The spacecraft status is nominal.

SUMER successfully completed its recommissioning. All seven mechanisms are working perfectly as before. The detector gain is nominal. Detector B has been fully recalibrated. No sensitivity loss could be measured. The sensitivity is exactly as before. Recalibration of detector A is ongoing. The rear slit camera is working, too.

This completes the recommissioning phase of the SOHO instruments. All twelve instruments are back to normal and fully functional (except the LASCO C1 coronagraph which is still being tested). Again my compliments to the scientists and engineers who designed and built these instruments and this spacecraft. They can really be proud of their workmanship.

I think this is also a good time to stop with these daily reports, in particular since we have resumed circulating minutes of our daily planning meetings which are also available on the web under the SOHO Operations pages.

It's still a miracle for me ...

The spacecraft status is nominal.

SUMER check out of its mechanisms is continuing. So far 3 out of the 7 mechanisms have been checked and are working fine.

The Spartan 201 satellite was successfully captured by the Shuttle Discovery at 20:48 UT today. All indications are that the mission proceeded flawlessly and is a complete success.

The spacecraft status is nominal.

Phase 2 of the SUMER recommissioning starts this evening.

SOHO is currently supporting Spartan 201-5 which was successfully deployed from Space Shuttle Discovery (STS-95) on November 1, 18:59 UT. Current coronal images including cotemporal Spartan WLC and SOHO/LASCO images are available at http://thalia.gsfc.nasa.gov/~gibson/SPARTAN/.
For more information about Spartan 201-5 see the Spartan home page at http://umbra.nascom.nasa.gov/spartan/ and the Spartan/UVCS pages at http://cfa-www.harvard.edu/cfa/spartan/

SOHO also supported the LASP/CU and SwRI rocket flight which was successfully launched at 18:20 UT today. For more information see http://lasp.colorado.edu/rocket/

The spacecraft status is nominal.

CELIAS and MDI have finished their recommissioning. Both have been declared nominal and fully operational.

The FOT has no remaining payload TSTOLs to upload. The next instrument re-certification activities are scheduled for November 2nd (SUMER).

The spacecraft status is nominal.

MDI finished uploading the detector flat field.

CDS has done a full Sun imaging test to calibrate the pointing of the instrument.

CELIAS has all the sensors in nominal mode and fully operational. SEM was alredy declared re-certified earlier this week. PM, MTOF and STOF science data are being evaluated. CTOF is as good as it was before the loss of attitude.

The spacecraft status is nominal.

CELIAS re-certification continues without problems. CELIAS/MTOF has been switched on today, so now all CELIAS sensors are on. As this was the only sensor on the spacecraft that remained off, all the detectors on board SOHO are powered on again.

The spacecraft status is nominal.

CELIAS recovery is proceeding as scheduled. CELIAS/CTOF housekeeping parameters are nominal and the high voltage settings have been increased once more.

CELIAS/STOF/HSTOF also shows nominal housekeeping, the solid state detectors and the HSTOF deflection system are now at operational levels. The microchannel plate bias has been enabled and set at check-out voltage levels.

CELIAS/SEM science data appear to be of excellent quality and show that no degradation of the SEM has occurred during the last few months. From Toni Galvin: "The measured solar flux ratio between the central order channel and the two side channels is about what it was, for quiet sun conditions, before the temporary loss of spacecraft data, and the absolute flux values are currently somewhat higher than they were at the end of June, which is quite reasonable due to the fact that we are on the rising part of the solar activity cycle. The measured flux increase during the limited data received thus far is not great enough, however, to know whether it corresponds to short term variations or a real increase associated with the eleven year solar cycle."

The spacecraft status is nominal.

CELIAS/STOF/HSTOF was powered on into manual mode on Sunday. All housekeeping parameters are nominal.

CELIAS/SEM was also powered on yesterday and is fully operational. Housekeeping is nominal, and after the evaluation of the science data completed today it has been declared recommissioned.

CELIAS/CTOF was switched on and placed into manual mode on Sunday, too. A calibration sequence was sucessfully completed. All high voltage supplies have been tested and initial voltages set. The microchannel plates are still somewhat cold, but their temperature is increasing gradually as the nearby electronics warm them up.

The recovery status of CELIAS can be followed at http://umtof.umd.edu/~galvin/celias_recovery/.

The spacecraft status is nominal.

CELIAS Digital Processing Unit (DPU) was successfully turned on at 17:56 UT. DPU software patches were successfully loaded. Tomorrow the CELIAS STOF sensor unit turn on is planned.

The spacecraft status is nominal.

As of today, 23 October 1998, after nearly 4 months since the loss of contact with SOHO on 25 June, we have 10 of the 12 instruments working nominally again (or close to nominal nearing the end of their recommissioning phase): GOLF, VIRGO, MDI, CDS, EIT, LASCO (except C1 which is still being tested), UVCS, SWAN, COSTEP, ERNE. The last instrument to be switched back on is CELIAS. It will have its day tomorrow, 24 October. SUMER will resume recommissioning on 2 November.

