What's New

Automated detection of CMEs from STEREO/SECCHI data is now available as part of the SEEDS: Solar Eruptive Event Detection System from the George Mason University Space Weather Lab.

The STEREO proposal to the 2008 Senior Review is now available from our publications page.

The PLASTIC level-1 data archived at the SSC have been moved down into a new level1 subdirectory to make way for new level-2 data which are now available.

Daily browse movies are now available from the CDAW Data Center. This website allows one to examine side-by-side images from STEREO Ahead and Behind, or from two SECCHI telescopes on the same spacecraft.

Normal operations have resumed on Behind, one day earlier than originally expected. Both spacecraft are now operating as expected.

The Behind star tracker has continued to perform nominally since December 23. Should no further problems develop, Mission Operations plans to resume normal operations on Friday's track (Dec 28).

The Mission Operations team was able today to command the star tracker on Behind back into operational mode. The star tracker continued to operate throughout the track. As a precaution, use of the star tracker was suspended at the end of the track, and the spacecraft was switched from the high gain to low gain antenna. Mission Operations will continue to staff tracks, and proceed with caution regarding ST usage. Contingency planning will continue as will discussion with the star tracker supplier.

Problems persist with the star tracker on Behind. The high gain antenna continues to point to Earth, and the Mission Operations team was able to use it to download science telemetry. All other spacecraft systems continue to operate normally.

The star tracker on STEREO Behind had an anomaly at 10:10 GMT this morning. This resulted in the spacecraft autonomously switching to the low gain antenna. All other spacecraft systems are healthy. Diagnostic telemetry is being collected, and corrective action is under consideration.

Science data is still being collected, but at the current low telemetry rate it is not possible to send it to the ground. Some science data may be lost when the onboard recorders reach their maximum capacity.

Running difference images and movies from the SECCHI Heliospheric Imager HI-2 telescope are now available on the SSC browse and image search pages. So far, only a few days are available, mostly in December 2007, but more days will be populated in the near future.

Unlike the other SECCHI telescopes, the HI-2 images are only processed from the full resolution level-0 science data. Thus, there is a delay of several days before any HI-2 images are available.

Data from the IMPACT STE detectors are now available on the SSC archive.

Realtime SWAVES radio beacon plots are now available on the In-Situ & Radio Space Weather Beacon Data page.

The STEREO Journal Publication Database is now online. Users are encouraged to submit published journal articles involving the STEREO mission for inclusion in the database.

Realtime SECCHI HI1 telescope images are now available on the Latest SECCHI beacon images page.

Daily MPEG summary movies are now available from the Daily Browse page.

Images from the SECCHI HI1 telescope are now available on the Daily Browse and Image Search Tool pages. Because the HI1 images are derived from the level-0 science data, they take a few days to appear on the website.

IMPACT Level-1 data files are now available.

Images from the SECCHI COR2 telescope are now available on the Latest SECCHI Beacon Images page. As they become available, these images will also appear on our Daily Browse and Image Search Tool pages.

Images from the SECCHI COR1 telescope are now available on the Latest SECCHI Beacon Images page. We hope to add images from the other SECCHI telescopes soon. As they become available, these images will also appear on our Daily Browse and Image Search Tool pages.

Several improvements have been made to the in-situ beacon pages at http://stereo-ssc.nascom.nasa.gov/beacon/beacon_insitu.shtml. The IMPACT magnetometer data is now in the standard Radial-Tangential-Normal (RTN) coordinates, and total magnetic field strength has been added to the plots. New pages have been added for solar energetic particle data.

The daily data browse pages are now available at http://stereo-ssc.nascom.nasa.gov/browse/. So far, only a few days worth of data are available, but earlier data will be steadily added. We're also working on adding more in-situ data, as well as the daily summary plots from SWAVES.

Realtime beacon in-situ plots are now available at http://stereo-ssc.nascom.nasa.gov/beacon/beacon_insitu.shmtl.

SWAVES data is now archived within the STEREO Science Center at http://stereo-ssc.nascom.nasa.gov/data/ins_data/swaves.

Real-time space weather beacon images from SECCHI are now on-line at http://stereo-ssc.nascom.nasa.gov/beacon/beacon_secchi.shtml.

SECCHI and PLASTIC science data are now available through the Virtual Solar Observatory.

New web page for auxiliary data, which is data produced by other observatories either in conjunction with the STEREO project, or which is useful for analyzing STEREO data.

