Atlantis mission to fortify future of the space station
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: November 14, 2009
KENNEDY SPACE CENTER, Fla. -- With the shuttle program entering its final year of operation, engineers are readying Atlantis for launch Monday on a three-spacewalk mission to deliver 15 tons of spare parts and equipment to the International Space Station as a hedge against failures when the shuttle is no longer available for service calls.
Awaiting a decision by the Obama administration on what sort of spacecraft will replace the shuttle and whether the moon or some other target will be NASA's next objective, the agency is pressing ahead with the Bush administration's directive to complete the space station and end shuttle flights by the end of 2010.
The International Space Station currently is only funded through 2015, but there appears to be widespread political support to extend operations through 2020. That would mean operating the lab complex for 10 years without the shuttle and its cavernous cargo bay to deliver large spares and other components.
With just six missions left on NASA's shuttle manifest between now and the end of fiscal 2010, Atlantis' mission is one of two devoted primarily to delivering critical spare parts and equipment - orbital replacement units, or ORUs - that are too large to be delivered by European, Russian or Japanese cargo ships.
"We're looking for the long-term outfitting of station, making sure the ISS is ready for the long haul and has the longest life capability possible," shuttle commander Charles Hobaugh said. "Our flight is one of the first flights that externally will provide a lot of those spare parts and long-lead type replacement items that are required to keep it healthy and running for quite some time."
Along with delivering spare parts and components, Atlantis also will bring astronaut Nicole Stott back to Earth after a three-month stay in space. It is the final planned use of a shuttle for crew rotation. From this point forward, U.S. astronauts will ride Russian Soyuz capsules to and from the station, at $50 million a seat.
But stockpiling spare parts is the core mission for Atlantis' crew and space station utilization flight No. 3, or ULF-3.
Mounted on pallets in Atlantis' payload bay are two spare control moment gyroscopes, used to control the station's orientation in space; a high pressure oxygen tank for the station's airlock; and a spare pump module, nitrogen tank and an ammonia reservoir for the lab's cooling system.
The pallets also carry a replacement robot arm latching end effector, or mechanical hand; a spare power cable spool used by the arm's mobile transporter; a solar array battery charge-discharge unit; and a device used to prevent potentially dangerous electrical arcs between the station and the electrically charged extreme upper atmosphere.
A box housing spare circuit breakers that can be installed by the station's robot arm and a Canadian robot known as DEXTRE is mounted on one of the pallets and a materials exposure experiment carried aloft in the shuttle's cargo bay will be mounted on ELC-2 during the crew's final spacewalk.
Atlantis also is carrying a spare S-band antenna assembly, along with supplies for the lab's six-member crew, gear for an amateur radio experiment and a system that can be used to track ships at sea.
The two cargo pallets will be mounted on the left and right sides of the station's main solar power truss and plugged into the lab's electrical grid to power heaters and provide telemetry. The new oxygen tank will be attached to the station's airlock during a spacewalk. The rest of the hardware will simply sit, waiting for the day it might be needed.
"It is establishing critical spares on board the International Space Station," said lead shuttle Flight Director Mike Sarafin. "We're going to warehouse parts that only the shuttle can deliver in large volume to the International Space Station for the pending retirement of the space shuttle, roughly a year from now.
"We're going to deliver two large external logistics carriers full of spares and position those outside the International Space Station so that when and if some of the hardware that's required to sustain the power production and thermal environment on board the space station eventually fails, we've got that hardware there and available and we don't need another vehicle to bring it to the space station."
After the shuttle is retired, supplies and equipment will be delivered to the International Space Station by unmanned Russian Progress spacecraft, the European Space Agency's Automated Transfer Vehicle, or ATV, Japan's new HTV cargo carrier and commercial providers now in the process of designing future vehicles.
On Nov. 12, a new Russian docking module called Poisk automatically locked itself to an upward facing port on the Zvezda command module, providing a fourth docking port for the Russian segment of the station - a necessity for long-term support of up to six full-time crew members.
But none of the unmanned cargo ships is capable of delivering the components routinely carried by the space shuttle that are too big to pass through the station's hatches. Most of the spares being launched aboard Atlantis have no other way of getting to the station.
The shuttle also provides a way to bring failed components back to Earth for repairs or refurbishment. Atlantis, for example, will bring down components in the space station's urine recycling system that have encountered problems in recent weeks.