The spacecraft status is nominal.

The Swan instrument is now fully recommissioned and will resume its nominal observing program on Oct 23. The -Z side sensor is fully nominal. The photometric count rate and Hydrogen absorption levels for this sensor have been found to be similar to the values they had in June 1998. The +Z sensor shows a change in the counting efficiency. The detector seems to be more sensitive than before at larger wavelengths. This means that the calibration procedures and curves for this unit will have to be reestablished. The first skymap measured yesterday with this sensor shows all the expected features. So all the previous scientific objectives in photometric mode should be maintained for both sensors. Hydrogen cell scientific measurements seem also to be recoverable, after a serious calibration effort.

The LASCO C1 camera mechanisms were tested and found to be working properly. Closed door C1 images show blur indicating that the Fabry-Perot filter plates are slightly misaligned. Continued testing of the C1 Fabry-Perot filter revealed response from all three piezos. Calibration data have been acquired to determine the wedge defection direction and magnitude.

The VIRGO team had a successful balloon flight in Southern France with measurements of the total and spectral solar irradiance during 45 minutes from an altitude of about 42 km.

The spacecraft status is nominal.

CDS opened its doors at 20:05 UT and acquired first light images both from the Normal Incidence Spectrometer (NIS) and Grazing Incidence Spectrometer (GIS). Both spectra look completely nominal. They are available at the CDS recommissioning page at URL: http://orpheus.nascom.nasa.gov/cds/diary/status.html

MDI tested their image stabilization system (ISS). UVCS happened to be rolling at the time, providing a convenient jitter source with which to test the system -- both open and closed loop. Several amplifier gains were tested; the nominal gain still appears to work the best. The ISS was left in open loop (safe) mode overnight but is in good working order.

The spacecraft status is nominal.

The CDS NIS detector is working.
Several dark exposures were made with the microchannel plate (MCP) switched off, these showed the normal particle events. Five more exposures were then made with the MCP ON and the hot spot, that we have seen since before launch, was visible, confirming that the NIS detector is working. For details see http://orpheus.nascom.nasa.gov/cds/dairy/status.html

SWAN:
As of today 20:00 UT, the -Z sensor is fully recommissionned. The count rate and Hydrogen absorption levels for this sensor have been found to be similar to the values they had in June 1998. Normal operations can resume for this sensor.

An anormal behaviour was found for the +Z sensor when the hydrogen cell was activated. The count rate increased for 24 out of the 25 pixels for a yet unknown reason. The 25th pixel shows an absorption pattern similar to what it was in June 1998. Tests of the +Z sensor hydrogen cell and detector are continuing.

MDI:
The MDI recommissioning is proceeding smoothly. Last night we turned on the MDI filter oven and adjusted the temperature to the standard operating point of 35 deg C. During the warm up of the filter oven, the filter tuning was changing and the dopplergrams shifted in intesting patterns - see for example http://mdiwww.nascom.nasa.gov/health_mon/gif/loi_img_hours.gif.

After the oven temperature stabilized, the MDI dopplergrams, continuum images and magnetograms appear very similar to those taken earlier this year. The Michelson tuning parameters used in the reload appear to be close to optimal. This indicates that the filter performance does not appear to have substantially changed due to the extended cold-soak. Evaluation of calibration images taken during the oven warm-up will determine if further adjustment of the tuning is needed.

Sample images taken with the oven at operating temperature can be found at:
Dopplergram: http://mdiwww.nascom.nasa.gov/gif_recovery/fd_V.gif
Continuum: http://mdiwww.nascom.nasa.gov/gif_recovery/fd_Ic.gif
Magnetogram: http://mdiwww.nascom.nasa.gov/gif_recovery/fd_M.gif

At this time, there are no known problems with the MDI instrument, and the MDI team should be able to return to standard observing shortly.

The spacecraft status is nominal.

CDS: The four mechanisms were excercised again today and are nominal. The instrument temperatures are being slowly lowered to our nominal operating temperatures.(Duty cycles 60%) The NIS detector electronics subsystem was switched on and succesfully tested. The GIS detector subsystem was switched on and succesfully tested. The HV's to the four detectors was successfully ramped up to 3KV. Further HV tests are continuing.

Test of all four SWAN mechanisms were sucessfully completed today. All mechanisms behave nominally. High voltage of the +Z SWAN sensor was switched on at 20:30 UT and slowly ramped up to its usual setting used before the mission interruption. A first analysis of the count rate shows a decrease of roughly a factor of 2 from what it was before. This can be compensated by increasing high voltage setting. High voltage of the -Z sensor was switched on at 21:00 UT. The count rate of this sensor is identical to what it was prior to mission interruption. Testing of both Hydrogen cells will be performed tomorrow.

