New tests on age-old problems

Back to space shcool after 36 years

Glenn wears his age with pride knowing that this was the key to his return to space.

"Although I always wanted to go up again, I never thought age would become an advantage to doing that, and yet here I am," he said.

He went into space aboard Space Shuttle Discovery with six other astronauts for a nine-day space mission. In orbit carried out a wide range of experiments looking at the relationship between ageing and spaceflight.

This research is possible because of Glenn's almost unique medical records. Nasa and the US marines have medical data on Glenn going back over 50 years. This provides a baseline from which to measure the effects of space flight on 77-year-old Glenn.

Ageing nation

At a recent press conference John Glenn pointed out that when he first flew in space in 1962 there were 17 million people over the age of 65 in the USA. Now there are twice as many.

Training for an arduous journey

These numbers give some idea of just how important research is into the ageing process and experiments in space may provide clues about why it happens.

"We know a lot about the Whats of ageing." Glenn says, "but not so much about the Whys. In space we hope to find out more about the Why of ageing."

During Discovery's nine-day mission the astronauts were to perform 83 experiments many of which were medical.

They included research into balance disorders. In space the sense organs that indicate orientation can get confused. Finding out why this happens and seeking a remedy may help those on Earth with balance and co-ordination problems.

"The research on this mission will contribute to building our knowledge and understanding of the ageing process," Glenn said.

Some experiments involve work before, during and after the mission. One investigation will study the effects of space travel on muscle wastage and Glenn's recovery back on Earth.

The recovery process

Just testing

That is the main point about the experiments that Glenn performed in orbit. His reactions to zero gravity and his recovery from it will be different from the younger astronauts.

It is expected that he will be more affected by stress and take longer to recover than the other astronauts.

Discovery's crew included two doctors. Nasa denied that they were included to keep a watchful eye over Glenn's health in space. "They were not teamed-up for that," says a Nasa spokesman.

Weightlessness can deplete the strength and minerals in astronauts' bones. On Earth many elderly people suffer from diseases that give them brittle bones for similar reasons. Is it possible that the two are related?

Mr Spaceman meets Mr Sandman

When he went to sleep in space Glenn wore a series of sensors to monitor his movements and wakefulness - sleep disturbances affect both astronauts in orbit and the elderly on the ground.

Scientists have pointed out that to make sense of Glenn's experiments other elderly people will have to follow him into space on future missions.