goetzfields ipdr

Goetz 1FIELDS iPDR – I&T

SPP/FIELDSIntegration and Test

Preliminary Design Review

Keith Goetz

University of Minnesota

[email protected]


FIELDS Block Diagram


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


Environmental Test Matrix


Planned ETU I&T Flow


Planned FM I&T Flow


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 cals in 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 SPP Environmental 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 bakeout plan 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


FIELDS Flight Configuration


FIELDS CPT Configuration


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

goetzfields ipdr – i&t spp/fields integration and test preliminary design review keith goetz...

Documents

test test procedure

test procedure test

ird requirements

instrument requirements

requirements verification

test plan

test procedures