauts and one private spaceflyer
rocketed
spaceward atop a Russian Soyuz rocket on a two-day
trek towards the ISS. Aboard are Expedition
14 commander Michael
Lopez-Alegria, flight engineer - and Soyuz
commander - Mikhail
Tyurin and U.S.
entrepreneur Anousheh Ansari, who became the first
female space tourist with the successful launch.
The Soyuz is currently about 720
miles (1,158 kilometers) ahead of the ISS but chasing the station from behind,
leaving about 18,000 miles (28,968 kilometers) of forward flight before it
catches up with the orbital laboratory, NASA said.
The space shot brings the number of
humans currently in Earth orbit to an even dozen: three on Soyuz, six aboard
Atlantis, and the three-astronaut
crew of Expedition 13 aboard the ISS.
"It really shows you how well we've
really come together as a team," said NASA associate administrator for space
operations William Gerstenmaier of the international partnership that allowed
such a feat during a NASA TV interview at the Soyuz's Baikonur Cosmodrome launch site in Kazakhstan. "This is truly
amazing."
The Soyuz TMA-9 spacecraft with
Ansari and the Expedition 14 crew will dock at the ISS on Sept. 20, just a few
short hours before Atlantis is expected to land at NASA's Kennedy Space
Center, now slated for
5:57 a.m. EDT (0957 GMT). The space station's current Expedition
13 crew must also jettison an unmanned
Russian cargo ship Monday night before the Soyuz docks.
"It's like some sort of intricate
ballet," NASA associate administrator Rex Geveden
said in the taped NASA TV interview. "It's a daunting thing to do."
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