Page 1 PROGRESS REPORT THE SOLAR-A SOFT X-RAY TELESCOPE (SXT) PROGRAM (CONTRACT NAS8-00119) (for December 2001) OVERVIEW The YOHKOH Mission is a program of the Japanese Institute of Space and Astronautical Science (ISAS) with collaboration by the U. S. National Aeronautics and Space Administration and the U. K. Science and Engineering Research Council. The YOHKOH satellite was launched on 30 August 1991 from Kagoshima Space Center (KSC) in Japan. The purpose of this mission is to study high energy phenomena in solar flares and the Sun's corona. Under an international cooperative agreement, Lockheed Martin, under NASA contract, is providing a scientific investigation using the Soft X-ray Telescope (SXT), one of the primary experiments of the mission. The SXT was developed at the Lockheed Martin Solar and Astrophysics Laboratory in cooperation with the National Astronomical Observatory of Japan, and the Institute for Astronomy of the University of Tokyo. MAJOR PROGRAMMATIC ACTIVITIES IN THE MONTH The most deleterious event of the 10+ years of Yohkoh operations occurred during the month when the spacecraft went into a slow roll. Recovery efforts have so far been unsuccessful due to a lack of adequate power. Although there is some hope that as the spacecraft precesses the batteries can be charged, it is not a very likely scenario. SOLAR ACTIVITY In early December the solar activitiy was low. A large number of microflares were observed in several active regions located on the disk, but only 5 M-class flares were seen in the GOES X-ray plot. In mid-December, activity picked up again with 9 M-class flares and 2 X-class flares. Most of this activity occurred in NOAA 9733. The two X class flares had GOES classes of X2.8 and X6.2 and were accompanied by 6 M-class flares. CAMPAIGNS No formal campaigns were supported during December. SCIENCE In a search for extreme over-the-limb events that might have non-thermal properties related to the celebrated moving hard X-ray source of April 18, 2001, Hudson found another intriguing over-the-limb event on October 16, 2000,. The parent flare occurred about 15 degrees behind the west limb, corresponding to an occultation height in the corona of about 20,000 km. In this flare, a novel kind of cornal dimming was observed. Why is this novel? It is because the post-flare loop system seems to have been blown away by the CME. Otherwise, with the long cooling times associated with these large structures, it still would have been there. In spite of the violence of CME's and their aptly-named "global restructuring" events in the lower corona, we often see the rest of the corona blithely ignoring what looks like a catastrophic disruption. The CME movie shows this phenomenon well enough in this case, in the sense that one half of the corona doesn't seem to know what the other half is doing, in spite of the presumed linkage through magnetic forces. If this disruption of a post-flare loop system could be confirmed in a better-observed case, preferably on the disk, it would help us a great deal to understand the energetics of CMEs. PUBLIC USE OF SXT IMAGES We are continuing to make Yohkoh/SXT images available for a variety of uses. Efforts continue to make selected images available on the LMSAL SXT WWW homepage (http://www.lmsal.com/SXT/). We receive requests for the Yohkoh posters (#2 and #3) by way of the form on the SXT homepage. Currently we receive requests via our homepage at the rate of 2 or 3 per day. The WEB access statistics in December were 96908 accesses and 6.301 Mbytes transferred for the SXT website and 140,734 accesses and 3,851 Mbytes transferred for the YPOP website. YOHKOH OPERATIONS AND HEALTH SXT experienced a normal level of Single Event Upset (SEU) events during the month: Shutter Error 06-Dec-01 Pass 3: 011206-0826 Recovered in the next pass. Data ended December 14 as a direct result of the near-total solar eclipse of that day, which Yohkoh intercepted