Astronaut Chris Hadfield spent months living in space aboard the International Space Station. Here, he describes how zero gravity changed his body and how he lived with the constant threat of high-speed micrometeorites.
CMDR CHRIS HADFIELD:
Once in a while you actually hear a meteorite ricochet off the outside of the space station. You hear a thump or a bang or a crack as something runs into the station and it’s a reminder of where you actually are.
When you’re inside a building, you think you’re kind of bullet proof. But when you hear one of those hit, you recognise that you’re actually in an aluminium bubble.
But like anywhere else, you get used to where you are and you focus on the reality of it.
We of course are worried about increased radiation on the space station. We always get a higher dosage than people on Earth, just like folks that live at high altitude. But when the Sun’s been particularly active, we have parts of the station that are better shielded where we can retreat to if we absolutely had to.
I increased muscle mass, I lost fat and I kept my bone density everywhere except across my hip cradle and my upper femurs, and there I lost about 8%. What’s critical is that I lost 8% of the soft trabecular bone, which is impact resistant. So when I came back, I was very susceptible to a broken hip and it’ll take about a year for that to reverse and for my bone to grow back.
There’s a list of problems we have to solve to leave Earth’s orbit reliably. One of them is bone loss. I think we’ve beaten a lot of the ones that were on the list a few years ago with the medical research that’s going on, but we have got to solve the bone loss problem.
Radiation, power generation, navigation, in situ resource management – all of that needs to
be done also but it’s one of the problems.
How incredible. Can you imagine being 220 miles up in the Space Station and hearing the ping of a meteorite?
Wow. Big respect to all who fly in space.