1. 1 Solar-B EIS Engineering Meeting at MSSL July 27 - 29, 1999 H. Hara (NAOJ)

2. 2 EIS/Solar-B Document Name Date Language Thermal Design Standard for Solar-B (DRAFT) Feb 12,1999 J Requirements for Structural Mathematical Models Mar 8,1999 E Mechanical Design Standard (DRAFT) Mar 8, 1999 J+E Environmental Conditions for Solar-B (DRAFT) Mar 8, 1999 J+E Contamination Control Program Plan for Solar-B (DRAFT) Mar 8, 1999 E Solar-B Electrical Design Standard (DRAFT) Apr 24,1999 J (DRAFT) July 27,1999 E Solar-B/Telescope Thermal Interface Condition (DRAFT) June 30, 1999 J+E Requirements for Interface Thermal Math Model of Solar-B Telescope (DRAFT) June 30, 1999 J+E Telemetry & Command Design Standard (DRAFT) not yet made Documents for Subsystem Design

3. 3 EIS/Solar-BRequests from System side to EIS 1. Position of Mounting I/F points. There is inconsistent with the I/F legs. Change the drawing to meet the I/F points before making structure math model. 2. Electrical relationship among ICU, MHC, and FPA. How these are connected by electrical lines ? 3. Ranges of temperature is too narrow. Widen the ranges (relatively urgent). 4. Show disturbance torque of each moving component (urgent issue). 5. 32 W solar power is input in EIS at entrance filter. Is this OK ? How is this energy to be treated ? 6. Number and location of survival heaters when EIS primary power is off. Temperatures for switch-on and switch-off controls should be reported. The survival heaters are controlled by HCE. At present three survival heaters are allocated to EIS by the request of Japanese side, though the usage is uncertain. This issue must be reported to the system side by July 15. summary report of satellite design meeting on June 30, 1999

4. 4 EIS/Solar-B Solar-B system issues summary report of satellite design meeting on June 30, 1999 Telemetry & Command system: ASTRO-F system was adopted. Summary of electrical interface related to EIS was shown (see Fig. 1 ). Satellite structure almost meet the size of fairing envelope. (exception: XRT & EIS. In case of EIS, interface points should be shifted to -Z direction.) ICU is put at low part of +Y side panel of bus structure (Fig.2). Weight of EIS: EIS-STR 50.3 kg, EIS-ICU 6.0 kg, EIS-HAR 4.0 kg. Margin of 9 kg is managed by system side in a different level of system issue. Power: ICU: W max = 60 W, I max = 2.3 A Heater power of 10 W is tentatively allocated to EIS because of no input. Thermal analysis of optical bench + mounting legs + bus structure was almost finished. Change of optical axes of SOT, XRT, and EIS is only 0.2-0.3 arcsec during the sun- synchronous orbit in the worst case. The infinite rigid body for telescopes is assumed in this analysis.

5. 5 EIS/Solar-B Solar-B system issues Harness: If there is an electrical harness whose length should be less than 4 m by some reason, we must report it to the system side. Power savings: Even in the case of sun-synchronous orbit, satellite night comes in some period. System asked all telescope teams if the power saving can be done during the night period or not for power saving. Bus voltage for SOT, XRT, and EIS is 28 +/- (A) V. (A) will be less than 2. Structure math model: The schedule of structure analysis was updated (see Fig. 3). Thermal math model: The schedule of thermal analysis was updated (see Fig. 4). summary report of satellite design meeting on June 30, 1999

6. 6 EIS/Solar-B Electrical Interface of EIS Fig. 1 EIS-STR HCE DIST TCI-B EIS-ICU MDP survival heater #1- #3 PIMDHU HKU T-sensor #1 - #7 T-sensor #8 - #9 DC/DC signal line primary power on/off CMD+TLM 28V primary power line secondary power line bus structure summary report of satellite design meeting on June 30, 1999

7. 7 EIS/Solar-B Location of EIS-ICU in Bus Structure EIS-ICU Fig. 2 summary report of satellite design meeting on June 30, 1999

8. 8 EIS/Solar-BSchedule of Structure Analysis bus subsystem SOT, XRT, EIS System side July Aug. Sep Oct. math model Coupled Load Analysis combine math models to satellite math model Fig. 3 summary report of satellite design meeting on June 30, 1999

