reaction wheel


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reaction wheel

[rē′ak·shən ‚wēl]
(mechanical engineering)
A device capable of storing angular momentum which may be used in a space ship to provide torque to effect or maintain a given orientation.
References in periodicals archive ?
Kepler was knocked out of commission last spring when the second of its four reaction wheels stopped working (SN Online: 5/15/13).
Jeffrey Ward, commented, "The DIRWA reaction wheels further fortify our capability in high-reliability spacecraft components and subsystems as we continue to vertically integrate the company to ensure the best value, all-US made, schedule-responsive products for our customers.
After losing two of its reaction wheels, which balanced the spacecraft, Kepler could no longer stay steady enough to stare at stars and detect planets.
Astronomers and engineers worked day and night to devise an ingenious way to repurpose the spacecraft, that was written off after the failure of its reaction wheels cut its mission short last year.
Kepler was launched in March 2009, and last year lost the use of two of its reaction wheels that helped keep it precisely oriented.
This also gave engineers the time to find workarounds for two glitches that threatened the mission: a problem with two of the four reaction wheels used to turn the spacecraft, and a small helium leak that could affect the thrusters vital for its final maneuvers.
The telescope's problematic reaction wheels prevent it from hunting planets any more, but astronomers continue to pore over almost four years' worth of collected data.
The observatory lost the second of its four reaction wheels in May, meaning it can no longer hold completely steady as it looks towards the stars.
Two of Kepler's four gyroscope-like reaction wheels, which are used to precisely point the spacecraft, have failed.
But engineers were unable to get the observatory's reaction wheels to begin spinning again.
Tasked to design a system that allows the ROIC to rotate in space on three axes the team chose to use reaction wheels, proven technology used to position the Hubble Telescope and other satellites.
Due to the low orbit (300km) atmospheric drag provides a stabilization torque that, used with reaction wheels and torque coils, provides stable pointing to within five degrees of Nadir throughout the orbit.