STS-134 Mission Specialists Drew Feustel and Mike Fincke will conduct the third spacewalk of the mission Wednesday. They will be trying a new pre-breathe protocol designed to replace the overnight campout in the airlock. The In-Suit Light Exercise (ISLE) is also expected to use less oxygen to prepare the spacewalkers for the higher oxygen environment that is required with the lower pressure inside the spacesuit.

They start this ISLE protocol by breathing oxygen for 60 minutes using a mask, followed by depressurization of the airlock to 10.2 psi.

They will then put on their spacesuits, followed by a 100-minute in-suit pre-breathe at suit pressure. This includes 50 minutes of light, in-suit exercise using a standard cycle ergometer and 50 minutes of in-suit breathing while resting. This method has been successful in reducing the nitrogen content in the spacewalker's blood in preparation for the depressurization and repressurization cycle. If it is successful, it might be used for the fourth and final spacewalk.

During the spacewalk, they will complete the external wireless antenna system work Feustel and Greg Chamitoff were unable to finish on the first spacewalk. The remainder of the work of the third spacewalk centers around increasing redundancy in the power supply to the Russian side of the station and extending the reach of the station's robotic arm to that area.

The latter will be achieved by adding a power and data grapple fixture to the exterior of the Zarya module. That will allow the arm to "walk" to the Russian segment, using that grapple fixture as a base.

The crew members for space shuttle Endeavour's STS-134 mission are Commander Mark Kelly, Pilot Gregory H. Johnson and Mission Specialists Michael Fincke, Greg Chamitoff, Andrew Feustel and European Space Agency astronaut Roberto Vittori.

During the 16-day mission, Endeavour and its crew will deliver the Alpha Magnetic Spectrometer (AMS) and spare parts including two S-band communications antennas, a high-pressure gas tank and additional spare parts for Dextre.

related report

Expedition 27 Crew Returns Home

After spending 157 days aboard the International Space Station, Dmitry Kondratyev, NASA Flight Engineer Cady Coleman and European Space Agency Flight Engineer Paolo Nespoli undocked from the station's Rassvet module at 5:35 p.m. EDT Monday. The crew landed safely at 10:27 p.m. southeast of the town of Dzhezkazgan, Kazakhstan.

Russian cosmonaut Kondratyev, the Soyuz commander, was at the controls of the spacecraft. He backed the Soyuz TMA-20 away from the station and halted it about 600 feet away. From there, Nespoli took still photographs and video of the complex with space shuttle Endeavour attached. The station slowly rotated 130 degrees to provide Nespoli with the best lighting and views during his photo opportunity.

Once Nespoli completed taking pictures, the Soyuz performed a separation burn at 6:15 p.m. to increase the distance from the station before executing a deorbit burn at 9:36 p.m.

The departure of Kondratyev, Coleman and Nespoli marked the end of Expedition 27. Remaining aboard the station are Expedition 28 Russian Cosmonaut and Commander Andrey Borisenko, NASA Flight Engineer Ron Garan and Cosmonaut Alexander Samokutyaev.

Three new crew members, Soyuz Commander Sergei Volkov, NASA Flight Engineer Mike Fossum and Japan Aerospace Exploration Agency Flight Engineer Satoshi Furukawa will launch from the Baikonur Cosmodrome on June 7. They will dock with the station and join its crew on June 9.

Share This Article With Planet Earth