LAT Environmental Test PDR1 GLAST LAT Project 3-4 May 2005 LAT Environmental Test Planning and Design Review 3-4 May 2005 EMI/EMC LAT Environmental Test Planning and Design Review 3-4 May 2005 EMI/EMC Michael N. Lovellette

LAT Environmental Test PDR2 GLAST LAT Project 3-4 May 2005 LAT EMI Test LAT test levels derived from 433-RQMT-0005_RevA & LAT-SS-0778 Draft EMI/EMC Test Plan: LAT-MD –Use CAL EMI test procedure as template –LAT-PS Test Suite: –CE102 Conducted Emissions, Power Leads, 10 kHz to 10 MHz, MIL-STD-462, CE03 –CECM Conducted Emissions, Time Domain, 150 MHz Bandwidth –CS102 Conducted Susceptibility, Power Leads, 10 kHz to 10 MHz, MIL-STD-462, CS02 –CSCM Conducted Susceptibility, Common Mode, 30 Hz to 150 MHz, MIL-STD-462, CS02 –CS06 Conducted Susceptibility, Spike, Power Leads, MIL-STD-462 –RE101 Radiated Emissions, Magnetic Field, 20 Hz to 50 kHz –RE102 Radiated Emissions, Electric Field, 10 kHz to 18 GHz, MIL-STD-461E –RS101 Radiated Susceptibility, Magnetic Field, 20 Hz to 50 kHz –RS103 Radiated Susceptibility, Electric Field, 30 MHz to 18 GHz

LAT Environmental Test PDR3 GLAST LAT Project 3-4 May 2005 LAT Power Interfaces SC-LAT Power Interfaces –SC PRU (P) - LAT PDU –SC PRU (R) - LAT PDU –SC PRU (P) - LAT SIU (P) –SC PRU (R) - LAT SIU (R) –SC PRU (P) - LAT VCHP +Y –SC PRU (P) - LAT VCHP -Y –SC PRU (R) - LAT VCHP +Y –SC PRU (R) - LAT VCHP -Y –SC PDU (P) - LAT MAKEUP –SC PDU (R) - LAT MAKEUP

LAT Environmental Test PDR4 GLAST LAT Project 3-4 May 2005 Test Limitations Deviations from nominal test –RS103 upper limit of 18GHz (40GHz) –Limited area of RS101 test Requires scanning each 10cm x 10cm area, ~16min/scan ~1450 scans for the LAT, another ~1200 for the radiators (~29 days) Scan selected locations around connectors, PMTs, BEA –LAT EGSE power supplies will be used for all EMI/EMC testing, no attempt will be made to duplicate expected characteristics of the S/V power –Limited B side conducted testing Emissions tests and susceptibility only where noted on A side –No heater circuit testing

LAT Environmental Test PDR5 GLAST LAT Project 3-4 May 2005 Open Issues Replace CSCM as run for CAL EMI with MIL-STD 461E CS114 derived CSCM test Update RE102 limits per proposal from Fred Blanchett

LAT Environmental Test PDR6 GLAST LAT Project 3-4 May 2005 EMI Test Configurations Split EMI test –Conducted tests performed in the high bay integration area –Radiated testing performed in anechoic chamber Conducted emissions and susceptibility tests with SIU and PDU do not require radiators, but do require good access to connectors

LAT Environmental Test PDR7 GLAST LAT Project 3-4 May 2005 Radiated Test Configuration

LAT Environmental Test PDR8 GLAST LAT Project 3-4 May 2005 MGSE/STE for EMI/EMC Testing LAT (on the TIP) is mounted on the Test Stand for EMI/EMC testing –LAT + TIP mounts to Test Stand –Radiators are not yet integrated for this test, since they are not part of the EMI/EMC Test Plan –LAT is rolled into the anechoic chamber –Dust Tent remains over the LAT for the entire operation, including during testing Auxiliary cooling is needed during the test, since the LAT will be on for the entire test duration EMI/EMC Test Configuration Test Stand Radiators not yet integrated for this test LAT Test Interface Plate

LAT Environmental Test PDR9 GLAST LAT Project 3-4 May 2005 LAT Radiated Test Configuration

LAT Environmental Test PDR10 GLAST LAT Project 3-4 May 2005 MGSE Requirements Flowing from EMI/EMC Test Plans See the table, below, for a list of all MGSE/STE that is needed for conducting the EMI/EMC test Test Stand –Provides clear access around the perimeter of the LAT for positioning antennae during the test –Provides clear access directly under the LAT for positioning an antenna Dust Tent –Capable of providing clean, dry environment before/during/after EMI/EMC testing –Provides clearance around LAT –Does not impact the radiated emissions or susceptibility tests (must be essentially transparent to EM radiation in frequency range of tests) Chill Bars and Auxiliary Cooling system –Operated during the test MGSE/STE Needed for EMI/EMC Testing

LAT Environmental Test PDR11 GLAST LAT Project 3-4 May 2005 Auxiliary Cooling and Mechanical Handling Auxiliary cooling plans –LAT needs to be cooled during the entire duration of EMI/EMC testing Chill Bars: one under each of the two X-wings on the Grid X-LAT Aux Cooling: using fly-away cooling lines already mounted to X-LAT Plate –This is room-temperature cooling to remove LAT process heat –Fluorinert FC-77 working fluid is a dielectric, and hoses are non-conducting, so the chiller system will be electrically isolated from the LAT Handling and mechanical operating procedures –LAT lifting procedure –Test Stand handling and operating procedure –Dust tent handling and operating procedure –LAT auxiliary cooling system operating procedure

