After a campout in the International Space Station's (ISS) Quest airlock, spacewalkers Stephen Bowen and Alvin Drew will suit up for the second spacewalk of the STS-133 mission. The extravehicular activity (EVA) is scheduled to start at 9:18 a.m. CST.

With a call from Mission Control Houston, space shuttle Discovery's crew woke at 4:23 a.m. to the song, "The Speed of Sound" by Coldplay. It was played for pilot Eric Boe.

"'Speed of Sound' reminds me of my passion for flying because space is an extension of aviation," radioed Boe. "What better way embodies that concept than our fine ship, the space shuttle Discovery? Launches as a rocket, orbits as a spacecraft, and returns to Earth as an airplane."

"We are ready for another great day in space," he continued, "and ready for a great EVA day."

Mission specialist Nicole Stott will choreograph Bowen's and Drew's EVA as the intravechicular (IVA) officer while mission specialist Mike Barratt and station commander Scott Kelly operate Canadarm2 from the robotic workstation in the station's cupola.

The two spacewalkers will perform a variety of different tasks during their excursion, including venting ammonia from the failed pump module they moved to a storage location on Monday's spacewalk. They'll also remove a lightweight adapter plate previously used to attach experiments to the exterior of the European Space Agency's (ESA) Columbus laboratory and remove insulation from the Tranquility node and newly installed Express Logistics Carrier 4.

The spacewalkers also will install a light on one of the crew equipment and translation aid (CETA) carts, install a light, pan and tilt assembly on Dextre, the space station's Special Purpose Dexterous Manipulator, and troubleshoot a loose radiator grapple fixture stowage beam, which would be used if a radiator ever needed to be replaced.

The spacewalk is expected to last six and a half hours.

Meanwhile crew members inside the ISS will continue moving cargo from Discovery and loading trash into the Japanese Kounotouri2 H-II Transfer Vehicle (HTV) for eventual disposal.

The second of two spacewalks for the STS-133 mission got underway at 9:42 a.m. CST as spacewalkers Steve Bowen and Alvin Drew switched their spacesuits to internal battery power. The planned six and a half hour extravehicular activity (EVA) was delayed briefly by having to replace an o-ring on a carbon-dioxide scrubbing canister in Bowen's suit.

Bowen, starting his seventh career spacewalk, exited the space station's Quest airlock first. As lead spacewalker, he is wearing the spacesuit with red stripes.

Drew, wearing an all-white spacesuit, is making his second spacewalk.

The majority of the two spacewalkers' scheduled time outside the station will be devoted to assorted tasks originally planned for spacewalks during Discovery's STS-131 mission in April 2010.

But first, Drew will spend about an hour finishing work with a failed pump module that began during this mission's first EVA on Monday.

Using a tool that he installed on the pump during the first EVA, Drew will open a vent and wait about two minutes for whatever remaining ammonia the module holds to be evacuated out into space. The vent tool will allow the pump module to empty without contaminating Drew's spacesuit.

Once done, Drew will remove the vent tool and take it back to the Quest airlock.

Meanwhile, Bowen will climb into the foot restraint on the station's robotic arm and ride it to the end of the European Space Agency's Columbus lab module to retrieve a lightweight adapter plate assembly that was used to attach experiments to the exterior of Columbus. Bowen will store it on the sidewall carrier in the shuttle's cargo bay to return home with Discovery.

This task was originally scheduled for STS-131, but canceled due to time constraints. Bowen will need to remove one bolt to retrieve the plate and install one bolt to secure it in the payload bay.

Drew, if not assisting Bowen with the adapter plate, will remove insulation from an avionics assembly on the recently-installed ExPRESS Logistics Carrier 4 (ELC4) and retrieve three sets of stowage bags from the crew equipment and translation aid (CETA) cart on the port, or left, side of the station's backbone truss.

Steve Bowen, having stowed a lightweight adapter plate assembly inside Discovery's payload bay, and Alvin Drew, having successfully vented a pump module of its remaining ammonia and removed insulation from the ExPRESS Logistics Carrier-4, will continue to work separately throughout the rest of the spacewalk.


Credit: NASA TV
Bowen, riding the Canadarm2 robotic arm, will install a second camera on the special purpose dexterous manipulator (SPDM), or Dextre robot.

Drew, after readjusting a sunshade blocking the view on a camera wedge that he and Bowen installed on Monday, will add a light on the port, or left side crew equipment translation aid (CETA) cart. To install the light, he'll disconnect a cable on a stanchion on the cart and connect it to the new light, then drive one bolt to hold it in place.

