SCI/TECH: Water to Boost Satellite Snooping, page 1

The Defense Advanced Research Projects Agency is working alongside Proton Energy Systems to develop a system that will extend the life of spy satellites which become useless once their fuel runs out and they burn up in our atmosphere. Just what is their solution....water?

Water To Boost Satellite Snooping
The new self-sustaining satellites would last much longer and give the military new flexibility in monitoring activities around the world.

Satellites today are similar to NFL offensive linemen -- they usually last from five to 10 years and have limited mobility. Most satellites use solar panels to provide the electricity for their day-to-day functions, while primarily relying on liquid fuel to power the thrusters that adjust their position, according to Michael Richardson, a researcher in the imaging science department at the Rochester Institute of Technology. Richardson said satellites use the excess solar power gathered during the day to charge batteries to allow tasks to be performed at night, but functions are sometimes shut down to save power.

Liquid fuel propellants add weight and volume to the satellites, increasing the cost and difficulty of the launch, Richardson said. It becomes a matter of "how much fuel can we pack on and still get it into space." Satellites use liquid fuel to power the thrusters that maintain their orbit and fight the Earth's gravitational pull. When the fuel runs out, the satellites are taken offline and allowed to drift as space junk before burning up in the atmosphere.

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