over the Pacific Ocean midway between Hawaii and the Galapagos. This resulted in a loss of control and an under-voltage condition. Please see the science nugget for December 21 for fuller details. The situation is analogous to that of SOHO during its temporary loss in 1998; we know where Yohkoh is and know that it is alive. Unfortunately it is rotating at about 1 RPM around its Y axis (solar EW direction of motion) and slowly precessing. The problem will be to coax it back into normal operations. The Yohkoh team is working hard on this. Page 5 DATA FLOW Month Full Frame Images Observing Region Images Received Lost Received Lost Loss % QT FL Tot Thru Oct-99 651807 237950 2615994 690277 3306271 1165106 25.94 Nov-99 7552 3425 20754 18772 39526 11974 23.25 Dec-99 7488 2791 22047 5354 27401 10663 28.01 Jan-00 5426 1736 19802 4040 23842 8958 27.31 Feb-00 6533 2052 21801 7017 28818 8982 23.76 Mar-00 6447 2007 22692 21914 44606 11192 20.06 Apr-00 6412 2100 31195 7214 38409 13438 25.92 May-00 6995 1556 28175 14961 43136 8967 17.21 Jun-00 7043 1722 24413 16369 40782 8690 17.57 Jul-00 6674 1920 23505 31739 55244 10235 15.63 Aug-00 9623 1996 20925 1197 22122 6577 22.92 Sep-00 8835 2240 22233 5764 27997 8307 22.88 Oct-00 6348 1524 23309 6629 29938 7916 20.91 Nov-00 6525 1639 20087 10318 30405 6972 18.65 Dec-00 6585 1918 20718 5422 26140 8071 23.59 Jan-01 5610 1231 20469 3161 23630 7317 23.64 Feb-01 6917 1497 25366 1144 26510 7871 22.89 Mar-01 6851 1272 26315 17139 43454 9470 17.89 Apr-01 5531 1804 15991 20001 35992 9216 20.39 May-01 7410 1758 21042 1767 22809 7152 23.87 Jun-01 7037 1024 24643 5760 30403 5075 14.30 Jul-01 7184 1805 19361 1340 20701 6358 23.50 Aug-01 6741 1443 25710 17252 42962 9100 17.48 Sep-01 6051 1610 22439 32802 55241 11073 16.70 Oct-01 6047 1691 23828 21155 44983 9600 17.59 Nov-01 5785 1400 18318 18211 36529 6689 15.48 Dec-01 3106 707 11169 5868 17037 3473 16.93 Total 824563 283818 3192301 992587 4184888 1388442 24.91 Number of Full Frame Images Received: 824563 Number of Observing Region Images Received: 4184888 Total: 5009451 Approximate Number of Shutter Moves/CCD Readouts: 8518516 NOTES: * The loss of images is mainly due to BDR overwrites, but there are also occasional DSN dumps which are lost. * It is common to have observing regions which contain more than 64 lines, which requires multiple exposures to make a single observing region image. This is why the number of shutter moves is larger than the number of images received plus those lost. Page 6 ENGINEERING SUMMARY TABLE Month Avg Dark Level # of Dark Spikes CCD Warmings Front Optical (DN) (e/sec) Over 48 Over 64 High / # Support Trans Temp /Days Temp (%) Nov-99 56.18 962.4 216210 45448 23.0 N/A Dec-99 322.57 10947.0 219637 128200 22.5 / 2 25.3 N/A Jan-00 52.05 807.7 201792 42952 23.4 N/A Feb-00 58.43 1046.9 224467 54721 23.8 N/A Mar-00 57.77 1022.1 222748 52251 22.9 N/A Apr-00 58.82 1061.4 226626 56663 22.2 N/A May-00 58.25 1040.1 224458 54512 21.2 N/A Jun-00 54.92 915.2 211118 54452 22.8 N/A Jul-00 55.59 940.3 212984 58793 19.3 N/A Aug-00 303.89 10247.0 221318 119077 56.9 / 2 21.7 N/A Sep-00 56.31 967.4 217301 52356 22.1 N/A Oct-00 57.27 1003.4 220417 57385 23.1 N/A Nov-00 60.95 1141.4 235715 56905 24.2 N/A Dec-00 507.86 17892.0 234170 164746 23.8 / 2 21.8 N/A Jan-01 56.19 963.0 216780 59581 22.2 N/A Feb-01 59.10 1071.9 228455 60621 23.5 N/A Mar-01 60.67 1130.9 234100 67374 23.1 N/A Apr-01 53.62 866.4 207391 61864 22.6 N/A May-01 57.37 1007.0 222277 66284 22.8 N/A Jun-01 54.12 885.2 208713 60958 21.6 N/A Jul-01 255.26 8424.4 230800 125597 22.5 / 2 22.7 N/A Aug-01 62.43 1196.6 240606 73530 22.3 N/A Sep-01 58.51 1049.7 225957 69416 22.4 N/A Oct-01 62.30 1191.8 241060 70628 23.2 N/A Nov-01 61.69 1169.1 237716 77109 22.0 N/A Dec-01 55.49 936.6 214372 65390 24.0 N/A NOTES: * The dark current calculations are using full half resolution 2.668 sec images not taken in during the SAA. The dark current rate assumes a "fat