The station crew has enough fresh water and stowage to get along with no major problems until refurbished hardware can be launched on an upcoming shuttle flight. But the issue illustrates the sort of capability that will be lost when the shuttle is retired.
"This is why these (spare components) need to fly now on the shuttle," said station Flight Director Brian Smith. "There's no other way to get these ORUs ... to the ISS. And these are all critical spares. You can tell by what their function is we have to have these pre-positioned because they all serve vital roles on the space station."
The good news, he said, is that "we don't have an immediate need for any of them. We're leaving them on the decks."
"To say which one is more critical, you kind of need a crystal ball to see which system is more likely to fail," he said. "They all serve a critical purpose. Losing CMGs, control moment gyros, is a big deal, because if you lose your non-propulsive capability to maintain attitude, the only thing you've got left is the propulsive control and the prop(ellant) is a consumable. When you start looking at the retirement of the shuttle and what it costs to fly prop, that becomes a big deal. So prop conservation has been a big theme for the last year or so. Which means the CMGs are that much more important.
"You can also talk about the external thermal control system. We've got two of those, loop A and loop B outside. Each one has a pump module, the NTA (nitrogen tank assembly) and ATA (ammonia tank assembly). Losing one of those loops is very significant. We'd lose cooling capability to half of the electronics on the U.S., European and Japanese part of the space station. So that could become very critical very quickly.
"So it's just a matter of what the next failure is going to be," he said. "I would say at this point in time, they have equal criticality, which is why they're on this flight."
Atlantis is scheduled for liftoff from launch complex 39A at the Kennedy Space Center at 2:28 p.m. EST, roughly the moment Earth's rotation carries the pad into the plane of the space station's orbit. The shuttle launch window closes Nov. 20 because of temperature constraints related to the station's orbit. The next shuttle launch window opens Dec. 6.
Atlantis' processing has been routine, but engineers have spent a fair amount of time evaluating a potential issue with the acoustic shock of main engine ignition.
The issue first came to light after the October 1998 shuttle flight that launched former Sen. John Glenn back into orbit. During liftoff, the door covering the shuttle's braking parachute fell off, prompting an investigation that ultimately led to liftoff acoustics.
Additional instrumentation was added to subsequent flights and the data seemed to show sound levels were in the expected range. But in a subsequent analysis, engineers realized the way the sensors were being calibrated did not adequately take into account how the vibration of the pressure transducers themselves interacted with the sound they were supposed to measure.
More accurate calibration showed the acoustic environment at engine startup "was a lot more severe than we thought," said Mike Moses, the shuttle integration manager at Kennedy. "It was definitely above what our design limit was."
Engineers then began analyzing shuttle structures to make sure they could safely withstand the unexpected acoustic environment. One area of concern involved bolts that hold maneuvering jet extensions, called "stingers," on the back of the shuttle's orbital maneuvering system rocket pods.
Boroscope inspections of the bolt in question showed no cracks, at least to the limits of the instrument's resolution. Engineers also examined qualification hardware built in the early days of the shuttle program that was subjected to vibrations simulating 100 missions to look for any signs of undue stress. No major problems were found and engineers believe Atlantis can be safely launched as is. But additional instrumentation was ordered to collect more data during launch.
Joining Hobaugh on the shuttle's flight deck for the 129th shuttle mission will be pilot Barry "Butch" Wilmore, Leland Melvin and Randolph Bresnik. Strapped in on Atlantis' lower deck will be Michael Foreman and Robert Satcher, an orthopedic surgeon-turned-astronaut. Hobaugh, Foreman and Melvin, a former pro football draft pick, are shuttle veterans while their crewmates are making their first space flight.
Assuming an on-time launch, Bresnik will miss the birth of his second child, a girl, scheduled for delivery Nov. 20, two weeks ahead of her December due date.
"She's a pretty amazing woman," Bresnik said of his wife, Rebecca, in an interview with CBS News. "She's actually the lead for international law here at the Johnson Space Center. ... Her sister's coming down if I'm not here to help out. We're very fortunate for that, and the NASA family here.
"While I'm sad, I'm disappointed, to miss the birth, I'm hoping she'll forgive me later on when I tell her why I wasn't there when she was born. Miracles happen and miracle childbirth is certainly something we've been astounded by the past nine months and we're not going to complain about the timing of it. It's just unfortunate these two amazing life events happen all at the same time.
"I just look forward to getting the call that mother and baby are safe and healthy," Bresnik said. "If we're still docked to the ISS, depending on when the launch date is, we ought to be able to see a video conference with them and talk to them afterwards. That'll be great."
