Page 1 PROGRESS REPORT THE SOLAR-A SOFT X-RAY TELESCOPE (SXT) PROGRAM (CONTRACT NAS8-40801) (for December 1996) 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 contract option to extend operations through January 1998 has been received from MSFC. Full funding for FY '97 has also been received. << Solar Activity >> Solar activity in December was low to moderate. Activity was highest during the first few days of the month as AR 7999 passed over the west limb, producing several C-class flares. After December 4, the X-ray background flux dropped significantly until December 10. From December 10 through December 25 a number of small active regions crossed the disk (AR 8003-8007) producing numerous sub-flares as well as a few C-class flares. After December 25, the X-ray background flux again dropped to the A-level. During the fainter periods, the disk was mostly covered with bright points and faint emission. The polar holes at both poles continued to be present during December. Yohkoh operations were suspended over the holidays, however, DSN passes were used to retrieve data at a slow cadence to maintain the continuity of the SXT movie. << Campaigns >> On December 9 SXT followed the large XBP at ~ 30S/00E, in coordination with SoHO CDS. Page 2 Yohkoh supported a campaign with SoHO JOP 057 to observe polar jetlets ran from December 10 through December 14. This campaign was in conjunction with EIT, SUMER, CDS, and ground based observatories. JOP 057's goal is to clarify the relationship between (quasi- stationary) polar jet like features seen in EUV (EIT), in W-L (Eclipses), and the SXR jets & jetlets recently analyzed using SXT sequences from Yohkoh. For Yohkoh operations, there is a text file accessible on the Web at http://www.space.lockheed.com/SXT/html2/First_Light.html which also lists the current SXT Chief Observer, or the Unix command: # finger campaign@isass0.solar.isas.ac.jp | more The SOHO target planning is available from: http://sohowww.nascom.nasa.gov/operations/targets/today << Science >> David Alexander and Tom Metcalf submitted a paper about the "Masuda event" (1992 January 13 limb flare) using Pixon and MEM analyses. This is a fascinating study since the pixon results differ from the MEM results. They believe that the pixon images have better photometry and they are using the improved light curves to study the thermal/non-thermal nature of the loop top source. Preparations continue for the Coordinated Data Analysis Workshop (CDAW) which is being organized along the lines of the successful series of Yohkoh CDAWs that were held at the University of Hawaii over the past few years. The workshop, to be held in January 1997, focuses on image reconstruction for HXT. Thanks to the efforts of Gary Linford and David Alexander, a new Yohkoh briefing package and video celebrating the fifth anniversary of the Yohkoh launch are now being distributed. The briefing package describes many of Yohkoh's scientific accomplishments during the last five years. The video places Yohkoh in the broader context of the space environment and gives and excellent introduction to Yohkoh science. << 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 51508 accesses and 1337 Mbytes transferred. Work has been completed for both the briefing package and the new SXT video and distribution has begun. << Yohkoh Operations and Health >> Yohkoh and the SXT continue to function very well. There has been no Page 3 further increase in stray light since 25 August 1996. The quiet patrol image has been changed to Al/Mg (DPE=17) to try to improve the performance of the active region selection algorithm for times when the Sun is very quiet. Prof Ogawara recently reported that the ISAS aerodynamics department estimates that the orbital life of Yohkoh is good until June, 2002, if an average solar activity for the coming maximum is