FOR THE DEEP SPACE PROGRAM SCIENCE:.EXPERIMENT (DSPSE) FLIGHT SOFTW ARlt" CSCI. June 1, Prepared for:

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3 ... TABLE OF CONTENTS _j_.. I ' SCOPE Identification... 3 CSCI Overview Document Overview APPLICABLE DOCUMENTS Government Documents Non-Government Documents ENGINEERING REQUIREMENTS FS External Interface Requirement Software/liard ware Interfaces Hardware Inputs Hardware Outputs ;... 7 Flight/Ground Software Interfaces Command Interfaces '... 7 Telemetry Interfaces CSCI Capability Requirements Executive Capability Requirements Executive Input Requirements Executive Processing Requirements Executive Output Requirements Prom and System Initialization Capability Requirements... 9 PROM and System Initialization Input Requirements... 9 PROM and System Initialization Processing Requirements Prom and System Initialization Output Requirements... lo Command Processing (CMDPROC) Capability Requirements CMDPROC CSC Description Command Types Command Definitions Command Functions CMDPROC CSC External Interface Requirements CMDPROC CSC Capability Requirements Real Time Commands : Real Time Command Input Real Time Command Processing Real Time Command Output Stored Commands Stored Command Input Stored Command Processing Stored Command Output Event Driven Commands Event Driven Command Input Event Driven Command Processing Event Driven Command Output Command Output Procedures CMDPROC CSC Data Elements Command Record Descriptor Command Record Fields Command Record Size TELEMETRY PROCESSING (TLMPROC) CSC

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5 Requirements LMPROC CSC Description Telemetry Functions...; LMPROC CSC External Interface Requirements TLMPRQC CSC Capability Requirements Telemetry Acquisition Telemetry Acquisition Input Telemetry Acquisition Processing Telemetry Acquisition Output Telemetry Reduction Telemetry Reduction Input Telemetry Reduction Processing Telemetry Reduction Output Telemetry Logging Telemetry Logging Input Telemetry Logging Processing Telemetry Logging Output LMPROC CSC Data Elements Analog Record Descriptor Analog Record Fields Analog Record Size Discrete Record Descriptor Discrete Record Fields Discrete Record Size Derived Record Descriptor Derived Record Fields _ 20 Derived Record Size COMMAND INPUT (CMDIN ) CSC CMDIN" CSC Description CMDIN" CSC External Interface Requirements CMDIN CSC Capability Requirements CMDIN Inputs CMDIN" Processing CMDIN" Outputs Telemetry Output (1LMOUT) CSC LMOUT CSC Description LMOUT CSC External Interface Requirements LMOUT CSC Capability Requirements CMDIN Inputs CMDIN" Processing CMDIN" Outputs Guidance, Navigation, & Control (GNC) Executive Capability 22 GNC Executive Input Requirements GNC Executive Processing Requirements GNC Executive Output Requirements Attitude Determination Capability Requirements Attitide Determination Input Requirements Attitide Determination Capability Requirements Attitide Determination Output Requirements Attitude Control Capability Requirements Attitide Control Inputs Attitide Determination Capability Requirements Attitide Control Output Requirements Autonomous Navigation Capability Requirements

6 ) Autonomous Navigation Input Requirements Autonomous Navigation Processing Requirements Autonomous Navigation Output Requirements Terminal:Guidance and Control-Capability Requirements Terminal Guidance and Control Input Requirements Terminal Guidance and Control Processing Requirements Terminal Guidance and Control Output Requirements Sensor Control and Data Processing Requirements Sensor Control and Data Processing Input Requirements Sensor Control and Data Processing Processing Requirements Sensor Control and Data Processing Output Requirements Delta V Control Requirements Delta V Control Input Requirements Delta V Control Processing Requirements Delta V Control Output Requirements Solar Array Control Capability Requirements Solar Array Control Input Requirements Solar Array Control Processing Requirements Solar Array Control Output Requirements Memory loads and dumps Capability Requirements Memory Load and Dump Facility Input Requirements Memory Load and Dump Facility Processing Requirements Memory Load and Dump Facility Output Requirements Event Logging and Distribution Capability Requirements Event Logging and Distribution Input Requirements Event Logging and Distribution Processing Requirements Event Logging and Distribution Output Requirements Processor Health and Status Capability Requirements Processor Health and Status Input Requirements Processor Health and Status Processing Requirements Processor Health and Status Output Requirements CSCI Internal Interfaces CSCI Data Element Requirements Adaption Requirements Installation-dependent Data Operational Parameters Sizing and Timing Requirements Safety Requirements Security Requirements Design Constraints Software Quality Factors Human Performance/Human Engineering Requirements Requirements Traceability QUALIFICATION REQUIREMENTS 36 Qualification Methods Special Qualification Requirements... PREPARATION FOR DELIVERY 37 NOTES

