A British engineering firm plans to make satellites that can manufacture their own gigantic antennas in space. They would then be able to monitor radio signals from Earth.
The idea, from Magna Parva in Leicester, is to launch satellites with a supply of raw materials that they can combine to produce long, thin structures such as booms or antennas. These components are difficult to deliver into space because they take up a lot of room and can be easily damaged. Being able to make them in space from raw materials would allow satellites to carry larger antennas.
Magna Parva wants to use this technique, called pultrusion, to make antennas for satellites in its planned Kleos constellation, a geolocation network that would track radio signals to spot illegal activity.
Maritime organisations could use Kleos to help inform investigations into illegal fishing or piracy, says Andy Bowyer, the company’s director. The International Maritime Organization requires all ships of a certain size, and all passenger ships, to use an automatic identification system (AIS). “If we’re getting a phone signal from the middle of the Atlantic from a position that doesn’t have AIS signal attached to it, is it a vessel doing something covert?” he says.
Bowyer says the satellite system could also monitor signal jammers, which can be used by thieves to interrupt a stolen vehicle’s on-board GPS tracker, for instance.
Tony Flavin at Chronos, a company that specialises in GPS, navigation and time monitoring technologies, is sceptical of this application. “On the ground you can detect GPS jammers because you’re very close to them,” he says. “Doing it from thousands of miles away I’d say is practically impossible.”
But Magna Parva claims its antennas would be able to locate a radio signal by analysing the time delay between multiple points of reception. Bowyer says the company aims to be able to pinpoint signals to within 50 metres on the ground and is working on a prototype to validate this, along with the deployment of the antennas, within the year.
The task is “very challenging”, says Kenneth Tong, an electrical engineer at University College London, but satellite-based monitoring has benefits. “The coverage is good – you are not blocked by buildings,” he says.
As well as allowing for larger antennas, Bowyer hopes that the pultrusion technology will lower the costs of launching a satellite, because there would be fewer large and delicate components to worry about. The system has so far been tested for resilience to vibrations and to see how it performs in a vacuum, and will undergo radiation testing next.
Stuart Burgess, an engineer at the University of Bristol, UK, says that the technique could have benefits for other space endeavours. “In a spacecraft there’s a fantastic lack of space,” he says. “If you can just take up raw materials and then manufacture when you’re up in space, there’s potentially a great advantage.”
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