A trio of
colorful mini-satellites floats free within the International Space
Station (ISS) during autonomous rendezvous tests.
Known by
the hefty moniker Synchronized
Position Hold, Engage, Reorient, Experimental Satellites (SPHERES), the
bowling ball-sized objects are designed to test control algorithms for
spacecraft by carrying out a series of unmanned
rendezvous and docking maneuvers.
Here, the
three satellites float with the space station’s U.S. Destiny module. The knobby
protrusions in their profile are tanks of pressurized carbon dioxide [schematic],
which the satellites use for propulsion within the ISS.
The SPHERES
project is led by researchers at the Massachusetts Institute of Technology’s
(MIT) Space Systems Laboratory. A member of the three-astronaut Expedition 14
crew snapped this view of the SPHERES satellites in action during a March 24,
2007 test.
-- SPACE.com Staff
Credit: NASA/JSC.
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