7 1 SCOPE 1. 1 Identification This specification establishes the requirements for the Deep Space Program Science Experiment (DSPSE) Flight Software (FS) CSCI. This Flight Software CSCI is composed of all the software executing on the spacecraft controller and sensor controller processor modules on the DSPSE spacecraft CSCI Overview The DSPSE software is partitioned into three segments; Flight Segment, Ground Segement, and Mission Operations Segment. The Flight Segment consists of all software which will reside onboard the DSPSE spacecraft. The Ground Segment consists of all ground station software including the Transportable Ground Station (TGS), Electrical Aerospace Ground Equipment (EAGE), and Electrical Launch Support Equipment (ELSE) which provides for command, control, and testing of the DSPSE spacecraft and launch vehicle. The Mission Operations Segment consists of all software for Mission Operations and Data Analysis. This specification details the software requirements for the Flight Segment. The software requirements for the Ground Segment and the Mission Operations segment are documented separately. The Flight Segment is composed solely of the Flight Software (FS) CSCI. Requirements Specification details the software requirements for the FS CSCI. composed of the following Computer Software Components (CSCs): This Software The FS CSCI is 1. Executive (0/S services, Device Drivers, Interrupt Handling, Initialization) 2.. Prom Capability an.d System Initialization 3. Command Processing 4. Telemetry Processing 5. Command distribution 6. Telemetry distribution 7. Guidance, Navigation, and Control Executive 8. Attitude Determination 9. Attitude Control 10. Autonomous Navigation 11. Terminal Guidance and Control 12; Sensor Control and Data Processing 13. Delta V Control 14. Solar Array Control 15. Memory Loads and Dumps 16. Event Logging and Distribution 17. Processor Health and Status. 18. GMT Maintenance 5

8 I Document Overview The purpose of this document is to identify the specific. requirements for the Flight Software CSCI. The document is organized in a manner consistent with the guidelines established by DI MCCR-80025A. This document is organized into TBD sections and TBD appendices. Section 2 identifies other documents which are relevant to the DSPSE Flight Software requirements. Section 3 defines the detailed performance and interface requirements. Section 4 identifies the qualification requirements for test and verification. Section 5 specifies the specific requirements for software delivery. Section 6 contains notes. Each requirement has an identifier associated with it that shall be used throughout the development process to track the requirement The convention used for these identifiers is as follows: nn - Interface Requirement FSA_nnnn - Adaptation Requirement nnnn - Capability Requirement FSD_nnn -Design Constraint Requirement FSE_nnnn - Data Element Requirement FSQ_nnnn - Quality Requirement FSZ_ nn - Sizing and timing Requirement FSS_nnnn- Security Requirement FST _nnnn - Qualification Requirement. i \.

9 7 2 APPLICABLE DOCUMENTS 2.1 Government Documents The following documents of the exact issue shown form a part of this specification to the extent specified herein. In the event of conflict between the documents referenced herein and the contents of this specification, the contents of this specification shall be considered a superseding requirement. SPECIFICATIONS 1. SSD-D-XXXXXXXX DSPSE Flight Algorithms, Date TBD. STANDARDS TBD. DRAWINGS TBD. OTHER PUBLICATIONS None. Copies of specifications, standards, drawings, and publications required by suppliers in connection with specified procurement functions should be obtained from the contracting agency or as directed by the contracting officer 2.2 Non-Government Documents The following documents of the exact issue form a part of this specification of the extent specified herein. In the event of conflict between the documents referenced herein and the contents of this specification, the contents of this specification shall be considered a superseding requirement. SPECIFICATIONS: 1. SSD-D-XXX:XXX DSPSE Flight/Ground Interface Control Document, Date TBD. 1. SSD-D-:XXXX DSPSE Flight Hardware/Software Interface Control Document, Date TBD. 3. SSD-D-XXXXXXXX Data Formats Documents, Date TBD. STANDARDS: TBD. DRAWINGS: None. OTHER PUBLICATIONS: None. ( \

10 8 3 Engineering Requirements 3.l FS External Interface Requirement The Flight Software (FS) CSCI interfaces with both the flight hardware and the ground software. The interfaces are detailed in the DSPSE Software/Hardware ICD and DSPSE Flight/Ground ICD respectively. Figure provides a diagram of all the Flight Software CSCI external interfaces. _jeoei I solar_anay_cmd"s ,...-"'-- sun_data Salsa - - Figure Software/Hardware Interfaces The specific commands for each software/hardware interface is specified in detail in the DSPSE Flight Hardware/Software Interface Control Document Hardware Inputs The FS CSCI shall accept raw, uncompressed Star Tracker, UVNis, LIDAR, LWIR, and SWIR sensor data (i.e. pixel images) from the Data Handling Unit for image processing. The FS CSCI shall accept and utilize the Star Tracker, UVNis, LIDAR, LWIR, and SWIR sensor status data for command verification of the sensors. The FS CSCI shall collect telemetry data via the local telemetry interface card. Telemetry shall be collected as specified in the DSPSE Software/Hardware ICD. The FS CSCI shall accept and process attitude and velocity increments from the Inertial Measurement Unit (IMU) for attitude determination and control. (The IMU provides 3 components of attitude and velocity increments for changes from inertial reference to spacecraft fixed reference). The FS CSCI shall accept and process the sun sensor data to determine the current sun angle. The FS CSCI shall be capable of retrieving data from the mass storage device onboard the spacecraft. The FS CSCI shall accept the reaction wheel speed The FS CSCI shall receive indication of TTI rocket firing and separation. The FS CSCI shall accept and process the current reaction wheel speed.

