Microsatellites 'pose global threat'

A satellite, no bigger that a domestic fridge, blasts into orbit from a secret military launch site.

Controlled from the ground, it stealthily moves towards the satellite of a rogue enemy country. Suddenly it explodes, destroying the second satellite and shutting down the communication capability of the country instantly.

It may sound like the beginning of a James Bond film, but scientists in the US have warned about the potential misuse of satellite technology.

Commercial companies, universities, space research institutions, such as NASA and ESA, are all in the development of this new spacecraft generation, called microsatellites.

Weighing less than 100kg, they provide GPS navigation, weather predictions, and Earth observation just like traditional satellites, but they are faster to build and much cheaper.

A typical microsatellite can cost as little as 10 million euros as opposed to hundreds of millions for traditional satellites.

About 400 microsatellites have been launched in orbit over the last 20 years for scientific, commercial and military purposes.

"Microsats save costs because the heavier a satellite is, the more it costs to send it into orbit," explains Dr Johan Köhler, a micro technology engineer at the European Space Agency.

"The launch is a major cost to any space mission."

'Indispensable part'

Satellite technology has become an indispensable part of modern society - being used for everything from mapping and weather forecasts to communications.

Physicist Laura Grego, from the Union of Concerned Scientists (UCS), said: "It's amazing how much satellites are involved in the conduct of civil and economic life in a way that people don't appreciate, but they are also very important to the way... the US conducts military affairs."

Dr Köhler explains that miniaturisation of satellites has been possible thanks to the results reached by nanotechnology research, especially over the last two decades. 'Satellite attack'

"If someone interferes with another satellite, or even if the interference is caused accidentally by a piece of debris, this kind of event is likely to start a war, because this can be confused for a satellite attack."

There are about 800 satellites orbiting over our heads at the moment: 66% are for communications, while 6% are in use by the military. The US owns more than half of the total in our skies.

D. Craig Underwood, researcher at the Space Centre of University of Surrey, UK, says the warnings of danger may be overstates.

"The growth of space technology is not something that cannot hold back. It is part of the world we live in," he says.

Surrey Space Centre works in partnership with Surrey Satellite Technology Limited (SSTL), the first professional organisation to commercialise low-cost small satellites for telecommunication and monitoring of natural disasters.