april 1, 2002nasa goddard space flight center characterization of a twelve channel optical fiber,...
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April 1, 2002 NASA Goddard Space Flight Center
Characterization of a Twelve Channel Optical Fiber, Ribbon Cable and MTP
Array Connector Assembly for Space Flight Environments
Melanie N. Ott, Shawn Macmurphy, Patricia Friedberg
Sigma Research and Engineering/
Goddard Space Flight Center301-286-0127
SPIE Conference on Enabling Photonic Technologies for Aerospace and Applications IV
April 1, 2002 NASA Goddard Space Flight Center
Outline
• Assembly enhancements
• Characterization plan
• Vibration Testing Results
• Thermal Testing Results
• Radiation Parameters
• Results of radiation testing
• Conclusions
April 1, 2002 NASA Goddard Space Flight Center
Cable Assembly EnhancementsW.L. Gore Kynar Ribbon Cable, OFS Fitel Commercial Optical
Fiber, MTP connectors and terminations by US Conec.
• 100/140/250 commercial optical fiber instead of 62.5/125/250.
• 140 micron ferrule holes.
• Non outgassing boots for connector and ferrule.
• Mated pair 5.24 m long with cable assembly tested.
April 1, 2002 NASA Goddard Space Flight Center
Characterization Plan All testing conducted: recorded before and after optical performance
data as well as insitu optical data.
• Vibration Induced Effects
– Verified survival and operational ability during launch using typical launch parameters ~ 14.1 grms total for protoflight small box components.
– 3 minutes per axis, 20 grms total.
• Thermal Induced Effects
– -20°C to +85 °C, 18 cycles and 38 cycles, 25 minute soak, 1 °C/min rate
• Radiation Effects
– Space flight environments from GSFC are less than 1 rad/min and more typically less than .1. Two dose rates used to possibly provide a model for extrapolation to lower dose rates.
April 1, 2002 NASA Goddard Space Flight Center
Cable Channels Optically Monitored During Testing
Test Cable Designation Channel Optically Monitored
Vibration
DUTA 1,3,5,6,8,10,12
DUTB 1,3,5,6,8,10,12
DUTC 1,3,5,6,8,10,12
Thermal
DUTA 1, 5, 8, 12
DUTB 1, 5, 12
DUTC 1,3,5,6,8,10,12
Radiation
DUTA 12
DUTB 12
April 1, 2002 NASA Goddard Space Flight Center
Vibration Testing
3 minutes/axis, 20 grms total, Optical data @ 25 µsec,and 5 sec sampling rate
X
Y Z
April 1, 2002 NASA Goddard Space Flight Center
Vibration Test Results: 25 µsec samplingDUT Test Set Vibration Test Axis Loss events
A X < 1.2 dB
A Y < 0.1 dB
A Z < 0.1 dB
B X < 0.1 dB
B Y < 0.1 dB
B Z < 0.1 dB
C X < 0.1 dB
C Y < 0.1 dB
C Z < 0.2 dB
Vibration induced events (dynamic losses) for channel six of each cable assembly, mated pair for each axis
April 1, 2002 NASA Goddard Space Flight Center
Vibration Test Results: 5 sec samplingDUT Test Set Vibration Test Axis Loss Recorded
A X < .08 dB
A Y < .10 dB
A Z < .11 dB
B X < .13 dB
B Y < .35 dB
B Z < .03 dB
C X < .15 dB
C Y < .40 dB
C Z < .28 dB
Summary of MTP vibration data (static losses) on channels 1,3,5,8,10, & 12.
April 1, 2002 NASA Goddard Space Flight Center
Vibration Test Results: DUT B, Y Axis
Optical transmission for MTP DUT B during Y axis vibration testing
-0.500
-0.400
-0.300
-0.200
-0.100
0.000
0.100
0.200
0.300
0.400
1 4 7 10 13 16 19 22 25 28 31 34 37
Data point (~ 5 sec/point)
Op
tica
l tr
ansm
issi
on
(d
B)
Ch 1
Ch 3
Ch 5
Ch 8
Ch 10
Ch 12
April 1, 2002 NASA Goddard Space Flight Center
Thermal Testing ResultsDUT Cable
Channel Max within a cycle
Max entire test duration
A 1 1.6 dB 1.8 dB
A 5 0.8 dB 1.3 dB
A 8 0.1 dB 1.4 dB
A 12 1.2 dB 1.4 dB
B 1 0.9 dB 1.2 dB
B 5 1.2 dB 1.9 dB
B 12 0.8 dB 1.1 dB
C 1 1.4 dB 1.6 dB
C 3 1.3 dB 1.3 dB
C 5 1.0 dB 1.2 dB
C 6 0.9 dB 1.6 dB
C 8 0.7 dB 1.0 dB
C 10 1.3 dB 1.4 dB
C 12 1.5 dB 1.6 dB
Thermal cycling:-20°C - +85°C, 1 °C/min ramp rate25 minute dwells.
DUT A & B: 38 cyclesDUT C: 18 cycles
April 1, 2002 NASA Goddard Space Flight Center
Thermal Testing Results
April 1, 2002 NASA Goddard Space Flight Center
Radiation Test Parameters
Cable Set DUT
Radiation Dose Rate
Total Dose Length
mated pair
A 4 rads/min ~ 62 Krads 5.24 m
B 27 rads/min ~ 403 Krads 5.24 m
April 1, 2002 NASA Goddard Space Flight Center
Radiation Results
April 1, 2002 NASA Goddard Space Flight Center
Radiation Results
April 1, 2002 NASA Goddard Space Flight Center
Radiation Results
A(D) = 7.47*10-4 .1993 D.8007
April 1, 2002 NASA Goddard Space Flight Center
Radiation Results
Cable Set Dose Rate Total Dose Attenuation
DUT A 4 rads/min 62 Krads 6.18 dB
DUT B 27 rads/min 403 Krads 15.18 dB
Extrapolated 0.1 rads/min 100 Krads 4.75 dB
Extrapolated 0.1 rads/min 10 Krads 0.75 dB
April 1, 2002 NASA Goddard Space Flight Center
ConclusionsVibration Summary
Dynamic test: 3 axis test, 3 min/axis, channel six of each DUT, 9 dynamic tests total. Losses < 0.1 dB, DUT A on X axis test highest loss @ 1.2 dB
Static test: < .4 dB
Thermal Summary38 cycles: DUT A ave loss: 1.48 dB, DUT B ave loss 1.4 dB18 cycles: DUT C ave loss: 1.38 dB
Radiation SummaryDUT A: 4 rads/min, 6.18 dB/ 5.24 m mated pairDUT B: 27 rads/min, 15.18 dB/ 5.24 m mated pairExtrapolated to 0.1 rads/min, .75 dB for 10 Krads, 4.75 dB for 100 Krads.
Final Visual Inspection: No damaged end-faces including all cables tested.
Before After
April 1, 2002 NASA Goddard Space Flight Center
Acknowledgements
Special thanks to NASA Electronic Parts and Packaging Program & Ken LaBel of the Radiation Effects Group for
support of this work.Thanks to:
Matthew Dodson, SigmaSteve Brown, GSFC
Claude Smith, QSS & Harry Shaw, GSFC
For more information see the website:
http://misspiggy.gsfc.nasa.gov/tva/authored/fo_photonics.htm