11 9 The FS 'CSCI shall accept and.process propellant tank pressure (if necessary to adjust control system parameters) Hardware Outputs The FS CSCI shall control the Star Tracker, UV Nisual, LIDAR, L WIR, and SWIR sensors through the Synchronous Addressable Serial Interface (SASI) bus. The FS CSCI shall control the filter wheels and camera gain for the UVNisual, L WIR, and SWIR sensors through the Synchronous Addressable Serial Interface (SASI) bus. The FS CSCI shall distribute local commands via the local command interface card. Local commands shall be distributed as specified in the DSPSE Software/Hardware lcd. The FS CSCI shall issue commands to the ACS/RCS subsystem via the local ACS/RCS interface card for controlling the reaction control thruster. The FS CSCI shall issue commands to the Solar Array Controller for controlling the angle of the spacecraft solar array panels relative to the sun. The FS CSCI shall be capable of storing data to the mass storage device onboard the spacecraft. The FS CSCI shall issue commands to control the reaction wheel speed Flight/Ground Software Interfaces Command Interfaces The FS CSCI shall accept and processing the following commands from the ground: Spacecraft epoch (position and velocity in TBD inertial coordinates at specified time) Asteroid epoch (position and velocity in TBD inertial coordinates at specified time) Delta V command: time of execution; desired attitude at time of firing; velocity increment to be achieved Attitude mode command: time; attitude mode; if applicable, desired attitude Filter wheel positions and camera gains for UV/visual, SWIR, and LWIR sensors Requests for image data collection for UV /visual, SWIR, and L WIR sensors. Enable/disable commands: autonomous navigation; autonomous terminal guidance and control; autonomous scheduling; solar array control; momentum dumping; automatic gain control of sensor cameras Telemetry I terfaces Periodic outputs are (rates are TBD): Estimated spacecraft attitude Computed spacecraft position and velocity Autonomous navigation updates to spacecraft position and velocity Aperiodic outputs are: Attitude control mode transitions

12 10 Actual delta V's achieved Software detected errors and anomalous conditions Autonomous updates to asteroid position and velocity 3. 2 CSCI Capability Requirements Executive Capability Requirements The Flight Software Executive provides the following capabilities underlying tasking, messaging, and software control features for the spacecraft software system. The Executive is responsible to prioritize tasks, deliver message from task to task, and to respond to interrupts, as well as task switching capabilities for the flight software system. Included as part of the executive software are the device drivers for the various subsystems. The executive will manage all tasks which are present onboard the spacecraft Executive Input Requirements The Executive Processing Module shall accept the following external stimuli : External Device interrupts from various interrupt sources on board the Flight Hardware Subsystems. ( All Interrupt Sources TBD ) The Executive Processing Module shall accept the following internal stimuli : Software Tasking request from operating modules of the flight software. Memory Allocation request from operating tasks in the flight software or from uploaded software modules. Exception Interrupts and software interrupts generated by the execution of the flight software code. Executive Processing Requirements The Executive Processing Module shall provide for Task Management capabilities. This management must include multi-tasking capabilities, which includes priority scheduling and sequencing. The Executive Processing Module must provide the various task with start, stop, and suspend commands. The Executive Processing Module shall provide for Intertask Communication between the various modules which are running in the processor. The communication may be accomplised in several different manners which include shared memory, message queses, pipes, and signals. Exclusion may also be specified by a task so that during desired periods of time other modules may not access messages which it is modifying. The Executive Processing Module shall provide for Memory Management Facilities, which include allocation, deallocation, and boundary definition for all task involved in the flight software system. The executive shall handle allocating needed memory at task startup, and also provide for memroy error handling procedures. The Executive Processing Module shall provide for Interrupt Services. These services will include 'C' interrupt handling routines, interrupt masking, lock & unlock functions, exception handling, and interrupt communication with other tasks present in the software system. Nested Interrupts will be allowed, and the Executive Processing Module provides the means for processor state storage and recovery.

