Getting a Hand Up on Spacewalks November 20, 2009Posted by skywalking1 in Space.
The Atlantis astronauts on STS-129 pulled off a superb EVA yesterday at the International Space Station (ISS). The physical demands of a spacewalk stem mainly from upper body exertion, particularly in hands and forearms. Most of the workload comes from getting the job done in those shuttle spacesuit gloves. They get the job done, but…
Shuttle gloves are not custom-made…suit technicians fit a number of standard sized gloves to your hand by adjusting finger length, palm width and wrist length, etc. Astronauts then try them out underwater and keep adjusting them (after each practice run) to improve the fit. For my EVA training, I found out where the hot spots and rubbing points were. Once the fit was as good as I could attain, I covered the sore spots on my hands before each run with moleskin. That kept my hands from being injured over the hundreds of hours of training in the gloves underwater. By the time I flew, those gloves were well broken-in, almost comfortable. Nevertheless, the gloves when inflated are stiff, and flexing the fingers and grasping objects relies on strong forearm muscles. Early in training I would find that I could not type for the rest of the day after an underwater training run. My fingers and forearms were as useless as noodles.
The fingers are fat and stubby. Picking up small objects in a gravity field would be problematic. Tools are made to be big and easy to handle in stiff gloves. Cables and connectors are designed with big latches and plugs to make the connections easier to mate. I did find I could use the gloves in orbit to do delicate pinching and grasping, but it requires concentration and hard muscle work to achieve that.
Some astronauts have such problems using the standardized gloves that to prevent injury, they get gloves custom-fitted to their hands. Gloves are much better — MUCH better — than the Apollo era. But for extended, routine work on the moon or an asteroid, or even for maintaining the space station, we need better glove technology to ease the workload and reduce wear and tear on hands.
In flight, my “new” suit gloves, meant to be used only in space, were significantly stiffer than the “comfortable” water-training gloves I’d used for months. One of my fingertips was pinched so badly on the first spacewalk that it went numb. The nailbed was bruised and painful after the EVA. On the second spacewalk, the glove’s neoprene liner had loosened under inflation and caused less of a problem — “break in” had taken place. Moleskin took care of all the usual hot spots. I did have to put a band-aid over one spot rubbed raw on my lower forearm, caused on the first EVA when I wore the suit’s forearm segment turned “elbow-inside” by mistake. The band-aid and putting the suit on correctly (:-)) fixed that on subsequent EVAs. My bad.
I wore moleskin and silk glove liners to prevent chafing. It would help a lot if the glove interior was less bumpy, abrasive, and had an overall smooth, friction-free lining. (the adjustment features and lacing to prevent the glove from blowing up like a balloon cause most of these problems). I would also like some kind of mechanical assist that would reduce the effort required to flex fingers and grasp for long periods. Athletic training overcomes most of this problem, but fatigue is always a concern after 6-7 hours.
I describe the current challenges spacewalkers experience working for up to 8 hours during spacewalks at the ISS in my book, Sky Walking: An Astronaut’s Memoir (www.AstronautTomJones.com).