Saturday, September 18, 2010

Astronauts' Fingernails Falling Off Due to Glove Design

An astronaut waves.If you're headed for space, you might rethink that manicure: Astronauts with wider hands are more likely to have their fingernails fall off after working or training in space suit gloves, according to a new study.

In fact, fingernail trauma and other hand injuries—no matter your hand size—are collectively the number one nuisance for spacewalkers, said study co-author Dava Newman, a professor of aeronautics and astronautics at the Massachusetts Institute of Technology.

"The glove in general is just absolutely one of the main engineering challenges," Newman said. "After all, you have almost as many degrees of freedom in your hand as in the rest of your whole body." (See a space exploration time line.)

The trouble is that the gloves, like the entire space suit, need to simulate the pressure of Earth's atmosphere in the chilly, airless environment of space. The rigid, balloonlike nature of gas-pressurized gloves makes fine motor control a challenge during extravehicular activities (EVAs), aka spacewalks. (See pictures of early U.S. space exploration.)

A previous study of astronaut injuries sustained during spacewalks had found that about 47 percent of 352 reported symptoms between 2002 and 2004 were hand related. More than half of these hand injuries were due to fingertips and nails making contact with the hard "thimbles" inside the glove fingertips.

In several cases, sustained pressure on the fingertips during EVAs caused intense pain and led to the astronauts' nails detaching from their nailbeds, a condition called fingernail delamination.

While this condition doesn't prevent astronauts from getting their work done, it can become a nuisance if the loose nails gets snagged inside the glove. Also, moisture inside the glove can lead to secondary bacterial or yeast infections in the exposed nailbeds, the study authors say.

If the nail falls off completely, it will eventually grow back, although it might be deformed.

For now, the only solutions are to apply protective dressings, keep nails trimmed short—or do some extreme preventative maintenance.

"I have heard of a couple people who've removed their fingernails in advance of an EVA," Newman said. ...

via Astronauts' Fingernails Falling Off Due to Glove Design.

God.  How did space gloves get so much worse between 1972 and now? Heck, the Apollo guys had gloves that were so good they could change the filters on their Hasselblad cameras ... and play the banjo.

Okay, I jest about the banjo. The above photo is fake, but my question about the gloves is serious.

The longest space walk record is:

Who made the world's longest space walk?

On March 11 2001 Jim Voss and Susan Helms had the job to rearranged the outside of the international space station to make room for Leonardo, an Italian cargo carrier.

Just minutes into the task Jim Voss lost his grip on a vital tool and watched helplessly as it floated away. Not to worry, the boys and girls at NASA are pretty smart and there was a spare onboard.

8 hours and 56 minutes later their task was complete and Jim Voss and Susan Helms were the proud owners of the world's longest space walk record. - link

This is only 1 hour 19 minutes longer than the longest moon walk in 1972.

  • Cernan and Schmitt - EVA 2

    • EVA 2 Start: December 12, 1972, 23:28:06 UTC

    • EVA 2 End: December 13 07:05:02 UTC

    • Duration: 7 hours, 36 minutes, 56 seconds

From the Apollo 17 mission, the photo AS17-163-24122 shows "Gene Cernan cleaning his fingernails." Well, you can only see one nail in the photo. Perhaps he is secretly removing his fingernails in this shot.

More on Apollo an fingernails in a minute, but first, a moon conspiracy question:

It takes light (or a radio transmission) 2 seconds to get from the moon to the earth, and another 2 seconds to get from the earth to the moon at a distance of 250,000 miles.

In this video shot on the moon during the last Apollo mission, Apollo 17, who is controlling the camera at 8:47 when both Schmitt and Cernan are in the picture? The camera seems to react by zooming out in about 2 seconds when one falls accidentally and moves out of the picture. The camera pan reaction at 9:01 is even faster. It seems almost instantaneous.

It could just be luck. Perhaps the camera zoom and the move were started before the astronaut moved. Was Evans remotely controlling the TV camera from the command module? I don't think so.

According to one site,  "The rover television camera was remotely controlled from Earth."  I assume the rover tv camera is the same one filming them in this video, the RCA J-Series Ground-Commanded Television Assembly (GCTA).

Cranes with invisible wires, however, do not explain the speed an object falls when dropped by the astronaut at 12:00. The camera speed would have to be slower.  But it just plain isn't.

Look at 1:59 in this clip:

The moon dust is falling slowly, but the astronaut who falls is kicking his feet quickly! You can have a slow camera or not. You can't speed up only part of the picture. To have a conspiracy and get the above video you'd have to have the entire set in partial free fall.  I can't buy that.

Getting back to the fingernails, the gloves were, in fact, a problem for the Apollo crews according to Heiken and Jones in a book called "On the moon: the Apollo journals."

Here is the Apollo 17 video library:


Cheng said...

Perhaps it's not the gloves getting worse. Possibly astronauts just aren't made of the right stuff anymore.

Intrachresodist said...

That was very good work, Xeno!