13 11 The executive module shall provide for-interfaces to the real-time timer. This will include providing for a Watchdog Timer with any task may reference in order to use for syncronization and control functions. The timer interface will be provides as part of the executive along with the The Executive Processing Module shall provide Device Drivers for all the interfaces between the flight software process modules and the satellite system hardware. The drivers will provide needed calls and status for each of the various driver types. A list of device drivers is shown below (PRELIMINARY) along with their primary TYPE Description. Driver Timer Interface SASI Bus Driver Sensor Data Interface Spacecraft Telemetry Spacecraft Commanding IMUDriver Solar Array Driver ACS/RCS EPS Driver TYPE Internal Peripheral Control Command Driver with Status Block Oriented Data Reception with Cmd Setup Block Oriented Data Reception with Cmd Setup Command Driver with Status Block Oriented Data Reception with Cmd Setup Command Driver with Status Command & Data Reception Command Driver with Status Executive Output Requirements The Executive shall generate the following external stimuli : Device Driver outputs necessary to interface the software process request with the hardware on board the satellite. (ALL Drivers are TBD). The Executive shall generate the followng internal stimuli : A response to a task allocation call with the proper status to the asking process. This output will indicate any error in task allocation. A response to a task request for memory allocation shall be return to the requesting task. This output will indicate any error in memory allocation or illegal memory request Prom and System Initialization Capability Requirements The PROM and System Initialization software includes all the software which needs to reside in DSPS spacecraft at system startup. This software must be on board in PROM and provide for the system startup procedures, default control capabilities, and safe system configuration without any ground intervention PROM and System Initialization Input Requirements The PROM and System Initialization Module shall accept the following external stimuli : System Reset and Powerup will cause a restart of the flight software code which reside in the systems PROM memory in the satellite hardware.

14 12 / - System Reset Command (from ground) The PROM and System Initialization Module shall accept the following internal stimuli: NONE PROM and System Initialization Processing Requirements The Executive Kernel will reside in the Hardware PROM along with all necessary kernel setup and initialization routines. This code shall contain all needed software startup code for the system hardware. At startup Hardware Checkout and Status software will determine the operability of the flight hardware system, and report any problem to the error logging subsystem. An initial Memory Map will be setup at system startup. This code will reside in the PROM of the Flight Hardware and will be a part of the initial hardware setup which takes place at system power up. An initial Satellite Control function must be present in the PROM on-board the satellite. This Control must be defined as well as any thruster & other control functions which must take place to place the satellite in a known safe-state at startup or during recovery. A Status Logging capability must exist in the PROM in order to notify the results _ of the initial startup of the satellite software and hardware system. This status logging will output results to Event Logging and Distribution System. Prom and System Initialization Output Requirements The PROM and System Initialization Module shall ouput the following external stimuli : Shall notify the Error Logging Facility and store any system errors which occur during startup and initialization. The PROM and System Initialization Module shall output the following internal stimuli : The desired self test stimulus to the various hardware peices in the satellite hardware in order to test the operability of all on board system. This will include memory tests, interface checking, response checking, and checksum of code segement to determine the validity of the on-board memory, and will stimulate recover if on-board memory is determined to be incorrect (TBD) { MAY USE Bulk Storage to hold copies of PROM memroy } Command Processing (CMDPROC) Capability Requirements CMDPROC CSC Description The CMDPROC CSC is required to perform the high level command interpretation functions for the DSPSE program. More specifically, the CMDPROC CSC provides the real time, stored, and event driven command interpretation functions. The CMDPROC CSC command requirements are divided into three functional areas for the purpose of defining its functional and performance characteristics: a. Real Time Command Function; b. Stored Command Function; c. Inference Engine Function.

15 Command Types The Cl\IDPROC CSC supports the following command types: a. Internal Commands; b. Physical Commands; c. External Commands. Internal commands provide directives to control the operation of the CMDPROC CSC or other CSCs executing along with the Cl\IDPROC CSC. Internal commands which are executed by the Cl\IDPROC CSC include such commands as: a. Accepting and verifying DSPSE script and database uploads; b. Readout specified DSPSE memory such as scripts, rules, and database records; c. Manage Scripts. A Physical command is one which controls a physical interface or device. Included in this type of command are the following: a. High level discrete commands such as relay drivers; b. Low level discrete commands such as TIL level pulses; c. Serial or magnitude commands. An external command is one which is sent from the processing equipment that is executing the CMDPROC CSC to another physical device that is external to the CMDPROC CSCs processing device. An example of this type of command are those that are issued to devices connected to a 1553B multiplexed data and control bus Command Definitions The Cl\IDPROC CSC supports command processing in three different scenarios. The processing scenarios are defined as follows: a. The CMDPROC CSC supports commands and command data that are executed immediately. These types of commands are known as real time commands. The CMDPROC may receive individual or multiple real time commands in a single command packet. b. The CMDPROC CSC supports commands and command data that are stored in memory accessible to the processing equipment that is executing the CMDPROC CSC. These types of commands are known as stored command scripts. c. The CMDPROC CSC supports actions such as commands and command data that are executed as a result of predefined events. These types of commands are known as event driven commands. The CMDPROC CSC processes commands that are identified by logical identifiers. These logical identifiers are translated into a formatted command prior to distribution to the destination device.

