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!

Wednesday, April 14, 2010

SDO Day 63.14159: More Tests

Today SDO ran the EVE Field of View and HMI/AIA Flat Field calibration maneuvers. HMI tested the re-transmission capability of the DDS by asking for re-transmissions of files that were not successfully transferred.

Tuesday, April 13, 2010

SDO Day 62: Still Testing After All These Weeks

SDO has continued instrument calibration for the past few days. These included an EVE cruciform and guide telescope monthly calibration. During the cruciform scan SDO left inertial mode (an attitude-control mode) and went into sun-acquisition mode. This was traced to a wrong number in a filter that slowly pushed the spacecraft in the wrong direction until an automated response cause SDO to enter sun-acq mode. The number was fixed and the GT calibration was run.

The EVE cruciform and HMI flat field maneuvers will run Wednesday.

This is why we test!

Monday, April 12, 2010

SDO Day 61: A Shakespearean Paean to SDO

A sonnet to SDO by one of our systems engineers

When sitting down to describe the events of the day,
I realize I’m growing weary of Haiku.
But still I’d like to express myself in some old fashioned way
And at the same time, try something new.
So tonight, I write in the form of a sonnet
Like the Bard would have, centuries ago.
But when it comes to news, though you might want it
I have very little to report that you don’t already know.
The Observatory continues her graceful figure eight,
SDOGS2 remains watchful and ready for command,
But there are no activities planned for this date,
And thus, the uplink is short on demand.
Thus concludes a nominal shift report:
I have expressed myself, and await your retort.

Saturday, April 10, 2010

Helios: An Exhibit of Eadweard Muybridge Photographs

Eadweard Muybridge is the father of stop action photography. He developed techniques to look at tumbling humans and moving animals. One of his most famous works was to see whether a galloping horse had all four hooves off the ground at the same time. Muybridge set up a series of cameras on the grounds of Stanford University and took 16 photographs that proved the horse gathered all four hooves under its belly at one instant in the gallop stride.

SDO uses similar techniques to make movies of coronal loops, magnetic fields, and prominence eruptions. We also need to ensure we sample the time intervals quickly enough and our pixels are small enough to see what is actually happening on the Sun. Muybridge answered similar questions as he studied animal locomotion.

Muybridge’s photographs are on display through July 18, 2010 at the Corcoran Gallery of Art in Washington DC.

Friday, April 9, 2010

SDO Day 58: Rolls are Complete

Our initial Science Reference Boresight was defined Friday. This is the target for the fine-guidance system in science mode, or it is the imaginary line that leaves SDO and hits the center of the Sun. All of the instruments can then figure out where they are pointed with very high accuracy.

SDO completed several calibration maneuvers this week, with more coming in next 10 days. Last nite the HMI/AIA roll was done. While SDO spins slowly around the axis pointing toward the Sun the instruments take measurements at different clock angles to check out their optics. We also tried stepping the high-gain antennas separately rather than together to see if the jitter was different.

The misbehaving high-powered amplifier on the SDO2 antenna was replaced and SDO2 is being brought back into full service.

We have left the vernal equinox eclipse season and look forward to almost 5 months of uninterrupted solar measurements!

Thursday, April 8, 2010

SDO EVE Rocket arrives at White Sands

PI Tom Woods and crew arrived in White Sands Missile Range, NM to integrate the EVE calibration rocket on Monday and perform initial checkouts of the payload to make sure it survived. All is going well, and the launch has been moved up to May 3. Upcoming tasks next week are the environmental tests - vibe, spin balance, and bend test. Hopefully we can get ITAR and security approval for pictures quickly and post those here in the near future.

Keep up to date with the status at:

Tuesday, April 6, 2010

SDO Day 55: Cruciforms and Raster Scans

Last evening the EVE cruciform was completed and the high-gain antenna raster resumed. A cruciform scan is a slow scan in a line through the Sun from East to West and another north to South, about 2.5 degrees in each direction. This is used to map out the field of view of the instrument. The high-gain antennas move quite a bit over a year and the raster scans are used to calibrate the pointing of the antennas.

Data continues to flow, SDO is GO!

Monday, April 5, 2010

SDO Day 54: A Day of Reflection

Sunday was a day to reflect on all of the data we have collected so far on the interaction of the instruments and the spacecraft. This week we begin a series of instrument calibration maneuvers and more testing of the high-gain antennas. First up is the EVE cruciform maneuver.

SDO is looking good!

Saturday, April 3, 2010

SDO Day 52: Instrument Jitter and Guide Telescopes

Today the instruments examined how they affect the pointing of SDO. FIlters and shutters inside the instruments have to rotate into new positions before each exposure, so SDO has a lot things spinning around. Each instrument ran their filters wheels and shutters to see how SDO moved. After that they tested the guide telescopes that are part of AIA. The "Science Reference Boresight" is determined by these guide telescopes, so understanding their behavior is crucial to SDO.

