TOPIC OF THE MONTH – WEIGHTLESSNESS

MANY astronauts experience low back pain during and immediately after space missions, and this is thought to be caused by withering of muscles which are usually used to maintain posture. Astronauts in the International Space Station do lots of resistance work with rubber bands to try and maintain muscle mass, but it is more difficult for them to maintain muscles in the back.

A recent study has been published which uses CT imaging to look at the size and composition of muscles in astronauts before and after a period of weightlessness.

The results showed that astronauts who spent several months on the International Space Station have significant reductions in muscle size and composition after returning to Earth and that the changes in composition hadn’t returned to normal even after four years.

This type of research has great importance for planning how to keep astronauts fit and healthy during space travel.

It’s hoped the types of exercise astronauts do in space can be changed to minimise this effect of muscle loss during space travel. However, their problems might not end there because the strength of gravity on the Moon and on Mars are much less than that on Earth (actually 83 per cent lower on the Moon and 62 per cent lower on Mars).

If we have colonies of humans living for long periods of time on the Moon or Mars we have no idea how living and working in such low gravity environments will affect humans.

It might be very difficult to return to Earth and rebuild lost muscle after long periods living on the Moon or Mars.