# Presentation: 526749

## Section 4

_***Section 4***_
***Flight Software***

*** ******. . . Ray Whitley***
*EO-1 WARP Flight Software Lead*

## Spacecraft Bus Architecture

- 4Mbps
- Sci Bkup

- 4Mbps

- 105 Mbps
- Science

- 2Kbps

- 4Mbps

- 1773 Data Bus

- - GSFC managed

- - instrument or procured

## MAP/TRMM Heritage

***MAP/TRMM Heritage***

***Litton Space Act personnel developed PSE & HSK software for MAP and for subsequent use on EO-1 ***
***Bulk of S/C bus software ported from XTE / TRMM to the Mongoose V with MAP civil servants and Litton Space Act personnel***
***Mongoose V, PSE, Comm, and HSK baseline builds received between 11/98 and 12/98***
***ACS attitude control derived from TRMM ACS flight code***
***ACE’s safe-hold algorithm derived from XTE / TRMM designs (same as ACS sun acquisition module in main processor)***

## Functionality By Processor

***Functionality By Processor***

***ACS/C&DH Mongoose V:***
***Attitude determination & control modes***
***Real-time & stored command distribution to all subsystems***
***Telemetry acquisition and frame generation***
***Time maintenance & distribution***
***SSR record and playback (s/c & instrument housekeeping data)***
***ACE RSN:***
***Independent safe-hold***
***Sensor data acquisition***
***Actuator commanding***
***Comm RSN:***
***Command reception & de-blocking***
***Telemetry transmission***
***Spacecraft time correlation***

## Functionality By Processor-2

***Functionality By Processor-2***

***HK RSN:***
***GPS time/position data acquisition***
***thermister data collection***
***High Output Parrafins (HOPS) deployment control & monitoring***
***Miscellaneous LVPC services***
***PSE RSN:***
***power subsystem monitoring & control***
***X-Band RSN:***
***Phased Array Antenna command distribution***
***Phased Array Antenna housekeeping data collection & monitoring***

## Functionality By Processor-3

***Functionality By Processor-3***

***WARP Mongoose V:***
***Science data record set-up and control***
***Science data X-band & S-band playback control***
***WARP RSN:***
***Command distribution for LVPS services inside WARP***
***Housekeeping data acquisition & monitoring for the WARP***

## Launch CPU/Memory Margins

## Verification Approach

***Verification Approach***

***Component & system level I&T at software lab prior to and at s/c delivery***
***Well documented and repeatable stol test procedures executed in lab and repeated upon delivery to spacecraft***
***Equivalent to “long form functional”***
***Code walk-thrus with panel of FSW peers, subsystem lead, & s/c systems engineering***
***Spacecraft subsystem functional, CPTs, “special tests”***
***Bus error injection and memory corruption***
***Processor stress test***

## Pre-Ship FSW Releases

## Problem Tracking Reports

## Significant Test Results

***Significant Test Results***

***All flight software components are now fully operational and healthy meeting both functional and performance requirements***
***significant problems uncovered during last three months of I&T, and since retified:***
***PSE shunting & power subsystem FDC requirements clarification***
***time maintenance with GPS data***
***inconsistent requirements in high-level FDCs (TSMs) and requirements just missing***

## Special Topic:

***Flight Software Maintenance Capability***

## On-orbit Sustaining Engineering

***On-orbit Sustaining Engineering***

***Maintenance Plan originally drafted by THC/Microtel in early September ‘99 include:***
***Key contractor personnel associated with the development of key flight software components***
***Available flight software development facility components for Swales and GSFC***
***Optionally augmenting maintenance facility with one or more higher fidelity breadboards***
***Have basic facility ready within days after spacecraft ships***
***For Training purposes,***
***Maintenance personnel participated in recent code walk-thrus of 2 mission critical flight software subsystems***
***Assisting in development of test data  to be used to verify FDCs and TSMs in the software lab***
***Gather, review, and configure all software specification & user documentation***
***Re-verify software load/dump/verify utilities prior to S/C launch***

## EO-1 Flight Software Maintenance Functional Organization Chart

## EO-1 Flight Software Maintenance Facility

## Slide 16

## Special Topic:

***Special Topic:***
***TSMs, Including Comprehensive Failure & Correction***

*** ******. . . Tom Feild***
*EO-1 Systems Engineer, GSFC Code 568*

## Comprehensive Failure Detection and Correction

***Comprehensive Failure Detection and Correction***

***EO-1 employs 2 methods to autonomously detect fault conditions and take appropriate action to safe the observatory:***
***TSM/RTS System ***
*A Telemetry Statistics Monitor (TSM) is a telemetry point or combination of points that are used to verify observatory health*
*A Relative Time Sequence (RTS) is a list of commands that can be executed in response to a hazardous condition*
*TSMs monitor spacecraft health and when they detect a fault condition they can execute an RTS and/or issue an event message*
*Runs on the ACDS Mongoose 5*
***FDC System***
*The Fault Detection and Correction (FDC) System consists of software checks and corrective actions that are embedded in the flight software running on the various processors on EO-1*

