Spacewalkers borrow tools, techniques

STS-117 spacewalkers will use tape-wrapped tools. similar those seen here on the tool carrier of astronaut Robert Curbeam, to help stow an ISS solar array.
STS-117 spacewalkers will use tape-wrapped tools. similar those seen here on the tool carrier of astronaut Robert Curbeam, to help stow an ISS solar array. NASA
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When NASA spacewalkers head outside the International Space Station (ISS) next week to install new solar arrays and other equipment, they'll have some new tape-wrapped tools at their disposal.

The four spacewalkers of NASA's Atlantis shuttle crew are borrowing techniques and improvised tools from two earlier ISS-bound shuttle missions, as well as new hardware of their own, to complete the three planned excursions of their STS-117 mission.

"Kind of the theme that's running through here is that we get to learn the challenges that other crews have faced," STS-117 mission specialist Patrick Forrester, a veteran spacewalker, said in a preflight briefing.

Two new tools will help Forrester and his fellow spacewalkers wrestle tough bolts into submission and swap out a station vent. Others will help spacewalkers coax an older ISS solar array into its storage boxes.

"There's always usually something new that comes up," Atlantis astronaut Steve Swanson, who is making his first spaceflight and spacewalk during STS-117, said in a preflight interview. "I hope I'm trained well enough to handle those situations."

Commanded by veteran shuttle flyer Rick Sturckow, Atlantis' STS-117 mission is set to launch tonight at 7:38 p.m. EDT from NASA's Kennedy Space Center in Cape Canaveral, Florida. The planned 11-day spaceflight will deliver a pair of new starboard trusses and solar arrays to the ISS and ferry a new crewmember to the orbital laboratory.

Sticky bolts, stubborn arrays
Chief among the STS-117 spacewalkers' new tools is a device designed to amplify the amount of force an astronaut exerts by 12 times to remove sticky restraint bolts on new space station segments.

During NASA's STS-115 shuttle flight in September 2006 — which delivered a pair of portside solar arrays to the ISS — spacewalkers struggled to remove vital launch restraint bolts that, if left in place, would have prevented the new station power plants from rotating to track the sun.

STS-117 spacewalkers will tackle a similar set of bolts while installing the station's new starboard solar arrays during their first two spacewalks, but will have a tool known as a "torque multiplier" to beef up the lock removal task. The device is typically reserved for use on bolts within a space shuttle's cargo bay, but has been adapted to fit ISS hardware, NASA officials said.

"Using that, we don't think that we'll have any problem pulling any of the launch restraints off," Swanson said in NASA interview.

Keith Johnson, NASA's lead STS-117 spacewalk officer, said the Atlantis astronauts will also rely on improvised tape-wrapped scrapers, pliers and hooked tools to help fold away an older solar array extending starboard from the top of the station's mast-like Port 6 truss during their second or third excursion. The tools were first used during December's STS-116 mission to free snags and incorrect folds on an earlier Port 6 array retraction.

"We have areas that we may need to poke or may need to get into position," Johnson said, adding that each of the tools are wrapped in translucent orange Kapton tape to ward off electric shocks from the old arrays.

During the third planned spacewalk of the STS-117 mission, astronauts Jim Reilly and Danny Olivas are expected to install a new hydrogen vent valve to the exterior of the space station's NASA Destiny laboratory that will allow the future activation of a U.S. oxygen generator to support larger outpost crews. But to do that, engineers had to come up with a new piece of hardware.

"The problem is that we don't have any standard tools to do that kind of remove and replace," Johnson said.

To install the new hydrogen vent, engineers came up with a "fluid fitting torque device" that is designed to fit around the vent's attachment point, drive loose a connecting bolt and free the spot for the new hardware.

"It's very heavy," Johnson said of the new tool. "It's kind of like a boat anchor as far as I'm concerned."

Altogether, the improvised and new tools in the STS-117 crew's spacewalking arsenal should clear the way for the station's new starboard solar arrays and bring the orbital laboratory one step closer to completion, mission managers said.

"Now, you'll see the symmetry," Johnson said of the space station's configuration once the three STS-117 spacewalks are complete. "[The] space station is starting to look like what we want it to look like."