Mission Status Center

To recap, space shuttle Endeavour crewmates Drew Feustel and Mike Fincke, working outside on the mission's third spacewalk, today established an operating base for the International Space Station's robotic arm on the Zarya module, creating the ability for the Canadian-made crane to cross borders from the U.S. to the Russian segments for the first time. The astronauts also wired redundant power paths to supply electricity to the Russian elements and plugged in new communications antennas that were bolted on the Destiny laboratory last week.

Today marked the 158th spacewalk devoted to International Space Station assembly and maintenance since construction began in 1998, the seventh so far this year. U.S., Russian, European, Japanese and Canadian astronauts have logged 995 hours and 13 minutes of EVA time at the station.

The third spacewalks performed on Endeavour's mission thus far have totaled 21 hours and 20 minutes.

This was the sixth EVA in the career of Drew Feustel and eighth for Mike Fincke. Drew has accumulated 42 hours and 18 minutes of spacewalking time in his previous excursions on this flight and the Hubble Space Telescope servicing in 2009. Mike's total now stands at 41 hours and 13 minutes after this flight and earlier Russian spacewalks at the International Space Station during Expedition missions.

EVA ENDS. Repressurization of the Quest airlock module began at 8:37 a.m. EDT, marking the official end of today's spacewalk by Drew Feustel and Mike Fincke. The EVA lasted 6 hours and 54 minutes.

The mission's final spacewalk is planned for Friday starting at 12:45 a.m. EDT for Fincke and Greg Chamitoff to transfer ownership of Endeavour's heat shield inspection boom over to the station.

The airlock hatch has been closed and locked. Standing by for repressurization.

Mike and Drew have ingressed the airlock module.

Now back at the airlock, the spacewalkers are going through tool inventories and cleaning up.

These two bonus chores at the Express Logistics Carrier No. 3 -- taking infrared imagery of the military experiment and adding some insulation to the spare gas tank -- are complete.

Now passing the six-hour mark in the EVA.

Drew says his eye feels better. So the spacewalkers are embarking on the next batch of activities.

The astronauts are holding at the airlock to see if Drew's eye improves before moving forward with the next tasks.

Drew says he's gotten something in his right eye and it's watering.

The spacewalkers are back at the airlock to stow equipment bags before they use the remaining time in the EVA to tackle some get-ahead tasks. Drew will use an infrared camera to image the U.S. military's Space Test Program experiment package on the ELC-3 pallet delivered by Endeavour. Mike plans to install some insulation on a high pressure gas tank's grapple fixture.

All of the electrician work for the two spacewalkers today appears to be complete. Activities have gone very smoothly and ahead of the timeline throughout this EVA.

Much of today's spacewalk work was slated to occur last summer during a space station crew EVA. But those plans were scrapped when a cooling pump failed and the astronauts have to turn their focus to their repairs. Mike Fincke explained in a pre-flight interview:

"The Expedition crew aboard the International Space Station last summer was getting ready to do the exact same spacewalk but then, right before they were about to go out the door, one of the pump modules for our space station air conditioning system went out, so we sent Doug Wheelock and Tracy Caldwell (Dyson) outside with Shannon Walker running the robot arm inside and they were able to save the space station and make that major repair in real time. Well, unfortunately Doug and Tracy didn't have a chance to do the original spacewalk that they were planning for, so we were able to extend our mission and complete this task because we had time in our training schedule and a chance to, it fit right into our schedule, so we're able to do that."

After installing the port-side electrical cables to the Russian segment earlier in the EVA, the spacewalkers are working to install a similar starboard-side path now that will serve as redundancy in the International Space Station's power grid.

"I guess you could say power optimization cabling...for things that are already working but could fail if a power channel went down," Greg explained. "The power channels aren't optimally distributed so that you lose the least number of things. There's some cables that we're going to reroute that basically go forward from the Russian segment to the U.S. segment that improves that. It's just a matter of routing some cables and some connectors that are difficult to get to."

This wiring chore has been completed, finally checking off the undone task from last Friday's spacewalk. To gain access with the connector ports, a section of outer metal skin on the Destiny lab was temporarily removed. And the multi-legs were plugged in with the new antennas, Destiny and Harmony.

In a pre-flight interview, Greg explained the function of these two new antennas installed outside the International Space Station:

"It's kind of your wireless hubs in your house or a network; it's basically a couple of antennas that enables a wireless system to be working outside the station.

