P00xxxx Page 1 PROGRESS REPORT THE SOLAR-A SOFT X-RAY TELESCOPE (SXT) PROGRAM (CONTRACT NAS8-37334) (for the month of January, 1992) OVERVIEW 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 from Kagoshima Space Center (KSC) in Japan, and renamed Yohkoh. The purpose of this mission is to study high energy phenomena in solar flares. 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 by Lockheed in cooperation with the National Astronomical Observatory of Japan, and the Institute for Astronomy of the University of Tokyo. MAJOR ACTIVITIES IN THE MONTH << Solar Activity and Observation Planning >> The instrument has performed well providing some spectacular FFI's showing the development of a large spot region near disk center and a rapid sequence of PFI's on a limb active region. Dr. Hugh Hudson and Dr. Keith Strong improved the SXT Quiet (high) table by including more X-ray exposures so there are no long gaps between solar X-ray images and that like-filters were better paired. A second similar table was designed and loaded to include 15.108 s exposures so that SXT commanders have the choice between these sequences depending on solar conditions. A calibration sequence, which is being designed to be run regularly, may enable us to further increase our FFI full-sun cadence by reducing the number of darkframe and diffuser images taken each orbit. Discussions were held about the advisability of running long exposure X-ray images and the dangers of running SXT during SAA. The long exposures provide vital information on the nature of the quiet Sun however they may be adding to the X-ray "ghosts" seen in the diffuser images. There is a small but finite chance that if Yohkoh gets a flare during SAA (when there is no flare available to activate AEC) it could add to the CCD ghost problem if SXT also happened to be in the process of taking several long exposures. Currently SXT is running using a low cadence of 15s exposures and the SAA's are mostly during Yohkoh nights. The question remains unresolved as to whether SXT should operate at all during SAA. P00xxxx Page 2 During the first part of the month a Max 91 Campaign was called to support the balloon flight of HIREGS experiment which was launched from Antarctica. Dr. R. Linn of U. C. Berkeley is the PI of this project. The payload was in-flight for approximately two weeks. Although solar flare activity was relatively low at the time, we expect to be able to compare SXT observations with HIREGS results at some future time when the balloon data has been adequately analyzed. The Yohkoh science bulletin board is now operational, at least in a preliminary form. Professor Uchida will be working with Dr. Keith Strong to improve its format and capabilities over the coming months. << Data Analysis Software >> Dr. Keith Strong, Dr. James Lemen, and Mr. Greg Slater have completed the second generation SXT movie which covers the full frame images taken between 7-Nov-91 and 6-Dec-91. They have added optical images, improved the color tables, and removed cosmic ray events. The procedure is still rather labor intensive, but the product is order of magnitudes better than the previous movie. Work is progressing to make the procedure automatic and to include the ability to make partial frame image movies. The personnel at ISAS received a demonstration of the Sony optical disk recorder by Mr. Hidenori Harada. It is an alternative format to the MII video tape format which was used recently to make the SXT movie. While the optical disk seems to have several advantages (in terms of speed and flexibility) over the tape unit, it is considerably more expensive and the disks can only be written on once, making the media an expensive option. The two units will be compared since they are both available. Ms. Fei-Mei Chou has taken the main orbit prediction program that NEC uses called AOSLOS and made the modifications necessary to run it on a DEC workstation. Currently it is necessary to run the program on the mainframe at ISAS and copy a text file over to the workstations to be used by other programs. The new procedure that is being developed will allow programs to use the AOSLOS results directly without making the intermediate file. The process will be faster and will allow higher accuracy. << Instrument Operations and Health >> An error detection patch was installed by Mr. Sam Freeland in the SXT microprocessor. This patch checks most of the RAM code for corrupted bits including rarely used parts of the code where SEU's might have gone unnoticed before. This is a much safer way to operate the instrument, although it may result in an increase in the rate of operational interruptions. There were two "warm reset" errors this week: Monday 27 Jan and Saturday 1 Feb (the later was detected during the 4th pass of the day and so there was no time for recovery before the Sunday holiday although the instrument was confirmed to be in its usual safe state during the 5th pass). We also had a "filter soft" error which P00xxxx Page 3 was mistakenly