Asteroids belted

UK engineers are to lead an ESA-backed investigation to discover the most effective technologies to protect the Earth from asteroid impact.

In a sign that the issue is moving up the space community’s agenda, researchers from the University of Glasgow will work with ESA and satellite specialist EADS Astrium to determine the best method of deflecting asteroids from a collision course with Earth.

They will consider everything from hitting the objects with nuclear weapons to dragging them with a solar sail, and devise accurate mission simulations.

Until now space agencies have neglected the topic of diverting asteroids, according to Dr Gianmarco Radice, project leader and member of the space systems engineering research group at Glasgow’s department of aerospace engineering. ‘Very little has been done by ESA and NASA to develop deviation methodologies,’ he said. ‘This is left more to the personal efforts of individuals rather than space agencies.

‘Most work in the UK and US has been on building up a statistical database of NEOs [near earth objects]. While we can predict with great accuracy where an asteroid will be in 1,000 million years time, we can’t say what would happen if an asteroid suddenly turned up on the edge of the solar system. Do we have the technology to prepare a mission in just a few years?’

Last month ESA’s Near-Earth Object Mission Advisory Panel (NEOMAP) said higher priority should be placed on developing a mission to actually move an asteroid, as opposed to simply observing them. NEOMAP chairman Alan Harris warned that in the chain of events between detecting a hazardous object and actually doing something about it, researchers have no experience of trying to alter an object’s orbit.

Several suggestions have been put forward for deflecting asteroids in the past few years, but these are at a primitive stage, Radice said.

One idea is to slam a spacecraft or nuclear weapon into the asteroid, while other ‘more promising’ methods would involve sending a craft to orbit the asteroid for several months, or even years, before nudging it off-course. This could be done by landing a propulsion device on the surface to give it a push, or by dragging it with solar sails. Another suggestion is that high-power lasers or microwave sources could be directed at the object to produce a vapour ‘blow-off’, changing the asteroid’s course.

To date ESA only has plans to test the impact method. The Don Quijote mission – which will be similar to a NASA mission to divert a comet, scheduled for launch this December – will slam a spacecraft into an asteroid to discover its composition, but the impact may also deflect it.

Dr Paolo D’Arrigo, a specialist engineer at EADS Astrium, expects to develop whichever technology the Glasgow team endorses.

‘We will have to develop tools to deflect an asteroid,’ he said. ‘The study will produce a definitive idea of what does and doesn’t work. This expertise doesn’t exist yet; there have been a lot of ideas about deflection, but not much research into the dynamics of what would actually happen to the asteroid.’

ESA and EADS Astrium will offer feasibility advice and allocate some R&D funding to support the project, but the EPSRC will provide most of the backing. The project is due to begin in January, and the team will meet with the space agency every three to four months.

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