Friday, April 2, 2010

SDO Day 51: High-gain Antennas and Jitter

SDO spent another day measuring the jitter of the spacecraft, this time how the motion of the two high-gain antennas affected the pointing of the instruments. The instrument teams helped with these tests while continuing to understand their own observing sequences.

Thursday, April 1, 2010

SDO Day 50: The Wheels on the Spacecraft Bus Go Round and Round

Today SDO worked to understand how the reaction wheels that provide our fine pointing control interact with the spacecraft. SDO needs to point at the Sun very accurately while taking an image every 0.75 seconds (which means rotating shutters and filters), rotating the high-gain antennas to keep them pointed toward New Mexico, and rotate the entire observatory once per orbit to keep it pointed at the Sun. Understanding how the reaction wheels work is a essential step toward getting ready to send out the "firehose" of data SDO will generate.

Wednesday, March 31, 2010

SDO Day 49: The Future

The doors are open and the CCDs are cold, what's next? For the next several weeks SDO scientists and engineers will work to check out and calibrate the instruments and to coordinate the spacecraft and instruments. I may call it "Focus and Center" but it is a busy time for everyone on SDO making sure these complex instruments do what is needed to get our data. In mid-April we plan to show the world how great the instruments are working at a "First Light Media Telecon."

Stay tuned, Go SDO!

Tuesday, March 30, 2010

SDO Day 48: AIA Gets Cool

All of the instruments are now working with doors open and cold CCDs.

From Karel Schrijver of the AIA team:

Around 20:00 UT Monday the AIA CCD heaters were turned off allowing the CCD to temperatures drop rapidly from about +40C to -70C and then slowly settle towards their final temperatures. With that drop in temperature, we saw the camera background decrease markedly, and the image quality in all channels improve dramatically.

The engineering images are beautiful, even though taken in an approximate focus position. Tomorrow, we plan to make a series of focus scans to determine an initial optimal focus, and work will start on calibrating the detector amplifier gains, instrument stabilization system response, etc., which will continue to improve image quality.

Monday, March 29, 2010

SDO Day 47: A Weekend of Work

SInce opening all nine doors, work has continued getting the instruments ready for normal science operations. HMI continues to work on sequences and the image stabilization system. EVE is working on understanding their data. AIA is looking at solar images superimposed on the thermal background of their still-warm CCDs and updated their on-board flight software.

Saturday, March 27, 2010

SDO Day 45: AIA Doors are Opened

The AIA team members at the MOC celebrate the successful opening of all four AIA telescope doors by 15:30 UTC (11:30 am ET) on Saturday. The doors were opened in the order (by telescope number): 1, 4, 3, and 2.

The AIA CCDs are still warm. On Monday the decontamination heaters will be turned off, and the sequencer will be started so the CCD cool-down can be observed.

All nine SDO instrument doors are now open.

Congratulations AIA!

SDO Day 45: EVE Doors Open and the Sun Celebrates

Almost immediately after the EVE doors opened active region 11057 provided some fireworks and let loose with 4 C-class flares! Here is a graph from the NOAA SWPC in Boulder, CO showing the GOES X-ray fluxes. The EVE doors were all opened by 19:43 UTC, and the flares started at 21:08 UTC.

EVE will study the energetics of such flares while HMI and AIA tell us how and why they form.

Welcome to Solar Cycle 24.

Friday, March 26, 2010

SDO Day 44: EVE Door Opened

At 3:43 pm ET all four EVE doors were open. HMI and AIA were able to measure the jolt of the doors.

Here is the EVE team in the MOC after the doors opened. Congratulations EVE.

AIA doors are to be opened tomorrow.

SDO Day 44: EVE Door Opening

EVE team members at Goddard getting ready to open the EVE doors.

Go EVE, let the Sun shine in!

SDO Day 44: Spacecraft Jitter Tests

Thursday was spent testing the "jitter" of the observatory. Why do we care? SDO needs to keep its imaging telescopes pointed at the Sun with a steady hand. Our pixels image an area of the Sun that is about 0.5" across. While that's a patch the size of New Mexico on the Sun, it easier to think of it in terms of a quarter.

If you ran to the top of the Washington Monument in Washington, DC and held up a quarter, your friend would have to stand on the Wilson Bridge (6 miles away, waiting for the drawbridge to be lowered) to make the quarter look 0.5" across. Imagine how steady they would have to hold the camera to take a picture. SDO must keep the cameras pointed that accurately while moving around the Earth, keeping the high-gain antennas pointed at New Mexico, and with all the motors running to move filters and shutters in the instruments.

It's good to do jitter tests!

Thursday, March 25, 2010

SDO Day 42: HMI Opens Door, West Coast Style

During the HMI door opening a large part of the HMI team was at Stanford. Here they are celebrating the successful door opening and our first chance to see what the HMI instrument will do for solar studies.

Congratulations HMI!

