Endeavour's mission to build another room on the station
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: February 5, 2010
KENNEDY SPACE CENTER, Fla. -- Reeling from a morale-sapping change of course, engineers are readying Endeavour for launch Sunday on NASA's final five shuttle missions, a three-spacewalk flight to attach a 15-ton crew module to the International Space Station.
The astronauts also will deliver replacement hardware to overhaul the lab's water recycling system, the complex equipment that turns sweat and urine into ultra-pure water for drinking, crew hygiene and oxygen generation. The system has been out of action in recent weeks because of higher-than-expected calcium concentrations in a critical distillation assembly.
To give that system time to operate and assess its performance before Endeavour departs, the crew plans to delay moving the life-support systems into the new module, possibly extending the flight by one day. If that is not possible, the life support racks will be installed by the station crew after the shuttle undocks.
"Currently, we have a lot of those life support racks spread throughout the station and they're in the locations where crew members are either doing scientific experiments or exercising or eating," said shuttle commander George Zamka. "The volume in which they're doing all that is fairly small.
"Once those racks have been moved into Tranquility, they will be out of the laboratory spaces so the labs can be for science and Tranquility will become the home for the water regeneration system, the atmospheric revitalization system and those things. And also exercise. ... So that's a big change for the astronauts."
The other major addition - the multi-window cupola - will improve the quality of life aboard the station. Full-time crew members now have sleep stations and internet access. With Endeavour's mission, they will get a bay window on the world.
Along with providing a home for a robot arm work station, the cupola will let the crew "look outside," Zamka said, "it'll be kind of a hemispheric place where they can look out and see tremendous views of the Earth."
Zamka and his crewmates - pilot Terry Virts, Kathryn Hire, flight engineer Stephen Robinson and spacewalkers Robert Behnken and Nicholas Patrick - are scheduled for liftoff from pad 39A at the Kennedy Space Center Sunday at 4:39:47 a.m. EST, roughly the moment Earth's rotation carries the pad into the plane of the station's orbit.
Forecasters are predicting a 70 percent chance of acceptable weather Sunday, improving to 90 percent "go" Monday and dropping back to 80 percent favorable Tuesday. NASA can make two attempts to launch Endeavour during that three-day period.
If the shuttle tries Sunday and Monday and doesn't make it, launch would slip to Feb. 13, after the Feb. 10 launch of NASA's Solar Dynamics Observatory science satellite. If Endeavour tries Sunday and Tuesday and doesn't make it, launch would slip to Feb. 14 and NASA would try to launch the SDO mission Feb. 11. If the shuttle takes off on schedule Sunday, SDO would go on Feb. 9.
Assuming Endeavour takes off on time, Zamka will guide the orbiter to a docking with pressurized mating adapter No. 2 on the forward end of the International Space Station around 1:18 a.m. Tuesday.
Tranquility, also known as node 3, was built by Thales Alenia Space of Italy. It is scheduled for attachment to the station during the crew's first spacewalk. Two additional spacewalks by Behnken and Patrick are planned to connect long ammonia coolant lines and to outfit the cupola, launched on one end of the new module and then moved to its permanent location on an Earth-facing port.
Going into the flight, NASA planners do not assume a mission extension. As such, Endeavour is scheduled to undock around 7:12 p.m. on Feb. 17 and to land back at the Kennedy Space Center around 11:13 p.m. two days later. If the flight is extended, those dates would slip accordingly.
"We are exceptionally excited about the prospect of sending this crew on its way to the International Space Station," said lead shuttle Flight Director Kwatsi Alibaruho. "This mission is not only the first mission of 2010, it's also expected to be the last night launch of the shuttle, and so many folks are excited about seeing that.
"This mission also represents the end of U.S. segment assembly. Node 3 is the last U.S.-produced module which will be added to the International Space Station."
Launch of the 130th shuttle mission comes just one week after the Obama administration unveiled NASA's fiscal 2011 budget, killing the agency's post-Columbia moon program and ordering a near-term switch to private-sector rockets for post-shuttle flights to and from low-Earth orbit.
The reaction of many space agency insiders has been decidedly negative, with some decrying what they fear will be a loss of institutional knowledge and operational experience, decreased safety and the absence of any long-range mission to move out of Earth orbit into the solar system.
