No 'focused' heat shield inspections needed
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: November 17, 2008
Initial analyses of laser scans Saturday and photos taken from the international space station as the shuttle Endeavour closed in Sunday indicate the orbiter's heat shield is in good shape, with no major problems that would require a so-called focused inspection later this week, officials said today.
While the analysis is not yet complete - and the shuttle is not yet cleared for re-entry - Endeavour's crew was told the time set aside for a focused inspection would now be used to speed up assembly and testing of water recycling gear needed to boost the station's crew size from three to six next year.
Assuming the crew gets the work done in time - and assuming no major hiccups along the way - pre-launch plans to add a day to Endeavour's mission might not be needed.
"We have cleared all issues with the reinforced carbon carbon wing leading edge system, so that system is in really good shape," said LeRoy Cain, chairman of NASA's Mission Management Team. "The tile, as you know we get a lot of imagery from the rendezvous pitch maneuver and the teams have been poring over that data for the last 24, 36 hours here. And they have determined we don't need any kind of focused inspection on any of the TPS, that is, on the tile or on the RSS.
"So that's really good news for us. We have a little bit more work to do in the next 12 or 18 hours here before we can clear the entire system for deorbit and entry, but we have seen enough to be able to ascertain that we don't need any kind of focused inspection. That was an important milestone for us as it always is."
Overall, Cain said, "Endeavour is doing extremely well. I anticipate by this time tomorrow we will, in fact, be able to completely clear the thermal protection system for deorbit and entry."
The astronauts, meanwhile, used the station's robot arm to pull the 27,000-pound Leonardo cargo module out of Endeavour's cargo bay earlier today and attach it to a downward-facing port on the space station's Harmony module. Motorized bolts locked the module in place and the astronauts spent the afternoon making preparations for opening the hatch. That milestone was accomplished at 6:43 p.m.
The module is loaded with more than seven tons of equipment and supplies, including two 1,700-pound water recycling racks that will be mounted in the station's Destiny laboratory module. The water racks will be tied into the module's potable water bus, along with a new toilet and galley. The astronauts, running ahead of schedule, plan to start unloading the equipment early Tuesday.
Converting condensate and urine into potable water is a requirement for NASA to boost station crew size from three to six next year as planned. Going into Endeavour's mission, flight planners held open the possibility of extending the shuttle mission one day to give the crew time to complete initial water system activation and to collect the first samples from a potable water dispenser, or PWD.
Engineers want to get samples on the ground as soon as possible for detailed laboratory analysis, both to confirm the system's overall operation and to provide calibration data for a less-capable analyzer that will be used in orbit. The station crew, meanhile, will test the water continuously for three months, sending additional samples back to Earth on the next shuttle mission in February. No one will be allowed to actually drink the recycled water until that analysis is complete.
With focused inspection now ruled out for Endeavour's mission, flight controllers hope to accelerate water system installation and initial activation.
"There is no focused inspection required," station flight director Ginger Kerrick radioed the crew from Houston earlier today. "That will open up about 10-and-a-half hours on flight day six (Wednesday). What we're looking to do is potentially pull activities from future flight days into that time slot with the overall goal of trying to add in the PWD (potable water dispenser) sampling. ... I know pre-flight, we had discussed the only way we could do it was with a plus-one day.
"Now that is all contingent on the fact that everything goes nominal," Kerrick said. "Of course, we're not going to know that by flight day six, but we wanted to position ourselves so if it all does go nominal, somewhere around flight day nine, we can make the determination as to whether or not we recommend we add the plus one (day) for the PWD."
Cain said it's too early to know if the crew will be successful getting samples without the need for an extra day and Kirk Shireman, deputy manager of the space station program at the Johnson Space Center, said earlier he fully expects problems as the astronauts work to hook up and activate the new hardware.
"It's all been designed and tested in a one-G environment," he said. "And so there are things that operate differently in space when you don't have gravity, you don't have convection from a heat flow standpoint. So, that's why you'll most likely see some difficulties. We kind of compare it back to the oxygen generation system initiation. It took us about a week to get that working. I'm optimistic it won't take us that long to get the water racks up and running, but the same kinds of things will be present."
The goal is to collect water samples from various points along the processing chain.
"We want to bring a sample home from several pieces of the system," said station flight director Holly Ridings. "We've got the urine processing system, we've got the water processing system and we're hoping to also get a sample from our potable water device that we'd like to hook up on this mission as well. ... It's a system that has to work together and we've got a process for systematically configuring that and integrating it into our space station, taking samples from each of the components, bringing them home on the shuttle, analyzing them on the ground and then making sure it's safe for our astronauts and cosmonauts on orbit to use that system."
The shuttle is plugged into the space station's solar power grid and mission managers don't anticipate any problems extending one day if necessary.
Installing the new water recycling gear is only one of the shuttle mission's major objectives. Another is attempting to clean and lubricate the station's right-side solar array rotation system, which has suffered extensive degradation since launch because of an unexpected loss of lubrication.
Astronauts Heidemarie Stefanyshyn-Piper, a former Navy diver, and Stephen Bowen, a former submariner, plan to stage the first of four spacewalks Tuesday to continue outfitting the station and to begin servicing the starboard solar alpha rotary joint, or SARJ. Both astronauts planned to spend the night in the station's Quest airlock module at a reduced air pressure to purge nitrogen from their blood and help prevent the bends after working in NASA's 5-psi spacesuits. The spacewalk is scheduled to get underway around 1:45 p.m.