Realtime coverage of STS-134 EVA No. 2

CBS News/Kennedy Space Center

11:40 AM EDT, 05/22/11 Update: Flight controllers praise astronauts for successful spacewalk

Lead spacewalk officer Allison Bolinger, clarifying the status of lost bolts during work to remove thermal covers from a solar array drive mechanism, said four of eight fasteners came free as astronaut Michael Fincke worked to remove the first two panels. He managed to catch three of the floating bolts in his gloved hand, but one got away and was lost overboard. The status of lock washers on the freed bolts was not immediately known.

"Our plan was to release six covers, three pairs of covers," Bolinger said. "We've had some history of issues with these bolts in the past but we thought we had worked through it and we'd discussed all the different training options in order to release these bolts successfully.

"But Mike started working on covers 16 and 17 and before we knew it, we started having issues with bolts. So in the end, we ended up with cover 17, three of its four bolts that should be captive to the cover, those bolts came uncaptive and Mike was able to stow those in his trash bag. And then on cover 16, we lost one of those four bolts, and that one we lost overboard."

It is not yet clear what caused the bolts to pop free, although engineers suspect deformed lock washers might have played a role. In any case, instead of removing six thermal covers as planned to provide the access needed to lubricate a solar array drive gear, flight controllers told Fincke to stop at four. He and fellow spacewalk Andrew Feustel applied as much Braycote grease as possible to the underlying drive gear bearing race and three of the four thermal cover were reinstalled without incident. Panel No. 17, which lost three bolts, was brought back inside.

"Overall, a very, very successful day," said station Flight Director Derek Hassmann. "I'm very proud of the teams on the ground as well as the crew on orbit."

10:20 AM EDT, 05/22/11 Update: Spacewalk No. 2 ends

Shuttle commander Mark Kelly peers into the International Space Station's Quest airlock awaiting the return of spacewalkers Andrew Feustel and Michael Fincke after an eight-hour seven-minute EVA. (Credit: NASA TV)
Astronauts Michael Fincke and Andrew Feustel began repressurizing the space station's Quest airlock at 10:12 a.m. EDT, officially ending a marathon eight-hour seven-minute spacewalk. The astronauts accomplish both of their primary objectives, recharging a solar array coolant system with ammonia and lubricating a solar array drive mechanism.

But trouble with bolts holding thermal covers in place on the solar alpha rotary joint mechanism put the crew behind schedule and in the end, only three of the four covers were re-installed. One was brought back to the airlock for a more detailed examination inside the station.

"Guys, congratulations, that was an awesome EVA," spacewalk coordinator Gregory Chamitoff radioed. "That was a lot of hard work and a lot of training leading up to this and you guys did really, really great. I'm proud to be part of your team."

"Thanks, Greg. Couldn't have done it without you, buddy," Fincke replied.

This was the 157th spacewalk devoted to station assembly and maintenance since construction began in 1998, the sixth so far this year and the second for the Endeavour astronauts. Total station EVA time now stands at 988 hours and 19 minutes while the total for Endeavour's mission is 14 hours and 26 minutes. Feustel, completing his fifth spacewalk, has now logged 35 hours and 24 minutes of EVA time, moving him up to 30th on the list of most experience spacewalkers. Fincke, completing his seventh excursion, has now logged 34 hours and 19 minutes, moving up to 32nd.

09:20 AM EDT, 05/22/11 Update: Astronauts complete drive gear lubrication, cover installation

Astronauts Andrew Feustel and Michael Fincke have completed lubrication of a massive solar array drive gear and re-installation of three thermal covers, the final task planned for today's spacealk. A fourth cover will be brought back inside the International Space Station for an examination after problems with retention washers that allowed at least one bolt to float away earlier.

Flight controllers have decided decontamination procedures will not be required for Feustel. While he was in the vicinity of an ammonia vent line during earlier work to recharge a solar array coolant system, controllers have concluded there is little likelihood that any trapped ammonia ice on his spacesuit could have survived the extended spacewalk. As a result, there is no need for a 30-minute "bake-out" procedure. But controllers are still discussing whether any testing is required to make sure.

As of 9:20 a.m. EDT, spacewalk duration stood at seven hours and 15 minutes. The astronauts are in the process of collecting tools and equipment before making their way back to the Quest airlock module.

