Monitoring space weather

Researchers at the University of Michigan are to design and deploy a satellite about the size of a loaf of bread to study space weather, thanks to a grant from the US National Science Foundation.

Undergraduate and graduate students will be heavily involved in the Radio Aurora Explorer (RAX) project, which will be led by the University of Michigan and SRI International, a California-based independent research and technology development organisation.

This CubeSat, as it is called, will be the first free-flying spacecraft built in part by University of Michigan students. Members of the Student Space Systems Fabrication Laboratory (S3FL) will play an important role. S3FL is an organisation that gives students practical space systems design and fabrication experience.

CubeSats, developed about five years ago, are approximately 4in cube-shaped devices that launch from inside a P-Pod, a special rocket attachment that was developed by California Polytechnic State University and Stanford University. There is a growing interest in CubeSats as they offer relatively inexpensive and simpler access to space. The RAX satellite will essentially be made of three CubeSats.

The RAX will measure the energy flow in the ionosphere, the highest part of Earth's atmosphere where solar radiation turns regular atoms into charged particles. Disturbances in the ionosphere can affect earth-to-space communications such as GPS signals, digital satellite television and voice and data transmission systems including Iridium and Globalstar.

James Cutler, assistant professor in the Department of Aerospace Engineering and a principal investigator on the project, said: 'This project will help us better understand space weather processes, how the Earth and sun interact, and how this weather produces noise in space communication signals - noise that translates to lower quality telecommunications capabilities and error in GPS signals.'

The RAX satellite will act as a receiver that will pick up signals from a ground radar transmitter. These radar pulses will reflect off disturbances, or space weather phenomena, in the ionosphere. It is scheduled for launch in December 2009.