16 Command Functions The CMDPROC CSC Real Time Command Function executes all real time comniands which come to the CMDPROC CSC. If the real time command is for the CMDPROC CSC, it is executed upon receipt. If an internal command is addressed to another CSC, the CMDPROC will route the command to the appropriate CSC. External commands are routed to the CSC that provides external bus interface services. The CMDPROC CSC Stored Command Function manages the storage of command scripts and executing these scripts from within DSPSE memory. These scripts, which are stored in the 'Script and Rule' partition, are executed by ground command or based on scheduled timers. The CMDPROC CSC Inference Engine Function supports special processing (such as commanding) in response to events which can occur during DSPSE operations. The events and the actions taken in response to the events are defined by rules. The events that can be monitored by rules include such things as interrupts, telemetry values, or command execution CMDPROC CSC External Interface Requirements TBD CMDPROC CSC Capability Requirements Real Time Commands Real Time Command In put The CMDPROC CSC Real Time Command Function shall accept commands and command data from the C:rviDIN CSC Real Time Command Processing The C:rviDPROC CSC Real Time Command Function shall execute all physical real time commands. The CMDPROC CSC Real Time Command Function shall execute internal real time commands immediately after the command is received. These commands shall control the following C:rviDPROC CSC functions: a. Start, initialize, pause, reset, and halt the stored command function. b. Start, pause, and halt the inference engine function. c. Stop a currently scheduled/executing script. d. Load, delete, and dump stored command scripts. e. Load, delete, and dump stored rules. f. Load, delete, modify, and dump database records. g. Select C&T database. h. Configure Tuning/Strategy{frace Parameters..

17 15 The CMDPROC CSC Real Time Command Function shall process real time commands with priority over the processing of any stored command scripts, and event driven commands. The CMDPROC CSC Real Time Command Function shall process all pending real time commands before any stored command scripts, or event driven command processing is resumed. The CMDPROC CSC Real Time Command Function shall not interrupt the processing of an individual stored command instruction, but rather shall accept and process the real time command when the stored command instruction has completed execution. The CMDPROC CSC Real Time Command Function shall accept script and rule uploads at the DSPSE uplink data rate. The CMDPROC CSC Real Time Command Function shall accept C&T database uploads at the DSPSE uplink data rate Reill Time Command Output The CMDPROC CSC Real Time Command Function shall distribute the real time commands in the order that they are received. The CMDPROC CSC Real Time Command Function shall distribute internal commands to the appropriate CSCs within the DSPSE. The CMDPROC CSC Real Time Command Function shall forward external commands to the appropriate data distribution esc Stored Commands Stored Command Input The CMDPROC CSC Stored Command Function shall retrieve stored commands and command data from the Script and Rule Partition in DSPSE processing equipment memory Stored Command Processing The CMDPROC CSC Stored Command Function shall interprete scripts which include commands and control instructions that: a. Control execution flow; b. Issue a script call, transferring control to that script and then returning upon completion; c. Delay, wait, pause, or halt script execution; d. Synchronize with another script; e. Schedule a script for independent execution; f. Evaluate a rule; The CMDPROC CSC Stored Command Function shall execute all physical stored commands. The CMDPROC CSC Stored Command Function shall execute a stored script when a command is received instructing the CMDPROC CSC to execute the script.

18 16 The CMDPROC CSC Stored Command Function.. shall schedule a stored command script for execution based on a specified delta time relative to the spacecraft time standard. The CMDPROC CSC Stored Command Function shall schedule a stored command script for execution on an absolute time basis with respect to the spacecraft time standard. The CMDPROC CSC Stored Command Function shall begin executing the stored command script no sooner than the specified execution time and no later than TBD milliseconds following the specified time referenced to the spacecraft time standard. The C:MDPROC CSC Stored Command Function shall support the concurrent execution of -qp to eight stored command scripts Stored Command Output The CMDPROC CSC Stored Command Function shall distribute commands contained within a stored command script in the order in which they appear in the script The CMDPROC CSC Stored Command Function shall distribute internal commands to the appropriate CSCs within the DSPSE processing equipment that is executing the CMDPROC CSC. The CMDPROC CSC Stored Command Function shail shall forward external commands. to the appropriate data distribution esc. Event Driven Commands Event Driven Command Input The CMDPROC CSC Inference Engine Function shall accept interrupt event notifications from interrupt service routines. The CMDPROC CSC Inference Engine Function shall accept telemetry event notifications from the 1LMPROC CSC Telemetry Reduction Function. The CMDPROC CSC Inference Engine Function shall obtain mission constraint rule information from the C&T database during logical command processing. The CMDPROC CSC Inference Engine Function shall obtain commanding event information from P1e C&T database during logical command processing Event Driven Command Processing The CMDPROC CSC Inference Engine Function shall process rules in response to events. These events shall include the following: a. External interrupts; b. Occurrence of a particular value for a discrete telemetry item in the C&T database; c. Occurrence of a value within a defined range for an analog telemetry item in the C&T database; d. Occurrence of a logical command being processed by CMDPROC CSC;