zero" of 30.5 DN and a gain of 100 e/DN. * The entrance filter failure of 13-Nov-92 eliminated the capability of taking optical images, so the optical transmission is not available after Nov-92. It also caused an increase in the dark current signal, however some of the increase shown here is an increase in the readout noise and is not a function of exposure duration. Page 7 PERSONNEL TRAVEL SXT Foreign Travel between 1-DEC-01 and 31-DEC-01 BARTUS 1-DEC-01 * 18-DEC-01 18 (total of 18 days) HUDSON 18-DEC-01 28-DEC-01 11 (total of 11 days) MCKENZIE 1-DEC-01 * 14-DEC-01 14 (total of 14 days) SATO 1-DEC-01 * 31-DEC-01 * 31 (total of 31 days) TAKEDA 1-DEC-01 * 29-DEC-01 29 (total of 29 days) ---------------------------------------------------------------- Grand Total of 103 days for 5 people NOTE: The "*" signifies travel that actually ends after 31-DEC-01 SXT Foreign Travel between 1-JAN-02 and 31-JAN-02 BARTUS 6-JAN-02 31-JAN-02 26 (total of 26 days) NITTA 4-JAN-02 21-JAN-02 18 (total of 18 days) SATO 1-JAN-02 * 6-JAN-02 6 (total of 6 days) TAKEDA 6-JAN-02 19-JAN-02 14 26-JAN-02 31-JAN-02 * 6 (total of 20 days) ---------------------------------------------------------------- Grand Total of 70 days for 4 people NOTE: The "*" signifies travel that actually ends after 31-JAN-02 Respectfully submitted, Thomas R. Metcalf Frank Friedlaender Page 8 ------------------------------------------------------------------------------- NASA REPORT DOCUMENTATION PAGE (IN LIEU OF NASA FORM 1626) --------------------|--------------------------|------------------------------- 1. REPORT NO. | 2. GOVERNMENT | 3. RECIPIENT'S DR-01 | ACCESSION NO. | CATALOG NO. --------------------|--------------------------|------------------------------- 4. TITLE AND SUBTITLE | 5. REPORT DATE Monthly progress report - for the month of | 10 January 2002 December 2001 |------------------------------- | 6. PERFORMING ORG | CODE: O/L9-41 -----------------------------------------------|------------------------------- 7. AUTHOR(S) | 8. PERFORMING ORGANIZA- T. R. Metcalf | TION REPORT NO: F. M. Friedlaender | |------------------------------- -----------------------------------------------|10. WORK UNIT NO. 9. PERFORMING ORGANIZATION NAME AND ADDRESS | Lockheed Martin Missiles and Space |------------------------------- Advanced Technology Center, O/L9-41, B/252 |11. CONTRACT OR GRANT NO. 3251 Hanover Street, Palo Alto Ca. 94304 | NAS8 - 00119 -----------------------------------------------|------------------------------- 12. SPONSORING AGENCY NAME AND ADDRESS |13. TYPE OF REPORT AND Marshall Space Flight Center (Explorer Program)| PERIOD COVERED Huntsville Alabama 35812 | Progress report for the month Contact: Larry Hill | of December 2001 |------------------------------- |14. SPONSORING AGENCY | CODE MSFC / AP32 -----------------------------------------------|------------------------------- 15. SUPPLEMENTARY NOTES ------------------------------------------------------------------------------- 16. ABSTRACT The SOLAR-A Mission is a program of the Institute of Space and Astronautical Science (ISAS), the Japanese agency for scientific space activity. The SOLAR-A satellite was launched on August 30, 1991, to study high energy phenomena in solar flares. As an international cooperative agreement, Lockheed, under NASA contract, is providing a scientific investigation and has prepared the Soft X-ray Telescope (SXT), one of the two primary experiments of the mission. --------------------------------------|---------------------------------------- 17. KEY WORDS (SUGGESTED BY | 18. DISTRIBUTION STATEMENT AUTHOR(S)) Solar-A, X-ray, CCD, | Space Science, Solar Physics ------------------------|-------------|----------|-----------------|----------- 19. SECURITY CLASSIF. | 20. SECURITY CLASSIF. | 21. NO OF PAGES |22. PRICE (OF THIS REPORT) | (OF THIS PAGE) | | None | None | 6 | ------------------------|------------------------|-----------------|-----------