Tim Peake launches space food science experiment

British astronaut Tim Peake has invited schoolchildren to help him in an experiment to learn more about how to grow food in space.

Major Peake wants pupils to plant the seeds of rocket leaves that have been in orbit and compare their growth with normal plants.

He said finding ways to grow food in space will be essential if humans are to travel and live on distant planets.

The Royal Horticultural Society and UK Space Agency will run the experiment.

Maj Peake is due to begin a six-month mission to the International Space Station (ISS) later this year. He will be taking with him more than a million seeds of rocket which will be distributed to 10,000 schools on his return.

Children are being asked to apply to do scientific experiments on the seeds to find out whether six months in space has affected them in any way.

According to Maj Peake, the experiments will feed into research that space agencies are carrying out to try to determine whether one day astronauts could grow their own food in space.

"For years, scientists have been researching whether the human race can survive on another planet in the future. In order to do this, we need to grow food in space and we need your help," he said in a video to promote the project.

"We are calling this special mission 'Rocket Science' and we can't do it without you," he added.

According to Alistair Griffiths, who is the RHS's scientific director, "the plan is to have a mass participation with schools".

Each astronaut on the ISS requires 5kg of food and water each day, according to the European Space Agency (Esa). They receive regular supplies from Earth.

But it would be incredibly expensive to do this for a permanent human colony on the Moon and would not be at all realistic for a return trip to Mars. The UKSA's Jeremy Curtis said that the proposed seed experiment would help in the development of food that could be grown in space.

"The human race is expanding and exploring further and further afield and one day - we don't know when - we will have human beings exploring the rest of the Solar System," he told BBC News.

"It takes a long time to get to the other planets and this means we will have to be able to provide food for astronauts on long duration missions and the only way to do that is to grow it."

There have been experiments on plants in space ever since the early days of human space travel in the 1960s.

These have shown that plants know which way is up even at very low levels of gravity. Germinating seeds send their roots toward the pull of gravity and their shoots away from it even when its tug is 10,000 times weaker than on Earth.

But other experiments, carried out aboard the space shuttle, have shown that some plants grow less well in the presence of light in low gravity.

According to Esa's Dr Jason Hatton, this suggests that techniques may have to be developed to increase yields in space.

"If the response to light is decreased, will plants behave in the same way as they do on Earth? If we colonise the Moon or Mars, would we be able to cultivate crops in the same way?"

Now that the ISS is fully operational, space agencies can study the effects of weightlessness and radiation in a carefully controlled conditions.

New science minister Jo Johnson visited the Rocket Science stand at this year's Chelsea Flower Show on Monday. He gave the project his seal of approval.

He told the BBC: "It's a great opportunity to inspire generations of young children to take an interest in space and the science that underlies these kinds of activities.

"It's a brilliant initiative between the RHS and the UK Space Agency. Half a million kids will be getting involved and it's tremendous to come and support it."

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