The striking colours. The spectrum of smells. The changing air. After six months away, Tim Peake will have a lot to get used to back on Earth. And what will take the most out of him physically is the gravity of his new situation: no more can he fly around his home, he now has to get used to the weight of his body and deal with the effects of living in space. Whilst in the microgravity environment of the International Space Station, his muscles have weakened, his bones have become less dense, and the pressure inside his eyeballs could be messed up, affecting his vision. This happens because our bodies are designed to adapt to their environments, which luckily means they can, in time, adapt right back to living on Earth. Phew!
It’s said to take one day on Earth to recover from each day spent in space. That means it will be another six months of rehabilitation until Tim is back to full fitness, and he won’t be doing it alone. Helping him and other astronauts in this effort are whole teams of doctors and physios, exercise specialists, and scientists researching new and better ways to help the body recover.