Wednesday, March 24, 2010

SDO Day 42: HMI Opens Door

At 11:00 am EST this morning HMI began opening their door. This door protected the front window and optics from damage but can now be opened to let the Sun shine in. Sunlight was used to illuminate the front window and study the optical performance of the telescope. A sunspot could be seen in these engineering images.

Noon: Here are the HMI team members who did the commanding in the MOC, congratulations HMI!

SDO Day 42: The Doors Begin to Open

This morning the HMI door will be opened. Engineering images to test HMI will begin to flow. These will start with pictures of the door opening that allow the HMI team to study scattered light inside the instrument.


Tuesday, March 23, 2010

HMI CCDs are Cold, EVE CCDs are Cooling

The instrument teams of SDO began their work to start taking data. HMI allowed its CCDs to cool over the weekend and EVE started the cooldown cycle on Tuesday. AIA plans to watch the Sun while their CCDs cool to operational temperatures later this week. The Ka-band transmitter was turned on and high-rate (150 Mbps) data is flowing to the SOCs.

Saturday, March 20, 2010

A Busy Day for the Instruments

Friday was a day to run in science mode. SDO ran all three instruments over night with test patterns.

The EVE instrument completed its component check outs.

HMI prepared to turn off the decontamination heaters on Saturday to allow the CCDs to get cold.

AIA worked with their guide telescopes and image stabilization system. AIA'S GTs tell us where we are pointing with great precision and they are important to test.

SDO continues to operate well. Another longer eclipse will happen tonight and an antenna handover will be done.


Friday, March 19, 2010

From Tom Woods, EVE PI

Great news for EVE: all of the EVE subsystems are now turned on and all are
doing very well !!!

We turned on ESP, MEGS-A CCD, and MEGS-B CCD for this first time this
morning. Their dark data look fine. Every component looks healthy.

Congratulations and thanks to the EVE team and GSFC SDO project team !!!!"

Thursday, March 18, 2010

Ka-band Up and Running

Wednesday was a very good day for the SDO observatory and team. The Ka-band transmitter was turned on, the antennas pointed at the ground station, and data started to flow. Both ground antennas locked immediately and had good signal strength. HMI and AIA generated test pattern data, which was transmitted to the ground and forwarded to the JSOC without any errors.

The SDO team is now working with the antennas to make sure they track the Earth with one rotation per orbit. This allows us to send 150 Mbps to the ground. So far the Ka-band system is looking great! GO SDO!!

Tuesday, March 16, 2010

SDO is on Station

The third Trim Motor Firing (TMF #3) was successfully completed Tuesday evening. This apogee burn raised our perigee to geosynchronous with an orbital period of one day.

SDO is on station, next is to start up the instruments!

Tracking SDO's Attitude with the Stars

How does SDO know where it is pointing? Seems easy, just point at the brightest object in the sky! But what about our roll angle around the Sun, or where is the Sun's North Pole? SDO uses star trackers to measure its attitude. CCD images (like this one) are compared to a library to see where the star tracker is pointed. Once we know where the star trackers point we can figure out our roll angle on the Sun.

Sunday, March 14, 2010

TMF-2 Complete, On to TMF-3 and Final Orbit!

Trim Motor Firing #2 was successfully completed this morning. This was different from our previous burns in being a perigee burn to raise apogee. The final orbit trim maneuver, TMF-3, is scheduled for Tuesday evening. It will be an apogee burn to raise perigee to geosynchronous and our period to one day per orbit.

SDO will see a lunar transit (the moon passing between the Sun and SDO) tomorrow morning starting at 7:22 am EDT. It will last over 3.5 hours but will not be seen on the Earth.

Friday, March 12, 2010

TMF #1 Completed, Perigee Now 35.3 Mm

The first Trim Motor Firing (TMF #1) was successfully completed Thursday evening. This apogee burn raised our perigee to 35,300 km, an orbital period of 23.6 hr. This means we are drifting 6 degrees to the east in every orbit. Two more thruster burns will be done, TMF #2 is a perigee burn to raise the apogee to its final value and TMF #3 is an apogee burn to raise the perigee to its final value. Our eastward drift will also be stopped and we will orbit the Earth once per day at the longitude of New Mexico.

Wednesday, March 10, 2010

Main Engine Plumbing is Vented

Tuesday night the main engine fuel and oxidizer lines were vented. SDO will now fly on thrusters for orbit station keeping and momentum control. Many thanks to the SDO propulsion team for building SDO's bi-prop system, the first to be designed and built at Goddard. Our next orbital maneuver (TMF #1) is scheduled for Thursday evening.

Tuesday, March 9, 2010

AMF-8 Moves SDO Perigee Altitude to 34.6 Mm

Apogee Motor Firing #8, the last orbit raising maneuver, was successfully completed Monday night. This burn raised the SDO perigee altitude to about 34,600 km for a period of about 23 hr. With this orbit SDO will appear to drift eastward toward our final longitude.