Assuming an on-time launch, the astronauts will be in orbit on Thanksgiving, preparing Atlantis for a landing at the Kennedy Space Center around 9:47 a.m. on Nov. 27.
Asked if the crew planned anything special for the holiday, Hobaugh said "the season is whatever the season is. It could be Christmas, it could be Thanksgiving, who knows? We're just always pleased to be in space and I don't care what they give us, it could be beef brisket, it could be tofu, it doesn't matter to me. We're going to enjoy ourselves no matter what we do."
The first two days of Atlantis' mission will follow the standard post-Columbia template, with the astronauts focused on setting up computers and other gear, testing their spacesuits and rendezvous aids and inspecting the ship's reinforced carbon carbon nose cap and wing leading edge panels for any signs of damage during ascent.
On flight day three, Hobaugh and Wilmore will oversee a carefully choreographed rendezvous with the space station, approaching from behind and maneuvering to a point about 600 feet directly below the outpost. Hobaugh then plans to initiate a mostly-automated 360-degree back flip maneuver, exposing the heat shield tiles on the orbiter's belly to the crew of the space station for a detailed photo survey.
"Positioned in the aft portion of the International Space Station looking out windows in the Russian segment, several station crew members will have cameras and shoot digital still images out the window of the tile surfaces on board Atlantis," Sarafin said. "All of those digital images will be sent to the ground before we complete our docking for review by the Debris Assessment Team and the imagery analysts on the ground."
Hobaugh then plans to guide Atlantis up to a point some 450 feet directly in front of the station, with the shuttle's tail pointed toward Earth and its open payload bay facing a docking port on the front end of the lab's Harmony module.
"From there, he'll maneuver in to the docking port," Sarafin said. "At a range of roughly 30 feet to the International Space Station, he'll perform a final alignment verification using the centerline camera. Once we verify we have a good alignment, we will go in and dock to the International Space Station.
"Once any residual motion has damped out, we'll retract the docking ring and complete a good hard mate to the International Space Station, verify there are no leaks at the pressure seals at that interface. Once those leak checks are performed, the crew will have a go to open the hatches and they'll greet each other and perform a safety briefing. And with that, the real core mission of STS-129 and ULF-3 will begin."
Waiting to welcome the shuttle crew aboard will be European Space Agency commander Frank De Winne of Belgium, cosmonauts Maxim Suraev and Roman Romanenko, NASA astronauts Jeffrey Williams and Stott and Canadian astronaut Robert Thirsk.
Williams and Suraev arrived at the space station in late September. Stott plans to return to Earth aboard Atlantis while De Winne, Romanenko and Thirsk plan to fly home aboard a Soyuz spacecraft Dec. 1. Williams and Suraev will have the station to themselves as the core members of the Expedition 22 crew until three more crew members arrive Dec. 23.
One of the first items on the agenda after Atlantis docks is to make Stott a member of the shuttle crew, meaning she will start sleeping aboard Atlantis for the duration of her stay in space. This is a normal procedure to protect against any unusual event that might force the shuttle crew to depart early or in a hurry.
Two-and-a-half hours after docking, Bresnik and Melvin, operating the shuttle's robot arm, will carefully lift ExPRESS Logistics Carrier 1 - ELC-1 - from its perch in the shuttle's cargo bay just in front of ELC-2. The first cargo carrier will be maneuvered to a position on the left side of the shuttle where the station's robot arm, operated by Wilmore and Williams, will latch on and take over.
After the shuttle arm lets go, ELC-1 will be moved to the Earth-facing side of the port three (P3) truss segment on the left side of the station's power truss and locked into place.
The ELCs measure 16 feet by 14 feet and can carry 9,800 pounds of hardware with a volume of 98 cubic feet. The pallets are wired to provide station power and telemetry to attached payloads. For Atlantis' mission, ELC-1 and ELC-2 will carry cargo on both upper and lower surfaces.
Mounted on ELC-1's upper deck are a 600-pound control moment gyroscope, the battery charge-discharge unit, the plasma contactor arc prevention device and a latching end effector for the station's robot arm. Mounted on the lower surface are a 550-pound nitrogen tank assembly, a 780-pound external cooling system pump module and a 1,700-pound ammonia coolant tank.