The Behind spacecraft flew by the Moon for the second and last time on January 21. Both spacecraft are now in heading away from Earth into their orbits around the Sun. The official science mission started January 22.

The baffle cover on the SECCHI Heliospheric Imager on Behind was opened on January 11. The scientists were thrilled to find that Comet McNaught was in the HI-1B field of view. The IMPACT SIT and SEPT covers were opened on Behind on January 16. All instrument covers are now open.

The A spacecraft performed its lunar flyby last Friday and is now in heliocentric orbit.  The drift rate of the spacecraft is +21.66 degrees/year (relative to the earth), this is well within its specification of 22+/- 2 deg/year. The B spacecraft also performed a lunar flyby, but its trajectory has another flyby scheduled for 21 January 2007.  The B spacecraft successfully completed its final trajectory adjustment maneuver on this Thursday.

All the subsystems on both spacecraft continue to perform very well.  On Monday, Dec. 11, the Ops team performed a peak power test on the A-spacecraft.  The arrays are producing slightly more power than expected  (720W vs 690W).  The G&C team has started to tweak the control algorithms with the result that mechanical oscillation of the SWAVES antennae has completely disappeared on both spacecraft.  They will continue to fine tune the system and are planning a test which would run all the wheels through all speeds to investigate the effect of wheel speed on jitter.

The SECCHI SCIP-B telescope doors (EUVI, COR1 and COR2) were successfully opened Dec. 13 at 6:30am. First light images were taken and reviewed by a bunch of very happy scientists on the east and west coasts.  Performance was as expected and comparable to the SCIP-A telescope images taken last week. In addition, there was a successful opening of the first HI telescope door on S/C-A. The HI images appear to be exceptional. This means that of the 10 SECCHI telescopes, 8 have successfully opened their doors and taken good images. The HI-B door, which covers the last 2 telescopes, will open at the end of December or early January, depending on when we verify that there will be no more B Observatory maneuvers.

The IMPACT SEPT-NS, SEPT-E and SIT doors were deployed Dec. 14 on Ahead. In anticipation of this exciting event, the Sun decided to become active making it easy to confirm the door openings in the science telemetry. There were 5 door actuations - one for SIT and two for each set of doors on SEPT-E and SEPT-NS. The door deployments for SIT, SEPT-NS and SEPT-E on Spacecraft B will be in mid January.

The SECCHI team opened the doors to the SECCHI SCIP-A instruments and took a few first-light images. Everything went absolutely smoothly. The three doors opened without incident. The first images look great even though they were sent down highly compressed to keep the downlink time reasonable.

The EUVI was opened first and an image from each of the four quadrants looked fine - no major tears or pinholes in the front filters. The sun is close to being in the center of the CCD, and the resolution is beautiful.

Then we opened COR2 and took an image--also beautiful, although there is a slight offpoint (which we expected). The exposure time is just about where we expected, about 3-4 seconds. We then took a pB sequence of 3 images with the result that streamers could be seen all the way to the edge of the field.

Then COR1 was opened and it was also as expected. A pB sequence shows the inner corona nicely out to about 2.5 R, which is what we expected.

Both the Ahead and Behind spacecraft performance continue to perform very well with all subsystems nominal. The instruments on both observatories continue to perform well. The SECCHI instrument team is planning to open the doors on the STEREO-A coronagraphs next week and is completing internal tests.

The definitive orbit solutions from FDF indicate that the STEREO A Observatory will achieve its required drift rate without further maneuvers. The STEREO B Observatory will require a 0.2m/s maneuver currently scheduled approximately December 8th. Both spacecraft will swingby the moon on December 15th, with a second lunar swingby for STEREO B on January 21st.

The guide telescope has been enabled on both spacecraft. G&C is assessing the performance of the attitude control algorithms and will upload new parameters in December.

The SWAVES team is now producing daily summary plots through their website at http://swaves.gsfc.nasa.gov. Follow the links to "data" and then "data plots".

Both the Ahead and Behind spacecraft performance continue to perform very well. So far, all the planned maneuvers have been completed successfully. The Mission Operations team is studying the current orbit of the Ahead spacecraft to see if any more orbital maneuvers are necessary. At least one more delta-V maneuver is planned for the Behind observatory.