Now that we are close to our final orbit the main engine plumbing will be vented to exhaust fuel and oxidizer from the lines. The first Trim Motor Firing (TMF #1) is planned for Thursday evening.

Saturday, March 6, 2010

A Successful AMF-7 Burn!

A successful Apogee Motor Firing #7 continued the string of smooth Main Engine burns since we removed the structural filter and lengthened the settling burn. AMF-7 raised our perigee altitude to approximately 25000 km, giving SDO an orbital period of about 19.2 hours. This sets SDO for one last trip "around the world" before Monday's AMF-8 actually moves SDO into a nearly geosynchronous orbit. After AMF-8, there will be three additional Trim Motor Firings (TMFs) to fix our operational orbit over White Sands.

Thursday, March 4, 2010

Our Orbit so Far

Here is the SDO orbit so far. The initial GTO, two intermediate orbits, and the estimated final orbit are shown to scale. Apogee Motor Firings (AMFs) all take place at the apogee of the orbit (the left side of the diagram) and are designed to lift the perigee (where SDO is closest to the Earth) up to a geosynchronous altitude. A few trim maneuvers will then move SDO into its final orbit. Perigee values are altitudes (height above the Earth).

Wednesday, March 3, 2010

AMF-6 Main Engine Burn Raises Perigee Altitude to 20 Mm

Apogee Motor Firing #6 was successfully completed Tuesday evening. The burn used about 6 minutes of ACS thruster firing and 13 minutes of Main Engine firing. This maneuver raised the SDO perigee altitude to about 20,100 km, or a period of 17.4 hr. The GNC team reported that the Main Engine burn was extremely quiet and the momentum disturbance due to the fuel sloshing was minimal. Due to the equipment outage at the Santiago ground station, most of ranging this evening was performed by SDOGS.

Monday, March 1, 2010

AMF-5, A Combined Thrusters and Main Engine Burn, Raises Perigee Above 15 Mm

Apogee Motor Firing #5 used the ACS thrusters and main engine to raise the perigee altitude of SDO to about 15,000 km on the way to our target of 35,800 km. (Using Kepler's law, my estimate of the current orbital period is about 15.4 hr.) We had a very smooth burn so we will use the main engine for the next burn that is scheduled for Tuesday evening.

Thanks to the slosh tiger team for their hard work on redesigning the flight software!

Saturday, February 27, 2010

AMF-4 Complete, Perigee Altitude Raised above 10 Mm

Apogee Motor Firing #4, a 50-minute burn using the ACS thrusters, was performed successfully on Friday. Our perigee altitude is now greater than 10,000 km as it continues to move away from the Earth toward a circular GEO orbit. The Slosh Tiger Team is recommending some tweaking to the ACS controller to allow main engine burns to resume. We are meeting today to discuss a "hybrid" burn for Sunday, 40 minutes on the ACS thrusters, followed by a 10-minute main engine burn.

Now that perigee is moving above the inner radiation belt it looks like EVE will no longer to able to measure trapped energetic protons and will have to wait for a solar signal. I hope these proton measurements can be used to improve our models of the inner radiation belt, especially AP8MIN, for the conditions present during this extended solar minimum period. That's what Living With a Star is all about!

Friday, February 26, 2010

Instrument Checkout and Testing Continues

Thursday on SDO: HMI & AIA completed their initial mechanism checkouts. Every instrument mechanism was moved in both directions. With the initial checkout complete HMI began their mechanism functional tests and completed testing the shutter mechanisms. The remainder of the HMI and AIA functional mechanism tests are scheduled for Saturday. EVE powered on their CCD survival patch heater.

Thursday, February 25, 2010

SDO Went Into Science Control Mode

SDO operated its ACS Science Control Mode for the first time on Thursday. In "science mode" the spacecraft uses AIA Guide Telescope signals for fine sun-pointing control. SDO stayed in science mode for more than an hour after which it was commanded back to inertial mode. Science mode worked very well.

HMI powered on its filter oven on Thursday. This oven keeps many of the optical elements at a constant temperature to allow the spectral scanning of the Fe 6173 line.

Wednesday, February 24, 2010

EVE team prepares for calibration rocket

While the EVE team continues to be busy with instrument commissioning, there is another task at hand that is critical to the success of the EVE instrument. This is preparing the first of five calibration sounding rockets that is set to launch May 5 from White Sands Missile range outside of Las Cruces, New Mexico. This sounding rocket caries an almost exact replica EVE instrument as the satellite version SDO EVE instrument. This sounding rocket, and the four that will follow over the prime SDO mission, will help determine any long-term degradation of the EVE optical system that may occur to help EVE obtain the most accurate measurements possible of the solar irradiance.
The picture shows the EVE calibration rocket in the rocket lab at the University of Colorado. The ESP channel can be seen on the left side, then the black optical cavities for MEGS B, A, and SAM channels continuing from left to right, respectively. Also seen in this payload is the prototype GOES R+ series X-ray Sensor (XRS) on top of the EVE optical package, and the prototype X-ray Photometer System (XPS) below EVE, both of which will help validate the rocket and SDO EVE measurements.