9. 9 EIS/Solar-BSchedule of Thermal Analysis Fig. 4 Flowchart during Phase A study Thermal design standard Thermal Interface Requirements to the telescope thermal math model Mar. 8 Telescope Team (EIS) System Thermal design Information End of May Analysis of Bus structure & Optical Bench for deriving temperature distribution temperature of I/F points temperature of boundary Thermal I/F condition Thermal model design Instruction I/F Thermal Math Model Themal design analysis of EIS Preliminary Beg. of July Time Thermal I/F condition Thermal model design Instruction Update System thermal analysis Phase A Thermal Design Analysis Phase A B End of Oct. Themal design analysis of EIS Detail Analysis of thermal distortion End of June End of July I/F Thermal Math Model Update End of Nov. End of Dec. summary report of satellite design meeting on June 30, 1999

10. 10 EIS/Solar-B MDP development schedule Specifications of MDP shall be fixed by the following dates: hardware related issues: August 31, 1999 software related issues: November 30, 1999 Purpose of PM tests (Feb 1 - Mar 31, 2001) Interface with SOT, XRT, EIS, DHU, TCI-B, HCE, DIST – establishment of hardware interface – establishment of software protocol – establishment of exposure sequence Confirmation of main processing functions – confirmation of processing command/telemetry – confirmation of processing science data including compression

11. 11 EIS/Solar-B PM test plan of MDP SOT XRT EIS I/F with mission instrument command transmission observation table parameter table command receipt satellite bus I/F satellite bus MDP receive image data bit comp. image comp. receive status data telemetry format primary power I/F create secondary power management satellite time

12. 12 EIS/Solar-B Electrical Interface with MDP EISMDP PIM HKU PIM DHU DR analog data (temperature) S/C bus image compression status data command EIS table write software patch science data table dump information of time MDP buffer status power control occurrence of flare flare position XRT DIST (power distributor) 28 V TCI-B COM uplink downlink PIM HCE (heater control) status temp. for HC command

13. 13 EIS/Solar-B Interface lines differential RS-422 line interface HS-26C31 HS-26C32 DATA CLOCK ENABLE MDP BUFFER STATUS COMMAND CLOCK ENABLE MDP EIS low-power RS-422 64 kHz Normal RS-422 1 MHz MDP Buffer Status line is used 1: for safe exchange of input buffer in MDP. 2: when post compression buffers become almost full. All electrical interface lines between EIS and MDP are digital interface lines. hardware command I/F for secondary power on/off status data interface DATA CLOCK ENABLE low-power RS-422 64 kHz hardware status I/F for secondary power hardware status I/F for others if required

14. 14 EIS/Solar-B Flow of image data processing in MDP Input Buffer SOT-A SOT-B XRT-A XRT-B EIS-A 8Mbyes EIS-B 8Mbyes bit comp. buffer A buffer B image compression Post Compression Buffer output buffer DHU EIS can use functions of bit compression & image compression in MDP. DPCM JPEG buffer A buffer B

15. 15 EIS/Solar-B Data lines Data line: normal differential RS-422 line, 1Mbps Science data (spectrum or image) Status data ( ~1 sec interval; Report of shutter & scan mirror motions will be required.) Dump data of EIS observation table Dump data of EIS compression table MDP knows kind of data by looking at the header part after the data are transferred. 12 bits data flow in this data line. maximum transfer speed: 1 Mbps (TBD) EIS Input Buffer in MDP: 1. double buffer system 2. buffer size: 8 Mbytes/buffer EIS MDP Concept of Data Format: fixed-length header + variable-length data maximum image size in a single packet = 256 kpixel science data: header + 12 bits CCD image data The number of pixels in the image data is a multiple of 8. Is this OK ? other data : header + 12 bit data (Upper 4 bits are all 0. Is this OK ?) EIS can send data to MDP at any time when a status of MDP buffer status line is READY.

16. 16 EIS/Solar-B Recommended status line interface status data interface DATA CLOCK ENABLE low-power RS-422 64 kHz HS-26C31 HS-26C32 DATA1 DATA2 DATA3 DATA4 DATA N Data format 8 bits 8 bits 8 bits 8bits 8bits REQUIREMENTS Request of sending status data is informed from MDP via command line, and EIS shall send status data to MDP within 0.5 sec. Data format is consistent with requirement of PIM. status request command from MDP via command I/F status data to MDP via status I/F < 0.5 sec

17. 17 EIS/Solar-B Data Compression CCDbuffer DHU DR 2.4 Gbits 14 bit 12 bit bit compression input buffer EIS MDP bit comp. image comp. post comp. buffer 2 Mbps (TBD) line for SOT, XRT & EIS 1 Mbps line 12 bits data for EIS JPEG EIS can use 2 Mbps line nominally for 0.5 s every 6 seconds. max. 167 kbps, but DR for EIS will become full in a short time. DPCM (selectable) header Capacity of DR will be ~3 Gbits, but only downlink 2.4 Gbits during the KSC/DSN contacts. Header includes information of data compression in MDP.

