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MPER EMC1 UCB, June 23, 2006
THEMIS
MISSION PRE-ENVIRONMENTAL REVIEW
Probe 2 EMC Test ResultsDavid Curtis
University of California - Berkeley
MPER EMC2 UCB, June 23, 2006
Probe 2 EMC Test Results
Launch Site Requirements• Test in Launch configuration with instruments off• RE02, RS03 per THEMIS ICD with Boeing
Self Compatibility Requirement• Test in plugs-out configuration with instruments on• RE02, RE04, RS03 per THEMIS Environmental Spec• Limit RE02 to science sensitivity band, 20Hz-1MHz, plus
the probe receiver band 1.7-2.3GHz• Limit RS03 to probe transmitter band. Also power up
transmitter to verify self-compatibility.
Test passed – see JPL test report 5132-06-035• Test report reviewed and approved by KSC
MPER EMC3 UCB, June 23, 2006
Probe 2 EMC Test Results
Launch Configuration RE02 Test Results• Well below spec 140-157udBV/m
• Dominated by EGSE• Tallest peak ~56dBuV/m – see next page
• Below spec at special frequencies:• 408-430MHz, ~30dBuV/m, spec = 38dBuV/m• 5.687 – 5.693GHz, ~54dBuV/m, spec = 95dBuV/m
MPER EMC4 UCB, June 23, 2006
Probe 2 EMC Test Results
MPER EMC5 UCB, June 23, 2006
Probe 2 EMC Test Results
Launch Configuration RS03 Test Results (20-40V/m)
• The only sensitivity was the IRU, which saw significant fluctuations at 80MHz, 160MHz, 300MHz, 900MHz, and 1.108GHz (see next page)
• At 1.108GHz found that IRU response returned to nominal at 7V/m.
• IRU functionality is not important on the launch pad. Further, these frequencies do not correspond to any known frequencies at the Cape
• JPL equipment could not test above 18GHz (spec was to 40GHz). 18GHz agreed to by KSC.
• Post test functional showed no performance degradation in any system
MPER EMC6 UCB, June 23, 2006
Probe 2 EMC Test Results
IRU RS03 sensitivity:
MPER EMC7 UCB, June 23, 2006
Probe 2 EMC Test Results
Operational Mode (plugs out) RE02 test:• 20Hz-1MHz test indistinguishable from facility background• Facility significantly above spec line below 100Hz, as
expected (below 14KHz measurement did not have a hard requirement)
• Receive band (1.77-2.3GHz) did not show anything above the test equipment noise floor, which was below the THEMIS receiver sensitivity level.
• Self compatibility tests indicate no problems in the probe receiver
MPER EMC8 UCB, June 23, 2006
Probe 2 EMC Test Results
Operational Mode RE02 test
MPER EMC9 UCB, June 23, 2006
Probe 2 EMC Test Results
Operational Mode (plugs out) RE04 test:
• See exceedances at harmonics of 60Hz, etc.• see same exceedances in ambient measurement
• Between chamber background peaks, easily meet THEMIS requirements, even at 0.5m from the probe.
MPER EMC10 UCB, June 23, 2006
Probe 2 EMC Test Results
MPER EMC11 UCB, June 23, 2006
Probe 2 EMC Test Results
Operational Mode (plugs out) RS03 test:
• Only interested in probe transmit band.• See no effect from either the probe transmitter or from
an external source at 30V/m
MPER EMC12 UCB, June 23, 2006
THEMIS PROBE
MISSION PRE-ENVIRONMENTAL REVIEW
EMC/POWERPeter Berg
University of California - Berkeley
MPER EMC13 UCB, June 23, 2006
EMC/BATTERY/SOLAR ARRAY
• CONDUCTED EMISSIONS TEST
• BATTERY TRENDING
• SOLAR ARRAY TEST
MPER EMC14 UCB, June 23, 2006
Conducted CM
Common Mode Conducted Emissions Through Umbilical
Probes BAU + IDPU + FGM + EFI + SCM + SST + ESA CM 28V
0
10
20
30
40
50
60
70
80
90
10.0E+0 100.0E+0 1.0E+3 10.0E+3 100.0E+3 1.0E+6 10.0E+6 100.0E+6
Frequency
dB
Probe 1
Probe 2
Probe 3
Probe 4
Probe 5
MPER EMC15 UCB, June 23, 2006
EMC SNIFF
MPER EMC16 UCB, June 23, 2006
Sample EMC Sniff
Probes 1- 5 BAU + IDPU + FGM + EFI + SCM + SST + ESA at J321 ESA HARNESS TO ESA
0
10
20
30
40
50
60
70
10.0E+0 100.0E+0 1.0E+3 10.0E+3 100.0E+3 1.0E+6 10.0E+6 100.0E+6
Frequency
dB
Probe 1
Probe 2
Probe 3
Probe 4
Probe 5
Probes 1- 5 BAU + IDPU + FGM + EFI + SCM + SST + ESA at J321 ESA HARNESS TO ESA
MPER EMC17 UCB, June 23, 2006
Battery Trending
Probe 1 2 3 4 5
Δ V -.42 -.42 -.42 -.39 -.33
Starting at 32 Volts, 850 mA was drawn from each battery for one hour.
MPER EMC18 UCB, June 23, 2006
SOLAR ARRAY TEST
1X
-1X 1Y -1Y 2X -2X 2Y -2Y 3X -3X 3Y -3Y 4X -4X 4Y -4Y
28.0 28.3 24.5 27.8 27.3 29.3 29.0 28.8 22.5 28.3 29.3 27.3 31.8 24.3 25.8 29.8
A pair of 500 Watt Halogen Lamps was Placed orthogonally centered to each of the four flanking solar arrays at approximately 2 feet. The increase in solar array current from ambient light by string in mA was noted, and averaged below.