From there, Drew will travel to a radiator beam on the first port segment of the truss and install a thermal cover on its valve module fluid line. He will also troubleshoot a radiator grapple fixture stowage beam originally installed on STS-131.

The beam is intended to temporarily store the necessary handles should a radiator ever need to be replaced. During its installation however, the STS-131 spacewalkers noticed the beam was looser than they expected. Experts on the ground think this might be because the two bolts securing it did not seat properly or were misaligned.

To fix that, Drew will release the two bolts and redrive them. If that does not work, Drew may be asked to remove the beam altogether and check it for clearance issues or even bring it inside for further troubleshooting.

Afterward, Drew will move over to the Tranquility node to remove thermal covers from some electrical connectors.

By this time, Bowen will have gotten off the robotic arm and since he'll be in the vicinity, he'll install a lens cover on the camera on the arm's elbow joint. The cover will protect the lens from erosion, which might be caused by the thruster plume of visiting vehicles that the arm is used to dock. It is attached using a lever that locks it into place.

The remainder of the spacewalk will be spent installing similar covers on other cameras.

Bowen will add one to one of Dextre's cameras (the one he did not install earlier). And Drew's last task will be to install a lens cover on the Payload ORU Accommodation camera.

The final spacewalk to enter space shuttle Discovery's cargo bay and the second of two extravehicular activities during the STS-133 mission came to a close six hours and 14 minutes after it began.

Spacewalkers Stephen Bowen and Alvin Drew reentered the International Space Station's Quest airlock and began its repressurization at 3:56 p.m. CST, marking the official end of their EVA.

"Super job today, you guys were very impressive. We're all very proud of you here in Houston," radioed Mission Control.


Credit: NASA TV
Working separately for most of the spacewalk, the two accomplished all the tasks set out for them and then some.

Bowen, riding the station's Canadarm2 robotic arm, removed a lightweight adapter plate assembly from the Columbus lab and stowed it for its return to Earth in Discovery's payload bay. He then installed a second camera on the special purpose dexterous manipulator, or Dextre, and removed an insulation blanket from the Canadian robot's side.

Bowen then got off the arm and installed a lens cap to protect its elbow joint camera from the thruster plume given off by spacecraft arriving and departing the station. He added a similar lens cap to a camera on Dextre and another to the payload attachment on the mobile transporter.

Bowen then performed an extra "get-ahead" task, relocating a robotic arm adapter to the Russian Zarya module.


Credit: NASA TV
Drew began the spacewalk venting a failed pump module of its remaining ammonia before moving over to the newly-installed ExPRESS Logistics Carrier-4, where he removed protective thermal blankets. Drew then fixed the sunshade on a camera wedge that Bowen and he had installed during the first STS-133 spacewalk on Monday.

Drew next added a light to a crew equipment translation aid cart and then successfully tightened the bolts holding down a couple of radiator grapple fixture stowage beams that an earlier mission's spacewalkers couldn't do. He then moved over to the Tranquility node to remove some insulation.

It was then that the lights on top of Drew's spacesuit helmet came loose. Bowen, coming to Drew's aid, was unable to reattach the lights and Drew returned to the airlock, followed a few minutes later by Bowen.


Credit: NASA TV
This was Bowen's seventh career spacewalk, raising his total time spent working outside in space to 47 hours and 18 minutes. He now ranks sixth among all worldwide astronauts and cosmonauts for time spacewalking.

Drew, completing his second spacewalk, now has a total of 12 hours and 48 minutes, the same as the total time for both STS-133 spacewalks.

Today's excursion was the 155th spacewalk devoted to station assembly and maintenance, bringing that total to 973 hours and 53 minutes. It was also the 244th spacewalk by U.S. astronauts.

As mission specialists Steve Bowen and Alvin Drew were conducting the second and final spacewalk of the STS-133 mission, their Discovery and International Space Station crewmates continued transferring cargo from the shuttle's middeck and began unpacking the Permanent Multipurpose Module (PMM) Leonardo.

By the time the spacewalkers reentered the Quest airlock, the astronauts inside the station had cleaned out the aisle way inside the PMM, moved the payload that had been packed at the front of the module to temporary stowage locations at the end cone and unloaded Robonaut and its related foam-encased parts into the Destiny laboratory, where they'll await being unpacked.

"How does Robonaut like his new home?" asked Mission Control.

"I think he's ready to get out and move around," replied pilot Eric Boe.

"Alright, have fun with that," teased capcom Megan McArthur.

"I think he realizes that it is his time soon to be out and running about on station," radioed Boe.


Credit: NASA TV