Masterson, Development and validation of empirical and analytical reaction wheel
disturbance models, [M.S.
In the second three orbits, three magnetorquers and one reaction wheel
are used for the stable mode.
In low-altitude mapping orbit, Dawn will prolong its hydrazine supply by switching to a "hybrid mode" of pointing, where it will use its two remaining functional reaction wheels
in combination with hydrazine thrusters to point itself.
The redesigned reaction wheels
were successfully launched last year on the Transition Region and Coronal Explorer, a satellite mission that is studying the sun's coronal region with the TRACE satellite in April 1998.
Zhou, "A novel vibration isolation system for reaction wheel
on space telescopes," Acta Astronautica, vol.
Caption: Steadied by Sunlight: Kepler's new mission, K2, uses sunlight to make up for a lost reaction wheel
and keep the telescope balanced.
Yang, "Spacecraft attitude and reaction wheel
desaturation control," IEEE Transactions on Aerospace and Electronic Systems, vol.
Speaking on the debacle Charles Sobeck, deputy project manager at Ames Research Center, told Discovery News, "People are definitely saddened by the loss of another reaction wheel
. It certainly is not good news for the mission, which has been performing so well and had so much promise for doing even better."
After losing an attitude-controlling reaction wheel
in October, HALCA resumed observations in December but lost control of its orientation a second time later that month because of a commanding error.