We have another question this week so let us go ahead and "Ask ARSE".
My teacher said that because we go to bed and the bed takes our weight off, we get a little bit taller overnight. If astronauts always have their weight off in space, do they get even taller?
Great question Marcus!
The short answer is yes they most definitely do get taller in the absence of gravity. What happens in bed or in space, is that your spinal cartilage expands like a sponge with no weight exerted on it.
You still have the remaining mass, however, weight is your mass in relation to gravity.
Astronauts can grow up to 3% taller in space over a regular 6-month interval on the ISS, which might not seem significant, but can mean a 6-foot tall person could gain a whole extra 2 inches!
Additionally, no gravitational resistance ravages the musculoskeletal system and makes astronauts weak and feeble. When they arrive back on Earth after too long they can struggle to move and perform the most basic of tasks.
While in space, all bodily fluids move upward, which is also why astronauts floating will appear to have a serious strain on their faces. Their head is engorged with blood!
Lastly, astronauts are no longer beneath our protective layer of magnetic field meaning they are blasted with radiation constantly and potentially could develop cancerous tumours. Oh no!
Thank you for your inquiry young spaceman and for spreading ARSE far and wide.