assumed. The error of this estimation is approximately +/- 2 years depending upon the actual solar activity. SXT experienced a normal level of Single Event Upset (SEU) events during the month: SXT bit map error 07-Dec-96 Pass 1: 961207-1444 recovered in pass 1. Page 4 << Data Flow >> ------------------------------------------------------------------------------ Month Full Frame Images Observing Region Images Received Lost Received Lost Loss % QT FL Tot Thru Sep-94 245701 108912 1067376 320935 1388311 543701 27.82 Oct-94 7244 2497 25868 5884 31752 10319 24.53 Nov-94 6569 1941 26243 1956 28199 9293 24.79 Dec-94 6429 2456 26763 2583 29346 11904 28.86 Jan-95 6870 2349 26103 1699 27802 10211 26.86 Feb-95 6556 2545 23635 3825 27460 10111 26.91 Mar-95 5915 2082 21485 3448 24933 8485 25.39 Apr-95 6244 2266 22946 4493 27439 9688 26.09 May-95 7084 2884 29617 2647 32264 15331 32.21 Jun-95 7210 3087 25251 307 25558 12045 32.03 Jul-95 6418 4145 21180 1639 22819 15109 39.84 Aug-95 7683 2597 26115 2181 28296 10537 27.13 Sep-95 6546 2853 22006 1753 23759 10433 30.51 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 7522 2716 31984 1536 33520 14489 30.18 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 5306 1707 18348 1887 20235 6668 24.79 Dec-96 0 0 0 0 0 0 0.00 Jan-97 0 0 0 0 0 0 0.00 Total 419298 177104 1729399 376383 2105782 846563 28.67 Number of Full Frame Images Received: 419298 Number of Observing Region Images Received: 2105782 Total: 2525080 Approximate Number of Shutter Moves/CCD Readouts: 4418564 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 5 << 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-94 47.34 631.3 64974 4346 19.0 N/A Nov-94 47.64 642.4 70877 4703 20.4 N/A Dec-94 47.82 649.1 74246 4917 21.5 N/A Jan-95 48.55 676.7 89758 5457 20.0 N/A Feb-95 48.70 682.1 92457 5781 25.2 / 3 20.5 N/A Mar-95 48.35 668.9 85527 5271 19.4 N/A Apr-95 48.72 682.8 93904 5627 19.1 N/A May-95 48.73 683.4 94000 5820 18.8 N/A Jun-95 49.08 696.3 100780 6281 19.6 N/A Jul-95 49.34 706.2 106408 6628 18.1 N/A Aug-95 49.72 720.4 114414 7101 19.5 N/A Sep-95 49.79 723.1 115165 7222 19.6 N/A 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 52.43 822.0 161292 12486 21.5 N/A Dec-96 N/A N/A N/A N/A 0.0 N/A Jan-97 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 6 << Personnel Travel >> SXT Foreign Travel between 1-DEC-96 and 31-DEC-96 HUDSON 1-DEC-96 * 8-DEC-96 8 16-DEC-96 31-DEC-96 * 16 (total of 24 days) NITTA 1-DEC-96 * 5-DEC-96 5 (total of 5 days) SAVY 1-DEC-96 * 31-DEC-96 * 31 (total of 31 days) WEBER 1-DEC-96 * 25-DEC-96 25 (total of 25 days) ---------------------------------------------------------------- Grand Total of 85 days for 4 people NOTE: The "*" signifies travel that actually ends after 31-DEC-96 SXT Foreign Travel between 1-JAN-97 and 31-JAN-97 CANFIELD 11-JAN-97 24-JAN-97 14 (total of 14 days) HUDSON 1-JAN-97 * 9-JAN-97 9 18-JAN-97 26-JAN-97 9 29-JAN-97 31-JAN-97 * 3 (total of 21 days) LEMEN 31-JAN-97 31-JAN-97 * 1 (total of 1 days) NITTA 6-JAN-97 31-JAN-97 * 26 (total of 26 days) SAVY 1-JAN-97 * 31-JAN-97 * 31 (total of 31 days) SLATER 30-JAN-97 31-JAN-97 * 2 (total of 2 days) ---------------------------------------------------------------- Grand Total of 95 days for 6 people NOTE: The "*" signifies travel that actually ends after 31-JAN-97 Respectfully submitted, Thomas R. Metcalf Frank M. Friedlaender Page 7 ------------------------------------------------------------------------------- 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 1997 December 1996 |------------------------------- | 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 1996 |------------------------------- |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 | 7 | ------------------------|------------------------|-----------------|----------- For sale by: Superintendent of Documents, U.S. Government Printing Office