Saturday, November 03, 2007
Long Distance ISS Repair
Thanks to NASA TV, I've been watching the STS-120 EVA that is in progress to repair a tear in one of the solar array panels on the ISS. Astronaut Scott Parazynski is on the end of an extender (OBSS) attached to the space station's robotic arm (SSRMS) to get him close enough to do the repair. With 100 volts or more in play (you can't turn off the sun), he is using insulated tools and a carefully designed procedure to make the repair. It's an amazing team effort with the EVA astronauts, the on-board crew, and the experts in Houston making sure that every step is as safe as possible. Humans are awfully good at this sort of dynamic problem solving. The robotic arms get a big assist (though these too are under skillful human control).
I took a couple of screen shots in Orbiter using a shuttle fleet scenario provided by David413 on the Orbiter forums to illustrate the EVA geometry. The one here gives an idea of how big the ISS/shuttle complex is and of how far from the shuttle and ISS living quarters the repair site is - about an hour away from getting back inside, making this space walk a bit more risky than usual (they normally like to no more than 30 minutes from getting an EVA astronaut back inside in case a problem develops). But Dr. Parazynski (originally a physician) is a very experienced EVA astronaut and he's making it look and sound easy, which of course it is not! More pix on Flickr.
N.B. The repair was successful and they were able to fully deploy the solar panel.