FIELDS MEP Thermal Vacuum Cycling iPER Gayle K. Martin Brent Mochizuki Sasha Siy Bill Donakowski Steve Marker January 26, 2017

Contents Objectives and Summary Thermal Design Mechanical Test Configuration Electrical Test Configuration Thermocouple Locations Test Profile Status

Objectives and Summary Test Objectives Qualify the flight model of the FIELDS MEP (Main Electronics Package) Verify that the MEP unit can bear the temperatures Provide workmanship and performance verification by stressing the components to flight allowable temperatures Test Summary Component temperatures will be tested to 10°C beyond flight model predicts (to flight allowable temperatures) 1 survival and 6 operational thermal cycles will be complete in vacuum CPTs will be conducted at the first and last operational cycles at cold and hot temperatures LPTs will be conducted for all other operational cycles 2 cold/hot starts

MEP Thermal Design Thermally coupled to spacecraft conductively and radiatively Conductively coupled to deck with thermal gasket (hard mounted to mounting plate in test) High emissivity external surface (black paint) Individual electronics frames with each board coupled to the frame Thermal parts Dedicated louvered radiator No heaters or MLI Thermistor Honeywell 705 (S/C monitored) Board level thermal analyses and tests complete AEB (2), DCB/RFS, DFB, MAG (2), TDS, LNPS(2)

Mechanical Test Configuration Chamber The MEP flight unit will be tested in the UCB/SSL Bayside thermal vacuum chamber There are two temperature zones for the TV test Chamber baseplate (heating & cooling) Chamber shroud (heating & cooling) Bayside chamber at UCB/SSL feedthrough port and thermal control rack Bayside chamber at UCB/SSL with aluminum baseplate and shroud

Mechanical Test Configuration Hardware The flight unit will be fully assembled The MEP will be hard-mounted (bolted) to a mounting plate then bolted to the chamber baseplate A “shelf” will be used to accommodate the instruments and harness The following instruments will be inside the chamber for the test FM V5 EM SCM 4 EM V1234 preamps The following instruments will be outside the chamber FM Mag-o in can FM Mag-I in can` MEP SCM V5 shelf V1 EM V2 EM V3 EM V4 EM Under shelf V1 V2 V3 V4 Schematic from front of chamber Schematic of components in test chamber as shown from top. Zone 1: Shroud heating & cooling Zone 2: Baseplate Mounting plate

Electrical Test Configuration Electrical configuration Instruments internal to the chamber will be connected directly to the MEP The harness will be connected via DB25 and BNC feedthroughs in the Bayside chamber V1234 & V5 stimulus will be connected to the Stim Rack via BNC Electrical isolation V5 will be electrically isolated with ChoTherm in the same configuration as the V5 TV configuration The V1234 EM preamps will be grounded to the baseplate with grounding wires Thermal control The flight MEP will be controlled and monitored via thermocouples and AnaWin2 controller Electrical configuration of the MEP test. Note on V1 is illustrated but the test includes V1234 EM units.

Thermocouple Locations Thermocouples will be mounted along the flight unit and instruments internal to the chamber to verify temperatures during thermal cycling The internal thermistor will verify that the temperatures have stabilized during instrument operation (not available during survival) 3 4 5 6 7 8 9 TC # Location  1 Baseplate  2 Shroud  3 MEP top (F) 4 MEP top (B) 5 MEP side 1 6 MEP side 2 7 MEP side 3 8 MEP side 4 9 MEP mounting plate 10 EM V1 preamp 11 EM V2 preamp 12 EM V3 preamp 13 EM V4 preamp 14 FM V5 preamp 15 EM SCM 15 14

Test Profile The test duration for the combined thermal cycling test will take ~7 days (with 4 hour soaks) Duration includes set-up and take-down time Instrument functions Pre-test functional Hot and cold operation CPTs (op cycles 1 and 6) Hot and cold operation LPTs (op cycles 2 through 5) Post-test functional Test parameters The transition rate of the instrument is not to exceed 3°C per minute Start of soak is defined when the control temperature is within 1°C of the test temperature Soak is defined as a minimum of four hour at case temperatures with a change in temperature of ±1°C Temperature set-points for each case Survival = -30°C to 65°C Operational = -25°C to 60°C The preamps in the chamber are qualified beyond the MEP set-points Temperature profile on following slide TQCM measurement will be made at the end of the test with the MEP followed by a background measurement without the MEP Future vacuum testing Additional vacuum exposure will occur on the flight hardware during Observatory level S/C test

