Orbiter: Discovery
Mission: STS-124
Payload: Kibo lab
Launch: May 31, 2008
Time: 5:02 p.m. EDT
Site: Pad 39A, Kennedy Space Center, Florida
Landing: June 14 @ approx. 11:02 a.m. EDT
Site: Shuttle Landing Facility, KSC
The Crew
Meet the astronauts flying aboard Discovery's STS-124 mission.
CDR: Mark Kelly
PLT: Ken Ham
MS 1: Karen Nyberg
MS 2: Ron Garan
MS 3: Mike Fossum
MS 4: Akihiko Hoshide
Up: Greg Chamitoff
Down: Garrett Reismam
Three spacewalks are planned during Discovery's STS-124 assembly
mission to the station.
Discovery passes final review for May 31 launch
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: May 19, 2008
NASA managers today cleared the shuttle Discovery for launch May 31,
at 5:02:09 p.m. EDT, on a long-awaited three-spacewalk mission to
deliver and attach Japan's huge Kibo laboratory module to the
international space station. The decision to proceed came after a
lengthy discussion on the health of the station's Soyuz lifeboat after
back-to-back re-entry problems that led to rough, off-course landings.
Russian engineers are still assessing what went wrong during the
descent of the Soyuz TMA-11 spacecraft April 19 when two of the three
modules making up the vehicle failed to separate properly before
atmospheric entry. The propulsion module ultimately broke free of the
crew section, allowing Yuri Malenchenko, outgoing station commander
Peggy Whitson and a South Korean space tourist to complete a steep but
otherwise safe landing in Kazakhstan.
It was the second such entry mishap in a row and Russian engineers
have launched a major investigation to determine what went wrong and
whether the Soyuz TMA-12 spacecraft currently docked to the station is
healthy. It is a critical issue because the three-seat Soyuz is the
station crew's only way home in the absence of a space shuttle in the
event of an emergency that might force an evacuation.
It is a critical issue for NASA as well because the agency plans to
rotate U.S. crew members during Discovery's flight, ferrying Gregory
Chamitoff to the station to join Expedition 17 commander Sergei Volkov
and Oleg Kononenko and bringing Garrett Reisman back to Earth. Another
shuttle is not scheduled to visit the space station until November.
The Soyuz TMA-12 spacecraft will serve as the station's lifeboat until
October when a fresh crew is launched aboard a fresh Soyuz. Current
plans call for Volkov, Kononenko and U.S. space tourist Richard
Garriott, who will ride the new Soyuz to orbit, to return to Earth
aboard the TMA-12 spacecraft Oct. 23.
Going into today's executive-level flight readiness review to set a
launch date for Discovery, NASA managers discussed a variety of
options, including whether to delay the shuttle flight until Russian
engineers get a better idea about the status of the Soyuz currently in
orbit.
But the Russian investigation into what went wrong during the Soyuz
TMA-11 descent is not expected to be complete until the end of June or
later and a one week to two week delay for Discovery would not improve
the station crew's safety margin.
Bill Gerstenmaier, NASA's chief of space operations, said the odds of
a station failure that would force a Soyuz evacuation are low - on the
order of 1-in-124 over six months - and that a safe landing would be
likely even if similar entry problems occurred.
"If something comes out of the investigation that says the Soyuz is
not acceptable as a return vehicle, then we would go take some
appropriate action," Gerstenmaier said. "But we haven't seen anything
along those lines. For emergency return, Soyuz is OK. ... But the
Russians are working through it methodically, trying to identify if
there's anything that would invalidate its use as an emergency return
vehicle. As long as that doesn't occur, then we proceed with our
normal plans. And I don't see anything between now and the 31st that's
going to change any of that thinking."
Sources familiar with recent NASA discussions on the Soyuz issue said
an assessment of the relative risks of various options played a key
role. While the odds of a station problem that would force evacuation
are thought to be around 1-in-124 over six months, the overall risk of
a catastrophic shuttle failure over the course of Discovery's mission
- including all phases of launch, orbital operations and re-entry - is
on the order of 1-in-78, according to NASA's latest assessment. Given
those relative odds, and the belief that the station is five times
more likely to suffer a non-recoverable failure in the absence of a
crew to repair it, NASA managers opted to press ahead with an
on-schedule launch for Discovery.
"It's a fairly low probability that we'd need to use (the Soyuz) in an
emergency case," Gerstenmaier said. "In fact, we analyzed that, we did
a probabilistic risk assessment of what the chances were of having to
use the Soyuz as a rescue vehicle. It's a low probability we're going
to have to use it. But if we use it, we think there's a good
probability it'll return the crew and do what it needs to do. So as a
parachute or a backup system, it has the reliability that we think we
need for a backup system. We have yet to prove it has the reliability
that we would use for a nominal return situation."
Discovery is in good shape and on schedule for launch May 31. The only
technical problem of any real concern since the shuttle was moved to
pad 39A was the failure of a multiplexer-demultiplexer computer system
that required a changeout. When the MDM, known as FA2, failed, it
caused two of the shuttle's four flight computers to lose
synchronization. In flight, that could force a crew to switch to a
backup flight system computer, limiting their ability to cope with
additional failures. But the MDM was successfully replaced and tested
and no concerns about it were raised during today's flight readiness
review.
"It's an extremely complicated mission," Gerstenmaier said. "Adding
the Kibo module is a big deal for the Japanese. This really brings
them up to speed. And adding the Kibo module is not easy. ... We need
to be careful we don't assume success and take our eye off of what
we're doing. We've got to stay focused. The Soyuz is fine, it will
take care of itself, we've got time to work that. That needs to get
resolved by the fall. The issue right now in front of is us we need to
be 100 percent ready to go fly this flight, we've got to be 100
percent ready to get the Kibo attached. ... We need to work all that
activity during the flight and that needs to be our focus."
Commander Mark Kelly, pilot Kenneth Ham, flight engineer Ronald Garan,
Karen Nyberg, Michael Fossum, Japanese astronaut Akihiko Hoshide and
Chamitoff plan to fly to the Kennedy Space Center on May 28 for the 3
p.m. start of their countdown to launch.
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