British scientists are planning to send a swarm of miniature spacecraft beyond Mars to study the origin of asteroids that might pose a threat to the
By Helen Briggs
BBC News Online science reporter
Thirty or more microsatellites would be released by a mother spacecraft on arrival at the asteroid belt, where billions of space rocks orbit the Sun.
Small, cheap satellites can visit asteroids
Like bees from a hive, the satellites, weighing as little as 20 kilograms, would fly past different asteroids.
They would collect images and other data, sending it all back to Earth via the main spacecraft.
The European Space Agency (Esa) has given the go-ahead for a feasibility study of the project, which is being led by the European space company Astrium.
Project scientist Paolo D'Arrigo described the concept as a "step change" in interplanetary exploration.
"The idea is for a swarm of spacecraft to visit 100 asteroids," he told BBC News Online. "Although it sounds far-fetched, it's not very far from the current level of technology that we have."
Dr Simon Green, of the Space Science Research Group at the Open University in Milton Keynes, said the probes would be the smallest ever interplanetary spacecraft.
"They're going to where the asteroids have originated," he said. "This gives us a chance to get up close to a very large range of these things.
"Each little 'bee' would have a very limited payload in terms of mass but you would have very many of them."
The 'bees' would be powered by solar sails or perhaps small conventional rocket engines.
The mission, known as Apies (Asteroid Population Investigation and Exploration Swarm), is in its early stages, and would not be possible for perhaps a decade.
Other British-led proposals, such as Simone (Smallsat Intercept Missions to Objects Near Earth), are further down the line and have been selected by Esa for future consideration.
Simone consists of a flotilla of five 120-kg satellites that would be sent to rendezvous with different asteroids.
The British company behind Simone, QinetiQ, based in Farnborough, Hampshire, is lobbying for Europe to take the lead in asteroid defences.
Although Esa is considering several proposals for such missions it has not yet committed major funds.
Nigel Wells of QinetiQ, study manager for Simone, said he hoped Europe would formulate a firm proposal to tackle near-Earth objects.
"We are ready and the scientific community is ready but it's up to the politicians now," he said.
Details of Simone are to be presented at the UK/Ireland National Astronomy Meeting in Dublin.