This
story was updated at 10:00 a.m. EDT.
CAPE
CANAVERAL, Fla. -- The space shuttle Endeavour and its seven-astronaut crew
will have to wait through at least four days of delay before launching toward
the International Space Station after a gas leak thwarted their planned
Saturday morning liftoff.
The gaseous
hydrogen leak was discovered before midnight while the shuttle's fuel tank was
loading in preparation for Endeavour's planned
launch today from Pad 39A here at NASA's Kennedy Space Center at 7:17 a.m.
EDT (1117 GMT). The shuttle's astronaut crew had not yet donned their
NASA-issue pressure suits or boarded the spacecraft for their marathon 16-day station
construction flight. NASA officially cancelled today's launch plans at
12:26 a.m. EDT (0426 GMT).
It will
take at least four days to ready Endeavour for a second launch attempt. At that
point, the schedule conflicts with the planned launch of two unmanned lunar
spacecraft due to lift off toward the moon on June 17 from the nearby Cape
Canaveral Air Force Station. Managers for the two missions will have to meet to
discuss which flight should go first.
"We
haven't even begun to work that out," said Mike Moses, mission management
team chair, today at a briefing here. "We'll start those negotiations
tomorrow and see where we get."
If
Endeavour is unable to launch before June 20, it must stand down until July 11,
when the space station is again in the right alignment.
Mystery
leak returns
A similar
leak thwarted the space shuttle Discovery's STS-119 launch in March, though
that issue was eventually fixed and the shuttle launched successfully.
"The
situation was almost identical to what we had two flows ago," shuttle
launch director Mike Leinbach said. "It was discovered at almost
identically the same time. It was eerily the same."
NASA does
not launch space shuttles with any known gas leaks at the pad because the
extremely flammable gas can cause an explosion during liftoff if it ignites.
"Hydrogen
is a very volatile commodity," Leinbach said. "It's a commodity you just
don't mess with."
Discovery's
STS-119 flight was ultimately able to launch four days later than planned after
ground crews swapped out the seal to a vent line that was carrying the gaseous
hydrogen away from the shuttle. The switch fixed the issue, though no root
cause was ultimately determined for the fault in the seal.
"They
never found a smoking gun for it," NASA spokesman Allard Beutel said.
Weather
forecasts predicted a pristine 90 percent chance of good flight conditions for
today's launch attempt.
Commanded
by veteran shuttle flyer Mark Polansky, Endeavour's seven-astronaut crew will
launch toward the International Space Station carrying a Japanese-built
porch for the outpost's massive Kibo laboratory. The 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 challenging spacewalks and challenging robotic arm work
that will require three space cranes, two on the station and one on Endeavour,
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
mission will mark NASA's third shuttle flight of the year and the second space
station construction flight of 2009. A May space shuttle mission aboard
Atlantis flew astronauts to the Hubble Space Telescope to perform a successful
final overhaul.
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.
advertisement