The instruments on both observatories continue to perform well. They were powered down prior to the P2 maneuvers and then powered back on successfully. The SEP Central, HET, LET, SIT, SEPT-E, SEPT-NS detectors on IMPACT have been successfully been powered on and checked out on both observatories. The Caltech team was able to correlate the first 100 minutes of data from the STEREO LET instrument on IMPACT with ACE data and the spectra were found to be consistent.

A spacecraft roll to calibrate the IMPACT Magnetometer was performed on each observatory. Initial results show that the test was highly successful.

PLASTIC continues to ramp up their high voltage levels on their MCPs. At the current HV levels they are starting to see counts from penetrating particles or photons on their position detectors. The SSDs are also seeing penetrating particles and photons.

The SECCHI team has completed their decontamination heating of the CCDs on the COR1 and COR2 telescopes and are preparing to do the same with the EUVI and HI telescopes.

All the spacecraft subsystems are performing very well. The Guide Telescope was enabled on the A spacecraft Sunday and acquired the sun. The GT on the B spacecraft was enabled Monday. In both cases the GT data looks good and the spacecraft algorithms are correctly using the data. The spacecraft pointing improved markedly with the GT enabled. There are more planned tests of the GT and spacecraft control algorithms in December and more tweaking of the control algorithms.

A complete functional test of the both SECCHI suites was completed at the end of last week and both suites are working well.

The SEP instruments on the B spacecraft were turned on for the first time this afternoon. Initial indications are very good.

Both spacecraft went through a 25 minute eclipse as they went through perigee this morning. The spacecraft behaved nominally throughout eclipse and are now on their way out to moon radius. The Ahead spacecraft was intentionally sent to Earth Acquisition mode in order to test the EA system. The operation of the spacecraft was completely nominal in EA and recovery from EA to Standby was nominal. The instruments on the A spacecraft were turned off as part of the EA test. The instruments were turned back on and are continuing with commissioning activities.

The PLASTIC SSD high voltage has been turned on both spacecraft. The MCP high voltages have been turn on at low voltage on both spacecraft. The MCP voltages will be ramped up to operational voltages over the next month.

This is STEREO's second week in Earth orbit(s). It is still in it's first of four phasing orbits--prior to the first lunar swingby. So far the planned commissioning activities have occurred without any serious anomalies. The major deployments of solar arrays, spacecraft separation, and high gain antennas occurred almost immediately after launch. Since then, the SWAVES antennas on each observatory have been deployed -- and SWAVES started producing significant science data.

This week, the significant commission events were the execution of the apogee propulsive maneuvers on both spacecraft that raised their perigees to altitudes that are comfortably above the atmosphere. These 'burns' were accurate to within 0.5% -- that is considered very good considering that the observatories have not yet been fully characterized. The other significant event was the deployment of the four meter rigid IMPACT boom on each observatory. The MOPS and Engineering teams performed other important activities: 1) the High Gain Antennae were successfully exercised over their full range of motion on both spacecraft. 2) The software team completed its assessment of observed SEU bit flips on the C&DH and G&C computers and uplinked a patch (after a change control board review) to correct an issue in the memory scrub software.

Currently, both observatories are operating nominally. All subsystems and instruments on both observatories have a GREEN health status. Some IMPACT detectors are currently saturated, possibly due to the proximity to Earth. This effect is still being investigated. MAG is seeing higher than expected offsets, which is correctable in software. SWAVES-Behind observes two interference signals (100 kHz and 16 kHz) associated with the boom deployment. With the booms deployed the spacecraft pointing has become very stable with the pointing much less than 7 arc-seconds. We have ended our 24/7 coverage from DSN and have gone to our nominal 3 hour tracks per day per spacecraft.

Engineering burns were performed on the C thruster set of both spacecraft. Both burns were completely nominal so all the thrusters have been checked out and are working. All the spacecraft subsystems are performing nominally.

Previous item should have reported that PLASTIC was also partially powered up successfully on both observatories.

The A1 maneuver was successfully completed on both spacecraft.

The two IMPACT booms have been deployed.

The High Gain Antennae were exercised through their full ranges of motion.

Spacecraft subsystems are performing normally. The SECCHI instrument suites were turned on on both observatories and all telescope subsystems passed their functional tests. The SWAVES instruments were turned on, and both sets of antennae were successfully deployed. Parts of the IMPACT instruments have been powered on.

The twin STEREO observatories were launched at 8:52 p.m. EDT. [Press release]