Living in Space

Space is empty. No food, no water, and very few oxygen molecules, widely scattered. Living in space demands that you take everything you need for living with you.

Because you are so far from heavenly bodies with their strong gravitational pull, you become 'weightless'. All the massive objects in space - the stars, planets and moons - have their own gravitational pull. The bigger the object, the stronger the pull. The closer you are to the object, the stronger its pull. In deep space, the pull is so slight that you float. This has strange effects on you:

• There is no 'up' or 'down'. Your balance system gives strange messages to your brain. As a result, you may suffer from space-sickness - not unlike sea-sickness.
• Because gravity squashes the soft discs between the vertebrae, you are actually taller (by two centimetres or so) when weightless. All your bones lose calcium and become lighter - a condition similar to osteoporosis.
• You feel as if you have been upside-down for a long time. Your heart, which has been pumping blood against gravity all your life, is pushing too much blood to your head. When it has adjusted, your heart slows down by around 10 beats a minute.
• Your legs become thinner because there is less fluid in the lower body; a condition astronauts call 'bird-legs'.
• The air you breathe out when weightless can accumulate more easily, and has to be moved around with fans to stop you suffocating. The waste carbon dioxide is absorbed by chemicals.
• Dust doesn't settle, and has to be filtered out.
• Drinking from a cup is impossible. The liquid floats, and so all drinks have to be sucked through straws.
• You can still swallow, but the food floats in your stomach.
• You have to be strapped down to sleep.

Some of these effects can be countered by increasing food and water intake, and especially by vigorous exercise, which helps prevent bone deterioration.

Astronauts also have to cope with the high g-loading of take-off and re-entry, which subjects them to a gravity pull three to eight times that on Earth; high levels of radiation, and problems with their body clocks, confused by the lack of day and night.

On top of that, they may suffer all the stress of living in confined conditions with very few people.

All the children will want to know how you use the toilet in space! The toilet is like a funnel; it has foot straps to stop you floating away. A stream of air carries the waste through the funnel and into a container. The water is evaporated off and recycled for drinking, or electronically converted to oxygen and hydrogen. The oxygen can be used for breathing.

For a personal account of life on Mir read Helen Sharmans interview, Resource Sheet 4.