NASA mission managers are meeting today to
discuss of fuel
tank repair efforts for the agency's delayed shuttle flight to the International Space
Station (ISS).
The
agency-wide video conference is evaluating ongoing repair work to the space shuttle Atlantis' external
tank, which suffered
extensive damage [image]
during a freak
February hail storm that delayed the orbiter's STS-117
mission to no earlier than late April or May. If tank experts decide to replace
the damaged tank with a pristine one, the swap would push the spaceflight to
June, NASA has said.
"It's an
opportunity to be able to [update] everybody at once on where the engineering
analysis is," NASA spokesperson Kyle Herring, of the Johnson Space Agency in
Houston, told SPACE.com Tuesday of today's meeting.
Shuttle
mission managers are expected to discuss today's meeting during a press
briefing slated for no earlier than 5:00 p.m. EDT (2100 GMT).
NASA is
hoping to launch Atlantis towards the ISS sometime between late April and May
21, after which the angle of the Sun on
the station's solar arrays would hinder the outpost's ability to support an incoming shuttle crew until
June 8, with that flight window running through about July 19, Herring said.
Commanded
by veteran
shuttle flyer Rick Sturckow, Atlantis' STS-117 mission is NASA's first of several ISS
construction flights planned for 2007. The mission was slated for a March
15 liftoff from the U.S. space agency's Kennedy Space Center in Florida before
a Feb. 26 storm peppered Atlantis' external tank with golf ball-sized hail, gouging
thousands of tiny divots in its foam insulation-covered surface [image].
Sturckow
and his five STS-117 crewmates must now wait until after a space
station crew swap, expected to be complete by April 20, to launch towards
the ISS. Their 11-day
mission will deliver a new
set of starboard solar arrays to the ISS.
External
tank engineers have
been hard at work sanding smooth the most minor hail-spawned dings on
Atlantis' tank, though more serious damage will require pouring or
hand-spraying new foam material to the afflicted areas [image].
Prior to
launch, shuttle fuel tanks are filled with some 526,000 gallons of super-chilled
liquid oxygen and liquid hydrogen propellant, which feeds an orbiter's main engines
during liftoff. A protective layer of foam insulation prevents ice from
building up on the tank's aluminum surface and adds some protection from
aerodynamic stresses experienced during the 8.5-minute ride toward orbit.
NASA has kept
close watch on fuel tank foam integrity since the 2003 loss of the shuttle Columbia
and its seven
astronaut crew. A briefcase-sized chunk of foam fell from Columbia's tank
during launch, damaging the orbiter's left wing heat shield and leading to its
destruction during reentry.
Since then,
NASA as made a series
of modifications to limit the amount of fuel tank foam shed during liftoff,
but there was likely little the space agency could do to guard against the type
of storm that struck Atlantis on Feb. 26, agency officials have said.
William
Gerstenmaier, NASA's associate administrator for space operations, told a
congressional subcommittee last week that hail storm was so localized over
Atlantis' Pad 39A launch site that, had the shuttle stood atop the nearby Pad
39B site, it would likely not have suffered as much damage.
"It was an
extremely isolated storm," Gerstenmaier said.
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