18. 18 EIS/Solar-B Command Lines MDP contractors would like to know: 1. list of commands required for EIS operation 2. how ICU reads commands from MDP (Please explain it.) 3. response time for a command 4. size of buffer ? 5. whether there is some restriction for the data format or not. Command line: low-power differential RS-422 line, 64 kbps Command answer back: receipt of command put the command data into status data for confirmation.

19. 19 EIS/Solar-B Hardware command interface Purpose: Irrespective of MDP CPU status, the secondary power on/off commands and others are sent via hardware command interface. HS-26C31 HS-26C32 + - 100Ω±10 4.7KΩ±10 driver receiver Driver device HS-26C31Receiver device HS-26C32 1 line/component No resistance MDPEIS STROBE DATA4 DATA3 DATA2 DATA1 DATA0 MDP STROBE DATA a b c reference: Solar-B Electrical Design Standards §8-(8) t 31.25 msec (min) command minimum interval of command transmission

20. 20 EIS/Solar-B Hardware status interface for secondary power Purpose: ON/OFF status of EIS secondary power relay is periodically monitored by a hardware logic circuits. EISMDP status 0 status 1 status N MDP EIS U1 C1 R1 R2 VDD : +5V ± TBD V U1 : CMOS 4049/4050 C1 : 220pF ± TBD R1 : 27KΩ± TBD R2 : 10KΩ± TBD Circuit type: TB-E-R Circuit type: TB-E-T + - MUX +5V 2.5KΩ Input impedance more than 1MΩ Logic 1 open (more than 1MΩ) Logic 0 close (10Ω) or reference: Solar-B Electrical Design Standards §8-(6) or (7) MDP EIS

21. 21 EIS/Solar-B Hardware status interface for important bi-level status + - 100Ω±10 4.7KΩ±10 driver receiver Driver device HS-26C31Receiver device HS-26C32 1 line/component No resistance MDPEIS MDP reference: Solar-B Electrical Design Standards §8-(8) Purpose: Important bi-level status data are periodically monitored by a hardware logic circuit. Status N+1 Status N+2 Status N+M HS-26C31 HS-26C32 N: Number of secondary power status M: Number of H/W status

22. 22 EIS/Solar-B Counter-plan for Errors When some error happens in EIS-CPU due to SEU, does EIS side request anything to MDP ? or does EIS side deal with the error by itself ? When some error happens in MDP due to SEU, does EIS side request anything to MDP backup system for safety ? or does EIS side deal with the error by itself ? MDP realizes stop of EIS CPU by the following procedure. MDP sends a status request command and waits for 0.5 sec. When the same procedure is done three times in a condition that status data do not come to MDP, MDP judges that EIS CPU is down.

23. 23 EIS/Solar-B Management Plan of Time EIS MDPDHU clock generator clock line in command line clock counter PIM 5 4 3 2 1 clock counter obtaining count c1 at a start of exposure obtaining count c2 at a start of data transfer. 1: header 2: count c1 at start of exposure 3: count c2 at start of data transfer 4: image parameter 5:image data obtaining c3 at start of data receipt obtaining c4 at start of receiving PIM time. PIM time These counts are added to compressed image data. These counts are added to image data. A: CCSDS packet header B: count c3 at start of receiving image data C: PIM time D: count c4 at start of receiving PIM time E: compressed image data E 4 D C B 3 2 1 A data line for image data In case of data except for science data, EIS only put counter value at start of data transfer.

24. 24 EIS/Solar-B Flare Detection The following is a baseline of flare detection. Detection of flares is done by XRT. 8×8 on-chip summation image covering the whole XRT field of view will be used for flare patrol. The flare patrol image will be taken every 30 sec (TBD). Information on flare detection is sent to EIS by MDP. 1. Flare detection 2. Flare location in XRT CCD coordinate; X=0-255, Y=0-255 (TBD) Duration of flare mode TBD time flare patrol image 30 s time for XRT data analysis (TBD) Flare! flare mode flare observation with EIS time for change of EIS FOV

25. 25 EIS/Solar-BCommand to MDP Type ClassificationCommand Types Command Block Type Discrete Command (DC) Block Command (DC+BC+...+ BC) Command Grouping Individual Command Organized Command (OG) Operation Type Real-time command Time-tagged command Operation Program (OP) Onboard-triggered command OP and Onboard-triggered command support only OG to execute.