Test Profile Operational TQCM Turn-on Turn-off Cold turn-on CPT Survival Operational TQCM Cold turn-on CPT Turn-on Turn-off LPT LPT LPT LPT LPT LPT LPT LPT

Status Mounting hardware Instruments are ready and available Harness Mounting plate and hardware clean & ready Shelf for housing V1234 preamps will use existing GSE Instruments are ready and available V1234 EM preamps & housing x4 (no mounting hardware) SCM EM with mounting plate and hardware V5 FM with mounting plate, ChoTherm and hardware Mags (external to chamber in cans) Harness Test harness ready with exception of the few identified in electric schematic that need to be remade Harness needs cleaning Ground straps All hardware in the chamber has been verified for vacuum compatibility and temperature limits

Back-up

Handling & Contamination Control All test articles and test hardware to be bagged and kept in clean room Personnel are to handle only with appropriate gloves and contamination gowning EMECP specifications shall be practiced during flight hardware handling, test set-up and test operations Contamination control of the instrument must follow the specifications in the SPP-FIELDS Contamination Control Plan 

Test Abort, Real Time Activity Assessment and Success/Failure Criteria Minor anomalies will be evaluated and fixed or alleviated in an attempt to continue testing Examples of minor anomalies include temporary loss of thermocouple, minor problems with hardware (cable movement) or problems with vacuum facility Response to minor anomalies will be made by Test Conductors at test site Significant anomalies will result in abort of further testing The UCB Test Engineer has the authority to stop testing if deemed damage may be occurring to the hardware, the test equipment functioning is suspect, output data is questionable, or test is not compatible with this procedure All anomalies shall be reported as part of standard Project Problem/Failure Reporting. Success/Failure Criteria Adequate temperature data collected at steady state from all test cases Meet all S/C requirements

MEP Other Thermal Testing Completed thermal tests ETU test Board testing Future thermal tests Thermal balance test on boom during SPP Observatory test estimated 12/2017

Design and Test Temperature Requirements Non-operational survival test limit 5°C Operational Testing & Flight allowable limit 10°C Analytical & design margin Operational prediction Maximum expected T-range -30°C -25°C -15°C 50°C 60°C 65°C Maximum expected T-range MEP

MEP EDTRD Thermal Requirements Complete Description 0179   Throughout thermal balance and thermal cycle testing, each instrument subsystem or instrument component shall be powered unless there is an identified potential for damage and a waiver has been obtained from APL 0186 Instruments shall be designed and tested to the thermal interfaces listed in Table 5-2 0189 Instruments shall complete a successful thermal vacuum flight qualification testing program prior to delivery to the spacecraft 0190 Testing program shall consist of thermal vacuum balance and thermal vacuum cycle 0191 All instruments thermal test plans shall be provided to the SC thermal engineer for review and approval 0192 Flight predictions shall demonstrate at least 10°C of margin within the instrument operational or survival test temperatures with the exception that for active heater control, 5°C of temperature margin is acceptable at the lower test limit 0195 The thermal cycling that all thermal hardware works as expected hardware for these instruments forgoing the thermal balance test shall demonstrate in thermal 0207 Instrument thermal vacuum cycle tests do not have to maintain the isolated coupling used during thermal balance. This should decrease transition time between cycles, thus total test time. Instrument component temperatures shall be based on flight model predictions if the isolation coupling is not flight-like 0208 Instrument component temperatures shall be tested to 10°C beyond flight model predictions 0209 Flight model testing shall complete six operational and one survival cycle 0212 CPT’s shall be conducted during instrument level TV testing 0213 Minimal functional tests shall be performed at all remaining plateaus if no CPT performed