## Working In Microgravity

A couple of the astronauts aboard the International Space Station took a walk outside today. Dangerous work. As New York Magazine reports:

An Italian astronaut, Luca Parmitano, nearly drowned during the station’s last spacewalk in July after water began pooling in her helmet.

This time they were outside removing a 780 pound pump. That’s 780 pounds on Earth. In microgravity it hardly has any weight at all.

Weight doesn’t really matter!

Microgravity makes it easier for the astronauts to move something, but that object still exerts force. Force is important. If your hand gets smashed by a hammer, it’s not the hammer’s weight that does the damage. It’s the force!

A little math coming up, but I’ll explain. Don’t panic.

The formula for force is F = ma, or force equals mass times acceleration. See what’s not there? Weight.

What is there is “mass.” Even in microgravity the pump’s mass is unchanged.

So, this pump that currently won’t register on a scale can smash your bones to bits! And, of course, with microgravity it’s easier to get the pump moving.

The astronauts will be back out in a few days to replace the bad pump with a spare. It’s another spacewalk fraught with peril and danger. Extremely physical work performed by major league nerds.

If you’ve read my blog any length of time you know I’m not a big supporter of the manned space program. However, that doesn’t stop me from appreciating how difficult and dangerous work in orbit is.

## Wally Schirra

With the passing of Wally Schirra, there are only two of NASA’s original astronauts left. If you watch TV and they call him Walter in the obituary, you can bet the person saying it isn’t old enough to remember.

Wally Schirra trained to go to space before anyone knew if it could be safely done. And after he went once he did it again and again.

When I first heard of his death, instead of flashing back to Mercury, Gemini or Apollo, I remembered Actifed. Wally Schirra was the first astronaut to ‘shill’ for a product – appearing in commercials for that cold relief medicine.

Of course, that’s preserved on youtube. What isn’t?

Schirra was a “Right Stuff” kinda’ guy, cool enough to fall asleep in the van on the way to the launch pad! I’m not sure if NASA even looks for that kind of astronaut anymore?

Interestingly, it was a surprise Schirra got after landing that is used as proof that Gus Grissom didn’t ‘blow’ his Mercury capsule’s hatch, allowing it to sink. Grissom was accused of panicking while waiting to get out – not a good reputation for a spaceman. It’s an ugly story that’s haunted Grissom’s legacy even after his tragic death in the Apollo 1 accident.

Upon slashdown, Schirra’s Mercury capsule was hauled up on the deck of the U.S.S. Kearsarge. When he blew open the hatch, the recoil from the switch was enough to leave a nasty bruise. Grissom had no bruise. Proof positive the hatch malfunctioned!