Ask Glenn

What would happen if you farted in a space suit?

It would be the worst kind of fart ever: you couldn’t deny it, you couldn’t escape it, and the smell would stay with you all the way back to the space station.

Spaceman

Couldn’t you just open a flap or something and let it out?

You mean open the suit? Er . . . no. You wouldn’t want to do that.

Why’s that, then? Would you suffocate?

Well, no – not necessarily. In many space suits, the oxygen supply is sealed off in the helmet, so you’d still be able to breathe even if you opened a flap somewhere else.

So why not just pop open a handy bum-flap, then?

Bad idea. Trust me on this.

But why?

OK, you asked for it...

For an astronaut (or cosmonaut) in space, the suit is all that stands between you and the deadly airless vacuum outside. Open a flap in your suit to let the fart out, and your blood would boil, your skin and internal organs would swell up, and – finally – you’d freeze.

Ooh, that’s gotta hurt. But why would that happen? And how can you boil and freeze at the same time?

This is all due to one thing: in Space there’s no atmosphere around you – so there’s nothing to keep your body under pressure, and nothing to absorb and retain heat.

I don’t get it.

OK, let me explain. On Earth, the atmosphere is constantly pushing against your body. Without it, your warm blood would boil. This is because there are two ways of boiling liquids: one is to heat them up, breaking the weak bonds between the molecules inside. The other is to drop the pressure around the liquid, taking away the squashing force that keeps the molecules packed tightly together. This allows them to drift apart, and the liquid turns into a gas.

The temperature of your blood is normally kept at about 37°C, and is happily kept liquid under the pressure of the atmosphere. But in Space, there is no atmosphere, so 37°C is enough to boil your body fluids. A space suit stops this happening by keeping the body under constant pressure. It does this by inflating on the inside (like a bike tyre) and constantly pressing against the skin. But if you released this pressure – by, say, opening a handy bum-flap to let out a fart – your blood would boil. This would also make your skin and organs swell up as the blood inside them expanded.

Yuck. Nasty. OK, what about the freezing bit?

This would follow the nasty blood-boiling bit if you found yourself in the shade (for example, if the earth, moon or your spacecraft is between you and the Sun). Without a thick atmosphere of gases to hold the heat, temperatures in shaded space reach well below –100°C. A space suit is lined with special insulating materials that stop you losing the heat inside (produced by your body) to the outside. Open a flap in it, and all the heat whooshes out of your suit and into Space, freezing you solid in seconds.

So, if you fart in a space suit, you’re stuck with it?

I’m afraid so. Of course, some of it will be recycled into the suit’s life-support system, so you’ll breathe a lot of it back in.

Urrgh!

The rest will drift out when you get back to the ship and take the suit off. No doubt making you very unpopular with the other astronauts, as you can’t open a window in there, either.

So no eating beans in Space, then?

Not unless you want to be called Major Fartpants all the way home...