08:30 AM EDT, 05/22/11 Update: Astronauts in home stretch of marathon spacewalk

Working in orbital darkness, astronaut Andrew Feustel lubricates the latching snares on the end of a Canadian robot arm attachment known as Dextre. (Credit: NASA TV)
Running almost an hour and a half behind schedule, astronauts Andrew Feustel and Michael Fincke have completed work to lubricate the snares in a Canadian robot arm attachment and to mount coolant system radiator stowage beams to the International Space Station's power truss. The spacewalkers are making their way back to the left-side solar array drive mechanism to complete work to lubricate a bearing race to reduce long-term wear and tear.

It is not yet clear whether the astronauts will have time to re-install thermal covers over the solar alpha rotary joint that were removed earlier to provide access to the drive gear. Problems with loose bolts in the covers put the crew behind schedule earlier. That lost time, plus another half hour that may be needed to make sure Feustel's spacesuit wasn't contaminated by ammonia coolant during earlier work to recharge the reservoir in a solar array, could add an hour or more to the EVA's duration.

Flight controllers are still assessing whether decontamination procedures will be required for Feustel because of his proximity to an ammonia vent line. If decontamination is required, the spacewalkers likely will not reinstall the four SARJ thermal covers and the work will be deferred to a future excursion.

07:00 AM EDT, 05/22/11 Update: Solar array drive gear lubrication work continues; spacewalkers running about an hour behind schedule

Work to lubricate one side of a massive solar array drive gear is complete. To bring the other side of the gear into view under four removed thermal covers, flight controllers will send commands to drive the left-side solar alpha rotary joint through 200 degrees, a procedure that will take about 45 minutes to complete. Once the drive is stopped, astronauts Andrew Feustel and Michael Fincke will apply more Braycote grease to the bearing race of the drive gear in a bid to reduce friction and increase the mechanism's operational lifetime.

While the SARJ gear is driving to its new position, Feustel will install a lens cover on a camera used by the Canadian Special Purpose Dexterous Manipulator, or Dextre, a robot arm attachment fitting that in some cases can take the place of a spacewalking astronaut. With the lens cover in place, Feustel plans to lubricate the snares used by Dextre to hold components in place.

Fincke, meanwhile, will install two grapple bar stowage beams that will provide a temporary mounting point for coolant system radiator panels if replacement operations are ever required.

The spacewalkers are running about an hour behind schedule, in large part because of problems with bolts holding the SARJ thermal covers in place. Only four covers were removed and only three will be re-installed at the end of the spacewalk. Flight controllers now estimate the spacewalk, originally planned for six-and-a-half hours, likely will run past the seven-hour 15-minute mark.

05:30 AM EDT, 05/22/11 Update: Bolt problem prompts change in plans for solar array drive mechanism lubrication

Trouble with bolts holding thermal covers in place on one of the space station's solar array drive mechanisms has forced flight controllers to modify plans for lubricating the underlying drive gear. When astronaut Michael Fincke removed the first two thermal covers, several supposedly captive bolts popped loose and floated free. Fincke managed to snag at least two bolts with his gloved hand, one from each panel, but two others apparently floated away.

Astronaut Michael Fincke, using a power tool, takes extra care removing bolts from thermal cover No. 13 over a solar array drive gear after running into problems with presumably captive bolts popping free. (Credit: NASA TV)
Flight controllers, unsure about what was causing the bolts to release from lock washers in the thermal covers, told Fincke and astronaut Andrew Feustel not to remove as many covers as originally planned and to lubricate the solar alpha rotary joint as best they can with reduced access.

"We're going to minimize the number of covers we're going to take off," astronaut Steve Swanson radioed the crew from mission control. "We're going to continue with cover 16, since we're partway done with that, we're going to do cover 13 and cover nine. And those are the only covers we're going to take off at this time, we'll do the best job we can at lubing it, etc., but that's how far we're going with the covers."

He told the Fincke not to drive the bolts all the way out with his power tool and instead to loosen them and attempt to make the final few rotations by hand to avoid putting too much stress on the materials.

"I'd like to be even more methodical than usual on these," Fincke told Feustel. "We'll get the job done, but be very careful."

"The obvious concern is foreign object debris, in other words, any of the bolts or washers coming free," said mission control commentator Kyle Herring. "The obvious desire also is to get the port solar alpha rotary joint lubricated because it will be quite some time before that opportunity presents itself again. So that's what the teams have been discussing in the background."

Working to finish removing cover No. 16, Fincke reported yet another bolt popping off. Again, he managed to catch it with his gloved hand.

"I got the bolt," Fincke reported.

"That's your, like, fourth great catch, Mike," astronaut Gregory Chamitoff said from the shuttle Endeavour's flight deck.

