Endeavor to deliver stamp sized "Sprite" micro-satellite experiment to ISS

The Space Shuttle Endeavor currently sits on the launch pad awaiting her final launch. On board is a tiny experiment that, if successful, could become a new and inexpensive tool for the exploration of space.

The actual size of a Sprite satellite.

Developed by Cornell University's Space Systems Design Studio, these postage stamp sized satellites named "Sprites" are to be mounted on the International Space Station's (ISS) Materials International Space Station Experiment (MISSE-8) pallet. They will be mounted externally so that they may experience the full affects of space. They will then be sent back to Earth in several years to study how they withstood the rigors of space. Three nearly identical Sprites will be mounted on ISS with the only difference being that each will transmit with a unique radio signature so that they can be told apart by researchers on the ground.

Other than their size, what makes Sprites so unusual is that they do not use an active form of propulsion. In fact they have no propulsion device mounted at all. Instead, the chip and the sun are its propulsion. Relying on solar winds, masses of these satellites could drift on the sun's currents of particles like bits of space dust.  While the concept of solar sails was firs proposed back in the 1920's, the concept was recently proven by the Japanese probe IKAROS.

Once the Sprites reach a planet (or even released near one by a larger craft), they would be able to take a wide variety of readings such as atmospheric pressure, radiation, and chemistry, amongst others. Some could drift down through the atmosphere, transmitting back their readings while others could ride the electro-magnetic currents that surround many planets. With each transmitting with different signatures, large masses of data could be transmitted at once giving a wealth of information.  And all done for less than it would cost to launch a single traditional satellite.