For over 10 years GTL has been developing novel rocket system components. Originally funded by DARPA, with additional funding by NASA, GTL has developed a novel composite system (BHL™) for cryogen storage and transfer. BHL is used to produce LOX and cryogen compatible components that leverage the full strength of carbon fiber. For ground systems, the reduction in thermal mass will be more advantageous than the mass reduction (1/4 the mass of existing state of the art equivalents). BHL has 5-7 times lower thermal mass than stainless steel components, and over 10 times lower thermal mass than aluminum components (for the same pressure capability). BHL tubes chill down in less than 10% of the time of stainless-steel tubes. This increases the quality of the cryogenic liquid, reduces bubble entrainment, and allows for longer tube run lengths.
Composite structures are insensitive to hydrogen embrittlement and are highly resistant to fatigue. Furthermore, composite structures CTE can be tailored allowing for a zero lengthwise CTE. This ensures that components will not move around, fighting connection points and interconnections, further reducing fatigue and failure mechanisms.
In addition to the nominal benefits, GTL has developed a novel flow sensor method based around BHL. This sensor will allow for monitoring of the flow velocity profile, quality, and fill level.
In this phase I effort, GTL will design and produce a series of test articles to demonstrate the application of BHL to ground systems. This includes the extension to very high pressures, ground handling damage testing, and flow sensor testing. GTL is experienced in cryogenic testing, LOX and LCH4 testing, propulsion system design and testing, and ground facility production. In the phase II, full scale components will be produced and delivered, and testing can be performed yielding a high-quality validation data set for TRL advancement.
Low thermal mass, low mass cryogenic compatible components and sensors are applicable to many of NASA systems including ground test facilities, launch vehicles, nuclear propulsion, landers, lunar and mars habitats, and other space systems. The significant reduction in mass of cryogenic storage and transfer from BHL will allow for the highest performing cryogen systems ever produced.
The DoD and commercial launch services will benefit greatly from BHL components. Similar to the benefits for NASA, the low mass, low thermal mass properties, among others, are very beneficial to nearly all space systems. BHL components will also be useful for commercial cryogenic ground systems to reduce boil-off and chill-down time.