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Last Updated: Thursday, 19 July 2007, 07:17 GMT 08:17 UK
Microsatellites 'pose global threat'
By Laura Margottini

Nasa satellite (Artists impression) Compton Gamma Ray Observatory
Could smaller satellites 'weaponise' space?
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 agencies such as Nasa and Esa, are all in the development of a 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.

DMC satellite, AlSAT-1, under manufacture at SSTL
Microsatellites are cheaper to launch into space
This has provided the sophisticated technology necessary for "pocket-sized" satellites, an idea theorised in the early 1990s by Siegfried W Janson, senior scientist at the Aerospace Corporation in California.

But the UCS warns that microsatellites could also be used in more destructive circumstances.

"There are also military reasons for the development of small satellites," explains Ms Grego.

Being so small, some even less than 10kg, they are difficult to detect. Their movement in space is much nimbler than "full size" satellites, which can be as large as a bus.

The high manoeuvrability of microsats enables them to perform tricky tasks such as refuelling and fixing satellites already in orbit, or correcting their trajectory to keep them on the right spot.

But Ms Grego says such manoeuvrability means they could also have a second use.

"With a microsat you can go close enough to other spacecrafts in order to repair them, but also to sabotage them," she says.

She says that they could easily approach and stealthily take pictures of a rival nation's satellites in order to spy on them, temporarily obscure their view, or even destroy them.

Actions which could bring along disastrous consequences, she warns.

'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.

Dr Craig Underwood, researcher at the Surrey Space Centre, UK, says the warnings of danger may be overstated.

"The growth of space technology is something we 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.

SSTL engineers work on the NigeriaSat-1 satellite that participates in the Disaster Monitoring Constellation (DMC)
Surrey Satellite engineers work on a satellite which helps disaster monitoring

In the last 25 years, they have launched 27 small satellites, ranging form 50 to 100kg. They developed the Giove-A satellite for the European Space Agency, part of Europe's Galileo navigation project. The small platform was launched in 2005.

Surrey Space Centre has shared technology programmes with countries such as China, Pakistan, Algeria, Nigeria, Turkey, and Vietnam, in order to help them build their own satellites.

"Ours are not aggressive military satellites; they have a different role," explains Dr Underwood. "They open up space to developing countries that otherwise cannot afford conventional space programmes, at a low cost entry."

He adds: "You see a lot of scary stories, in particular in the US, saying these are anti-satellites weapons and so on, but this is ridiculous. All our satellites are governed by UK laws and policies."

But Laura Grego reckons that the entire international community should begin to look at the issue of space regulation.

She refers to the Outer Space Treaty ratified in 1967 by 98 nations, the US included, which is still the basic legal framework of international space law.

UCS says that despite space being militarised, it has not yet been "weaponised", and this should be prevented.

"We cannot ban all space technology, but what we really would like to see is an international law against satellite destruction, any testing and use of weapons," says Ms Grego.

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