While ELC-1 is being maneuvered into place, Foreman and Satcher will be reviewing procedures for the first spacewalk the next day before camping out in the Quest airlock module at a reduced pressure of 10 pounds per square inch. The campout protocol is designed to help prevent the bends after working in NASA's low-pressure spacesuits.
"This is an agressive mission in the sense that we've got a lot of key objectives that if we don't accomplish those on the days they're planned, it's going to have a ripple effect downstream," Smith said. "Specifically, flight day three is really the linch pin on this mission.
"We need to get docked, get ExPRESS Logistics Carrier 1 out of the payload bay and installed and get the crew into EVA campout to go out the hatch on a spacewalk the very next day. That is a lot of activity in one day, and if the docking takes longer than planned, if the robotic activities associated with ELC-1 take longer than planned or we just get behind, that's going to ripple down stream.
"Atlantis doesn't have the power transfer capability that the other two vehicles have, so we also have limited consumables from a power production standpoint on board. So we've got to get three spacewalks done, two ELCs out of the payload bay in 11 days. It's complex from that standpoint."
Assuming the docking and transfer of ELC-1 go smoothly, Foreman and Satcher plan to begin a six-and-a-half-hour spacewalk on flight day four, Nov. 19, starting around 9:20 a.m. EST. Melvin and Wilmore will operate the station's robot arm during the spacewalk while Bresnik will serve as the spacewalk coordinator.
With Satcher anchored to the end of the station's robot arm, Foreman will unbolt the spare S-band antenna assembly in the shuttle's cargo bay and hand it to his crewmate, who will then carry it up to a storage point on the central Z1 truss that houses the station's four control moment gyroscopes.
"It's a really cool ride for Bobby, he's going to have a good time," Smith said.
Both spacewalkers then will bolt the antenna into place.
"Our first task is to take another spare part out of the space shuttle's payload bay, the SASA payload, which is S-band Antenna Support Assembly, which is basically a spare S-band antenna for the space station," Foreman said in a NASA interview. "It's an antenna that failed on orbit. They brought it back, refurbished it, now it's ready to go and we'll put it back into the spare location.
"So I will go out of the airlock, go over to the payload bay and start getting that thing ready to hand off to Bobby. Bobby's going to go out, get into the robotic arm and they'll maneuver him over into the payload bay on the end of the arm. He'll grab that thing after I unbolt it and he'll ride the arm back to Z1 where it gets installed in the spare location and I'll translate back over there and help him install it."
At that point, the two spacewalkers will split up.
"After we get (the SASA) installed, I will also pick up a set of cables from our tool box in the back of the payload bay, take those over to the Z1 location also and start stringing those things up for a future mission to use while Bobby continues to ride the arm and he goes into his lube-job-man role as the lubricator of a couple of the latching end effectors, the POA latching end effector and the JEM RMS latching end effector."
The former is a payload attach fitting on the robot arm's mobile transporter while the latter is the latching end of a Japanese robot arm attached to the Kibo laboratory module. Both latching systems utilize snares that rotate closed to lock onto a payload's grapple fixture. Because of past issues with the snares, regular lubrication is a now standard operation.
"He'll go and apply some grease to the snares inside those latching end effectors to make sure that they don't have a problem later in life," Foreman said. "So he's doing some preventive maintenance basically on those while I do that spare cable task. And then I go over to Node 1 and there's a slide wire over there, a safety slide wire, that is no longer usable, so I'm going to take that off, bring that back in and we'll also have a handrail to swap out over there. I take one handrail off, install a different handrail that actually has some ammonia line cable connectors on it that will be used on a future mission."
The day after the first spacewalk, flight day five, is reserved for a so-called focused inspection of the shuttle's heat shield if any problems are spotted during the inspections carried out the day after launch and during final approach to the space station. If no major problems are seen that require a second look, the crew will forego the focused inspection and devote the day instead to internal supply transfers and preparations for a spacewalk by Foreman and Bresnik.
Assuming an on-time launch, flight day five would fall on Nov. 20, the day Bresnik's daughter is scheduled for delivery.
Before the second spacewalk gets underway on flight day six, Hobaugh and Melvin will use Atlantis' robot arm to pull ELC-2 from the shuttle's cargo bay. Like ELC-1, hardware is mounted on both sides of ELC-2.
A second spare control moment gyroscope is mounted on the pallet's upper surface, along with the 1,240-pound high-pressure oxygen tank and a cargo transport container housing spare remote power control module circuit breakers.