"We're watching very closely and Spanky's doing a great job of being gentle," Swanson said. "And again, he gets the golden glove award for another catch. That's fantastic. We really don't have a good answer now why that's happening. We're going to have to talk about it."

Pressing ahead, Fincke removed panel 13 and nine without incident, reporting that each cover's bolts remained in place.

While that work was going on, Feustel used a nitrogen vent tool to purge an ammonia line used earlier to re-fill the coolant reservoir in the station's left-side outboard solar array. He reported a spray of ammonia ice crystals exiting the vent tool toward the rear of the station, staying well clear to prevent any hitting his spacesuit.

"I saw one piece that looked like it was headed my way, it was headed low, so I can't confirm it actually made contact," he reported. "It went out of my view sort of down past my waist and my legs. That was the only piece that I felt would be worth looking for. The other items were small, probably less than a centimeter in size, flakes, that were headed my way. The one piece that was coming was probably one-and-half centimeters in diameter, maybe a little larger."

Feustel then joined Fincke at the solar alpha rotary joint to begin lubricating the drive gear with Braycote grease.

04:25 AM EDT, 05/22/11 Update: Ammonia coolant recharge complete; engineers assess bolt problem

Astronauts Andrew Feustel and Micheal Finke connected a final few ammonia jumpers, completing a path from a storage tank to the International Space Station's outboard left-side solar array. Then, after a successful leak test, Feustel made final connections and threw two valves to begin flowing about five pounds of ammonia to the port six solar array to replace coolant that's been lost due to a slow leak.

Mike Fincke's helmet cam view of the port solar alpha rotary joint's main drive gear after a thermal cover was removed. At least one bolt holding a cover in place popped free and floated away. (Credit: NASA TV)
The astronauts were on the lookout for leaks, but no obvious problems were reported and the ammonia recharge procedure was completed without incident. Feustel then worked to attach a nitrogen vent tool to the ammonia line to purge any coolant still trapped inside before breaking down the cross-segment jumpers used to get the coolant to the far left end of the station's power truss.

Working in parallel, Fincke gathered tools and began work to remove thermal covers on the left-side solar alpha rotary joint, or SARJ, a massive drive mechanism used to rotate the outboard solar arrays to track the sun. In a critical bit of preventive maintenance, the astronauts plan to use grease guns to lubricate the drive gear to reduce friction and long-term wear and tear.

At least one bolt used to hold a cover in place popped out and floated away as the cover was removed. Flight controllers asked Fincke to hold off removing any additional covers while engineers assessed the issue and what, if anything, to do about a locking washer that appeared to be floating free inside the bolt's housing.

In this helmet cam view, a bolt can be seen popping loose as a thermal cover was removed from the space station's left-side solar alpha rotary joint. Fincke was able to catch the bolt, but another one floated free. (Credit: NASA TV)
"I was really careful with these bolts and it didn't help me out," Fincke commented. A few minutes later he added, "I can confirm I was super extra careful and I was very surpsied to see it shoot."

Flight controllers joked about having Fincke wave his hands about to gently coax the washer free. But a more serious attempt likely will be made because of the threat a loose washer could pose to the geared solar array drive mechanism.

The covers in question have been removed and replaced before, and engineers suspect some of the lock washers may have been bent slightly, reducing their ability to hold the bolts in place. Flight controllers are re-evaluating how many covers to take off and whether the SARJ drive gear can be lubricated with fewer panels removed.

"Spanky, sorry you're having such a hard time with those bolts, buddy," Feustel radioed, using Fincke's nickname.

"Yeah, man, I was being really careful, too," Fincke replied.

"Yeah, I heard you. Bummer."

"That's all right," Fincke said. "We have a great team. We'll figure it out."

"We'll get photos, we'll lube what we can and we'll put back together what we can," Feustel said.


02:20 AM EDT, 05/22/11 Update: Spacewalk No. 2 begins

Floating in the International Space Station's Quest airlock module, Andrew Feustel and Michael Fincke switched their spacesuits to battery power at 2:05 a.m. EDT (GMT-4) to officially begin a planned six-and-a-half-hour spacewalk, the second of four planned by the Endeavour astronauts.

For identification, Feustel, call sign EV-1, is wearing a suit with solid red stripes around the legs while Fincke, EV-2,is wearing a suit with no markings.

The primary goals of the excursion are to add about five pounds of ammonia to the coolant system of the International Space Station's left-side outboard solar array and to lubricate a massive solar array drive mechanism to reduce long-term wear and tear.

This is the 157th spacewalk devoted to station assembly and maintenance since construction began in 1998, the sixth so far this year, the fifth for Feustel and the seventh for Fincke.