LAT Environmental Test PDR12 GLAST LAT Project 3-4 May 2005 MGSE Issues for EMI/EMC Testing Dust Tent –This is needed for EMI/EMC testing, because of the dirty conditions outside the test cell, and the potential for particulates to rain off the overhead anachoic foam –Dust tent will need to be designed to be essentially transparent to EM radiation in frequency range of tests Transportation issues –The EMI/EMC chamber is a long way from our high-bay “home base” Transportation route is circuitous and floor surfaces are of varying quality –Need to load-test a wooden trestle over abandoned railroad tracks –We plan to pathfind this route to ensure there are no problems in maneuvering the LAT –The EMI/EMC chamber has a ¾” door sill/threshold We plan to build a ramp to roll up and over the sill This will definitely by prototyped with the pathfinder, since the LAT c.g. is moderately high

LAT Environmental Test PDR13 GLAST LAT Project 3-4 May 2005 Conducted Test Considerations Fully test: –SC PRU (P) - LAT PDU –SC PRU (P) - LAT SIU (P) Limited test: –SC PRU (R) - LAT PDU –SC PRU (R) - LAT SIU (R) Conducted susceptibility tests may require changing bus protection unit settings

LAT Environmental Test PDR14 GLAST LAT Project 3-4 May 2005 Conducted Test Harness Require access to power harness ~2 m from LAT I/F –CE102, CS102 (10kHz - 150kHz), CSCM (30Hz - 150kHz), CECM –All conductors of power circuit must be connected to a single 1/4” lug on line conditioner –All conductors must be gathered into a bundle so that a current probe may be connected around them Require access to power harness ~5cm for LAT I/F –CS102 (150kHz - 150MHz), CS06, CSCM (150kHz - 150MHz) –Small bare section of a single conductor to attach clip lead for hf injection EMI shielding not required on breakout harnesses Harness specification in work –See R. Bielawski talk

LAT Environmental Test PDR15 GLAST LAT Project 3-4 May 2005 Radiated Test Harness No access to conductors required Harness must be fully shielded –Includes all connector savers Any test ports must be closed out or have shielded harnesses –“back door” Test harnesses must be shielded –Accelerometers –TCs & thermistors Harness supports not directly connected to the LAT should be nonconducting material, wood or PVC

LAT Environmental Test PDR16 GLAST LAT Project 3-4 May 2005 Grounding All LAT EGSE must be capable of ≤2.5mOhm connection to facility ground –BPU –VSC –Computers Chiller must be connected to LAT via nonconducting tubing –Chiller chassis must be capable of ≤2.5mOhm connection to facility ground LAT and or LAT MGSE must have ground points on all four sides capable of ≤2.5mOhm connection to facility ground –To obtain grid to ground ≤2.5mOhm

LAT Environmental Test PDR17 GLAST LAT Project 3-4 May 2005 Test Software Emissions Testing –Utilize the FSW Charge Injection Calibration function to inject charge into a large number of detectors. The number of channels into which charge can be injected will be limited by: a) FSW design (which is not yet complete); and b) The number of channels which can physically be injected with charge in any given one second cycle. The one second cycle is required to provide repeatability during the Emissions frequency sweeps. Susceptibility Testing: –A variation of the test described in the End-to-End (ETE) Test Plan, LAT-MD-03489, paragraph 2.2.1, item 4, "Nominal Rate Cosmic Ray Test" will be used. This test is run at ambient temperature and at nominal voltage, timing, threshold, and trigger configurations. Both Cosmics and the external trigger function are used to create on- orbit trigger rates. The external trigger rate will be set so that the total trigger rate will be at or near the nominal expected on-orbit values. –The externally triggered events should have very low occupancy, monitor to see if occupancy goes up –The cosmic ray events should remain constant, monitor to see if rate goes up. –Need real time continuous go/no go

LAT Environmental Test PDR18 GLAST LAT Project 3-4 May 2005 Test EGSE Software Tools Displays of natural trigger rates and occupancy of externally triggered events should be strip chart type Other error status, checksum, etc. should latch

LAT Environmental Test PDR19 GLAST LAT Project 3-4 May 2005 RE101 – All LAT Equipment

LAT Environmental Test PDR20 GLAST LAT Project 3-4 May 2005 RE102 - Integrated LAT

LAT Environmental Test PDR21 GLAST LAT Project 3-4 May 2005 CE102 Spacecraft PRU – LAT DAQ

LAT Environmental Test PDR22 GLAST LAT Project 3-4 May 2005 CE102 Spacecraft PRU – LAT SIU

LAT Environmental Test PDR23 GLAST LAT Project 3-4 May 2005 Conducted Emissions Common Mode – All LAT Equipment

LAT Environmental Test PDR24 GLAST LAT Project 3-4 May 2005 RS101 Perform – BEA and Tracker Tower

LAT Environmental Test PDR25 GLAST LAT Project 3-4 May 2005 RS103 Perform – BEA and Tracker Tower

LAT Environmental Test PDR26 GLAST LAT Project 3-4 May 2005 CS102 Spacecraft PRU – LAT DAQ

LAT Environmental Test PDR27 GLAST LAT Project 3-4 May 2005 CS102 Spacecraft PRU – LAT SIU

LAT Environmental Test PDR28 GLAST LAT Project 3-4 May 2005 Conducted Susceptibility Common Mode – All LAT Equipment

LAT Environmental Test PDR29 GLAST LAT Project 3-4 May 2005 CS06 Operate – All LAT Equipment

LAT Environmental Test PDR30 GLAST LAT Project 3-4 May 2005 CS06 Perform – All LAT Equipment

LAT Environmental Test PDR31 GLAST LAT Project 3-4 May 2005 Action Items