Shuttle Endeavour cleared for launch next week
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: June 3, 2009
While the shuttle Endeavour's crew reviewed emergency procedures at the launch pad Wednesday, NASA managers held an executive-level flight readiness review and cleared the ship for blastoff June 13, at 7:17:15 a.m., on a complex space station assembly mission.
"We're running on all cylinders right now," Nickolenko said. "We're hitting our stride. The pace that we are challenged to work towards to make the manifest is going to require us to keep on pace and keep that work flowing. ... But it's all doable, manageable, the team's are seasoned and I believe they're focused."
Over the past month, NASA launched the shuttle Atlantis on a successful mission to service the Hubble Space Telescope, the Russian space agency launched an additional three crew members to the International Space Station, Endeavour was moved from pad 39B to pad 39A for final processing and Atlantis was returned to Florida from California where it landed May 24.
Endeavour's crew - commander Mark Polansky, pilot Douglas Hurley, flight engineer Julie Payette, David Wolf, Christopher Cassidy, Thomas Marshburn and space station flight engineer Timothy Kopra - flew to Florida Tuesday and reviewed emergency procedures at the pad Wednesday. All seven plan to strap in aboard the shuttle Thursday for a dress-rehearsal countdown.
Aboard the space station, meanwhile, commander Gennady Padalka and NASA flight engineer Michael Barratt plan to carry out two spacewalks, one Friday and the other next Wednesday, to rig the Zvezda command module for the eventual attachment of another docking port.
"It's been a really amazing schedule over the last couple of months," Polansky said today at the launch pad. "It's tight from the standpoint that we're here in Florida to climb in the vehicle tomorrow. We're going to go back home, take a day off, go into quarantine Saturday, come back down here Monday night and launch next Saturday. I mean, that's really tight.
"But I know from a training perspective, we're ready," he said. "It would be great if we could just climb in and go tomorrow, but I think our families would be a little upset because they're not here!"
The 16-day flight features five spacewalks to install an external experiment platform on the Japanese Kibo research module, to swap out batteries in the station's oldest set of solar arrays and to deliver critical spare parts. Endeavour also will ferry Kopra to the lab complex for an extended stay and bring Japanese station flier Koichi Wakata back to Earth.
Endeavour was hauled to pad 39B in April to serve as a rescue vehicle for the crew of Atlantis. In the Hubble Space Telescope's orbit, the Atlantis astronauts could not seek safe haven aboard the space station if any major problem developed that might prevent a safe re-entry.
Engineers actually started a countdown for Endeavour late in Atlantis' mission to keep the rescue option open as long as possible. As it turned out, no such flight was needed and after bad weather blocked multiple attempts to bring Atlantis back to Florida, the ship was diverted to Edwards Air Force Base, Calif.
But the wisdom of processing Endeavour in parallel was made clear during a post-landing inspection of Atlantis. Space debris, a greater threat at Hubble's high altitude, apparently hit one of the shuttle's braking rocket nozzles, damaging the inner and outer surfaces. The shuttle spent much of the mission flying tail first to shield more sensitive areas from debris impacts.
As it now stands, NASA will only have three days to get Endeavour off the pad or the flight will be delayed until after the planned June 17 launch of NASA's Lunar Reconnaissance Orbiter. Going into the campaign, Nickolenko said the team would make two back-to-back attempts if necessary, but not three.
If the launch is delayed, and if the lunar orbiter takes off on time, NASA may be able to make additional attempts to launch Endeavour on June 19 and 20. After that, the flight would slip to July 11 because of temperature constraints related to the space station's orbit.
"The folks have done just a tremendous job getting ready to go fly again," said Bill Gerstenmaier, chief of space operations at NASA headquarters. "The Atlantis mission was a tremendous success and it really enabled us to be here. As we went through the flight readiness review today, it became really obvious that Atlantis was a very clean vehicle, it had very few anomalies. ... We didn't have a lot to talk about. The vehicle was really in great shape."
One question mark after Atlantis' flight was what caused the failure of an avionics box just before liftoff May 11. The box in question, one of four used to control the movement of the shuttle's elevons and rudder-speedbrake assembly, shut down moments after main engine ignition, the apparent victim of a short circuit.
The failure did not affect the shuttle's climb to orbit or its re-entry. But engineers wanted to make sure the issue was understood in case it was the result of some fleet-wide problem, or wiring deficiency, that might affect Endeavour.
An inspection of the wiring leading into and out of the box in question was carried out at Edwards and no obvious shorts were found. Likewise, a resistance test found no issues that would confirm a short. Engineers now plan to inspect the box itself as soon as it can be removed from Atlantis' aft avionics bay.
In the meantime, a detailed analysis was carried out indicating the odds of a similar problem aboard Endeavour were sufficiently remote to press ahead for flight. Unless an obvious problem is found aboard Atlantis that would raise a concern for Endeavour, the launch team plans to proceed with flight.
Another issue that was discussed at the flight readiness review was the loss of foam insulation from Atlantis' external tank that impacted the ship's forward right wing in an area known as the chine. While the debris caused minor impact damage to several heat-shield tiles, it did not pose any threat to the crew and no in-flight repairs were needed.
But because the foam came from the upper liquid oxygen section of the tank, which poses more of a threat to the shuttle's heat shield, engineers are paying close attention to make sure the issue is understood and that it's not a sign of a more serious problem.
Most other foam losses experienced in recent flights have come from the liquid hydrogen section of the tank, caused by temperature changes as the fuel is consumed. In those cases, foam releases occur late in the ascent, after the shuttle is out of the thick lower atmosphere, and pose little or no threat to the heat shield.
That mechanism does not explain foam losses from foam on the oxygen tank, or its main feed line, like that seen during Atlantis' ascent.
"The other foam losses we've seen have been back on the hydrogen tank, where it's the cryo-pumping foam loss that occurs typically late," Gerstenmaier said. "If foam comes off in this area (of the oxygen tank), it's going to come back to the chine area like we saw on Atlantis, or it'll come back to the (wing leading edge) area. So this is a very sensitive area from a transport standpoint.
"So again, it's not out of family. In fact, it's consistent with what we've seen before, there's no real indications here we've got a problem. But in the spirit of preventing a future problem, (we're looking at) is there something we can learn from this?"