MoD backs satellite 'origami radar antennas'

The UK's Ministry of Defence (MoD) has approached start-up Oxford Space Systems (OSS) to design antennas for a sovereign satellite radar system.

Ministers envisage a constellation of British spacecraft gathering intelligence for operational and tactical applications in the 2020s.

OSS has novel technology that fits the satellites' requirement to be low-cost.

Oxford's carbon-fibre antennas stow away in very small volumes for launch but then spring into shape in orbit.

The particular design being sought for radar is known as "wrapped rib", explains OSS CEO and founder Mike Lawton.

"Think of a builder's tape measure. We have these ribs of carbon fibre that are wrapped into a very small space around a central hub. When we allow these ribs to deploy, they naturally want to take their original shape. They spring out and form a really quite stiff backing structure," he told BBC News.

The approach has been called "origami engineering".

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The antennas would transmit (via a smaller inner-structure) and receive the radar pulses that are used to map the surface of the Earth.

The great advantage of this type of observation is that the pulses are not obstructed by cloud and will sense the ground even in darkness.

This makes radar a powerful tool for the military. Currently, the UK relies on other friendly forces or commercial companies to provide these kinds of pictures. But Project Oberon, as the MoD has dubbed it, would fly a sovereign network of spacecraft.

The project is still in the R&D phase, and the MoD is talking to a number of other British companies about what they too could contribute.

Surrey Satellite Technology Limited and Airbus recently launched an all-UK radar satellite and the armed forces are evaluating the usefulness of its pictures.

For this next phase, OSS will develop a 3-3.5m deployable antenna under a £1m contract, with the aim eventually of making 5m structures for radar applications.

"We're hoping we can fly even what comes out of this R&D phase, by working with the platform designer," said Mr Lawton, whose company is based in Harwell.

"It won't be the full performance and it certainly won't be the full resolution required by Project Oberon, but it would allow us to demonstrate the kinematics of deployment, to prove the antenna will unfurl in orbit."

A key objective for OSS is to take a slice out of the telecoms market.

The big communications satellites use antenna reflectors that can be over 10m in diameter. It's technology that is dominated by American companies such as the Harris Corporation and Northrop Grumman. OSS wants to be a European player.

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