AMF-3 Burn Completed

Apogee Motor Firing #3, a 50-minute burn using the ACS thrusters, completed this evening with no issues.

Tuesday, February 23, 2010

SDO Launch is the Astronomy Picture of the Day

The waves created by the SDO Launch are the Astronomy Picture of the Day for February 23, 2010. You can see the sundog on the right side of the picture and the rocket in the middle.

Monday, February 22, 2010

A Great Day for Instruments!

HMI powered on the Image Stabilization System and both cameras. The operational heaters set points were increased from 10C to 15C and are controlling the instrument temperature nicely. The instrument is responding nominally.

AIA went from a minimal power state to being fully powered. This primarily meant powering up the Camera Electronic Boxes and the ISSs. With the ISSs powered up one is now able to see Guide Telescope signals, which indicate that the GTs are quite healthy and relatively aligned with one another. The thermal control system is appropriately controlling the AIA thermal environment. Over the next few days the temperatures will be increased to aid in outgassing.

EVE completed their scheduled commissioning procedures without errors. These procedures verified EVE autonomy rule functionality, EVE diagnostic channel packet receipt, all 4 filter wheels are functioning nominally and EVE instrument notification commands.

AMF 2B Raises Perigee by 1500 km

Orbit circularization maneuver AMF #2B, using the ACS thrusters, was accomplished successfully tonight. The burn was 50 minutes long (as designed), and all hardware and software performed as expected. There is now quite a bit more data for the continuing fuel slosh analysis, and the perigee has been increased by approximately 1500 km.

The data collected on this burn will be used to refine our understanding of the fuel slosh dynamics with the goal of returning to main engine burns as soon as we can. But until such an understanding is reached, we will continue with orbit circularization maneuvers using the ACS thrusters.

Sunday, February 21, 2010

Second Main Engine Firing Stopped Early by Spacecraft

February 19, 2010

The second Apogee Motor Firing (AMF #2) this evening was autonomously aborted after 30 seconds due to high system momentum. The Observatory is safe, the on-board system detected an unexpectedly high momentum, aborted the burn, and returned the Observatory to sun-pointing. Preliminary investigations do not show any indication of a hardware problem, more likely is that the combination of the settling burn (with the ACS thrusters prior to the main engine firing) immediately followed by the initial main engine burn exceeded the limits that were set (i.e. limits were set too low given this particular timing and fuel tank fill conditions). The plan is to continue reviewing the data to confirm the theory. If all holds, the next AMF burn would be scheduled for Sunday evening.

Friday, February 19, 2010

First Main Engine Burn Completed

February 17, 2010: SDO completed the first of 9 main engine burns that will raise the spacecraft into its final geosynchronous orbit.

Thursday, February 18, 2010

A Successful Beginning for the Solar Dynamics Observatory

Thu, 11 Feb 2010 12:23:25 PM EST

Shortly after separation, the team confirmed the spacecraft's solar arrays deployed correctly and are generating power. All the crucial post-separation events "happened like clockwork," said NASA Launch Director Omar Baez.

This concludes live coverage of the countdown and liftoff of the Atlas V rocket carrying the Solar Dynamics Observatory. For further mission information, please visit . Thanks for joining us!

Spacecraft Separation!

Thu, 11 Feb 2010 12:12:43 PM EST

NASA's Solar Dynamics Observatory is on its own in Earth orbit after a perfect liftoff from Cape Canaveral Air Force Station in Florida at 10:23 a.m. The spacecraft separated from the Centaur upper stage right on time.

Second Main Engine Cutoff

Thu, 11 Feb 2010 12:10:12 PM EST

Now one hour and 46 minutes into the flight of the Solar Dynamics Observatory, the Centaur's main engine has completed its second and final burn. The vehicle is moving to spacecraft separation attitude. The spacecraft will separate from the Centaur momentarily.

Second Main Engine Up and Burning

Thu, 11 Feb 2010 12:06:08 PM EST

The Centaur's RL10 main engine reignited on time at 12:05 p.m. for a three-minute burn. The Solar Dynamics Observatory spacecraft will separate from the Centaur about three minutes after the second main engine cutoff.

Centaur Positioning for Second Burn

Thu, 11 Feb 2010 12:03:11 PM EST

The Centaur has stopped its slow thermal-control roll in advance of its second main engine burn, now about three minutes away.

Centaur's Second Burn Coming Up

Thu, 11 Feb 2010 11:50:05 AM EST

At the time of the Centaur main engine's second burn, known as MES2, the vehicle and spacecraft will be high above the Pacific Ocean northeast of Australia. The burn is expected one hour and 42 minutes into the flight. Data picked up by the Tracking and Data Relay Satellite System indicates a healthy SDO spacecraft and a healthy Centaur.

