210 likes | 323 Views
SPP/FIELDS Integration and Test Preliminary Design Review. Keith Goetz University of Minnesota Goetz@umn.edu. FIELDS Block Diagram. Interface Control Documents. Spacecraft to FIELDS General Instrument ICD is at rev dash (7434-9066) FIELDS Specific ICD ( 7434- 9055)
E N D
SPP/FIELDSIntegration and TestPreliminary Design Review Keith Goetz University of Minnesota Goetz@umn.edu
Interface Control Documents • Spacecraft to FIELDS • General Instrument ICD is at rev dash (7434-9066) • FIELDS Specific ICD (7434-9055) • Minor open issues don’t preclude ETU development • MOC-SOC ICD • Well developed and familiar from RBSP and STEREO • FIELDS to SWEAP ICD (SPF_MEP_105_SWEAP_ICD) • Preliminary release signed on both sides • Subsystem ICDs are well along • MEP, CDI, RFS, TDS, DFB, MAG, AEB, LNPS, PA, SCM • Connectors and pin-outs (SPF_MEP_110_Connectors) well defined
Requirements Verification • Verify Instrument Requirements per IRD • Meet/Verify Quality Requirements per QA Matrix (7434-9096) • Meet/Verify Contamination Requirements per CCP (SPF_SMA_003) • Verify Environmental Requirements per ERTRD (7434-9039) • Verify EMC Requirements per EMECP (7434-9040) • Verify Spacecraft Interface Requirements per GI ICD (7434-9066) • Verify Spacecraft Interface Requirements per FIELDS ICD (7434-9055) • Verify SWEAP Interface Requirements per FIELDS-SWEAP ICD (SPF_MEP_105) • Verify Performance Requirements per FIELDS IRD (SPF_SYS_010) • Approach Described in FIELDS Verification, Validation, Test, and Calibration Plan (SPF_IAT_002)
I&T Plans • Philosophy • Requirements are verified as early as possible at a low level • Verifies subsystems, Retires risk • Requirements are verified at the highest level of assembly possible • Often involves verifying a requirement at several levels • Maintain flexibility in test sequencing to maintain schedule • Tests on ETU and Flight Units • Subset of tests on ETU to qualify the design where practical and possible • Full tests on Flight units • Typical Test Levels: • Subassembly (circuit board): functional • Component (e.g. V1, MAG, SCM, MEP): functional, mass properties, vibration, TV, deployments, magnetics • Instrument: functional, calibration, interface, EMC, TV
Validation • All instrument requirements are captured in IRD • IRD contains columns detailing how and where the requirement is met • IRD doubles as verification cross reference matrix • Systems Engineer is responsible for verifying test procedures meet requirements and responsible for verifying that all requirements are met by following test plan
Procedures • Each test will be documented by a Test Procedure • Test procedure shall identify IRD requirements to be verified by the test • Test procedure shall include pass/fail criteria • System Engineer, QA, Subsystem lead to sign off on procedure before use • System Engineer, QA to sign off on completed as-run procedure • QA to ensure Red-lines to be transferred into procedure before next use • Each completed test to be documented by a Test Report • ETU and subassembly test reports may be a combination of the as-run procedure and lab notebook • System Engineer to sign off on test reports, and determine if test adequately verifies associated requirements • Discrepancies found during tests to be documented in a Problem Failure Report (PFR) • Starting with first functional tests at FM subassembly level • Includes any problem (including software) not immediately identified as a test setup or operator problem which cannot stress the flight article • QA will track PFRs to closure with concurrence of the Failure Review Board (includes APL)
Calibrations • Co-I hardware institutions will deliver fully calibrated sub-assemblies • Once FIELDS instrument is fully integrated • Several verification calsin ambient and at temperature • Timing • SWEAP • Antennas – as mechanical elements – can be tested separately
Interfaces • Interface tests verify interfaces meet requirements from ICD and/or specifications. • FIELDS ETU to be tested with APL S/C mini emulators • FIELDS FM to be tested with APL S/C emulators • FIELDS TDS ETU/FM to tested with SWEAP (at UCB) • At other times (prior to Observatory I&T) interfaces simulated with GSE • Board, Component level tests performed with • Board Interface Simulation GSE • Instrument-level tests performed with: • APL-provided spacecraft emulator • Command and Telemetry GSE software • Stimulation GSE or internal test signal • SWEAP simulator (FIG) • Deployment actuator simulators • GSE functionality, design described in GSE section
Mechanical Testing Antenna mechanisms can be tested independently of electronics Full functional testing Vibration TV Where appropriate, testing will include whips
Thermal Testing • Tests per SPPEnvironmental Spec • 1 survival and 6 operational thermal vacuum cycles • Temperature ranges detailed in thermal presentation • Per FIELDS V&V and T&C plan • V1-V4 PAs in one range • V5 PA in one range • MAG sensors (at GSFC) • SCM assembly (at LPC2E) • MEP is the simplest • Includes all sensors • Antenna mechanisms • Proposed Thermal Balance test using ETU FIELDS boom and ETU sensors
EMC Tests • Tests per EMECP • Deep Dielectric Discharge Test • Interfaces Only for MEP (Shielded) • All points on sensors outside S/C body • DC Magnetics (sniff test) • ETU and Flight Units, Component level • Target Is <10nT DC at outer most sensor on MAG boom • Results of sniff test reported to Magnetics Working Group for analysis and possible mitigations • Test to be performed by APL personnel
EMC Tests • Surface Charging / Electrostatic Cleanliness • Measure resistance between exposed surfaces • Requirement <105 ohms per square to chassis ground • Some surfaces may be covered with thermal blankets • blanket testing needs to be done at Observatory level • repeated late in the flow • Ground Bonding and Isolation • Chassis bonding • < 2.5 milliohms between adjacent chassis elements • < 5 milliohms box to chassis • Ground Isolation • >1Mohm primary to secondary (chassis) ground • Measured at Instrument-level EMC testing • ETU and FM • Turn On/Off Transients • In-rush and transient current profile limits per EMECP document • Measure in-rush current and transient profile at Instrument-level EMC • ETU and FM • CE, CS, RE, RS Tests as detailed in EMECP. • ETU will only do CE measurements on the bench
Contamination • FIELDS Contamination Control Plan documents how FIELDS will meet Project contamination control requirements • The only significant FIELDS contamination sensitivity is the antenna surfaces • Will be in storage through most of I&T • Special handling procedures apply when antennas are exposed • No purge requirement at any point • Instrument I&T will be in Class 100,000 facility at UCB • Subassemblies / Components delivered to I&T will be inspected and cleaned as needed prior to integration into components • When Instrument is not in a Class 100,000 environment the unit will be bagged • Flight units will be baked out per FIELDS bakeoutplan prior to delivery to APL • Vacuum bakeout at max survival temp for at least 48 hours with TQCM
S/C-level I&T • FIELDS and APL have had preliminary discussions w/r/t S/C level I&T • FIELDS integration will involve a number of elements (~20) • FIELDS magnetic sensors will have protective enclosures • FIELDS will have external stimulus to support CPT functional testing • Antennas will not be deployed at Spacecraft level • Too hard to implement off-load GSE at spacecraft level • First motion without whips • Actuator simulators will be provided to perform simulated boom deployments • simulators contain flight-like resetable actuators (or equivalent loads) • simulators attach to S/C deployment harnessing • Simulators can be used at spacecraft-level TV
Conclusion • Requirements are understood • Instrument I&T plans are taking shape • Previous experience helps • Spacecraft I&T plans are just getting started • Previous experience helps here too • FIELDS is ready to move into ETU development