Live in Orbit: Backup Grease Gun Readied

NASA is preparing to modify a caulking gun for use as a backup grease gun during at least one of Endeavour's last two spacewalks, after two grease guns were lost earlier this week.

The grease guns were lost during the mission's first spacewalk Tuesday when an untethered bag of tools floated away from Heidemarie Stefanyshyn-Piper. They were supposed to help clean and lubricate an International Space Station rotary joint.

But during a second spacewalk Thursday, Stefanyshyn-Piper made up for being short a grease gun by making more use of grease-coated mitts called "wet wipes."

She said today during a news conference that she was happy to continue using that technique during Saturday's third spacewalk.

"I think the greased wipes seems to be the most practicable way to go," she said. "That's the way we're going to press going in to (spacewalk) three."

Nevertheless, NASA officials gave the go-ahead to modify one of two caulking guns stored on the shuttle. They normally would be used to repair damage to the orbiter's reinforced carbon wing leading edges.

One concern is that the caulking gun nozzles are a bit wider and could leak grease. But procedures for narrowing a nozzle are being sent up to the astronauts.

The backup grease gun may not be ready until the fourth and final spacewalk, planned Monday. If the nozzle can't be modified properly, it will be left in a station airlock rather than carried in an astronaut's bag where it could leak.

"We're on board with that plan," mission commander Chris Ferguson told mission controllers in Houston. "I think it sounds like a great idea."

IMAGE NOTE: Click on the image to enlarge it. Endeavour has two caulking guns that would be used to apply a pre-ceramic polymer sealant impregnated with silicon carbide - called Non-Oxide Adhesive eXperimental, or NOAX - to the shuttle's reinforced carbon wing edges. Photo credit: NASA.