26. 26 EIS/Solar-BCommand System Block Diagram TLM CMD DHU/DR ground PIM MDP EIS-E Observation table for EIS SOT FPP-E XRT status science data command status data command status data command status data observation table for XRT observation table for SOT Real-time command real OG execution OP/OG upload time-tagged command OP/OG

27. 27 EIS/Solar-BData length of Command Command Block Type Maximum data length (bytes) DC 1 DC+BC+…..+BC real time 1 + 252 OP/OG 1 + 13 time-tagged 1 + 8 DC is used for single task such as ON/OFF, START/STOP and ENA/DIS. BC is used for data transmission such as program load, table upload, and so on. Real-time commands are sent from the ground and are immediately executed. Time-tagged commands are stored in DHU and executed at a specified time in a resolution of about 1 sec. 32 commands can be stored in DHU.

28. 28 EIS/Solar-BOP & OG OP: Operation Program; a group of time-line commands consisting of OG. 512 (TBD) time-line slots are prepared for OP. Each time line is executed at a time defined by time interval between consecutive two time lines. The unit of time interval is TBD sec. OP is started at a Kagoshima contact pass. OG: OrGanized command; One OG has 16 (TBD) command slots. Discrete command or block command data is included in each slot. 256 (TBD) OG can be stored in DHU. Time interval between two slots in an OG is 62.5 msec. Example of OP: CE #OG Interval 00 0 121 NOP 01 3 32 KSC LOS 02 22 85 DSN AOS …… 129 255 OP STOP Example of OG: 00: 03-DC-11 08: 05-DC-42 01: 09: 05-BC-12 02: 03-DC-23 10: 05-BC-45 03: 11: 05-BC-32 04: 12: 05: 13: 06: 14: 07: 15: 03-DC-44

29. 29 EIS/Solar-BMTM Test (May 15 - Aug 31, 2001)

30. 30 EIS/Solar-BMechanism & Operation Mechanism: purpose frequency direction angle of rotation or shift outside observation: DOR: protect inside from dirty environment once/year ar. Y-axis 180deg/ 10 sec LOK: increase of stiffness once/mission ar. X-axis ~30 deg GRA: focus adjustment once/year ± Z-axis ±0.5 mm/10sec CLM: opening of vacuum enclosure once/mission ar. Y-axis 90 deg/10 sec SLI : focus adjustment once/mission? ± Z-axis ±0.5 mm/10sec change slit/slot once/hour ? ar. X-axis 90 deg/10 sec MIR: change field of view once/day ? ± X-axis ±5arcmin/10sec during observation: MIR: scan for raster observation once/ 1 sec ar. Y-axis 1 arcsec/ 0.5 sec reset to start position once/5-10 min ar. Y-axis 8 arcmin/ 5 sec SHU: adjust exposure duration once/ 1 sec ar. Z-axis ~60 deg/0.1 sec (SLI: change slit/slot once/ hour ar. X-axis 90 deg/10 sec )

31. 31 EIS/Solar-BDisturbance Torque (order of estimation) momentum of inertia estimated by CMB unit (g cm 2 ) scan mirror: I y = 4.89e4 shutter : I z = 36.7 slit : I x = 44.3 Disturbance torque during a motion: T = d (I )/ dt ~ I (dt) -2 scan mirror: [raster step] = 1 arcsec, dt = 0.5 sec T = 4.9e4 10 -7 4.8e-6 0.5 -2 = 9.4e-8 (N m) [motion to home position] = 4 arcmin, dt = 5 sec T = 4.9e4 10 -7 4.8e-6 240 5 -2 = 2.3e-7 (N m) t 0.5 s shutter: = 30 deg, dt = 0.1 sec T = 36.7 10 -7 4.8e-6 3600 30 0.1 -2 = 1.9e-4 (N m) slit: = 90 deg, dt = 10 sec T = 44.3 10 -7 4.8e-6 3600 90 10 -2 = 1.9e-4 (N m) = 6.9e-8 (N m) 6.9e-6 (N m) for dt = 1 sec

32. 32 EIS/Solar-BAcceptable Level of Disturbance Torque from handouts distributed in satellite design meeting held on June 30, 1999