Another nitrogen tank assembly is bolted to ELC-2's lower side, along with another coolant system pump module and a spooled power line designed to play out and retract as the robot arm's mobile transporter moves along the front side of the station's solar power truss.
After Hobaugh and Melvin pull ELC-2 from the cargo bay, Williams and De Winne will lock on with the station's robot arm to maneuver it into place on the right side of the power truss. About halfway through the ELC-2 installation procedure, Foreman and Bresnik will begin the mission's second spacewalk.
"On EVA 2 we go outside and we get a couple of antennas that are going to be put on the outside of the Columbus (laboratory) module," Bresnik said in a NASA interview. "One of them is a (maritime navigation system) antenna that will go on the front side of the Columbus. The other one's essentially a ham radio antenna that'll go on the bottom side out of the starboard end of Columbus. So we're both going to go ahead and put the antennas in and string the cable, get it powered up.
"Then we head over and we're going to go ahead and take an antenna that is up on the starboard side that has to be maneuvered over to the port side to make room for the AMS, or Alpha Magnetic Spectrometer, that's going to come up on the final shuttle mission."
Once that work is done, Foreman and Bresnik will make their way to the lower side of the S3 starboard truss segment to deploy another cargo mounting mechanism like the ones used to anchor the ELCs. That will allow "other flights to come up and put their hardware on the cupboard, or the shelf of the space station for later use," Bresnik said.
"And then the last thing we're going to do is we're going to take an antenna that helps with the wireless video system when we're doing EVAs, we're going to take and install an antenna that was inside the airlock, we're going to take it out with us and install it back on the S3, back where we're doing the (payload attach system) system and put that out there so we've got better coverage when we have our crew members going out to do an EVA."
Following EVA-2, the astronauts will enjoy a bit of off-duty time on flight day seven before reviewing procedures for the third and final spacewalk the next day. As with the previous two excursions, the spacewalkers - Satcher and Bresnik - will spend the night in the Quest airlock module.
The final spacewalk has three primary objectives: moving the new oxygen tank from ELC-2 to the hull of the Quest module and connecting it to the airlock's pressurization system; mounting the Materials on International Space Station Experiment 7 - MISSE-7 - on ELC-2; and deploying another external payload mounting mechanism on the upward-facing side of the S3 truss segment.
"The major task we're going to do is installing the oxygen gas tank so we're bringing up some atmosphere for the space station," Satcher said in a NASA interview. "It comes up actually on ELC-2, which is going to be stored all the way out on the end of the space station, on the starboard end. So we've got to go out, way out there and get it, coordinate with the robotic arm, SSRMS, because we have to take it off of ELC-2, hold it in position for the arm to grapple it and transport it all the way back over to the airlock where we will go and install it onto the airlock.
"Now before we can install it there, there're some MMOD shields, which are micrometeorite debris shields, that protect the space station from these strikes that we (have) got to move out of the way, so we'll be detaching those, moving them out of the way and then we can install the gas tank.
"The other major activity is we'll be deploying these material science experiments called MISSEs," Satcher said. "Actually Randy will be getting those out of the cargo bay of the shuttle and bringing those over to ELC-2 where they're installed and deployed and I'll also be doing some rerouting of some cables on Node 1 in anticipation of future install of Node 3. So those are the major activities that we're going to do and it should take us a full six or seven hours to get that done."
The day after the third spacewalk - Nov. 24 - the astronauts will hold a traditional in-flight news conference and enjoy a half day off before a brief farewell ceremony and hatch closure to wrap up the docked phase of the mission.
The next day, Nov. 25, Atlantis will undock from the International Space Station. Wilmore, flying the shuttle from the aft flight deck, will pilot Atlantis through a 360-degree loop of the lab complex before departing the area.
The astronauts will celebrate Thanksgiving in space with a crew meal following a test of the shuttle's re-entry system. The day after Thanksgiving, the shuttle will return to Earth, weather permitting, landing back at the Kennedy Space Center around 9:47 a.m.
With Atlantis back on the ground, NASA will be poised to enter its final few months of shuttle activity, working to complete the International Space Station and transitioning from assembly to utilization.
"Quite a few things are going on and we tend to stay that way," said space station Program Manager Mike Suffredini. "You'll see us start to transition more and talk more about the research and giving more priority to research up mass along the way. That's why we built the ISS and we're at that position, we're ready to start focusing more on that even though we have a little more assembly left to do. We're all looking forward to that over the next several years."