NASA Administrator Charles Bolden insists those fears are unfounded, saying the new direction will give the agency a chance to focus on developing new technologies to facilitate eventual deep space missions while turning over more mundane flights to and from low-Earth orbit to the private sector.
Asked when NASA might unveil a long-range exploration strategy to replace Constellation, he said "it's more than a couple of weeks but it's less than years."
"We're already starting to form tiger teams that will help us come up with a schedule for how we're going to go about developing a new plan, a bold plan for exploration," he said. "Anybody who talks about exploration beyond low-Earth orbit, there are some places that naturally come to mind - the moon, Mars, asteroids, other near-Earth objects. ... We hope very soon to be able to give you a very definitive time schedule on which we hope to reach some of these destinations."
Asked about the perception that NASA is turning its back on manned spaceflight, Bolden said "we are not abandoning human spaceflight by any stretch of the imagination."
"I think we're going to get there perhaps quicker than we would have done before," he said, adding later that commercial manned rockets could be flying by 2016 if not earlier.
NASA's $19 billion 2011 budget supports extending the space station's life through 2020 and provides money to support the shuttle program through the end of 2010 or early 2011 if technical problems prevent NASA from launching all five remaining flights before the end of fiscal 2010 as planned.
Between the end of shuttle operations and the debut of whatever vehicle replaces it, U.S. astronauts will be forced to hitch rides to the station aboard Russian Soyuz rockets at more than $50 million a seat.
Closer to home, the shuttle workforce at the Kennedy Space Center and surrounding communities is facing the loss of some 7,000 jobs when the shuttle is retired later this year. Despite the cancellation of the Constellation moon program and uncertainty about what sort of rocket will replace the shuttle - and when - NASA managers say the workforce remains focused on safety.
"Distraactions are there, shock is there, undertainty," said shuttle Launch Director Mike Leinbach. "But I do not worry about the folks on console when they're doing their job. I do not worry about the people in the (Orbiter Processing Facilities) when they're working on the orbiters. I don't worry abnout folks when they're working on the ground support equipment. ... When teams are faced with challenges they come together and they act like a professional team.
"We will not be distracted on the console, we will not be distracted working on the orbiters. I have no doubt about that. It's a very, very, very professional team."
As for the commercial rockets and capsules that follow the shuttle, Bolden said last week the agency "will set standards and processes to ensure that these commercially built and operated crew vehicles are safe."
"No one cares about safety more than I," he said. "I flew on the space shuttle four times. I lost friends in the two space shuttle tragedies. So I give you my word these vehicles will be safe."
For Endeavour's crew, as for all post-Columbia shuttle flights, the first two days of the mission will be devoted to checking out rendezvous tools, testing the spacesuits and equipment needed for station assembly work and carrying out a series of rendezvous rocket firings to catch up with the lab complex. Given Endeavour's launch time, the mission will be conducted in the deep overnight hours, U.S. time.
During their second "day" in space, the astronauts will use a 50-foot-long boom attached to the end of the shuttle's robot arm to inspect the ship's reinforced carbon carbon nose cap and wing leading edge panels, which experience the most extreme heating during re-entry.
Data from a laser scanner and a high-resolution camera on the end of the orbiter boom sensor system, or OBSS, will be downlinked to Earth for analysis. That data will be folded into an ongoing study of ascent video, radar readings and data from wing leading edge sensors to look for external tank foam insulation losses and any signs of heat shield damage during the climb to space.
Another major inspection will be carried out during Endeavour's final approach to the station.
Approaching from behind and below, Zamka and Virts plan to position the shuttle 600 feet directly below the space station and then carry out a computer-assisted back flip, or rendezvous pitch maneuver, exposing the protective tiles on the shuttle's belly to the station crew. Using powerful telephoto lenses, the lab crew will snap hundreds of photographs and downlink them to the ground for analysis.
With the RPM complete, Zamka will fly the shuttle up to a point 400-feet directly in front of the station. From there, with Endeavour's nose pointed toward deep space and its payload bay docking port facing the station, the shuttle commander will manually guide the spaceplane in for a docking with pressurized mating adapter No. 2 on the front end of the forward Harmony module.
