# Presentation: 442316

## Fiber Optic Cable Assembly Characterization Studies at 

***Sigma Research and Engineering / NASA Goddard Space Flight Center***
***Component Technologies and Radiation Effects Branch***
- _[Melanie.](mailto:Melanie.ott@gsfc.nasa.gov)__[ott](mailto:Melanie.ott@gsfc.nasa.gov)__[@](mailto:Melanie.ott@gsfc.nasa.gov)__[gsfc](mailto:Melanie.ott@gsfc.nasa.gov)__[.](mailto:Melanie.ott@gsfc.nasa.gov)__[nasa](mailto:Melanie.ott@gsfc.nasa.gov)__[.](mailto:Melanie.ott@gsfc.nasa.gov)__[gov](mailto:Melanie.ott@gsfc.nasa.gov)_
***301-286-0127***
***URL:  http://misspiggy.gsfc.nasa.gov/tva/authored/fo_photonics.htm***

***Fiber Optic Cable Assembly Characterization Studies at ***
***NASA Goddard Space Flight Center***

- The Team:
***Patricia Friedberg, Matthew Dodson, Shawn Macmurphy, ***
***Dan Ginghold, Juan Vela***

- NEPP Workshop 2002: Optical Cables for Space Flight

## Outline

- Objectives
- Qualification performance testing
- Failure modes and innovative test methods
- Typical characterization plan
- Examples: epoxy studies
- Examples: MTP studies
- Examples: Cable studies
- Examples: Radiation studies
- Conclusions: planned work

- NEPP Workshop 2002: Optical Cables for Space Flight

## Objectives

- To enable the usage of commerical off the shelf optical fiber interconnection technology for space flight use.
- To develop innovative test methods to make the path to usage quicker and less expensive.
- To provide a variety of alternatives to a variety of environments.

- NEPP Workshop 2002: Optical Cables for Space Flight

## Performance Testing and Requirements for Optical Cable Assemblies 

- Thermal cycling
- Bend test
- Low and high temperature cable bend
- Flexibility
- Impact
- Accelerated aging
- Jacket shrinkage
- Flexure endurance
- Humidity resistance
- Cable blocking
- Freeze test
- Cable clamping
- Fluid immersion
- Cable-to-cable abrasion
- Jacket tensile strength and elongation
- Vibration
- Ambient light susceptability
- Cable twist bend
- Cable twist

- Insertion loss
- Return loss
- Crosstalk
- Numerical aperture
- Transmission capacity
- Attenuation
- Mating durability
- Fungus
- Toxic hazard, Odor, Flammability
- Vacuum stability
- Atomic oxygen
- Solar UV radiation
- Plasma
- Ionizing radiation
- ESD
- Thermal shock
- Strippability
- Crush resistance
- Strength testing

- NEPP Workshop 2002: Optical Cables for Space Flight

## Technology Validation

- What do I validate this technology?
- Failure modes study
- What approach do I take?
- System type approach to the assembly
- How?
- System analysis (materials, design,compatibilities etc)
- Characterization plan that takes into account the greatest number of failure modes for space flight.
- Design innovative testing methods to expedite validation

- NEPP Workshop 2002: Optical Cables for Space Flight

## Failure Modes and Testing

| Failure or degradation mode | Condition | Validation Method |
| --- | --- | --- |
| Optical materials/materials changes  | Vacuum, temp, aging | Analysis, thermal cycling, vacuum testing. |
| Attenuation from environment | Temp, radiation | Analysis, Radiation exposure
Thermal cycling,  |
| Materials shrinkage  | Aging, temp | Thermal cycling |
| Cracking | Temp, vibration, handling, design, termination process | Thermal cycling, vibration, analysis |

- NEPP Workshop 2002: Optical Cables for Space Flight

## Characterization Plan

- Materials analysis and test,
- Termination validation as a system.
- Thermal vacuum use configuration when possible.
- Thermal cycling,
-  long dwell at extremes, 1 °C/min to extent of specification, -20°C to +85 °C for COTS, -55°C to +125°C for Space, 40 cycles, 25 – 30 minute soak, 1 or 2 °C/min rate.
- Vibration testing,
-  Random vibration to protoflight levels,
- 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
- Radiation analysis and test.
- Two dose rate test and extrapolate to environment Space flight environments from GSFC are less than 1 rad/min and more typically less than .1.

- NEPP Workshop 2002: Optical Cables for Space Flight

## Materials  Characterization 

- Through analysis, identify COTS materials without heritage (epoxy, coating, etc) for use in space assembly.
- Validate through termination process as a system, (cure for epoxy, strip test for coatings, visual, optical performance.)
- Validate through test methods,
- Thermal (array connector ), ASTM-E595
- ASTM-E595 in assembly configuration (simplex connector).
- ASTM-E595 in cable configuration (coating material with and without connector).

- NEPP Workshop 2002: Optical Cables for Space Flight

## Epoxy Studies

- Tracon BA-253 only fiber optic epoxy
- 	Tested AngstromBond AB9119, 9112 in configuration and out, AB9119 passed using ASTM-E595.
- MTP connector assembly, epoxy not approved for flight
- 	MTA-022, BA-253 failed termination study for use on MTP.
- 	Evaluation through termination and test of new epoxy AB9320.
- 	If AB9320 passes, next use ASTM-E595 to verify that the epoxy will not outgass and will be compatible with system.

- NEPP Workshop 2002: Optical Cables for Space Flight

## MTP Assemblies Studies

- MTP array connector with 12 optical fiber ribbon cable,
- 	-  62.5/125/250 micron, commercial system.
- 	-  100/140/250 micron, spaceflight system.
- 	-  Termination study

- NEPP Workshop 2002: Optical Cables for Space Flight

## MTP Characterization ; 100/140 space flight vibration test 

*Vibration Test Results: DUT B, Y Axis*

- NEPP Workshop 2002: Optical Cables for Space Flight

## MTP Termination Study

- 62.5/125 MTP assembly study: found failures related to
- termination process.
- 	During process, cracking
- 	Epoxy alternatives necessary for 100/140 version.
- Currently conducting a study on process and epoxy
- 	Curing,
- 	Visual,
- 	Optical Performance,
- 	Thermal Cycling,
- 	ASTM-E595 on alternative epoxy

- NEPP Workshop 2002: Optical Cables for Space Flight

## Cable Studies

- -55°C to +125°C, 20 min dwell at extremes, 2 °C/min

- NEPP Workshop 2002: Optical Cables for Space Flight

## Radiation Studies

- A(D) = 7.47*10-4 .1993  D.8007

- MTP Assembly
- 4 rads/min &
- 27 rads/min at
- +25 °C, 1300 nm
- 5.24 m with mated
- pair.

- NEPP Workshop 2002: Optical Cables for Space Flight

## Radiation Studies: Actual Data

- Commercial 62.5/125/250 OFS Fitel Collected Data

- NEPP Workshop 2002: Optical Cables for Space Flight

## Radiation Studies: Extrapolation

- Commercial 62.5/125/250 OFS Fitel Extrapolated Data for -25°C

- NEPP Workshop 2002: Optical Cables for Space Flight

## Planned Work

- MTP twelve channel array connector and optical fiber ribbon cable
- 	Termination study
- 	Alternatives to epoxy, materials study
- Diamond AVIMS characterization for space flight
- Radiation: Optical fiber database for space flight environments.

- http://misspiggy.gsfc.nasa.gov/tva/authored/fo_photonics.htm
- http://www.nepp.nasa.gov/

- This work is funded by NEPP Packaging Project &
- Electronics Radiation Characterization Project

- NEPP Workshop 2002: Optical Cables for Space Flight