## Failure Detection and Correction Philosophy

***Failure Detection and Correction Philosophy***

***Philosophy is ‘Keep it Simple’***
***Only conditions that threaten observatory health are addressed***
***Simplest ‘safe’ action is taken, often to power off the device whose health is in question***
***The TSM/RTS System is the primary method of detecting and correcting hazardous conditions on EO-1***
***Except for certain instrument fault conditions, when one hazard has both a TSM/RTS action and an FDC action then the thresholds are set such that the TSM/RTS will trip first***
***All TSMs, RTSs, and FDCs will be tested prior to launch***
***Many ACS FDCs can only be tested on the high fidelity simulator***
***Many instrument FDCs only tested prior to instrument delivery***
***All TSMs/RTSs or FDCs will be retested after every new software load.  Many are tested during the CPT.***

## Event Messages

***Event Messages***

***The Observatory sends down ‘Event Messages’ to provide information on all significant events that occur on the observatory such as:***
***Changes in spacecraft configuration (e.g. data rates, filter tables, day/night transitions)***
***Anomalous events such as activated TSMs, RTSs, and FDCs***
***All Event Messages are stored in VR-2***
***VR-2 is downloaded during each pass ***
***Provides Flight Ops Team with immediate access to information on spacecraft health and autonomous actions***
***Event messages are generated by:***
***ALL TSM activations***
***All RTS calls by TSMs***
***Most FDCs***

## TSMs

***TSMs***

***Current version is TSM Rev G ***
***Contains 33 TSMs (plus 17 monitor point TSMs)***
***Loaded on November 30, 1999***
***3 problems have been identified to date***
***2 TSMs have tripped when not expected***
***1 TSM did not trip when expected***
***Most already tested***
***21 tested in special test***
***6 to be tested during CPT (12/6 to 12/10)***
***3 require retest***
***3 require troubleshooting***

## TSM Rev G

## TSM Rev G (continued)

## (EEPROM) RTSs

***(EEPROM) RTSs***

***There are 256 RTSs***
***1 to 64 are loaded in EEPROM ***
***65 to 256 are RAM only***
***40 to 55 are reserved for the MOC (Not used for fault correction)***
***1 to 39 and 56 to 64 are used for Fault Correction (48 total)***
***34 are currently used;  14 are spares***
***#5 and #39 are also used by the MOC.  They may use others.***
***Current EEPROM version is RTS Rev E ***
***Loaded on November 30, 1999***
***No problems with RTSs have been identified***
***32 tested in special test (All OK)***
***16 to be tested during CPT  (12/6 to 12/10)***
***16 to be tested by the MOC (12/13 to 12/14)***

## RTS Rev E

## RTS Rev E (cont.)

## FDCs

***FDCs***

***Additional Failure Detection and Correction is found in the various processors on EO-1***
***These are called Fault Detection and Correction (FDC) routines***
***FDCs contained in ACDS, ACE RSN, PSE RSN, Comm RSN, X-Band RSN, WARP M5, Hyperion, ALI, and AC***
***Most are enabled at power-up and during nominal mission mode ***
*** ******The ACS FDCs are mode dependent and not all are used in any one mode***
***Most can be individually enabled or disabled***
*Some instrument FDCs cannot be disabled*
***Several are disabled for launch***

## FDCs (continued)

***FDCs ****(continued)*

***All have been tested***
***Many of the ACS FDCs can only be tested on the EO-1 hyperdynamic simulator***
***Most of the Instrument FDCs were tested before integration onto EO-1***
***The rest have been tested on the observatory***
***When a new software load is performed, all FDCs in that software load are retested***
***ACS FDCs are tested on the EO-1 hyperdynamic simulator***

## Use By Flight Operations Team

***Use By Flight Operations Team***

***FDCs ***
***Autonomous.  Cannot be called directly by Flight Ops***
***Updates require new software load***
***Most can be enabled and disabled***
***TSMs***
***Autonomous.  Cannot be tripped directly by Flight Ops***
***Updates require table load or new M5 load***
***Can be enabled or disabled or placed in ‘watch’ mode***
***RTSs***
***EEPROM RTSs 40 to 55 and all RAM RTSs (65 to 256) are reserved for the MOC***
*Others, such as RTSs 5 and 39 are used by the MOC*
***EEPROM updates require table load or M5 load***
***All RTSs can be enabled or disabled***

## Summary

***Summary***

***All RTSs and all but 2 TSMs will be tested by December 14, 1999 ***
***2 TSMs need special tests that may require a GSE change***
***Potential problems have been identified with 3 TSMs***
***Being investigated by Flight Software and Systems***
***After these items are completed the EO-1 Failure Detection and Correction System will be ready for launch***
***If software changes are made then re-testing will be required***