Endeavour to launch on 'home improvement' flight
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: November 13, 2008
The shuttle Endeavour is poised for blastoff Friday on a space station "home improvement" mission with a "yuck factor" twist: Delivery and installation of a new toilet and complex water processing gear designed to convert urine into ultra-pure water for drinking, food preparation, personal hygiene and oxygen generation.
The astronauts also plan to install a new galley and two cabin-like sleep stations that will provide privacy and radiation protection, all part of a long-range plan to boost the station's full-time crew from three to six next year. The expansion requires on-board recycling because rockets servicing the station cannot deliver enough fresh water to support six full-time astronauts.
"Recycling is a must," said space station flight director Ron Spencer. "We can't be delivering water all the time for six crew. So the highest priority is to install and activate the water treatment hardware first. And we want to have this operate for 90 days before we give a go for six-crew operations on board station. We want to start this 90-day clock as soon as possible. We're actually going to try to activate this hardware, the initial activation of it, during (Endeavour's mission) so that we can get the first processed water sample returned home on that shuttle mission to verify acceptable water quality."
Sandra Magnus, a space station flight engineer hitching a ride to the lab aboard Endeavour, said building and perfecting a closed-loop life support system is a critical first step toward eventual flights to the moon and Mars.
"When you go to the moon, when you go to Mars, you have to be able to survive more or less on your own resources," she said. "You can't build a system, build a colony, build a life style that's dependent on deliveries from afar. And so you do need to have a system like this, which allows you to be self-sufficient. This is a first step towards that."
But in the near term, she said, "there's definitely a yuck factor because it's just, maybe a nightmare people have, you know, that they'll have to do this."
"It's funny, because we're not really drinking our own urine, we're drinking water that's been reclaimed from a process that urine was an input for," she said in an interview. "And it's something that when you think about humans moving off of the planet, we need to create these closed life support systems.
"It's funny, too, because our planet itself is a closed life support system. And you ARE redrinking your urine every day, you are redrinking water that's been recycled, reclaimed and cleansed. But the system is so large and the process, the time cycle for the system, is so long, that people don't realize it. So we're sort of distilling, if you will, the process down into a couple of days or a week that we experience here on the planet naturally. People don't think about it, so the yuck factor is that much more apparent."
Joining Magnus aboard Endeavour will be commander Chris Ferguson, pilot Eric Boe, space station veteran Don Pettit, and spacewalkers Heidemarie Stefanyshyn-Piper, Stephen Bowen and Robert "Shane" Kimbrough. Boe, Bowen and Kimbrough are making their first flight while Ferguson, Magnus, Pettit and Stefanyshyn-Piper are making their second.
Magnus will remain behind aboard the station with Expedition 18 commander Mike Fincke and flight engineer Yury Lonchakov when Endeavour departs, replacing outgoing flight engineer Gregory Chamitoff. Launched to the station last June, Chamitoff will return to Earth aboard Endeavour in Magnus' place.
Endeavour's launching at 7:55 p.m. Friday comes five-and-a-half months after the most recent station assembly mission. NASA worked through the summer and early fall preparing to launch the shuttle Atlantis in mid-October on a mission to service and upgrade the Hubble Space Telescope. Endeavour was processed in parallel to serve as an emergency rescue vehicle for the Hubble crew in case of problems with Atlantis that might prevent a safe re-entry.
But Hubble Servicing Mission No. 4 was put on hold when an electronic component aboard the observatory failed Sept. 27. Testing a spare unit on the ground and preparing it for flight is expected to delay the Hubble flight to May at the earliest. After assessing a variety of options, NASA managers opted to press ahead with the next two station flights as planned - Endeavour this month and Discovery in February.
Unlike recent station missions that added modules, solar arrays or truss segments to the station, Endeavour's flight is devoted to delivering some 14,400 pounds of equipment and supplies inside a logistics module that will be temporarily attached to the station's forward Harmony module. The shuttle also will deliver a spare rotary connector that lets huge folding radiators turn to efficiently dissipate heat and bring a depleted coolant system pressurization tank back to Earth.
Assuming an on-time launch, NASA managers are expected to extend the docked phase of Endeavour's mission by one day to give the combined crews more time to complete the water system installation and activation. In that case, the shuttle crew would undock the day after Thanksgiving and land back at the Kennedy Space Center the afternoon of Nov. 30.
Getting the water recycling system up and running is a critical milestone in the life of the station, enabling the outpost to support an expanded crew starting next May. Up to this point, water has been delivered by Russian Progress supply ships and by the space shuttle, whose fuel cells produce water as a by product. But NASA plans to shut down shuttle operations in 2010 and Russian, European and Japanese cargo ships cannot provide enough water to support full-time station operations.
"We will not go to six people unless the water recovery system is working," Fincke said in an interview. "And the reason is resupply. With the Columbia disaster, we went from three people to two people and the biggest thing that made us do that was resupply and the resupply of water. And it's going to be hard enough to resupply water for six people without recycling more water than we have right now. And that really is urine reprocessing. We call it water, but it's really urine reprocessing.