19 17 The CMDPROC CSC Inference Engine Function shall process rules which are composed of two parts: the premise and the action. If an item in the premise. changes, the CMDPROC CSC Inference Engine Function shall evaluate the condition specified in the premise of the rule. If the premise condition evaluates to true, the action portion of the rule shall be scheduled. The CMDPROC CSC Inference Engine Function shall support a priority ordered queue to process the rules scheduled. The CMDPROC CSC Inference Engine Function shall execute scheduled rules in order of highest priority to lowest priority. Any stored command script scheduled from a rule action shall be processed in accordance with the normal stored command script scheduling algorithm. The CMDPROC CSC Inference Engine Function shall evaluate mission constraints in the mission constraint rule list of a command database record prior to distribution whenever the command is processed. If a mission constraint rule evaluates to true, the action specified in the mission constraint rule is executed. The command being processed can be rejected in the action. If a command is rejected by a mission constraint rule, the command shall not be executed. The CMDPROC CSC Inference Engine Function shall execute rules with the priority assigned at the time the rule was defined Event Driven Command Output The CMDPROC CSC Inference Engine Function shall distribute commands contained within a rule in the order in which they appear in the rule. The CMDPROC CSC Inference Engine Function shall distribute internal commands to the appropriate CSCs. The CMDPROC CSC Inference Engine Function shall forward external commands to the appropriate data distribution esc Command Output Procedures 1BD FSE_ FSE_ FSE_ CMDPROC CSC Data Elements The CMDPROC CSC Command And Telemetry database shall reside in the C&T database partition in the DSPSE global memory. The CMDPROC CSC Command And Telemetry database shall define the individual logical command actuators that the CMDPROC CSC will control. The CMDPROC CSC Command And Telemetry database records that support mission constraint rule lists shall allocate space for a list of mission constraint rule identifiers. Command Record Descriptor Command Record Fields FSE The Command And Telemetry Database command record descriptor shall include the following data fields: a. Record type;

20 18 b. Run time flags; c. Mission constraints rule list pointer; d. Forward rule list pointer; e. Backward rule list pointer; f. Serial data word storage; g. Serial data parity or discrete command level indicator; h. Address of the command interface; i. Command interface channel number; j. Output driver ID; Command Record Size The command record descriptor is expected to have a nominal size of 26 by tes. The nominal record size is provided to aid in determining DSPSE memory requirements. The size may vary to accommodate processor word alignment requirements and the addition or deletion of data fields TELEMETRY PROCESSING (TLMPROC) CSC TLMPROC CSC Description The TLMPROC CSC is required to perform the telemetry monitoring functions for the DSPSE. More specifically, the TLMPROC CSC provides the telemetry acquisition, telemetry reduction, and telemetry logging. The TLMPROC CSC telemetry requirements are divided into three functional areas for the purpose of defining the functional and performance characteristics: a. Telemetry Acquisition Function; b. Telemetry Reduction Function; c. Telemetry Logging Function; Telemetry Functions The TLMPROC CSC Telemetry Acquisition Function acquires data from the DSPSE analog to digital converters and discrete telemetry interface. The acquisition function routes the collected telemetry data to the Telemetry Reduction function of the TLMPROC CSC and to the TLMOUT esc. The TLMPROC CSC Telemetry Reduction Function processes the telemetry data collected by the acquisition function so the data can be used by the CMDPROC CSC. The Telemetry Reduction Function filters the telemetry data by removing unchanging data. The TLMPROC CSC Telemetry Logging Function provides the capability to store telemetry data on board the DSPSE space vehicle for delayed transmission to a ground support facility TLMPROC CSC External Interface Requirements 1BD

