The Reaction Wheels
required for the attitude control for these missions are also one of the key micro-vibration sources.
In 2013, the mission appeared to be over when two of four reaction wheels
failed and the spacecraft lost its stability.
Millennium Space Systems said it has shipped its first set of RWA-1000 reaction wheels
to commercial customer SSL in Palo Alto, CA.
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.