This story was updated at 11:44 a.m. EDT.
CAPE CANAVERAL, Fla. - The oft-delayed space shuttle
Endeavour will have to wait at least one more day to launch while NASA
investigates whether lightning strikes near the launch pad yesterday caused any
damage.
No positive signs of harm to Endeavour have yet been found
from the violent lightning storm Friday afternoon, but mission managers called
for a 24-hour delay to investigate before resuming the countdown
to lift off.
"We need to be 100 percent confident that we have a
good system across the board," said Mike Moses, Endeavour's mission
management team chairman, during a Saturday briefing. "We've seen nothing so
far that indicates anything was actually affected by the lightning strike. But we
have to check and that's what takes time."
Thunderstorms have lately plagued the seaside region of the
Kennedy Space Center here, and sensors counted 11 lightning strikes within
about 0.3 miles of Endeavour's perch on Launch Pad 39A Friday.
Although no lightning directly impacted the orbiter, fuel
tank or solid rocket boosters (SRBs), a near enough strike could have induced a
strong current that could disable the sensitive electronics in the orbiter, or
the pyrotechnics in the SRBs.
"The concern is mostly in those pyrotechnic
systems," Moses said. "There's a lot of things that have to go right.
That's why we need to double check everything."
Mission managers hope an extra day will be enough time to thoroughly
check out Endeavour.
"I have high confidence we'll get there in 24 hours,
but I certainly cannot guarantee it," Moses said.
If no serious signs of damage are found, Endeavour could try
to launch again as early as Sunday at 7:13 p.m. EDT (2313 GMT) on its planned
16-day construction mission to the International Space Station. The weather
outlook is slightly better for Sunday than today's forecast, with a 60 percent
chance of favorable conditions expected.
Repeated Delays
Endeavour's STS-127
mission has already been held at the ground after a persistent leak of
gaseous hydrogen twice prevented the shuttle from lifting off. NASA has said
the leak, a potentially dangerous gas flow from a vent pipe leading off the
vehicle's 15-storey external tank, has been fixed.
After a thorough investigation, ground crews traced the
problem to a misaligned plate on the tank. NASA repaired the plate and
successfully tested the system last week. Mission managers said they're
confident the issue won't pose a problem anymore.
Commanded by veteran shuttle
flyer Mark Polansky, Endeavour's STS-127 mission will launch toward the
International Space Station carrying vital spare parts and a Japanese-built
porch for the outpost's massive Kibo laboratory. The marathon 16-day mission
will also ferry rookie NASA astronaut Tom Kopra to the station to replace
Japanese astronaut Koichi Wakata, who has lived aboard the orbiting lab since
late March. Wakata is Japan's first long-duration astronaut and has watched
over his country's $1
billion Kibo laboratory at the station.
Set to launch spaceward aboard Endeavour with Polansky and
Kopra are STS-127 pilot Doug Hurley and mission specialists Chris Cassidy,
Julie Payette, Tom Marshburn and Dave Wolf. Payette represents the Canadian
Space Agency, while the rest are NASA astronauts. Five spacewalks are planned.
Kopra is beginning a three-month mission to the space
station as a flight engineer on the outpost's six-man Expedition 20 crew. He
will join two Russians, another American and astronauts from Belgium and Canada
on what is the station's first full six-person crew.
Endeavour's 16-day mission will mark NASA's third shuttle
flight of the year and the second space station construction flight of 2009.
If Endeavour is unable to launch Sunday, a third attempt is
possible on Monday, with a 70 percent chance of good weather. NASA has until
July 14 to launch the shuttle before standing down to allow avoid a traffic
conflict with an unmanned Russian cargo ship also due at the space station this
month. If the mission is unable to launch by then, NASA can try again on July
27.
SPACE.com is providing continuous coverage of STS-127
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 2:30 p.m. EDT (1830 GMT).
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