21 TLMPROC CSC Capability Requirements The.lLMPROC CSC shall collect, process, and store telemetry data according to the following requirements Telemetry Acquisition Telemetry Acquisition Input The Telemetry Acquisition function shall accept telemetry data from the DSPSE analog to digital converters and digital data interfaces Telemetry Acquisition Processing The Telemetry Acquisition function shall be capable of sampling 128 analog telemetry items per second. The Telemetry Acquisition function shall be capable of sampling 128 bits of digital telemetry data per second Telemetry Acquisition Output The Telemetry Acquisition function shall output telemetry data to the Telemetry Reduction function of the TLMPROC CSC. The Telemetry Acquisition function shall output telemetry data to the TLMOUT esc Telemetry Reduction Telemetry Reduction Input The TLMPROC CSC Telemetry Reduction Function shall accept telemetry data from the analog to digital converters, discrete telemetry input devices, and serial telemetry physical devices that are a part of the processing equipment that is executing the TLMPROC CSC. The TLMPROC CSC Telemetry Reduction Function shall accept telemetry data which includes data produced by other CSCs executing within the processing equipment that is executing the TLMPROC CSC. The TLMPROC CSC Telemetry Reduction Function shall accept telemetry data which includes data produced by other subsystems that are external to the processing equipment that is executing the TLMPROC CSC. The TLMPROC CSC Telemetry Reduction Function shall accept and process telemetry data at a minimum rate of TBD bits per second Telemetry Reduction Processing The TLMPROC CSC Telemetry Reduction Function shall process each telemetry item by doing the following: The TLMPROC CSC Telemetry Reduction Function shall query the C&T database to determine the value of the reject flag. If the flag is set, the telemetry item shall - be discarded without further processing.

22 20 For telemetry logging.purposes, the. TLMPROC CSC Telemetry Reduction Function shall query the C&T database to determine if the item is selected for entry in the telemetry storage log. If the item is a candidate for logging, the TLMPROC CSC Telemetry Reduction Function shilll compare it to the previously stored value in the database to determine if a significant change has occurred based on the Telemetry Log Aperture in the C&T database. If a significant change has occurred, TLMPROC CSC Telemetry Reduction Function shall center the Telemetry Log Aperture about the new value and route the telemetry item to the TLMPROC CSC Telemetry Logging Function. If a significant change has not occurred the item will not be entered in the Telemetry Storage Log. For telemetry data filtering purposes, the TLMPROC CSC Telemetry Reduction Function shall compare the received raw value for the specified item to the previous raw value for a significant change. The Change Detection Aperture from the C&T Database shall be used to evaluate for significant change. The TLMPROC CSC Telemetry Reduction Function shall, if a significant change has not occurred, discard the item with no further processing. The TLMPROC CSC Telemetry Reduction Function shall, if a significant change has occurred, store the new value in the C&T database telemetry record and shall notify the CMDPROC CSC of such event The TLMPROC CSC Telemetry Reduction Function shall, if the telemetry item is an analog, convert the value to engineering units using the coefficients specified by the C&T Database record for that item. The TLMPROC CSC Telemetry Reduction Function shall store the value in engineering units in the database record. The TLMPROC CSC Telemetry Reduction Function shall evaluate the alarm limit values if they exist in the C&T database for all analog telemetry items. The resulting alarm state, if any, shall be stored in the database record Telemetry Reduction Output The TLMPROC CSC Telemetry Reduction Function shall output telemetry data to the Telemetry Logging Function of the TLMPROC CSC. The TLMPROC CSC Telemetry Reduction Function shall send telemetry event notifications to the CMDPROC CSC whenever a monitored telemetry sensor changes value significantly Telemetry Logging Telemetry Logging Input The TLMPROC CSC Telemetry Logging Function shall receive telemetry data from the TLMPROC CSC Telemetry Reduction Function Telemetry Logging Processing The TLMPROC CSC Telemetry Logging Function shall maintain a telemetry storage log which resides in memory accessible to the DSPSE processing equipment. The TLMPROC CSC Telemetry Logging Function shall store normalized telemetry data in the telemetry storage log.

23 21 The TLMPROC CSC Telemetry Logging Function shall, as a default, terminate the storage of telemetry data when storage space is exhausted Telemetry Logging Output FSE_ FSE_ FSE_ FSE_ The TLMPROC CSC Telemetry Logging Function shall periodically output a telemetry message indicating the status of the Telemetry Log. This message shall indicate whether telemetry logging is currently active and whether the partition is full. The TLMPROC esc Telemetry Logging Function shall output the contents of the Telemetry Log to the TLMOUT CSC. TLMPROC CSC Data Elements The TLMPROC CSC Command And Telemetry database shall reside in the C&T database partition in the DSPSE global memory. The TLMPROC esc Command And Telemetry database shall define the individual telemetry sensors that the TLMPROC CSC is to be responsible for moiritoring. The Command and Telemetry database records shall support forward and backward rule lists. The TLMPROC CSC Command and Telemetry database records that support forward and backward rule lists shall allocate space for a list of rule identifiers. A database item's forward rule list shall include the identifiers of each rule that references the database item in its premise. Analog Record Descriptor Analog Record Fields FSE_ The Command And Telemetry Database analog record descriptors shall include the following data fields: a. Record type; b. Run time flags; c. Mission constraints rule list pointer; d. Forward rule list pointer; e. Backward rule list pointer; f. Bit length of item; g. Engineering value storage; h. Telemetry Reduction option flags; i. Alarm level indicator; J. Engineering unit conversion coefficient group ID; k. Raw value storage; 1. 'Center' value storage; m. Change detection aperture; n. Telemetry logging aperture;

