Spacewalkers Face Danger to Save Station

Nov. 2, 2007 — -- Planning for one of NASA's riskiest spacewalks ever conceived is down to the wire.

Team Four, a group on standby to tackle any emergencies that come up during a space shuttle or space station mission, has been activated in Mission Control, headed by flight director Ginger Kerrick. The group launched into action Sunday, when astronaut Dan Tani opened a panel on a solar array and found metal shavings, indicating something wasn't working the way it should.

The solar array troubles have multiplied for the space agency since Tani's discovery Sunday. When Cmdr. Pam Melroy attempted to deploy another solar array earlier this week, she discovered it was torn.

Hundreds of engineers and spacewalk experts are working around the clock, scrambling to come up with a safe way for two spacewalking astronauts to fix that torn solar array without getting electrocuted.

Astronauts spend much of their training practicing spacewalks and working out the details before they launch, but no one did any advance planning before Discovery launched for this emergency spacewalk now scheduled for Saturday.

Spacewalkers Scott Parazynski and Doug Wheelock will be working a long way from safety inside the space station as they attempt to mend a torn solar blanket that is generating 120 volts of electricity. The solar array can't be turned off, so it is in essence a live wire that could shock or even electrocute the astronaut if he slips up.

Derek Hassman, lead space station flight director, believes that won't happen.

"We've got adequate controls in place where we are comfortable with the shock hazard," said Hassman.

Astronaut Dave Wolf heads spacewalk planning for the astronaut office. He is confident the teams at the Johnson Space Center can choreograph this spacewalk safely but worries about putting Scott Parazynski on the end of a 90-foot arm and boom with an extension that will leave him more than 30 minutes away from safety if something happens during the spacewalk.