believed to be a more serious problem and this caused the loss of some observing time. Discussions were held between Sam Freeland and Tsuneta-san about making the recovery from these errors a series of simple OG's that would make the process more reliable and less time consuming. The current procedure requires each set of commands and code patches to be sent byte by byte from the ground. Using OG's would allow the patches to remain on the spacecraft and a single command would start a series of commands. The chance of errors would be reduced significantly. Mr. Freeland is currently testing a second series of patches which would allow the SXTE-U to recover from most of the SEU errors found by itself. Current recovery requires manual commands from the ground where as the newest patches would allow the microprocessor to recover on its own. << Data Flow >> Distribution of the second test data tape has been delayed because of time spent on improving the error recovery procedures and SXTE-U software modifications. A test tape should be out in the month of February and final distributed data tapes by mid-March. The processed reduced spacecraft pointing information from NEC is still unavailable. Dr. Hugh Hudson has analyzed the HXT aspect sensor (HXA) data and compared it to the SXT image pointing. The correlation is very good and we will probably be able to use either the HXA data or the two dimensional fine sun sensor (TFSS) in the interim. << Problems >> The decline in the transmission of the Aspect Sensor received more attention this month. The analysis of this problem is continuing. In January, the CCD Thermo-electric cooler (TEC) was turned off for a few days and the transmission seen through the narrow band analysis filter increased. It has been suggested that there might have been some contamination or ice on the CCD which outgassed. In the month of February an experiment will be performed where the TEC is turned off and then the CCD heated to +20 C to see if the increase in transmission through the narrow band analysis filter occurs again. << Papers and Conferences >> Several of the Japanese members of the SXT team have volunteered to give papers at the forthcoming science meeting at Mitaka, Japan on the 12-13 February 1992. Preparation for that meeting is in progress. P00xxxx Page 4 << Personnel Travel >> In the first week of January, Dr. Jim Lemen, Mr. Greg Slater, Dr. N. Nitta, and Dr. K. Strong traveled to Japan to assist in the operations of SXT and the analysis of the data available. Dr. Lemen returned after approximately 3 weeks. Mr. Slater will return in mid-Feb. Dr. Nitta will be there for 2 months and Dr. Strong for 3 months. Mr. Sam Freeland made a one week visit to test some modifications to the SXTE-U flight software to perform additional error checking and to test some analysis software packages at ISAS. << Plans for February 1992 >> 1. Continue to complete the document package. 2. Continue the Data Analysis and Reduction software development effort. 3. Continue mission operations and data analysis at ISAS. 4. Future Personnel Travel - Mr. Mons Morrison will travel to ISAS on 24-Feb to relieve Mr. Slater. Mr. Morrison will be there for 3 months. Respectfully submitted, Mons D. Morrison Frank Friedlaender P00xxxx Page 5 -------------------------------------------------------------------------------- UNIVERSITY OF HAWAII ACTIVITY REPORT (DR. R. CANFIELD) No input required for this month -------------------------------------------------------------------------------- UNIVERSITY OF CALIFORNIA AT BERKELEY No input required for this month -------------------------------------------------------------------------------- STANFORD UNIVERSITY (DR. P. STURROCK) No input required for this month -------------------------------------------------------------------------------- SOLAR PHYSICS RESEARCH CORPORATION (KAREN L. HARVEY) No input required for this month P00xxxx 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 | February 10, 1992 January 1992 |-------------------------------- | 6. PERFORMING ORGANIZATION | CODE: O/91-30 -----------------------------------------------|-------------------------------- 7. AUTHOR(S) | 8. PERFORMING ORGANIZA- M. D. Morrison | TION REPORT NO: P00xxxx F. M. Friedlaender |-------------------------------- -----------------------------------------------|10. WORK UNIT NO. 9. PERFORMING ORGANIZATION NAME AND ADDRESS | Lockheed Palo Alto Research Labs B/252 |-------------------------------- Solar & Astrophysics Laboratory O/91-30 |11. CONTRACT OR GRANT NO. 3251 Hanover Street, Palo Alto Ca. 94304 | NAS8 - 37334 -----------------------------------------------|-------------------------------- 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 Jan, 1992 |-------------------------------- |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, Washington, D.C. 20402-0001 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ No. Delivered From Subject Lines 2 Feb 1 0:33 POSTMAN [From: >> Tuesday, Feb 11, 1992 12:42 PM PST