Space Station Spacewalkers Stymied By Stubborn Bolt

Hugh Pickens writes "Reuters reports that astronauts at the International Space Station ran into problems after removing the station's 100-kg power-switching unit, one of four used in a system that distributes electrical power generated by the station's solar array wings, and were stymied after repeated attempts to attach the new device failed when a bolt jammed, preventing astronauts from hooking it up into the station's power grid. Japanese Astronaut Akihiko Hoshide got the bolt to turn nine times but engineers need 15 turns to secure the power-switching unit. 'We're kind of at a loss of what else we can try,' said astronaut Jack Fischer at NASA's Mission Control Center in Houston after more than an hour of trouble-shooting. 'If you guys have any thoughts or ideas or brilliant schemes on what we can do, let us know.' Hoshide suggested using a tool that provides more force on bolts, but NASA engineers are reluctant to try anything that could make the situation worse and as the spacewalk slipped past seven hours, flight controllers told the astronauts to tether the unit in place, clean up their tools and head back into the station's airlock. NASA officials says the failure to secure the new unit won't disrupt station operations but it will force engineers to carefully distribute electrical power from three operating units to various station systems and says another attempt to install the power distributor could come as early as next week if engineers can figure out what to do with the stubborn bolt. 'We're going to figure it out another day,' says Fischer."

Comments

Re:Red Green solution

[Joce640k]

But, since I do have an armchair and since I am an engineer I figure they will ultimately have to try some sort of lubricant or thread treatment, the risk of snapping off the bolt is too high.

If anybody bothers to read the article it mentions "metal shavings on one of its bolts and around the housing" when they removed the bolt and now it won't go back in again.

Looking at a few random posts it doesn't seem like anybody bothered - none of them are remotely related to the problem (ie. the thread needs cleaning).

Applying more force to a damaged thread will probably make it much, much worse. NASA is right to not force it.

Anecdote: This happened to my bike pedal. The pedal has a steel thread and the crank is aluminum. After a couple of months the aluminum gave up the ghost and the pedal fell out. I put some Araldite on the bolt and what was left of the crank thread and screwed it together. It's been fine ever since, maybe they could do that. :-)