Centaur, SDO Still in Coast Phase

Thu, 11 Feb 2010 11:30:34 AM EST

After a spectacular on-time liftoff at 10:23 a.m. and a flawless ride into space, the Solar Dynamics Observatory spacecraft remains attached to the Centaur upper stage in a parking orbit. The Centaur's main engine will burn once more to position the spacecraft for separation. That second burn is expected at approximately 12:05 p.m.

Centaur First Engine Burn Complete; Beginning Coast Phase

Thu, 11 Feb 2010 10:39:31 AM EST

The Centaur's main engine cut off on time, ending its first burn. Centaur and spacecraft are in a parking orbit, entering a coast phase scheduled to last about an hour and 27 minutes.

TDRS System Tracking Flight

Thu, 11 Feb 2010 10:35:04 AM EST

Antigua has lost tracking data as the vehicle and spacecraft travel out of range. All the vehicle's systems continue to perform as expected as the Tracking and Data Relay Satellite System tracks the flight.

Flight Perfect So Far

Thu, 11 Feb 2010 10:30:28 AM EST

Data is coming in from the Antigua tracking station and so far the flight is going very well, exactly as expected.

Centaur First Main Engine Start

Thu, 11 Feb 2010 10:28:21 AM EST

The Atlas V booster has completed its burn and separated from the Centaur upper stage. The Centaur main engine is burning now at 22,300 pounds of thrust; it will propel the SDO spacecraft through the rest of its flight into space. At the top of the rocket, the payload fairing has opened and fallen free, exposing the spacecraft to the space environment. The flight is going very smoothly.

Atlas V Rattles the Space Coast

Thu, 11 Feb 2010 10:25:11 AM EST

The Atlas V carrying the SDO spacecraft is shaking the Space Coast as it goes supersonic, passing the area of maximum aerodynamic pressure known as Max Q. Everything looks good on the vehicle.

Liftoff of NASA's Newest Solar Observatory!

Thu, 11 Feb 2010 10:23:10 AM EST

NASA's Solar Dynamics Observatory is on its way into space, seeking a vantage point in orbit where it will examine our sun in more detail than ever before. The Atlas V carrying the SDO spacecraft is thundering into the Florida sky on 863,000 pounds of thrust. The booster's RD-180 engine will burn for about four minutes before the booster burns out and separates from the Centaur upper stage.

T-1 Minute and Counting

Thu, 11 Feb 2010 10:22:35 AM EST

Liftoff is one minute away.

T-3 Minutes and Counting

Thu, 11 Feb 2010 10:20:42 AM EST

The Atlas propellant tanks are being brought up to flight pressure and the flight termination system is on internal power.

T-4 Minutes and Counting

Thu, 11 Feb 2010 10:19:07 AM EST

We're now four minutes away from liftoff of the Atlas V rocket with NASA's Solar Dynamics Observatory! The sky is clearing above Launch Complex 41 and winds are below limits. Stand by for liftoff.

SDO Spacecraft Switching to Internal Power

Thu, 11 Feb 2010 10:14:47 AM EST

The Solar Dynamics Observatory spacecraft is switching to internal power, signaling that launch is on schedule for 10:23 a.m.

NASA Ready to Proceed

Thu, 11 Feb 2010 10:12:27 AM EST

NASA Launch Director Omar Baez has polled his team and everyone reports they're ready to proceed with the countdown.

T-4 Minutes and Holding

Thu, 11 Feb 2010 10:09:15 AM EST

Countdown clocks are holding at T-4 minutes for 10 minutes. This hold may be extended if the launch team chooses to target a launch time later in the launch window.

All Atlas V and Centaur propellants are at flight level.

Weather Looks Favorable for Launch

Thu, 11 Feb 2010 10:08:09 AM EST

Launch Weather Officer Clay Flinn just briefed the launch team on the latest weather conditions. Clouds passing over the pad right now are not thick enough to violate the launch commit criteria, and Flinn predicts we'll be "green" for that thick cloud rule for at least another 45 minutes, well into today's launch window. Winds are 15 knots, gusting to 18, although isolated gusts above 20 knots are possible.

30 Minutes Until Launch

Thu, 11 Feb 2010 09:54:02 AM EST

We're about half an hour away from the opening of today's launch window at 10:23 a.m. The countdown continues to go very smoothly, with winds and clouds the only topics of concern. Winds are hovering near the 20-knot limit, occasionally gusting above it, but generally staying below it. An area of clouds moving east across Central Florida is believed to be thin enough not to impact launch, but a weather aircraft is monitoring it and relaying data back to forecasters with the 45th Weather Squadron.

Flight Termination System Checks Complete

Thu, 11 Feb 2010 09:47:32 AM EST

Range Safety has completed their final set of communication checks between range antennas and the Atlas V vehicle. That's the communication loop the rocket's flight termination system would use to destroy the rocket if it veered dangerously off course.

