ISS handrail issues mean spacewalk issues

NASA space station managers are testing hardware on the ground to make sure the handrails that keep spacewalking astronauts from flying off into space don't break.

They discovered the potential problem recently, International Space Station managers said during a news update today. While checking out a handrail tube on the ground, they saw it had been treated at a higher temperature than it should have been. The overheating could have changed the properties of the aluminum, raising fears of a fracture when cargo or people are tethered to those rails.

They don't think all the U.S. "dog bone" rails are affected, but they can't trace the origins of each rail closely enough to rule some out. Instead, they're testing the metal on the ground to make sure it's OK in orbit. By tomorrow, they think they'll be confident in the materials, and in a spacewalk, tethers could be attached to the handrail supports. By the middle of April, toughness tests should be complete that would clear worries about the handrail tubes attached to the supports, said Kirk Shireman, deputy program manager for the station.

Handrails on the Russian segment and on the shuttles are not suspect, he said. Until the issue is settled, a U.S. spacewalk isn't authorized.

Neither is a Russian spacewalk, because the crew hasn't been able to find the lithium hydroxide canisters used to scrub poisonous carbon dioxide from the Russian spacesuits. They probably will find them, Shireman said, and in the meantime, more canisters will come up on a Progress supply ship.

The shuttle crew coming in July is expected to do three spacewalks; the station crew arriving next week also plans spacewalks.

Managers made some other points as they near a Soyuz launch March 29 that will bring a new two-man crew to the station:

• The shuttle flight scheduled for July would add a third crew member to the station for the first time since the Columbia accident, Thomas Reiter. He'll stay into the following crew's increment.
  
• The "golf experiment," as Shireman called it, is still under review. That's the Russian plan to hit a golf ball from the station during an August spacewalk, which has raised concerns about the possibility it might strike and damage the ISS.
  
• The current crew, Bill McArthur and Valery Tokarev, got a lot done in their spare time. McArthur did about 13 extra days' worth of work on mission controllers' "honey do" lists, said flight director Sally Davis. In addition, "Bill was kind of Mr. Organizer on board," manager Pete Hasbrook said. The station is always in need of organization, since it's still loaded with cargo and trash and expects to get even more stuff when the next shuttle visits. And things get lost, like the aforementioned canisters.