Thursday, May 28, 2015

SDO/EVE Calibration Rocket Did Not Follow Planned Trajectory

The SDO EVE calibration rocket was cut down by range safety about 16 seconds after launch. The rocket did not fly the planned trajectory and was cut down when it appeared that it could fly out of the White Sands Missile Range in New Mexico. The payload was recovered and will be prepared to fly again. The reflight could be as soon as next year.

Wednesday, May 20, 2015

Launching a Sounding Rocket to Help Calibrate NASA's SDO

Tomorrow at high noon Mountain Time, the SDO EVE calibration sounding rocket will launch from White Sands Missile Range in New Mexico. It is only 15 minutes of flight with 5 minutes of solar viewing, but we use that data to calibrate the EVE and AIA instruments on SDO. The wavelengths of light these instrument measure can't be measured from the ground. Every 2 years or so we send a copy of the EVE instrument to make the same measurements as the flight instrument that orbits the Earth. The two measurements should agree and where they don't, the on-orbit instrument data is adjusted.

More details are in the SDO EVE Calibration rocket rocket article on SpaceRef or the SDO NASA webpage.

Tuesday, May 19, 2015

DDS offline, Back online at 0130 UTC (9 p.m. ET)

The SDO DDS went offline at about 2247 UTC (6:47 p.m. ET). The SDO Flight Operations Team is looking into the outage.

UPDATE: As of 0130 UTC (9 p.m. ET Tuesday) the SDO DDS in back online and delivering science data to the SOCs. All data downlinked while the DDS was offline will be sent by retransmissions.

Wednesday, May 13, 2015

IRU Calibration Maneuver is Complete

Today's IRU calibration Maneuver has finished. Here is a short movie showing what SDO did. We first pointed the high-gain antennas away from the Earth (that's why we didn't receive any science data). Next came a roll, 2 pitches, 2 yaws, 2 rolls, and a final roll back to our normal orientation. If you have ever waved your smartphone in a figure-8 to calibrate the navigation, you know what we were doing!
Thanks to the SDO FOT for taking the overnight shift to do this maneuver.

Tuesday, May 12, 2015

IRU Calibration Maneuver

SDO will perform an IRU Calibration maneuver on May 13, 2015 from 0400 UTC  (Midnight) to 1200 UTC (8 a.m. ET). The spacecraft will perform a series of roll, pitch, and yaw maneuvers designed to exercise the ACS. Science data may not be available during this time.

Wednesday, May 6, 2015

Momentum Management Maneuver #22 Complete

SDO executed Momentum Management Maneuver #22 today at 1815 UTC (2:15 pm ET). We used 48.8 gr (1.72 oz) of propellant to change the reaction wheel speeds to the desired rotation rates. Science data may be missing from 1800-1830 (UTC) while the burn was executed.

Tuesday, May 5, 2015

SDO 171 and 304 images get brighter

We've adjusted the settings on the AIA 171 Å (yellow) and 304 Å (orange) images - the Sun isn't getting brighter, the settings have been changed so features show up better.  The image below shows the comparison. 

Friday, May 1, 2015

Happy 5th Birthday to SDO Science Data!

Today is the 5th birthday of SDO Science Data. On May 1, 2010, SDO was commissioned as a NASA observatory and began sending science data to scientists and the public. We have watched Solar Cycle 24 rise to solar maximum, storing about 7 PBytes of data, releasing almost 200 million images, and having about 1900 scientific papers published describing new things we have learned.
I thought I would share two new images that show the solar magnetic field as only SDO can. The first is the average of the HMI magnetic field at each point on the Sun. White areas show where the magnetic field points out of the Sun and black regions are where the field points into the Sun. Grey regions have a magnetic field of zero. The Carrington longitude is used to give features on the Sun a position. We use the sine(latitude) rather than the latitude to avoid having the Sun look distorted like the Mercator maps of the Earth. The little circles are individual active regions. Even though this is an average over the last 5 years, we can see diagonal swaths of field in both the north and south hemispheres.
The other picture is how much each point on the Sun changed over those five years. The white points changed a lot while the black points changed very little. Now you see the diagonal lines a little better. Most of the changes in the solar magnetic field happen in the "active latitudes" where sunspots and flares are found. Very little happens at high latitudes. There is also very little happening along the Sun's equator.
You should compare these pictures with the averages of AIA 171 released two years ago.

SDO was launched to study the Sun's magnetic field. It is done a great job of recording the magnetic field, flares, filaments, and coronal holes during the rise of Solar Cycle 24. As Solar Cycle 24 fades SDO will continue to measure and report the magnetic field and what that magnetic field does in the solar atmosphere.

Thanks to the HMI for creating the maps of the magnetic field I used to create these pictures, and many thanks to the entire SDO team for the amazing mission they have run for the last 5 years.

SDO is GO!