Waiting to welcome Endeavour's crew aboard will be Expedition 22 commander Jeffrey Williams, Russian flight engineers Maxim Suraev and Oleg Kotov, Japanese astronaut Soichi Noguchi and NASA flight engineer Timothy Creamer.
After a brief welcome ceremony and a mandatory safety briefing to familiarize the shuttle crew with space station emergency procedures, the combined crews will get to work, transferring spacesuits from Endeavour to the lab and using the station's robot arm to remove the OBSS from the shuttle's payload bay and hand it off to the orbiter's robot arm.
The next day, flight day four, Behnken and Patrick will prepare their tools and equipment for the first of three planned spacewalks while their crewmates move supplies and hardware from the shuttle to the space station. That afternoon, the shuttle crew will enjoy a half day off to relax and catch its collective breath.
Williams, meanwhile, will spend much of that day and the next installing replacement equipment in the station's water recycling system.
The station's urine processor has been shut down in recent weeks because of problems with a critical distillation assembly. More recently, blockage in a line knocked out the part of the system that converts condensate into clean water.
"We brought home the other failed distillation assembly on the last shuttle flight," said station Program Manager Mike Suffredini. "Through a failure investigation, we found calcium deposits inside the distillation assembly and we're doing quite a bit of investigation to determine how to prevent that in the future.
"One way is to not process to as high a concentration of brine inside the system, meanin g we empty the tank that carries the ultimate waste from the urine processor, we empty it a little more often. So we want to run the processor with the new distillation assembly inside long enough to fill the tank up to the new level we plan to operate at, remove that tank and bring it home.
"That will take us almost the entire mission, from the time we're able to install the spare until the time the crew has to depart," Suffredini said. "That's what's driving us not to do the rest of the rack moves until the urine processor can move."
As for the presumed line blockage problem with the water processing system that is preventing conversion of condensate, a filter will be carried up aboard Endeavour that should resolve the issue.
"When the shuttle arrives we'll install the filter and then we'll activate the water processor along with the urine processor and recover our regenerative (environmental control and life support) system by the end of the mission," Suffredini said.
The station has plenty of stockpiled water for extended operations while work to fix the current problems is carried out. Station Flight Director Bob Dempsey described the repairs as "an extensive amount of work."
"Once they complete that work, we'll activate from the ground and begin processing the urine and we'll watch that very closely," he said. "We'll process as much as we can through the mission so the filter/tank assembly gets to be used as much as we can and verify that the system is working in its new configuration and then we'll bring it back on the last day."
As it now stands, the oxygen generation system, the U.S. toilet and the water processing system racks bound for Tranquility will not be moved into the new module during the normal shuttle timeline. If the flight is extended one day as managers hope, the Endeavour astronauts should be able to get some, if not all, of the equipment transferred.
"It is likely during this mission we won't be moving all the regenerative ECLSS (environmental control and life support system) racks into node 3," Suffredini said. "If we get favorable conditions such that we can have (an) extra day and nothing else is needing that day, we may in fact stay one extra day and finish that work. It's not required, we can get the racks all moved during the stage (after Endeavour departs). But the preference is to try to do it during docked ops."
Behnken and Patrick will spend the night of flight day four in the station's Quest airlock module at a reduced pressure of 10.2 pounds per square inch. This now-routine "campout" procedure helps purge nitrogen from the spacewalkers' bloodstreams prior to spending a day in NASA's 5-psi spacesuits.
The primary goal of the first spacewalk is to prepare Tranquility for its extraction from Endeavour's cargo bay and its installation on the left-side port of the Unity module. Robinson will serve as spacewalk coordinator. Behnken, wearing a suit with red stripes, will go by the call sign EV-1 while Patrick, wearing an unmarked suit, will be EV-2.
The spacewalkers will make their way from Quest to the shuttle's payload bay and then split up. Behnken, working at the back of the cargo bay, will remove eight thermal blankets from the module's berthing mechanism while Patrick, working at the forward end of Tranquility, disconnects a shuttle power cable used to operate heaters inside the module.
