GFTS® Spaceflight Heritage
Though graphite thermal straps / "thermal shunts" / "thermal cables" have been studied since the late 1960's, TAI alone, perfected and fabricates the only graphite fiber thermal strap products. We began research on, and built our first GFTS® in 1996, and were later awarded USAF SBIR Ph I and follow-on Ph II programs (in 1996 & 1997), to further develop GFTS® and thermally-conductive vibration isolation technology for cryocoolers.
Today, TAI's GFTS® assemblies not only have spaceflight heritage; they have been subjected to--and successfully passed--some of industry's most grueling qualification/test requirements ever applied to thermal strap products, in Boeing's CST-100 Starliner, and JAXA's ASTRO-H programs (see our spaceflight qualification data table at the bottom of the page).GFTS® have been used in a variety of advanced thermal management applications, both space and ground-based, in areas such as: antennas, electronics boxes, battery pack cooling, radiators, cryocoolers, optical systems, SWIR & VNIR cameras, star trackers, cryogenic refrigerator compressors, communication & radar power electronic systems, and electromechanical systems. Our GFTS® products have flown--or will be launching soon--on the following programs:
- NASA's ORION Spacecraft - Launched December 2015. TAI designed and assembled dozens of GFTS® assemblies (for NASA, Ball Aerospace, and Lockheed Martin), for the Data Acquisition Systems and Phased Antenna Arrays on the Orion Multi-Purpose Crew Vehicle. TAI is still filling follow-on FM orders for ORION at present.
- JAXA's ASTRO-H (Hitomi) - Launched February 2016. TAI designed and assembled dozens of GFTS® assemblies for JAXA, for PC-B Compressors, and cryocoolers on ASTRO-H.
- Numerous Department of Defense Satellite Programs (Program Names Withheld) - Launched in 2016 - 2017, and others set for launch in 2018 - 2020. TAI is currently filling follow-on FM orders for multiple programs.
- ESA & NASA's Spectral Imaging of the Coronal Environment (SPICE) instrument (on Solar Orbiter) - Launches February 2019. TAI designed and assembled multiple straps to cool chips and other components.
- Boeing's CST-100 Commercial Crew Vehicle - Launches in August 2018. TAI designed and assembled over 100 prototype and FM GFTS® assemblies for the crew module battery system.
- NASA JPL's GRACE-FO - Launched May 22 2018. TAI designed assembled prototype and FM GFTS® and CuTS® assemblies for Airbus and NASA JPL.
- DLR's EnMAP - Launches in 2019. TAI designed and assembled prototype and FM GFTS® assemblies for the SWIR detectors.
- GPS III - Launches in 2018. TAI designed and assembled numerous prototype and FM GFTS® assemblies for Honeywell and other prime contractors on the program.
- Ball Aerospace's GEMS UV-VIS Spectrometer (GEO-KOMPSAT-2B Satellite) - Launches 2018. TAI designed and assembled proto-flight GFTS® assembly to provide mechanical decoupling with heat pipe.
- TAI has also provided prototype and FM GFTS® assemblies for several other customers including: OHB, Thales Alenia, Selex, CSA-Moog, Toshiba, NRL, L-3 and others.
Pictured (Top Left): NASA Launches ORION spacecraft (photo credit: United Launch Alliance).
TAI manufactures our GFTS® product using our GraFlex bundles (GraFlex I and II), and our new GraFlex III Woven Graphite Fiber Sheet (made from graphite fiber with thermal conductivity of 800 - 1,000 W/m-K). Each GraFlex bundle consists of thousands of individual carbon fibers wrapped with a special polyester cord for support. These graphite fibers have 2.75 times the thermal conductivity of copper at room temperature and one quarter of the density. Therefore, on a thermal conductivity/mass basis, they are twelve times more weight efficient than copper, and over six times more weight efficient than aluminum.
Our proprietary GFTS® fabrication process realizes up to 95% of the material thermal conductivity while providing a metal interface configuration for bolting the strap between the heat source and sink. The graph below shows the temperature dependent thermal conductivity of the graphite fiber in comparison with other typical thermal strap materials. End fittings are made using a variety of materials (though aluminum is the most common choice for most applications). All GFTS® assemblies are made using only NASA-approved, extremely-low outgassing materials, making them ideal for contamination sensitive applications.
Pictured (Top): Custom GFTS® with GraFlex I Above Custom GFTS® with GraFlex II. (Bottom): GraFlex I, GraFlex II (twice the number of fibers as GraFlex I), and GraFlex III woven fiber sheet.
Graphite Thermal Conductivity vs Al and Cu Straps
GFTS® vs. PGS and Graphene Sheet Straps
GFTS® Space Qualification Test Data
GFTS® assemblies have undergone extensive testing and qualification under severe environmental and launch conditions. If your program requires stiffness, shock, vibe or other types of qualification testing, let us know, and we will happy to work with you to develop your SOW and spec accordingly. In the table below, you can find examples of some of the testing extremes which our straps have undergone in previous space flight programs.
Pictured: GFTS® FM Assemblies in Handling Fixture - NASA ORION Spacecraft (FM Hardware Designed & Fabricated April 2016).
GFTS® Flexibility Demonstrations
Flexibility and stiffness have long been a concern in thermal straps used in satellites and other aerospace applications. Watch the videos below to see a demonstration of the flexible nature of these straps.