Story Continues BelowToday's EVA, the first of three scheduled for the mission, began at 9:17 p.m. EST when Behnken and Patrick switched their spacesuits to internal battery power and exited through the station's Quest airlock.

The main task for the spacewalkers was to assist Kathy Hire and Terry Virts who worked the station's 50 foot long robotic arm to lift Tranquility out of Endeavour's payload bay and berth it to the Unity connecting nodes port-side common berthing mechanism.

After Tranquility, designated Node 3, was attached to the station, Behnken and Patrick set about the task of connecting temporary data and power cabling that will regulate the module's temperature and systems until it is permanently hooked into the station's power and cooling systems.

"Houston, for EVA, you guys can be advised we have good avionics and heater cable activation, so all those connections look good down here," radioed CAPCOM Hal Getzelman from mission control at Johnson Space Center in Houston, TX.

"Great news,Houston. We appreciate it," intravehicular spacewalk coordinator astronaut Stephen Robinson replied from on board Endeavour.

"Well thank you, Steve," replied Behnken. "I'm really glad for how successful it was, for getting this far and getting that power on node 3. Let the activation of node 3 begin!"

"I whole heartedly agree," Patrick said. "It's been a great year of training with all those wonderful trainers back in Houston and I also really appreciatd the support from our friends at the NBL who made all the training possible."

"A noble start for the STS-130 EVA extravaganza!" Robinson concluded.

Tranquility represents that last major piece of U.S-built hardware to be delivered to the space station and essentially completes the U.S. segment of the outpost. On the shuttle's final mission later this year, astronauts will leave a specially-modified Multi-Purpose Logistics Module, MPLM, at the station as a sort of "bonus" module since the MPLM's will no longer be needed after assembly of the station is complete and the shuttle fleet retired.

The final module, re-designated a Permanent Multipurpose Module, PMM, is built in Italy by Thales-Alenia Aerospace under contract to NASA.

Leonardo is the MPLM that will be converted to a PMM. STS-133 is currently the last scheduled Space Shuttle Launch and is scheduled for September 16, 2010. The PMM will be transferred to the station through the Shuttle robotic arm and mated to the nadir facing port of Unity.

The spacewalk ended at 3:49 a.m. EST Friday morning and brings the total EVA time on ISS to 861 hours and 34 minutes. This was Behnken's fourth spacewalk (he had three previously on STS-120 that brought Harmony to the station) and Patrick's first.

(The Spacearium / SpaceflightNews.net)