While astronauts inside the space station use the lab's robot arm to pull Tranquility from Endeavour's payload bay and install it on Unity, Behnken and Patrick will pre-stage two large bags containing ammonia coolant lines and insulation needed for the second spacewalk. They then will move to the Canadian DEXTRE robot and remove a stowage tray that will be replaced during a subsequent flight.
"On the first spacewalk, the biggest concern is getting power to node 3 after it's attached to the space station," Behnken said in an interview. "The timer that's running on it for its keep-alive power is longer than an EVA but not long enough to go to the next EVA."
With Tranquility mated to Unity's left port, Behnken and Patrick will work to connect power and data cables. But the systems those cables support will not be activated until later, after the ammonia coolant lines are connected during the second and third spacewalks. In the meantime, Patrick will connect a cable to provide keep-alive power to the module's internal heaters.
The next day, the astronauts plan to outfit the vestibule between Tranquility and Unity and then to open the main hatch. But until the cooling system is activated and the module's electrical systems powered up, the astronauts will have to work with flashlights and temporary ventilation hoses while they complete initial preparations.
NASA originally planned to attach Tranquility to Unity's Earth-facing port, but engineers decided to move it to the left side of the module to improve visibility for robot arm operators and to provide more clearance for Soyuz spacecraft docking at a nearby Russian port.
But connectors needed to circulate ammonia coolant to and from Tranquility were not correctly positioned, or "clocked," for Tranquility to be attached to Unity's left-side port. Long 16-foot extension hoses were ordered, but problems during recent pressure tests forced NASA to develop an alternative approach.
NASA managers ultimately decided to connect shorter flight-qualified hoses to solve the problem while improvements were ordered to bring the longer hoses up to flight standards as a backup.
For redundancy, the space station has two independent cooling loops and during a second spacewalk on flight day seven, Behnken and Patrick plan to connect the supply and return lines for coolant loop A. Coolant loop B will be connected during the third spacewalk.
First, they will have to unfold a large sheet of multi-layer insulation and tether it in place. Then, the coolant lines will be laid down and the insulation wrapped around them.
"That's the biggest single challenge in all three of the EVAs, is getting the ammonia lines right," said Patrick. "Because there are four of them, and then there's this huge piece of insulation that we call MLI, for multi-layer insulation, it's about 20 feet long but it looks like it's a hundred feet long, shaped like a Y.
"It comes out of the bag very carefully and deliberately and we lay that down along the path of the ammonia jumpers. We put that MLI insulation behind some tethers that hold it in the right place and then, one at a time, we take the ammonia jumpers out of their bag and connect them to the lab and the new node 3 and open the valves."
While no one expects any leaks, the astronauts will be prepared for possible decontamination procedures if any problems are encountered.
"When we first open up the valve and allow the ammonia to flow, that'll be our first indication if there's any leaking," Dempsey said. "If there's something that happens at that point, there's not really any automated computer response. We will shut down the lines, have the crew take some sort of response, which may be to close the valve or something like that.
"If you didn't do anything with a leak, you could drain a large quantity of ammonia," he said. "However, we do have a number of valves at various places, mainly right on both sides where we will open the valves and connect them, that we could shut."
As for the astronauts, procedures are in place to "bake out" any ammonia that might adhere to their spacesuits.
"The second spacewalk, the big issue is the potential for exposure to ammonia," Behnken said. "If we were to release any of that ammonia that will be in those lines after we open the valves, we'll expose ourselves to that and we don't want to bring ammonia inside the space station. Just a very small amount of that could poison the crew on board.
"We have had some ammonia operations in the past that have leaked ammonia on crew members and there are extensive procedures for getting into the sunlight and making sure that ammonia sublimates, bakes off so that you don't bring any of it back inside."
The day after the second spacewalk - flight day eight - the astronauts will remove the multi-window cupola from the outboard end of Tranquility and move it to its permanent position on the module's Earth-facing port. The cupola was launched on the end of Tranquility to fit in Endeavour's cargo bay. Once in its final position, the astronauts working in Tranquility will begin making internal connections between the cupola and the larger module.
On flight day nine, a pressurized mating adapter docking port temporarily stowed on the upward facing port of the forward Harmony module will be moved to Tranquility's outboard port, the same port used by the cupola for launch. The shuttle crew will enjoy another half day off before preparing for the third and final spacewalk on flight day 10.