"By reprocessing urine and getting the fresh water out of it, we'll be able to make up our margins, especially because we can see the shuttle isn't going to be flying a few years from now. So this is a pretty critical time for us and the water racks, all the environmental and life support systems that we're putting up, the crew quarters and the galley, people have been working really hard and it's been a stressful time for them.
"Sandy and I as well as Greg Chamitoff and the other shuttle crew guys, we're going to work really hard so we don't mess it up."
While work is going on inside the station's Destiny laboratory module to install two water recycling system racks, the toilet and the galley, Stefanyshyn-Piper, Bowen and Kimbrough plan to stage four spacewalks to mount the rotary coupler on the station's exterior, to continue outfitting the recently added Japanese Kibo module and to service the lab's degraded right-side solar alpha rotary joint, or SARJ.
"This mission is all about home improvement, home improvement both inside and outside the international space station," Ferguson said. "On the inside of the space station, the walls are largely up. We've had some large modules delivered in the last year. Well, it's moving day, it's time to fill them up. And on the outside, on the outside we have some never-before-attempted repair work. That repair work will be to, hopefully, improve the performance of a faulty solar alpha joint rotation mechanism with grease. We've never tried anything like this. So on our first EVA out there on flight day number five, Heide and Steve will hit the bricks with grease guns, scrapers and new trundle bearings in an attempt to bring new life back to the solar alpha joint."
The station is equipped with two massive SARJ joints designed to rotate outboard solar arrays like giant paddle wheels, keeping them face-on to the sun as the lab complex orbits the Earth. The left-side SARJ is operating normally, but the 10-foot-wide drive gear on the right side has suffered serious erosion and degradation on at least one of its three bearing surfaces, subjecting the mechanism to high vibration and generating extensive metallic debris.
To avoid excessive stress and fatigue that might eventually lead to failure, the joint is no longer allowed to "auto-track" the sun and is only repositioned occasionally to improve electrical output.
Based on analysis of collected debris and a trundle bearing removed earlier, engineers believe the problem was caused by a lubrication failure.
"We have concluded the most likely cause of this anomaly is due to high friction, which was caused by the loss of lubrication in the joint when it flew," said station Program Manager Mike Suffredini. "The way we lubricate that joint is we put a gold plating on the (trundle bearing) rollers. This is a very soft material and over time, it kind of wears off the roller and finds its way onto the race and fills in the very small microscopic holes and provides basically a lubricant that will wear over time. But it was intended to wear very slowly over time.
"We have found through a bit of research in the paperwork that was put together before we flew and some of the information we gained from the trundle bearing we returned home that we believe the gold prematurely came off these rollers, either because of a condition pre-flight or because of the process used to install the gold just wasn't adequate for the conditions that it saw, that we wore it off prematurely on the starboard side. We have proven through testing that once you take the lubrication off this joint, it will damage the race very, very quickly."
During Endeavour's mission, Stefanyshyn-Piper, Bowen and Kimbrough, working in two-person teams, plan to replace the remaining 11 trundle bearing assemblies, or TBAs, on the right side SARJ. Using grease-impregnated wipes, the spacewalkers will attempt to blot up the metallic shavings contaminating the race. Dry wipes will be used to finish the job and grease guns will be used to lay down beads of lubricant. The drive gear will be turned between spacewalks to let the bearing rollers distribute the grease across all three bearing surfaces.
A similar lube job is planned for the lab's healthy left-side rotary joint as preventive maintenance. In both cases, the major challenge will be to keep the grease under control and prevent debris from floating away, contaminating the crew's spacesuits or possibly working its way into other delicate mechanisms.
"We want to make sure we get the grease where it's supposed to go and that's on the race rings to help lubricate the SARJ," Stefanyshyn-Piper said. "When you go out there to do this work, even though it's not a fine, delicate task, it is a fine, delicate task in the sense that you don't want to get grease all over yourself and everywhere else. And so you've just got to work slowly and very deliberately on what you're doing."
If the cleaning and lubrication go smoothly, engineers hope to be able to use the starboard SARJ in a manual mode and, when power requirements are high, to auto track for short periods. While both SARJ mechanisms include a backup drive gear for redundancy, NASA managers want to operate the starboard SARJ on its primary gear as long as possible.
"Once we get this all cleaned up, we'll look at the vibrations," Suffredini said. "We're assuming the vibration levels will be very low and that will allow us, if there come times when we need short intervals of auto track in order to get the power we need for utilization, then we'll do that.
"Today, we know we have enough power to do everything we need to do on orbit and protect the payloads with continuous power. But we do know there are periods when we won't be able to do much additional research during those times. And that's where, if we clean it up and it looks really good and the vibrations are low, that will give us that advantage, to be able to auto track sometimes when you need the additional power to keep doing utilization."