## 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.

## It’s Just Not Practical

People talk about travel to distant planets and space exploration. It’s so heroic. So romantic.

It’s not going to happen.

No, really. No one alive today will ever live on, or travel to, another planet. Sorry.

The challenges are astounding. Earthlings aren’t readily adaptable to living off planet. We can’t even live on most of the Earth!

At 10,000 feet above sea level our breathing is already labored. We can’t live very far below ground either.

We can’t live in the sea. We can’t live where it’s too hot or cold. We can’t live where it’s too dry or too wet.

This comes to mind because the International Space Station is experiencing plumbing problems.

Earlier Wednesday, the pump module on one of the space stationâ€™s two external cooling loops automatically shut down when it reached pre-set temperature limits. These loops circulate ammonia outside the station to keep both internal and external equipment cool. The flight control teams worked to get the cooling loop back up and running, and they suspect a flow control valve actually inside the pump module itself might not be functioning correctly. – NASA

Keeping the temperature constant is integral to astronauts living up there. There are currently six aboard.

It is all we can do, we being a dysfunctional international consortium of governments that runs the space station, to keep a handful of scientists safely in orbit 257’ish miles up.

Going to a planet is much, much more complicated. Farther away–distance and time. More hostile environment. We’re nowhere near ready to solve these problems.

Up on the ISS there’s hope a cooling solution will be found. Since this is an external problem, repairing it will probably require a trip, or two, or more, outside.

As amazing as astronauts making repairs on their space station while in orbit is, going to a distant planet is orders of magnitude more difficult and more expensive.

It’s just not practical and it never will be.