The goals of the third EVA include connecting the ammonia coolant loop B hoses, removing large insulation blankets from the aluminum shutters protecting the cupola's windows, removing the launch locks that secured the shutters during launch and routing video and data cables between Tranquility, the cupola and PMA-3.
"It's going to be amazing," Patrick said of the cupola. "It's like an observation bubble on an aircraft that let's you get right out there and look all the way around, forwards, aft, left and right and down towards the planet. It's an unprecedented view for people on the space station.
"What it's really for, of course, is robotic operations. The second robotics work station will be set up in the cupola either toward the end of our mission or immediately afterwards and that will allow people to do robotic grapples of approaching spacecraft with a direct out-the-window view, which is a really good thing to have."
Said Zamka: "That'll be tremendous, to be able to stick your head in there and have an outside look back at the space station."
The cupola, also built by Thales Alenia Space, weighs 1.6 tons and measures 7.15 feet across and about 5 feet high, featuring six trapezoidal side windows and a 31.5-inch circular top window, the largest ever launched into space. Each window features a protective "scratch" pane on the interior side, two inch-thick pressure panes and a debris pane on the outside to protect against space debris impacts.
"You basically have multiple layers of protection," Dempsey said. "The shutters are made of aluminum so they are lightweight and don't take up too much mass but do provide a fair amount of structural protection."
When not in use, the windows will be covered by the aluminum shutters, which are manually cranked open and closed by the astronauts. The greatest threat from a debris standpoint is from the front, along the direction of the station's 5-mile-per-second velocity vector. Shutters on the forward-facing windows typically will remain closed unless visibility in that direction is needed. Trailing windows can remain open for longer periods.
Hire will be responsible for opening the shutters for the first time.
"We have flight rules that involve protecting the windows, so we have these shutters on the external side of the windows that we'll keep closed anytime basically somebody's not looking out the window," Hire said. "Certainly, they'll have a good number of the windows open when they're performing robotic arm operations once we move the robotic control station into the cupola."
She said no commands from the ground are required to open the window shutters. While station astronauts presumably will be able to open shutters as desired, "there are external cameras on other parts of the space station that might be pointed over that way and some one might see a shutter open or something like that," Hire said.
She said the astronauts were looking forward to taking in the vista when the cupola is activated and the shutters are finally opened. She said the view should be spectacular, "especially flying over things like a big thunderstorm or something, where you see the lightning jumping from the tops of the different clouds. We send beautiful pictures back to the ground, we take high definition pictures, they're great. But this just doesn't compare.
"We're going to try everything we can to capture that experience and bring that back for you."
Dempsey said a window could be repaired in orbit if necessary, although it would take a fair amount of time to accomplish. A replacement window would have to be launched to the station and the repair work would require two spacewalks.
"We do have spare window assemblies that we could take up and install," Dempsey said. "We do not currently have them or plan to put them on orbit. But they are available. If we had a minor bit of damage, we would probably just close the shutter and keep it closed until we can repair it. If we had major damage, there's the potential that we'd have to close off the entire cupola, but that's very low likelihood.
"What we would do, there's an assembly that would be installed on a spacewalk and placed over the window and shutter assembly, which would then allow us to keep the inside pressurized as we pull that window out, not unlike repairing a window on the Earth. Then put in a new window, make sure the seal is good and then on another spacewalk we'd take that outside cover off."
Following the third and final spacewalk, the astronauts will spend flight day 11 wrapping up the transfer of equipment and supplies from the station to the shuttle. The joint crews will enjoy a final meal together and then the Endeavour astronauts will move back aboard the shuttle. Hatches will be closed and leak checks performed before the crew goes to bed.
The next day, with Virts at the controls, Endeavour will undock from the station. Assuming an on-time launch, undocking would occur around 7:12 p.m. on Feb. 17. After a one-lap photo-documentation fly around, Endeavour will leave the area and the crew will carry out another heat shield inspection to look for any signs of damage that might have occurred since the shuttle reached orbit.
Zamka, Virts and Robinson plan to test the shuttle's re-entry systems on flight day 13 while their crewmates pack up for the trip back to Earth. Landing at the Kennedy Space Center is targeted for 11:13 p.m. on Feb. 19.