Page 1 PROGRESS REPORT THE SOLAR-A SOFT X-RAY TELESCOPE (SXT) PROGRAM (CONTRACT NAS8-40801) (for December 1997) 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, 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 Palo Alto Research 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 effort to provide contractual coverage for continued operations in Japan is finally being addressed at GSFC and Lockheed Martin is preparing a proposal for that effort. << Solar Activity >> In early December, AR 8113 calmed down as it transitted the disk. There were several C class flares, but only one M class. There was an appearance of loops connecting two active regions across the equator. The regions have opposite leading polarities, which suggests this event is an example of a helicity selection effect at work. A large arcade eruption was observed on 6-Dec. The GOES flux went up at about 1200 (6-Dec). In mid-December, the "spectacular" arcade of AR 8113 persisted for over a week, as it transitted the west limb. Two prominence eruptions were reported at the time of the arcade formation, and another occurred early morning of 1997-Dec-12 UT. An LDE profile was observed, but X-ray levels were low due to the obscuration of the limb. Otherwise, there were several small active regions forming at high latitudes across the disk, and only a handful of small C-class flares were observed. The GOES background level remained at low B. In late December, Solar x-ray flux levels remained low, with a few C-class events. A large arcade could still be seen passing behind the west limb, while a new one rose over the east. Page 2 << Campaigns >> There were no official campaigns in December, however, an attempt was made to catch jets on the leading edge of AR 8113. Also, A special dark calibration table was used for one S/C orbit, to better understand the dark-signal's time profile. << Science >> Metcalf and Alexander began a systematic spectroscopic study of flares with above the loooptop hard X-ray sources using the pixon reconstruction algorithm. The goal of the study is to determine the properties of trapped and precipitating electrons during the flares. The improved photometry provided by the pixon algorithm allows for a more accurate determination of the electron properties than previously available. << 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 Lockheed SXT WWW homepage (http://www.space.lockheed.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 140507 accesses and 3463 Mbytes transferred. << Yohkoh Operations and Health >> Yohkoh and the SXT continue to function very well. There has been no further increase in stray light since 25 August 1996. SXT experienced a normal level of Single Event Upset (SEU) events during the month: SXT Bitmap error 08-Dec-97 Pass 1: 971208-1031 recovered in the same pass. SXT Bitmap error 10-Dec-97 Pass 3: 971210-1136 recovered in the same pass. SXT Bitmap error 19-Dec-97 Pass 1: 971219-0721 recovered in the same pass. Page 3 << Data Flow >> Month Full Frame Images Observing Region Images Received Lost Received Lost Loss % QT FL Tot Thru Sep-95 326469 140614 1364588 353350 1717938 677167 28.05 Oct-95 6937 3502 22177 3853 26030 13044 33.38 Nov-95 5745 2944 21252 517 21769 12119 35.76 Dec-95 6163 2615 24059 901 24960 11652 31.83 Jan-96 6474 2530 27015 1708 28723 14151 33.01 Feb-96 6200 2581 21380 890 22270 10773 32.60 Mar-96 6908 2869 25437 1460 26897 12274 31.33 Apr-96 7172 2124 45445 671 46116 18848 29.01 May-96 6925 2426 30272 1089 31361 12367 28.28 Jun-96 7515 2723 31952 1536 33488 14521 30.25 Jul-96 5954 1995 29886 4769 34655 12427 26.39 Aug-96 7214 3010 21187 1607 22794 9887 30.25 Sep-96 6904 2618 29906 303 30209 12663 29.54 Oct-96 7405 2853 16463 1842 18305 8034 30.50 Nov-96 7001 2296 24292 5395 29687 9340 23.93 Dec-96 7144 2643 25331 2087 27418 10412 27.52 Jan-97 7186 2747 21126 1257 22383 9915 30.70 Feb-97 6016 2034 22097 1072 