Astronauts give Atlantis full post-launch inspection
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: November 17, 2009
A preliminary assessment of ascent imagery and data beamed down during an inspection of the shuttle Atlantis' nose cap and wing leading edge panels shows no signs of any significant heat shield damage, the chairman of NASA's Mission Management Team said Tuesday.
"Atlantis and the Atlantis crew are doing exceedingly well," LeRoy Cain told reporters. "We couldn't be more pleased with how this mission is going so far."
During Atlantis' climb to orbit Monday, engineers only spotted about three "debris events" in which foam insulation could be seen falling from the shuttle's external tank. In all three cases, the debris pulled away after the shuttle was out of the dense lower atmosphere, which can result in impact velocities high enough to damage the shuttle's fragile heat shield.
The Atlantis astronauts spent about six hours Tuesday using a laser scanner on the end of a 50-foot-long robot arm extension inspecting the orbiter's reinforced carbon carbon nose cap and wing leading edge panels, which experience the most extreme heating during re-entry.
While it will take engineers several more days to sift through the data, Cain said a preliminary assessment found no areas of concern.
"The preliminary assessment of some of the data we've seen on imagery and some of the downlinked information we have from the vehicle is that Atlantis' performance was just really good, outstanding performance of the external tank during ascent," he said.
"We saw very few events that are of interest for us to look at. Of course, we'll look in great detail at all of that data over the course of the next few days and go through our normal processes ... for clearing the vehicle (for entry) as we spend our time docked to the International Space Station."
Atlantis is on track to dock with the space station Wednesday around 11:53 a.m. EST. During final approach, commander Charles Hobaugh will put Atlantis through a 360-degree back-flip maneuver, allowing the station crew to photograph heat shield tiles on the shuttle's belly. That data will be folded into the ongoing assessment to determine if there are any other areas of concern.
"We're very much looking forward to the day tomorrow where the crew will get docked safely with the space station, we'll get the hatches opened ... and after that, the crew will get on with the primary objetives of the mission," Cain said.
Along with delivering some 15 tons of supplies and equipment to the station - and bringing flight engineer Nicole Stott back to Earth after three months in space - Atlantis also will bring home a critical component in the lab's urine recycling system that recently malfunctioned.
The distillation assembly in the processor that helps convert urine and condensate into potable water apparently suffered an internal mechanical problem after a series of restarts following work to clear internal blockage.
The 166-pound distillation assembly, which measures 16.5-by-30-by-16.6 inches, will be returned to Earth aboard Atlantis. NASA hopes to launch a replacement on the next shuttle mission in February.
The urine recycling problem and another recent issue with the station's water processing system are not expected to have any impact on the Atlantis mission.
"Neither one of those issues are going to affect our ability to have a safe rendezvous and docking with the space station," Cain said "In fact, neither one of the issues will affect our ability to have a completely nominal docked mission with the space station crew and with the two vehicles."
The station has enough fresh water to support the station's crew for several months even without the urine recycling system. NASA managers say they hope to have the system back in operation well before any shortages could occur.
For readers interested in the technical details, here is how lead shuttle Flight Director Mike Sarafin described the urine processor issue earlier Tuesday:
"The urine processor assembly that is used as part of the regenerative life support equipment on board the space station, it was delivered a year ago, has what they all a distillate assembly in there, that's where they basically separate the water from the rest of the urine and condensate that is collected on board the space station for, basically, a cleansing process, to be used as potable drinking water or what we call technical water that an be used for any number of reasons, including cooling fo the space suits
"The distillate assembly, we think, was plugged up about two weeks ago. They went through a process to recover that by putting back pressure on the line and they actually unplugged it and they tried to get it running again. As part of trying to get this distillate assembly, which has a rotating mechanism in there, kind of a centrifuge-type mechanism, to try to get that running again, they had it shut down a number of times. It was shut down based on a measurement that measures the quality of the water that's coming out of it to make sure that, again, it's mostly pure water coming out of this thing before it goes through the full cleansing process.
"And it wasn't achieving the standard required to proceed further down in the system. We'd start it up, it would process a little bit of water and it would shut down. We'd start it up, it would process a little water and shut down. And each time, it would look a little bit better with respect to this one measurement. We thought, eventually, it was just trying to get the right balance in the system as far as the amount of water, urine and condensate in there before this thing would finally process properly.
"In that process of starting it up and shutting it down, the distillate assembly encountered a current spike on the rotating part of the mechanism and it indicated a problem with the actual mechanism. Folks are uncomfortable operating it further because it could indicate a mechanical problem, a bearing-type of failure, and they want to get that hardware to the ground. As a result, we're unable to process any additional urine on board the space station using that hardware."