Winds have increased a bit, occasionally bumping up above the 20-knot limit, which is exactly what forecasters predicted might happen. We're still expected to find a time during the launch window when winds stay within limits.

Atlas Liquid Oxygen Tanking Complete

Thu, 11 Feb 2010 09:37:04 AM EST

At T-37 minutes and counting, the Atlas V booster's liquid oxygen level has reached 97.5 percent, and topping is under way.

Centaur Tanking Update

Thu, 11 Feb 2010 09:26:09 AM EST

About half of the Centaur's liquid hydrogen has been loaded aboard. There are about 40 minutes left in the Atlas V/Centaur tanking process.

The countdown clock is at T-47 minutes and counting. Our next hold -- and the final planned hold for today -- will begin at T-4 minutes at 10:09 a.m.

Seeing the Sun in High Resolution

Thu, 11 Feb 2010 09:23:07 AM EST

The Solar Dynamics Observatory's Atmospheric Imaging Assembly will allow scientists to see the entire disc of the sun in very high resolution -- 4,096 by 4,096 millimeter charge-coupled device, or CCD. The light-sensitive CCD stores image data and converts it to color. In comparison, a standard digital camera uses a 7.176 by 5.329 millimeter CCD sensor.

Centaur Liquid Hydrogen Tanking Under Way

Thu, 11 Feb 2010 09:12:23 AM EST

The team is beginning to load 12,680 gallons of liquid hydrogen into the Centaur upper stage. Atlas V liquid oxygen loading just passed 50 percent.

Spacecraft Test Team "Go" for Launch

Thu, 11 Feb 2010 09:07:27 AM EST

The Solar Dynamics Observatory test team reports there are no problems with the spacecraft, and with the exception of the switch to internal power, SDO is ready to fly. The spacecraft will change to internal power after launch managers commit to a launch time. Right now, the team continues to aim for the opening of today's launch window at 10:23 a.m.

Winds Staying Within Limits

Thu, 11 Feb 2010 09:03:02 AM EST

Winds are staying below the 20-knot limit, and launch managers are cautiously optimistic the weather and wind will stay "green" for liftoff at 10:23 a.m. The area of clouds approaching from the west is expected to reach the launch area around launch time, but forecasters believe the clouds are too thin to pose a problem. A weather aircraft is going to fly into the clouds soon, providing more conclusive information.

The liquid oxygen level on the Atlas V booster just passed 30 percent.

Centaur Liquid Oxygen Loading Complete

Thu, 11 Feb 2010 08:54:04 AM EST

The Centaur upper stage's liquid oxygen level has reached 95 percent. At this point, the "topping" process will pump small amounts of the propellant into the tank to replace any that evaporates during the rest of the countdown.

Centaur Tanking Status

Thu, 11 Feb 2010 08:50:23 AM EST

The liquid oxygen level aboard the Centaur upper stage is at 80 percent, and the hardware that will be used during the upcoming liquid hydrogen load is being chilled.

Atlas V Tanking Begins

Thu, 11 Feb 2010 08:46:13 AM EST

Atlas V chilldown is complete and the team is beginning to load liquid oxygen into the booster. The Eastern Range is "green," or "go," on all counts and there are no problems in work. It's a very quiet countdown at this point.

Centaur Tanking Status

Thu, 11 Feb 2010 08:37:48 AM EST

At T-96 minutes and counting, the Centaur upper stage liquid oxygen loading just passed 30 percent.

Atlas liquid oxygen tanking will begin in about five minutes.

Countdown Update

Thu, 11 Feb 2010 08:21:39 AM EST

Although winds are marginal and occasionally gusting above the limit, the overall trend is much better than yesterday's. An area of clouds has appeared off to the west, and a weather aircraft will fly out and take a closer look at the clouds' thickness and temperature.

Launch managers will decide about five minutes before launch -- the last minute of the T-4 minute hold -- whether to commit to launch at 10:23 a.m. If they decide to wait until further in the window, due to wind or another issue, they will stay in the T-4 minute hold and the spacecraft will remain on external power until the decision is made to come out of the hold.

T-2 Hours and Counting

Thu, 11 Feb 2010 08:13:08 AM EST

Countdown clocks are ticking backward once more as the T-2 hour hold comes to an end. Today's countdown continues to go smoothly, with no technical issues reported.

Launch Team, Range Ready for Tanking

Thu, 11 Feb 2010 08:11:25 AM EST

The launch team is ready to begin filling the rocket's propellant tanks with cryogenic liquid oxygen and liquid hydrogen. The booster's RP-1 tank is already loaded. Tanking will begin with "chilldown," which cools and conditions the ground equipment and transfer lines that will come in contact with these extremely cold propellants.

The 10-foot-wide, 41.5-foot-tall Centaur upper stage will be filled with 4,150 gallons of liquid oxygen and 12,680 gallons of liquid hydrogen; the Atlas V booster's propellant tanks hold 48,860 gallons of liquid oxygen and 25,540 gallons of RP-1.