"There are experiments and payloads outside the space station. They need to communicate to the data system and they're installing a couple of antennas and all the wiring for that to enable those pieces of equipment or experiments to communicate to internal systems through those antennas."

Wrangling all the legs of this wiring bundle is what the spacewalkers are doing now. Greg offered a little preview:

"It's a lot of wiring. It's a little messy with long wires and it takes a while but that's going to be in the front of the space station near the shuttle, and the thing that's maybe a little interesting about that is just that in order for us to do that they have to disable some things internally. We may lose communication. We may have to wave through the window and say everything's OK, and then go down and finish the work and come back and say everything's OK. We'll see how that goes but it should be interesting."

Now three hours into this spacewalk as the crew steps away from the scripted timeline to accomplish the leftover task from the mission's first EVA. They are installing the wiring bundles for the pair of communications antennas bolted to the Destiny module last week.

In a pre-flight interview, Drew Feustel described this power supply cable work:

"We have some other cable routing, which we're calling Y-cables for lack of a better word, but they're essentially two cables that have a Y–split in them. They fairly long but they also are strung along the Russian module and part of the U.S. module right where the connections made what we call Node 1, and the Russian module, and these are redundant power supply cables for the Russian segment. So we're going to install two of those and provide the capability for redundant power supply to the portions of the Russian segment."

The second phase of the spacewalk has begun as the astronauts start wiring redundant power paths to supply electricity to the Russian elements.

The operating base for the International Space Station's robotic arm has been established on the Zarya module, creating the ability for the Canadian-made crane to cross borders from the U.S. to the Russian segments for the first time.

A pre-staged fiber optic cable stretching from from the U.S. segment has been plugged to the video signal conditioner and a protective cover wrapped around the box to complete the PDGF installation task on this spacewalk.

Spacewalk choreographer Greg Chamitoff talks about hooking up the PDGF:

"It's got a lot of connections to make and installing it there and that'll allow the robotic arm to base itself in that point and then work closer to that part of the space station for the long duration. It's a good thing for us to have that ability to have the robotic arm work there and I think they have some specific tasks in mind for that potentially later.

"It's amazing what the Canadian robot arm, Canadarm No. 2, can do aboard the International Space Station," spacewalker Mike Fincke said in a pre-flight interview. "Both ends are fully functional, and not stationary, so you can actually inchworm across the space station; we have a little train for it so the arm can grab onto a grapple fixture and then the other end can grab onto a grapple fixture. The arm moves back and forth, up and down the truss; it's really amazing. It's an incredible crane that we need to help build the space station.

"The problem is the truss ends at a certain spot and we can only reach to some parts of the space station; we can't reach to the other parts, especially the Russian parts. Well, some really smart engineers on the Russian side and American side said, yeah, well, we can just put a grapple fixture out at the right on the FGB, which is the Functional Cargo Block (Zarya), which is pretty much where the American and Russian parts of the space station meet, and then we can actually reach out and help our Russian partners with new modules and extend the reach of our robot arm."

Next to install is the video signal conditioner and its wiring. Mike will attach the box and engage a single bolt. Drew will connect three cables between the VSC and the PDGF.

The power and data grapple fixture and the support frame have been firmly connected to Zarya. After getting the structure "soft docked" on the module, the spacewalkers twisted three brackets to secure it and then applied final torquing to attach the PDGF permanently.

The astronauts have scooted the power and data grapple fixture over the Zarya to begin the installation job.

With Zarya now readied, it's time to fetch the power and data grapple fixture from the airlock. Both Mike and Drew will have to work in tandem to transport this large structure from Quest, across Unity and onto Zarya.

"Compared to our other spacewalks, this is just going out the door and moving along outside for a very short period, very short distance, but PDGFs are very big so we're going to actually tend it between us because there's no weight, right, so we're going to float it between us, make sure it doesn't float away. We'll have some tethers on it, and take it to the outside of the FGB and bolt it down," spacewalker Mike Fincke said in a pre-flight interview.

"Then the tough part is for the power and data. So we have to connect the power and data lines, long cables back to the American segment and Node 1 and the Lab. So it's going to be pretty exciting to do that."

This insulation that's been detached from the space station is getting bundled together and wire-tied on a handrail. It could be disposed of during a future Russian EVA.