24 22 o. Alann limits Analog Record Size Analog record descriptors are expected to have a nominal size of 76 bytes. The nominal record size is provided to aid in determining DSPSE memory requirements. The size may vary to accommodate processor word alignment requirements and the addition or deletion of data fields Discrete Record Descriptor Discrete Record Fields FSE_ The Command And Telemetry Database discrete record descriptor shall include the following data fields: a. Record type; b. Run time flags; c. Mission constraints rule list pointer; d. FoiWard rule list pointer; e. Backward rule list pointer; f. Bit length of item; g. Current value storage; h. Telemetry Reduction option flags; i. Alarm level indicator Discrete Record Size Discrete record descriptors are expected to have a nominal size of 24 bytes. The nominal record size is provided to aid in determining DSPSE memory requirements. The size may vary to accommodate processor word alignment requirements and the addition or deletion of data fields Derived Record Descriptor Derived Record Fields FSE_ The Command And Telemetry Database derived record descriptor shall include the following data fields: a. Record type; b. Run time flags; c. Mission constraints rule list pointer; d. FoiWard rule list pointer; e. Backward rule list pointer; f. Current value storage (2 words); g. Telemetry Reduction option flags; h. Alarm level indicator.

25 Derived Record Size Derived record descriptors are expected to have a nominal size of 26 bytes. The nominal record size is provided to aid in determining DSPSE memory requirements. The size may vary to accommodate. processor word alignment requirements and the addition or deletion of data fields COMMAND INPUT (CMDIN) CSC CMDIN CSC Description The CMDIN CSC accepts and validates uplink data from the link interface hardware. Valid uplink data are routed to the CMDPROC CSC for functional processing. Uplink data that does not pass validation tests are discarded CMDIN CSC External Interface Requirements 1BD CMDIN CSC Capability Requirements CMDIN Inputs The CMDIN shall accept uplink data received via the link interface hardware in accordance with the specifications identified in the Hardware/Software Interface Control Document CMDIN Processing CMDIN shall validate uplink data. Uplink data validation shall consist of (1) verifying that a proper authenticate count has been received and (2) verifying that the uplink data are error free using the error detection data contained within the uplink data. If uplink data can not be validated, the CMDIN shall discard it and report the event in the downlink telemetry. The authenticate count shall be validated by comparing the count contained in the uplink data with the count contained in a non-volatile 32-bit register that is used to store the expected authenticate count. If the count received in the message matches the register, the count shall be considered validated. If the received count and the register do not match the command shall be considered invalid. C:MDIN shall increment the authenticate count register each time uplink data is validated. The authenticate count register shall be initialized in TBD manner. The error detection code shall be validated in TBD manner. CMDIN shall maintain TBD status information for inclusion in the housekeeping telemetry CMDIN Outputs CMDIN shall output validated uplink data to the CMDPROC CSC for functional processing.

26 Telemetry Output (TLMOUT) CSC TLMOUT CSC Description The TLMOUT CSC formats telemetry data received from the TLMPROC and CMDPROC CSC and then outputs the data to the housekeeping telemetry interface hardware TLMOUT CSC External Interface Requirements TBD TLMOUT CSC Capability Requirements TLMOUT Inputs TLMOUT shall receive raw telemetry data packets from the TI...MPROC CSC. TLMOUT shall receive internal telemetry data packets from the TLMPROC CSC. Internal telemetry data consists of derived or status telemetry items that are generated by other DSPSE CSCs. TLMOUT shall receive internal telemetry data packets from the CMDPROC CSC TLMOUT Processing TLMOUT shall format the telemetry data packets into housekeeping telemetry frames for incorporation into the downlink telemetry. The format of the housekeeping telemetry frames shall be specified in the TBD document. Each housekeeping telemetry frame shall include a 16-bit frame synchronization pattern. Each housekeeping telemetry frame shall include a frame counter. Each housekeeping telemetry frame shall include the current uplink status. Each housekeeping telemetry frame shall include the current spacecraft time. The current authenticate count shall be included in each housekeeping telemetry frame. The housekeeping telemetry frame shall include a frame counter TLMOUT Output TLMOUT shall output housekeeping telemetry frames to the link interface hardware in accordance with the specification contained in the Hardware/Software Interface Control I;Jocwnent Guidance, Navigation, & Control (GNC) Executive Capability Requirements The GNC Executive coordinates requests for attitude control and pointing; generates desired spacecraft attitude; if enabled, schedules attitude control based on on-board estimates of spacecraft position and mission phase; and monitors reaction wheel status for momentum dumping.