Friday, May 14, 2010

SDO Day 93: SDO Becomes an Operating Mission

SDO was declared an operational mission today at the Goddard Space Flight Center. This means we have shown the spacecraft and instruments are ready to collect science data. The science teams are working on making that data available to the scientists and space-weather public.

Monday, May 10, 2010

SDO Day 89: Our Next Poem

We have had haikus and sonnets written about the commissioning phase. Now a First Light poem, written by Stuart Atkinson about the prominence eruption on March 30, 2010.

First Light...
And at last, the secret of our solar system's star has been revealed:
Concealed beneath its brightly shimmering, ever-shifting shells
Of ancient hydrogen a mighty dragon lies; planet-sized
Eyes flashing with photon fire, riding the great plasma tides
Boiling up from Sol's deep core, it roars in raw delight,
Feeding on the brutal fusion light throbbing beneath its feet...
Hiding in the Sun's dark heart it bathes in nuclear fire,
Revelling in its fury, rolling in it, each beat of its wings
Sending great waves of energy slamming up into the
Chromosphere to ripple and roil across Sol's surface
In tsunamis of atomic fire, to the amazement of those watching,
Wide-eyed, on Faraday's far-away Earth...
But these images reveal the dragon is not alone;
The Sun's firestorm fields clearly have shielded
Our prying eyes from flocks of phoenixes flying
In the dragon's wake. Each time a starfirebird bursts
Through the seething surface of our star we see
A glorious prominence leaping into space;
Every feathered, towering arch traces out the path
Of a phoenix's graceful rise and fall.
Each time one manages to break free
Of the Sun's greedy gravity we see a
Fiery red banner billow out, tatter and tear,
Flapping away like it had never been there...
© Stuart Atkinson 2010

Tuesday, May 4, 2010

SDO Day 83: EVE Calibration Rocket Launch

Check out the launch of the EVE calibration rocket launch at It shows the countdown and the rocket flying away.

Some cool things to see in the on-board aft-viewing camera (time is from the payload clock timer) :
8:45 launch and spinup
10:02: yo-yo despin
10:05: ejection of yo-yo despin cables
10:10: Black Brandt 2nd stage falling away toward Earth
10:12: Shutter door with crush bumper opening
10:16: Switch to nose-viewing camera
10:20: Nose cone ejection and seeing the nose cone fall away
10:40: Solar acquisition

Monday, May 3, 2010

SDO EVE calibration rocket launch day!

Today, May 3, at 2:12 pm ET/12:12 pm MT the SDO EVE calibration rocket will launch from White Sands Missile Range, NM. Everything is looking good for an on time launch. No real time video is allowed due to security reasons on the Missile Range, but the CCD data and video from the cameras (one pointing forward, one aft) will be posted as soon as possible. Follow the day's progress at:

Wednesday, April 28, 2010

SDO Day 78: Just the CCD Facts, Ma'am

SDO has 10 CCDs, 8 inside the science instruments and 2 in the star trackers. The science CCDs operate at very low temperatures. The EVE CCDs are 2Kx2K pixels and operate at -100 C. The HMI and AIA CCDs are 4Kx4K and operate at about -70 C. HMI has 2 high-grade visible light CCDs while AIA and EVE treated their CCDs to make them more suitable for detecting extreme ultraviolet light. To cool a CCD we hook it to a radiator panel and keep the Sun off the panel. Thermal radiation leaving the panel is enough to send into space the small amount of heat generated by operating the CCD.

An example of how the Sun affects our satellite fleet happened on April 5, 2010. Unusually violent solar activity caused the Galaxy 15 satellite to stop responding to ground commands. A backup satellite is being moved into position and it is hoped that Galaxy 15 will be recovered.

Monday, April 26, 2010

SDO Day 76: Getting Ready for Science Data

SDO is moving toward becoming an operational science mission. The data will be available from several sites in a variety of formats. SDO scientists and engineers are working to set up those access points, but we won't be ready for regular data releases until mid-May.

Next step is the EVE calibration rocket, scheduled to fly on May 3, 2010 from the White Sands Missile Range.

Friday, April 23, 2010

SDO Day 73: The End of Jitter Testing

Thursday marked the end of image quality jitter testing on SDO. For the past few days the observatory has spun reaction wheels, rotated high-gain antennas, and moved filter wheels. All this to see how each mechanism affected the staring at the Sun. All of the data must now be analyzed and our fine pointing refined to allow us to stare at the Sun.

This week also saw the isolation of the main engine. We no longer need the large thrust provided by the main engine and the pipes carrying fuel and oxidizer to it have been closed and sealed. Thanks for the lift!

Thursday, April 22, 2010

SDO Day 72: First Light Data is Released

The principal investigators of the SDO science investigation teams, Philip Scherrer (HMI), Alan Title (AIA), and Tom Woods (EVE) joined Dean Pesnell and Lika Guharthakurta in an SDO First Light press conference yesterday at the Newseum in Washington, DC. The announcement has garnered a lot of press and many examples of those few solar events that saw fit to appear between March 30 and April 8 are now available. Here is an example from March 30, 2010, just after the AIA CCDs were allowed to cool. Such a lovely prominence eruption at 10 o'clock!

Congratulations to the SDO team members around the world for getting us to the beginning of the science mission.

Monday, April 19, 2010

SDO Day 69: A Weekend Summary

Over the weekend SDO completed the HMI roll maneuvers and began preparing for the image quality jitter tests. The next major activity is to isolate the main engine. First, the isolation pyros on the main engine will be fired to isolate the Helium pressurant and main engine from the observatory. After that is the first 2 Nms delta-H thruster maneuver, used to dissipate momentum.

Friday, April 16, 2010

SDO Day 65: Calibration Maneuvers

The EVE cruciform maneuver was completed yesterday. Other tests included the high-gain antenna handover with stagger stepping and no-step requests. These tests are required to keep the observatory from moving too much while taking an image with HMI and possibly AIA.

Next Tuesday we plan to have an Delta-H thruster burn. These momentum unloads are required to keep the reaction wheels spinning at the correct speeds.

Next Wednesday we are having a First Light Press Conference at the Newseum in Washington, DC. Stay tuned for proof that the instruments on SDO are working great!