EIT recommissioning has been successfully completed. No damage or degradation could be detected. In fact, due to the long and warm bake out, the sensitivity has increased by approximately 60%.

Recommissioning of the other instruments is progressing smoothly.

The spacecraft status is nominal.

SWAN was successfully switched on at 17:25 UT. All parameters are nominal. Internal heaters of the outer mechanisms have been switched on. SWAN will wait 24 hours until thermal equilibrium is reached before resuming testing of the instrument.

Recommissioning of the other instruments is progressing smoothly.

The spacecraft status is nominal.

CDS was successfully switched on at 19:55 UT. The Command and Data Handling System and the Experiment Power Supply show nominal telemetry. The Mechanism Subsystem (MCU) was powered on and basic heater circuit checks were successful - CDS heaters remain off for the present with thermal stability being maintained by the s/c heaters until other subsystems have been tested. Both the Slit and Mirror mechanisms have been succesfully tested. Details are available as they happen on the CDS Web page at http://solg2.bnsc.rl.ac.uk

The spacecraft status is nominal.

Momentum management, orbit correction and roll maneuver were successfully completed on 17 October, 03:30 UT.

The spacecraft status is nominal.

UVCS has successfully completed its first O VI mirror scan above the east limb and has successfully taken its Lyman-alpha "re-commissioning first light spectrum". It then has been brought in safe state for the upcoming spacecraft maneuvers. For more details see http://cfa-www.harvard.edu/uvcs/recommission.html.

The checkout of LASCO/EIT continues to be very successful. Absolutely no problems were encountered during the chechout of the LASCO C2 telescope system. The C2 door was opened and the corona was imaged first in H-alpha, and then with the normal orange filter. The images are excellent. No image degradation is perceived. The C2 and C3 doors then were closed in preparation for the spacecraft maneuvers scheduled for Friday, October 16.

MDI recommissioning is also progressing successfully. A first Dopplergram was successfully acquired.

The spacercraft status is nominal.

Check out of the LASCO coronagraphs continued. The LASCO C3 door was opened and solar corona images were successfully acquired. The image quality looks fine. An EIT and C3 observing sequence was loaded to run over night.

MDI continued with software uploads.

At 00:09 UT UVCS has successfully taken its "recommissioning first light spectrum" in the O VI channel. Looks good! Details are available at http://cfa-www.harvard.edu/uvcs/recommission.html.

The spacecraft status is nominal.

The LION instrument of the COSTEP experiment was successfully switched on at 16:04 UT after MDI had verified that its door is open. All pertaining digital and analog housekeeping channels display characteristics identical to the LION performance prior to the mission interruption, some detector leakage currents show even better (lower) values. Subsequent LION recommissioning and calibration verified that the LION science channels respond to the radiation environment as expected, and no signs of degradation during the unpowered time interval could be detected.

The LASCO/EIT electronics box was successfully switched on at 17:33 UT and is working well. All four cameras have been loaded and are returning good status. The LASCO C1 Fabry-Perot has also been loaded. Dark images have been taken from all four cameras. The EIT camera has been completly checked. Sun images in all four wavelengths have been taken and they look great! Apparently the 3 months bake-out was very beneficial to the CCD. The latest EIT images are available on the web at: http://umbra.nascom.nasa.gov/eit/eit_full_res.html LASCO recommissioniong will continue over the next several days. Details about the LASCO/EIT recommissioning can be found at: http://lasco-www.nrl.navy.mil/recommiss/recom_sum.html

MDI turned on the limb tracker and verified open loop functionality. Several additional commissioning test have been performed and an upload of observing programmes has been prepared. MDI took several new images with a warmer filter oven and they look good. For more details see http://quake.stanford.edu/~phil/restart/restart.html

UVCS also made excellent progress in their recommissioning activities. They successfully recommissioned the occulter mechanisms, the O VI and Ly-alpha grating mechanisms, the O VI and Ly-alpha slit mechanisms, and the roll and pointing mechanisms. The UVCS door was successfully opened and both detectors were powered on. For details see http://cfa-www.harvard.edu/uvcs/recommission.html

I guess this was a good day.

The spacecraft status is nominal.

Lost guide star and went into RMW mode at 17:26 UT. Back to normal mode at 17:55 UT.