The spacewalkers have begun their work on Zarya. They are removing five pieces of multi-layer insulating blankets from the module to uncover the locations were the robotic arm's power and data grapple fixture (PDGF) and video signal conditioner (VSC) box will be installed today.

Drew and Mike have egressed the airlock, gotten their tool bags organized and traversed to the front end of the Russian Zarya module, the very first element of the International Space Station to be launched back in 1998.

In a pre-flight interview, Drew Feustel offered this preview of the spacewalk:

"This involves installing a power and data grapple fixture, or a base, for Canadarm2. So the Canadarm space station arm has a capability of walking around the space station from end to end to do different tasks. The Russian segment doesn't really have any of those bases for the arm to walk on to, and this is an opportunity for us to actually attach one of these base station mechanisms onto what we call the FGB or Functional Cargo Block portion of the space station (Zarya), to allow the arm to walk onto that position and do some tasks in areas that it wouldn't have been able to reach previous to this.

"So this is an activity that's been on the book, I believe, for a number of years and, hasn't found a home and we think we've found an opportunity to do it then on our mission. The advantage to doing it on our mission on EVA 3 is that Mike Fincke has spent a considerable amount of time on the Russian segment in the Orlan spacesuit, so by having he and I go out on that task, being that he has some familiarity that I don't have, that's an advantage to us as a team to get out there and do that work."

EVA BEGINS. The spacewalkers switched their suits to internal battery power at 1:43 a.m. EDT, marking the official start time for today's EVA by Drew Feustel and Mike Fincke. This is the third of four spacewalks planned during Endeavour's mission at the International Space Station.

Depressurization is complete and Drew has opened the Quest airlock's outer hatch leading to space.

In a pre-flight interview, Greg Chamitoff talked more about the ISLE protocol that appears to have gone very well today:

"When you watch those science fiction movies and two people go out the door for a spacewalk, they don't take 48 hours to do it. They just somehow jump in the suit and they're gone. In real life it takes us a lot of time and we'd like that to be faster. For example on the first spacewalk we're doing campout which is one of the normal things we do on the space station. We go into the airlock the night before, we depressurize the airlock down to 10.2 [pounds per square inch] -- 14.7 is a normal atmospheric pressure -- down [to] 10.2. We breathe some oxygen off masks in that process, and we sleep at the lower pressure, and it's just like scuba diving in a sense.

"What you're trying to do is get the nitrogen out of your body, out of your bloodstream, out of your tissues, and that process by sleeping at 10.2 overnight you get a certain amount out, by breathing oxygen it helps that, and then the rest of the process to getting out the door makes sure that when you go all the way out it's like coming up from depth. It's the opposite of scuba diving: in scuba diving you go down, it pressurizes, then it pushes nitrogen into your tissues and if you come up too fast the nitrogen can't escape and can give you the bends. Here it's the opposite. We're going to a lower pressure first, and so that you would get the bends on the way out not on the way back in. This is the normal process we go through by sleeping overnight in the airlock.

"Another technique is to do exercise where we're breathing hundred percent oxygen and we do exercise on a bike and do a certain prescription of that which is based on our particular physiology, body weight and aerobic capacity and then another sequence of oxygen breathing and pressure changes before we go out the door.

"This is a brand new technique that would allow us not to have to spend the night sleeping in the airlock locked up, not have to do the exercise before basically get in the suit and spend a little more time in the suit doing some with hundred percent oxygen, doing very small motions just to make sure that you have some metabolism going. You're not sleeping in there, you have to be doing something; you're in there a little longer waiting to go out the door but overall the whole process is much simpler and you can do it on the day of the spacewalk.

"We're going to try that on, and a lot of work has been done by a lot of people to make this protocol work out. We'll try that on third spacewalk and, if it works great, we can do it on the fourth one, too."

With the Quest module's inner hatchway now closed, depressurization of the airlock has begun in advance of today's EVA.

The spacewalkers have been outfitted with the SAFER backpacks that would enable an untethered astronaut to fly back to the station and they have moved inside the section of the airlock that will be depressurized shortly.

And the spacewalkers have begun their light exercise, something the ground team has dubbed Hokey Pokey in spacesuits.

"It's pretty simple activities," Drew Feustel. "We're just going to move our arms, move our legs a little bit and try to get the blood flowing a little more than we normally would and sort of wait there and purposely do it, so it's really not much more than the things you would normally do moving your arms and legs as you get into the suit, but it's purposely taking those actions to ensure that you've covered yourself and provided that level of protection against decompression sickness."

