Iridium, the bankrupt satellite telephone network, is being reborn and physicists aim to use the spacecraft to monitor space weather.
Brian Anderson of the Applied Physics Laboratory at Johns Hopkins University in Baltimore says the magnetic sensors on the 66 Iridium satellites will allow for the first time continuous mapping of the gigawatts of power that flow between space and the Earth鈥檚 upper atmosphere.
鈥淓ssentially, we now have a network of weather stations in space,鈥� he says.
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The $5 billon network was bought by Iridium Satellite on 13 December for about $25 million. The new company has already signed a $72 million, two-year, air time contract with the US Department of Defense.
Iridium Satellite hopes to relaunch a commercial service early next year, with call charges of about $1.50 per minute, compared to the original $7.
Driven by the solar wind, the amount of power coming into the atmosphere can vary several fold in less than an hour. Solar flares can cause electrical storms in the Earth鈥檚 atmosphere that knock out satellites and disrupt power grids.
A network of land-based radar stations called SuperDARN (Dual Auroral Radar Network) already keeps track of the electric field surrounding the planet. But for a complete picture of space weather, the power in the system must be measured.
Power is a combination of the electric field and current and the magnetometers on the Iridium satellites can provide the current measurement.
Iridium will not give advanced warning of electrical storms, Anderson says. But it will help scientists understand the conditions that lead to electrical storms, making them easier to forecast in the future.
鈥淭he plan is to develop a knowledge base that will enhance other forecasting techniques,鈥� Anderson says. The contract with Iridium Satellite lasts at least two years.