Second Spacewalk of Atlantis Mission gets Underway

Dan Burbank and Steve MacLean, two of the shuttle’s six-member crew of Atlantis, ventured out of the International Space Station at 5:05 a.m. ET on Wednesday for the second of three spacewalks.

Their task is to work on a solar power unit that was attached to the station yesterday. When activated, this unit will double its electricity supply.

Brent Jett, the commander of Atlantis wished the duo luck and said, "Steve and Dan, have a great time out there." Burbank was delighted when he ventured out and said, “A great day out there….Boy, that is pretty. Not something you see every day."

Since the 2003 Columbia disaster, this 17-1/2 tons, $372 million unit is the first addition to the space station. It consists of a 45-foot long truss structure which holds solar energy panels. Once unfolded, its length would be 240-foot.

The Solar Alpha Rotary Joint of the unit will move the solar arrays to catch the energy-generating sunlight. The astronauts will spend most of their six hour spacewalk releasing locks and restraints placed on the joint to protect it. After they finish, Mission Control will send up commands to put the joint through a series of tests.

Prior to this, Joe Tanner and Heidemarie Stefanyshyn connected power cables to the unit after it was placed on the space station using a robotic arm. This task was completed on the mission's first spacewalk on Tuesday.

Coming Friday, Ms Piper and Mr Tanner will again go out in space to continue installation of the unit and perform a few other tasks. This will be the final spacewalk of this mission. The shuttle crew is scheduled to be back at Kennedy Space Center on Sept. 20.

NASA has planned 14 more shuttle flights to finish the station before the aging shuttle fleet is retired in 2010.