CAPE
CANAVERAL, FLA. – The launch of NASA's space shuttle Discovery will fly no
earlier than March 15 after a gas leak thwarted an attempted
liftoff on Wednesday, mission managers said today.
NASA postponed
Discovery's spaceflight earlier today after detecting a leak in a hydrogen
gas vent line as the shuttle began fueling up for a planned launch tonight at 9:20
p.m. EDT (0120 GMT March 12).
Mike Moses,
head of Discovery's mission management team, said engineers will begin inspecting the faulty gas line on Thursday and shuttle officials will meet that afternoon to review launch plans.
Moses said that delaying until March 15
will mean having to cut one spacewalk and three days from Discovery's flight,
which was planned to last 14 days and include
four spacewalks.
If the
mission is delayed even more, to March 16, Discovery astronauts would complete
only two of four spacewalks and the mission will run only 10 days, Moses said
during a briefing here at NASA's Kennedy Space Center after the launch attempt.
The changes
are necessary to make room for a Russian Soyuz spacecraft that is already
scheduled to launch toward the International Space Station on March 26. If
Discovery doesn't launch by March 17, NASA would have to stand down until after
the Soyuz launch and a space station crew change. The next launch window would
open on April 7.
"This
is life in the space business. Sometimes things happen," said Moses. If
Discovery's flight shifts to April, it would likely cause a ripple of delays
for NASA's other shuttle launches this year and the planned shift to a larger,
six-person crew aboard the space station this May, he added.
At about 2:30
p.m. (1830 GMT) today, about two hours after ground crews began fueling Discovery's
massive orange external tank, engineers noticed a leak in a gaseous hydrogen
line coming from the tank. The line vents off flammable hydrogen gas, created
as the super-cooled liquid hydrogen propellant in the tank boils, in order to
keep the tank at the right pressure.
NASA
officially scrubbed the launch plan at 2:37 p.m. EDT (1837 GMT).
"Our business
requires perfection and our vehicle was not perfect today," said NASA
launch director Mike Leinbach.
Mission
managers say today's scrub has nothing to do with earlier
issues on the shuttle related to fuel control valves in the orbiters main
engines. This problem forced Discovery's launch to be delayed about a month
from an initial launch date set for Feb. 12.
Engineers
ultimately replaced the three valves on Discovery with a set proven to be free
of damage, after a similar valve cracked on the shuttle Endeavour during its
November 2008 launch. Though that issue posed no problem to Endeavour, mission
managers spent weeks testing to make sure Discovery would be safe.
Discovery's
seven-astronaut
crew, commanded by veteran astronaut Lee Archambault, is due to head toward
the International Space Station on NASA's first construction flight of the year.
The shuttle will ferry up a final pair of U.S.-built solar wings and the last
segment of the space station's backbone-like main truss.
It also is
set to deliver Japanese astronaut Koichi Wakata, who will serve as his
country's first long-duration astronaut when he stays aboard the station as an
Expedition 18 flight engineer for six months. Wakata is set to replace NASA
astronaut Sandra Magnus, who will fly home aboard Discovery.
Filling out
Discovery's crew are STS-119 pilot Tony Antonelli and mission specialists
Joseph Acaba, Steven Swanson, Richard Arnold II and John Phillips.
SPACE.com
is providing continuous coverage of STS-119 with reporter Clara Moskowitz at
Cape Canaveral and senior editor Tariq Malik in New York. Click here for mission
updates and SPACE.com's live NASA TV video feed. Live launch coverage begins
at 4:00 p.m. EDT (2000 GMT).
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