Fourth Excursion Pushed To Saturday, Fifth Will Have To Wait

Mission managers at NASA once again pushed off a planned spacewalk to address issues with the International Space Station's power generating systems.

A planned fourth spacewalk during the STS-120 visit of the shuttle Discovery has been moved to Saturday, NASA tells ANN. The fifth spacewalk originally scheduled for that mission was pushed back until after Discovery undocks from the ISS, which is scheduled to happen Monday.

On Wednesday, ISS Program Managers changed the priority of the fourth spacewalk from inspection of a rotary joint to repair of a ripped solar array. As ANN reported, spacewalking astronauts noticed the tear Tuesday, as the new solar panel deployed.

"We believe we are in a condition where we could over time tear the blanket further, and if we tear the blanket, if we do enough damage to the blanket, we could potentially get in a configuration where we couldn't stabilize the array," said ISS Program Manager Mike Suffredini, reports Voice of America news. "And if we can't stabilize the array, we'll have to figure out what to do about that, and we don't have a lot of options."

Engineers on the ground are still working to determine why the solar panel ripped... and, thus, to find a way to repair the damage.

Meanwhile, on Thursday the shuttle and station crews continued spacewalk preparations, transfer activities and enjoy some off-duty time. They also spoke with former President George H.W. Bush, and First Lady Barbara Bush, in a teleconference from Johnson Space Center in Houston, TX (shown below.)

The spacewalk preparations include studying procedures, building tools and resizing a spacesuit glove. Mission Specialists Scott Parazynski and Doug Wheelock will conduct the fourth excursion.

Parazynski will ride the Orbiter Boom Sensor System, the shuttle’s robotic arm extension, attached to the station’s robotic arm to access a damaged solar array. Wheelock will provide guidance to the arm operators while they are maneuvering Parazynski.

FMI: www.nasa.gov