23169 8961 27.89 Mar-97 7152 1300 26991 1209 28200 6394 18.48 Apr-97 6018 1055 23639 3890 27529 5349 16.27 May-97 7703 1455 29574 3783 33357 7121 17.59 Jun-97 7706 1522 25786 1396 27182 7908 22.54 Jul-97 8614 1385 32503 431 32934 6559 16.61 Aug-97 7316 987 23136 3519 26655 4990 15.77 Sep-97 7051 1479 33646 9596 43242 8887 17.05 Oct-97 7023 1134 26813 1827 28640 6043 17.42 Nov-97 6483 1287 25478 15306 40784 6735 14.17 Dec-97 0 0 0 0 0 0 0.00 Jan-98 0 0 0 0 0 0 0.00 Total 506398 196728 2051431 425264 2476695 938541 27.48 Number of Full Frame Images Received: 506398 Number of Observing Region Images Received: 2476695 Total: 2983093 Approximate Number of Shutter Moves/CCD Readouts: 5201882 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 4 << 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 (%) Oct-95 50.29 741.9 126452 7911 20.2 N/A Nov-95 50.11 735.1 122163 7814 25.2 / 2 20.3 N/A Dec-95 50.19 737.9 123705 7927 22.6 N/A Jan-96 50.81 761.3 136197 8888 21.5 N/A Feb-96 50.67 755.8 133263 8705 22.5 / 2 21.5 N/A Mar-96 50.85 762.9 136982 8973 20.3 N/A Apr-96 51.14 773.6 142250 9500 19.9 N/A May-96 51.16 774.4 140697 10018 19.1 N/A Jun-96 51.56 789.2 147705 10634 20.7 N/A Jul-96 57.45 1010.2 146293 12228 19.8 N/A Aug-96 52.58 827.5 165676 12393 19.6 N/A Sep-96 52.47 823.3 162784 12350 20.0 N/A Oct-96 52.21 813.8 157689 12047 22.5 / 2 21.3 N/A Nov-96 52.45 822.9 161683 12534 21.9 N/A Dec-96 53.08 846.2 171224 13860 22.9 N/A Jan-97 52.35 818.9 164785 11354 23.8 / 7 23.3 N/A Feb-97 51.95 803.9 159426 10346 21.1 N/A Mar-97 55.99 955.6 158428 12190 21.2 N/A Apr-97 53.14 848.4 176207 13265 20.8 N/A May-97 52.96 841.7 172052 13094 20.7 N/A Jun-97 53.69 869.0 182460 14849 19.8 N/A Jul-97 54.44 897.3 184518 20173 22.5 / 2 21.1 N/A Aug-97 54.06 883.1 188485 15549 20.1 N/A Sep-97 54.77 909.7 196501 17757 21.0 N/A Oct-97 54.85 912.8 198157 17857 21.5 N/A Nov-97 55.17 924.8 202153 18993 22.5 / 2 23.2 N/A Dec-97 N/A N/A N/A N/A 0.0 N/A Jan-98 N/A N/A N/A N/A 0.0 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 5 << Personnel Travel >> SXT Foreign Travel between 1-DEC-97 and 31-DEC-97 ACTON 29-DEC-97 31-DEC-97 * 3 (total of 3 days) HUDSON 1-DEC-97 * 13-DEC-97 13 19-DEC-97 31-DEC-97 * 13 (total of 26 days) SAVY 1-DEC-97 * 31-DEC-97 * 31 (total of 31 days) WEBER 1-DEC-97 * 20-DEC-97 20 (total of 20 days) ---------------------------------------------------------------- Grand Total of 80 days for 4 people NOTE: The "*" signifies travel that actually ends after 31-DEC-97 SXT Foreign Travel between 1-JAN-98 and 31-JAN-98 ACTON 1-JAN-98 * 31-JAN-98 31 (total of 31 days) HUDSON 1-JAN-98 * 31-JAN-98 * 31 (total of 31 days) MCKENZIE 30-JAN-98 31-JAN-98 * 2 (total of 2 days) SAVY 1-JAN-98 * 31-JAN-98 31 (total of 31 days) ---------------------------------------------------------------- Grand Total of 95 days for 4 people NOTE: The "*" signifies travel that actually ends after 31-JAN-98 Respectfully submitted, Thomas R. Metcalf Frank Friedlaender Page 6 ------------------------------------------------------------------------------- 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 1998 December 1997 |------------------------------- | 6. PERFORMING ORG | CODE: O/H1-12 -----------------------------------------------|------------------------------- 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 Palo Alto Research Labs B/252 |------------------------------- Solar & Astrophysics Laboratory O/H1-12 |11. CONTRACT OR GRANT NO. 3251 Hanover Street, Palo Alto Ca. 94304 | NAS8 - 40801 -----------------------------------------------|------------------------------- 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 | of December 1997 |------------------------------- |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 | ------------------------|------------------------|-----------------|----------- For sale by: Superintendent of Documents, U.S. Government Printing Office