The countdown will pick up once again at 8:13 a.m. as we come out of the T-2 hour hold.

SDO's Suite of Instruments

Thu, 11 Feb 2010 08:03:09 AM EST

The Solar Dynamics Observatory will rely on three advanced science instruments to meet the mission's goals. The Atmospheric Imaging Assembly, an array of four telescopes, will observe the solar surface and atmosphere. The Extreme Ultraviolet Variability Experiment will measure changes in the amount of ultraviolet light the sun emits. Finally, the Helioseismic and Magnetic Imager will create maps of the sun's magnetic fields and look past the sun's surface.

Atlas V Will Provide SDO's Ride

Thu, 11 Feb 2010 07:54:39 AM EST

Built by United Launch Alliance, the 191-foot-tall Atlas V-401 rocket that will boost SDO into space is composed of the orange booster stage topped by the Centaur upper stage. The spacecraft is mounted inside the protective payload fairing above the upper stage.

The next major countdown milestone is the start of the "tanking" process, when storage tanks in the rocket's booster stage and upper stage are filled with propellants. The booster's RD-180 main engine runs on a combination of liquid oxygen and Rocket Propellant-1 fuel, a refined kerosene usually referred to as RP-1. The Centaur's RL10 engine is powered by liquid oxygen and liquid hydrogen.

T-120 Minutes and Holding

Thu, 11 Feb 2010 07:43:08 AM EST

Countdown clocks across Cape Canaveral Air Force Station have paused at T-2 hours for a 30-minute built-in hold. The countdown will resume at 8:13 a.m.

Solar Dynamics Observatory: NASA's Newest Sun-Watcher

Thu, 11 Feb 2010 07:40:03 AM EST

Our nearest star is the dominating force behind Earth's climate -- and space weather throughout the solar system. Powerful solar flares, fierce coronal mass ejections and other intense solar events can disrupt communications and power systems on Earth, and threaten astronauts living and working outside the relative protection of our atmosphere.

The Solar Dynamics Observatory is embarking on a five-year mission to investigate -- in unprecedented detail -- the energy processes driving the sun's stormy activity. The 6,555-pound spacecraft will return 1.5 terabytes of data every day -- equal to half a million downloaded songs -- and provide detailed images of near-IMAX-quality high resolution. The mission is the first of NASA's Living With a Star Program.

Weather Update

Thu, 11 Feb 2010 07:34:23 AM EST

Launch Weather Officer Clay Flinn just briefed NASA Launch Manager Omar Baez and the rest of the launch team about today's weather forecast. There's no threat of clouds or precipitation interfering with today's liftoff, and although winds are gusting to the 20-knot limit, "by the front of the window, we should be in decent shape," Flinn said. It's a chilly morning at Florida's spaceport, with temperatures expected to rise into the lower 40s during the countdown.

In the event of another scrub today, weather on Friday will be considerably worse, with rain in the forecast. Weather on Saturday would be better, although winds would remain a problem.

At T-130 minutes and counting, the launch pad is being cleared to prepare for loading of extremely cold, or cryogenic, propellants. The Eastern Range has completed its check of the hold-fire system that would allow range personnel to stop launch for safety reasons.

Countdown Conducted from Atlas Spaceflight Operations Center

Thu, 11 Feb 2010 07:21:50 AM EST

A few miles south of the launch pad, launch managers and controllers are monitoring the countdown from their consoles inside the Atlas Spaceflight Operations Center. The blog console is located inside the nearby Launch Vehicle Data Center, where we're listening to the launch team's communication channels along with launch support personnel.

Solar Dynamics Observatory Ready for Launch

Thu, 11 Feb 2010 07:18:08 AM EST

Welcome once again to the launch countdown for NASA's Solar Dynamics Observatory aboard a United Launch Alliance Atlas V rocket. The launch team hasn't encountered any problems that would prevent liftoff at 10:23 a.m. EST from Cape Canaveral Air Force Station in Florida.

Today's main concern will be the weather. Winds are likely to be close to the 20-knot limit, but lower than yesterday's launch attempt, when winds exceeded limits throughout the countdown and ultimately scrubbed the liftoff. The forecast for today is better, with 45th Weather Squadron forecasters predicting a 60 percent chance of weather favorable for launch. Launch Weather Officer Clay Flinn will provide a detailed weather briefing in just a few minutes, so we'll share that information with you.

Coming Up: Countdown Coverage

Thu, 11 Feb 2010 06:21:50 AM EST

Today's live coverage of the launch of Solar Dynamics Observatory will begin at 7:15 a.m. EST.

Wednesday, February 17, 2010

Follow the Countdown

Wed, 13 Jan 2010 12:39:56 PM EST

Join us on launch day and follow the action as the clock ticks toward liftoff of NASA's Solar Dynamics Observatory aboard an Atlas V rocket.