Wednesday, January 23, 2013
Momentum Management Maneuver Today
Today at 1946 UTC (2:46 pm ET) SDO will fire its thrusters to change the spin rates on the reaction wheels. The science data will stop at about 1940 UTC and resume at 2006 UTC. We use these reaction wheels to keep SDO pointing at the Sun. They change their speed as SDO orbits the Earth to counteract the torques caused by solar radiation pressure, magnetic dipole, and the gravity gradient in our orbit, and the high gain antennas. When the rates approach the limits, we use the thrusters to drive them back. UPDATE: The thrusters fired successfully and used 66 grams of propellant during the burn.