Improving communications from space

Jul 22 2011
VERTIC Blog >> Arms Control and Disarmament

By Rebecca Pryce, London

Today, space-based satellite monitoring systems face a problem. Their sensors, which are become ever more sophisticated, produce more information than can be easily transmitted back to earth. Installing better computing equipment on the satellites could break this bottleneck. But can today’s complicated chips withstand one of the great hazards of orbit, space radiation?

To find out, the National Nuclear Security Administration (NNSA) set up the SEU Xilinx-Sandia Experiment. The present iteration of the project is called SEUXSE II (or ‘Suzie-2’). It was developed to test how possible space-based monitoring systems will stand up to the rigors of space radiation. The system was installed on the hull of the International Space Station on 18 May 2011, as part of the Material International Space Station Experiment-8 mission.

The results seem encouraging. On 11 July 2011 the NNSA announced that Suzie-2 had successfully begun broadcasting data, and proving that it is able to cope with radiation levels in space. This system works by monitoring and characterizing single event upsets on off-the-shelf commercial computer chips. These single event upsets are caused by Cosmic Rays, the effects of which are currently unknown on computer chips; making SEUXSE II vitally important in testing whether these computer chips can be integrated into space-based operating systems or not.

SEUXSE II has replaced SEUXSE I, which had been successfully monitoring single event upsets on computer chips for the past 18 months. The main difference between the two devices is an upgraded space qualified computer chip. The hope is that this newer version will provide a deeper insight into the effects of space radiation on these computer chips—thereby enabling appropriate modifications to be incorporated in future designs.

These new computer chips are ‘Field Programmable Gate Arrays’ (FPGAs). An integrated circuit can be configured, changed, by the customer after it has been manufactured. In other words, it is able to be programmed in the field. These types of chips are very useful for space technology. Because these chips are reconfigurable they can change task once a different configuration of circuitry is compiled, allowing satellites to change task mid-mission. Also, these chips can be assigned to a number of different tasks without interruption from other logic blocks within the circuit. In addition, FPGAs are increasingly being used in security and defence. Their high performance and configurability make them popular in electronic warfare, image processing and global positioning systems.

Data collected by SUESXE II will further help scientists to determine the possible use of FPGAs in space. In particular, the technology may be useful for space-based monitoring of nuclear test explosions. Satellites have been used by states to monitor nuclear testing for more than half a decade. For political reasons, satellites were not allowed to form part of the CTBT verification regime. However, state parties to the future Comprehensive Nuclear Test Ban Treaty (CTBT) may use information collected by satellites when raising compliance concerns. Other state parties pledge not to interfere with this data collection (see articles IV.A.5 and 6). Moreover, additional monitoring technologies may be included in the multilateral verification regime at a future date (see article IV.A.11).

For now, though, the technology will enhance the United States’ national technical means to detect nuclear testing. In the words of Ms Anne Harrington, the NNSA Deputy Administrator for Defense Nuclear Nonproliferation, ‘this research is a vital investment in our ability to detect, localize, and analyze the global proliferation of weapons of mass destruction and ensure treaty compliance in the future.’

Last changed: Jul 22 2011 at 3:01 PM




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