Now fully dressed in their spacesuits with helmets on, the spacewalkers are moving closer to today's EVA. In a pre-flight interview, Mike Fincke offered his take on this new In-Suit Light Exercise protocol that will be used this morning:

"The American spacesuit runs at roughly a pressure inside of four pounds per square inch—normal atmospheric pressure here on planet Earth [at sea level] is about 14.7 pounds per square inch -- so we're running at a lower pressure, but it's pure oxygen. Like most deep sea divers, we have to be careful as we go from a higher pressure to a lower pressure and back, so that the nitrogen that's in our bloodstream doesn't bubble off like a can of soda would pop when you open it up, the bubbles come everywhere. That would give us the bends.

"So in order to avoid the bends from running a suit at four pounds per square inch, we have a prebreathe protocol where we breathe oxygen for a period of time. Well, we've gotten smart about this. It used to be that we would have to just stay in our suit, mind our own business and sit there for four hours breathing pure oxygen; that was the old, old kind of protocol.

"Then we realized that we can actually take, if we did this work in an environment that was like a higher altitude, so to speak, or less, less air, so less pressure of air, air pressure, like at 10.1 pounds per square inch instead of 14.7, that would make our prebreathe time in the suit less.

"Well, now we're even smarter saying, well, if you actually exercise while you're on pure oxygen you can even have a smaller prebreathe time, and now we're taking it even to another level for this where we're actually doing some exercise while we're in the suit so we're combining the best of both worlds and hopefully save the amount of prebreathe time, the amount of oxygen that we're using, which is a consumable -- every molecule of oxygen we have to bring up with us in one form or another, up into space -- so this way we're going to save our time, save our oxygen, and still be just as safe, and so the science, medical science, continues to amaze me."

The latest version of the NASA Television schedule (Rev. H) can be downloaded here.

Today the astronauts are using a new pre-spacewalk procedure for the first time to fight against any decompression sickness. Drew Feustel explained in a pre-flight interview:

"We were introduced to a prebreathe option by Mike Gernhardt, an astronaut in the corps, and it's called the In-Suit Light Exercise prebreathe protocol. We call it ISLE, I-S-L-E, for In-Suit Light Exercise protocol. ... What we typically do for a space station mission, we camp out in the station's airlock at a lower pressure to allow our bodies to purge the nitrogen that's in our blood stream. Then in the morning when we wake up and start to prepare for the EVA and have to allow other crew members to come in to help us we have to put on hundred percent oxygen breathing masks and maintain that oxygen seal around our face so that we don't introduce more nitrogen back into our blood.

"We have another option aside from campout which is called exercise prebreathe protocol, which doesn't involved camping out at 10.2 (pounds per square inch) overnight in the airlock but involves us waking up in the morning, donning an oxygen mask and riding a bicycle for 10 minutes at fairly high level of exertion to get the hundred percent oxygen flowing through our blood and then purging that nitrogen by doing exercise.

"Now we have a third option which is called the In-Suit Light Exercise prebreathe protocol which involves us having a normal sleep period the night before, waking up in the morning and then donning the spacesuits, so getting into the spacesuit like we normally would, and then decreasing the pressure in the airlock and having the suits at that nominal pressure, and then performing exercise in the suits and it's not really exercise as much as it is just moving your arms and legs for a certain period of time.

"Now you've got the advantage, you're on a hundred percent oxygen and you're at a lower pressure and you're exercising so you're sort of combining the airlock campout prebreathe with the exercise prebreathe with the suit itself. ... So that sort of avoids exercising on a bike or camping out overnight. It just puts you in the suit, starts you moving your arms and legs while you're breathing a hundred percent O2 at a lower pressure, and all those things combined allow us to go out the door and have better protection against decompression sickness symptoms while we're outside working at those lower pressures."

After two low-key days for the space shuttle Endeavour astronauts, they have been awakened by Matchbox Twenty's "Real World" for Flight Day 10 that will see Drew Feustel and Mike Fincke head back outside for the mission's third spacewalk starting around 1:45 a.m. EDT.

The main objectives include installing an operating base for the station's Canadian robotic arm on the Russian Zarya module and routing external wiring from the Unity node, plus accomplishing the left-over task from the first EVA to lay the cabling to new communications antennas on the Destiny lab module's hull.


Read our earlier status center coverage.