The long DSN pass on 11 October was lost due to an emergency of TDRS-7. Phase II of the UVCS recommissioning therefore was delayed by a day. UVCS recommissioning continues to proceed smoothly. The door has been partially opened. For further updates see: http://cfa-www.harvard.edu/uvcs/recommission.html

MDI was successfully switched on at 19:39 UT. The control processor, image processor, camera, and mechanisms (shutter, tuning wheels, calibration wheels) have been successfully switched on. All are functional. The first picture was taken at 22:23 UT. Shutter, camera and image processor worked nominally. The images show faculae and sunspots, and the limb appears sharp, indicating that there is a reasonable light path through the instrument. The images are also well centered. One of the "first light" images is available on the web at: http://mdiwww.nascom.nasa.gov/~zowie/tmp/MDI-recov-2.gif The MDI operators-log is available at http://mdisas.nascom.nasa.gov/cgi-bin/monlog For more information see the SOI home page at: http://soi.stanford.edu/

The spacecraft status is nominal.

UVCS has been successfully switched on at 17:27 UT. Current is nominal and all temperatures are reasonable. NRT commanding from the UVCS EOF workstation works smoothly. A memory checksum test has verified the integrity of the UVCS flight software. At 19:03 UT UVCS was switched to "standby" mode.

Progress of the UVCS re-commissioning activities can be followed "live" on the UVCS recommissioning page at URL: http://cfa-www.harvard.edu/uvcs/recommission.html

The spacecraft status is nominal.

COSTEP and ERNE (CEPAC) were successfully switched on at 10:33 UT, and both instruments are working fine.

The turn-on sequence (based solely on TSTOL procedures) went smoothly and resulted in ERNE and COSTEP/EPHIN being in nominal observation mode by 11:30 UT. The LION sensor of COSTEP was not turned on yet, as the MDI door must be open when LION is powered up due to known straylight interference. Temperatures, power consumption, and all instrument housekeeping channels showed nominal values. The common subsystems of ERNE and COSTEP, the low voltage power converter LVPC and the data processing unit CDPU, were also functioning nominally.

EPHIN recommissioning including calibration, extended calibration, and patch uploads was finished by 14:00 UT. First analysis of science channels shows nominal behaviour, especially all detectors in the particle telescope are alive and display characteristics identical to their performance prior to the loss of the spacecraft. No sign of adverse effects due to thermal stress during the deep freeze have been detected so far.

The performance of both ERNE sensors, LED and HED, is good. HED has even improved in the sense that one of the detector leakage currents, which was slowly increasing during the flight, has now returned to its initial value. Recommissioning of ERNE, which includes two long calibration sequences, was started at 20:00 UT and is still ongoing.

GOLF is also back to nominal observing mode. All instrument parameters (except the quarter-wave mechanism) have been returned to previous settings and the instrument sensor is already close to reaching a thermal equilibrium. The daily pulse has been correctly received this night at 00:00. As it requires many hours of NRT commanding to bring the quarter-wave mechanism in the previous position, it was decided to move it to the closer position where the instrument samples the red wing of the sodium lines instead of the blue wing. A decision on the future observing configuration will be taken by the GOLF team after analysis of the data.

The spacecraft status is nominal.

GOLF was successfully switched on at 17:37 UT. All subsytems are functional. A quarter wave mechanism which had moved by approximately 75 deg is being brought back to the nominal position.

VIRGO announced a preliminary figure for the solar constant: 1365.66 Wm^-2

SUMER is back in safe mode with its door closed. Recommissioning of SUMER will be resumed early November.

The spacecraft status is nominal.

A Fine Pointing Sun Sensor (FPSS) offset of -198 arcsec has been applied to bring the S/C back to the nominal pointing position.

Further tests on the SUMER-B detector performed last night were successful. The B detector now is working nominally, too.

VIRGO continues to work fine.

Tomorrow we will switch on GOLF.

The spacecraft status is nominal.

VIRGO was successfully switched on at 17:55 UT. All instruments (SPM-A, SPM-B, PMO-A, PMO-B, DIARAD, and LOI) have been tested and are working fine. VIRGO is back to nominal.

The spacecraft status is nominal.

SUMER was successfully switched on by the FOT at 18:21 UT. The door was opened through NRT commands at 19:41 UT. Both detectors were switched on. Detector A is working fine, testing of detector B is still ongoing.

The spacecraft status is nominal.

Today the SSU patch was loaded, which was planned for uplink in June to improve the startracker's robustness against single event upsets. The patch did not perform as expected, leading to a transition to RMW mode at 17:46 UT. The spacecraft was back in normal mode at 19:56 UT after re-establishing the previous configuration. The cause for the malfunction of the patch is under investigation.

Further tests with gyro A did not produce any new results.

An instrument recommissioning meeting with technical experts and operations personnel from all instrument teams is scheduled for Tuesday, October 6. A draft timeline for the instrument recommissioning is available at: http://sohowww.nascom.nasa.gov/~soc/recommiss.html.

Spacecraft status is nominal.

Problems were encountered during uplink of the star sensor unit (SSU) patch this morning. The problems have been identified and another attempt will be made tomorrow.

Telemetry subformat #5 has been uplinked and ESR monitoring has been enabled.

Click here to escape from frames