Wednesday, January 30, 2013

EVE Field of View and HMI/AIA Flatfield Today

Today, starting at 1315 UTC (8:15 am ET), SDO will execute the EVE Field of View maneuver followed by the HMI/AIA Flatfield at 1630 UTC (11:30 am ET). During these maneuvers the science data will be interrupted. These maneuvers and last weeks' Delta-H thruster firing were flipped in the schedule published earlier.

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.

Thursday, January 17, 2013

Ben Franklin's Birthday

January 17 is the birthday of Benjamin Franklin, born this date in 1706. He was a scientist, diplomat, and printer. He also studied sunspots. In a letter to Humphry Marshall he wrote "It is however remarkable that tho’ large Spots are seen gradually to become small ones, no one has observ’d a small Spot gradually to become a large one; at least I do not remember to have met with such an Observation."

This letter was sent in February 1773 from Franklin in London to Marshall in Pennsylvania. At this time an ongoing scientific debate was whether science in England was the same as science in the North American colonies. Franklin synchronized experiments on both sides of the Atlantic to explore whether electricity behaved the same. Observations of the Sun were part of this effort.

Happy Birthday, Ben!

Wednesday, January 2, 2013

SDO Maneuvers for Early 2013

We have announced maneuvers and special operations for the first eight months of 2013
16-Jan-2013: EVE Cruciform
23-Jan-2013: EVE FOV & HMI\AIA Flat Field
30-Jan-2013: Delta-H #13
17-Feb-2013: Handover Season Begins
03-Mar-2013: Eclipse Season Begins
07-Mar-2013: Solar RFI (~418 seconds)
08-Mar-2013: Solar RFI (~440 seconds)
20-Mar-2013: Station Keeping Maneuver #06
25-Mar-2013: Eclipse Season Ends
10-May-2013: Handover Season Ends
06-Aug-2013: Lunar Transit (~76 minutes)
Each maneuver comes with a loss of solar pointing or interference with the radio downlink.

Tuesday, January 1, 2013

Happy New Year 2013!

As we begin another year, how about a disk problem? It appears that the SDO webserver didn't change smoothly to 2013. It will be fixed as soon as possible.