According to a lead engineer on the project’s building team, NASA’s newest liquid hydrogen storage sphere is set to become the world’s largest liquid hydrogen storage unit when it comes online this summer, knocking a storage unit NASA built-in 1966 off the top of the list.
The CB&I Storage Solutions storage sphere will be the first liquid hydrogen sphere created in North America in over 20 years when it is finished in the next two months. It will be about 50% larger than the 1966 construction, at 1.25 million gallons, and both will be located at the Kennedy Space Center.
“Until this new sphere is placed into operation, the 1966 construct will still be the world’s largest liquid hydrogen sphere,” CB&I Engineering Team Leader John Jacobson stated during a Department of Energy workshop on Feb. 23. “However, in the next decade or two, this will be surpassed.”
While NASA’s 1966 hydrogen tank was used to power the now-defunct space shuttle, the larger 1.25 million gallon tank will power the agency’s future Space Launch System rocket, which the agency claims would lay the groundwork for human travel beyond Earth’s orbit.
Since the 1960s, large-scale liquid hydrogen storage technology has made little progress, according to Jacobson. Nonetheless, the sphere that will be completed this year will increase liquid hydrogen storage capacities in two ways. Instead of employing a perlite insulation system for the tank’s innermost layer, glass bubbles will be used, a more expensive option that is expected to increase performance by 40 percent to 100 percent.
The new sphere will also feature a NASA-developed internal heat exchanger for active thermal regulation. According to Jacobson, the tank’s maximum boil-off rate will be less than 0.05 percent each day.
“The new NASA sphere’s size is already stretching the boundaries of traditional construction,” he stated. “Design advancements are necessary to scale that up further and accomplish a step-change in storage capacity.”
According to CB&I, the business has already accomplished design advancements outside the limits of the NASA project. It revealed last year that it had completed a proprietary design for a 40,000 cu m storage sphere, which is nearly eight times larger than the one being built for NASA.
“We have substantially enhanced the possibility of storing large-scale volumes of liquid hydrogen in the last three years,” Jacobson added.
In the future, the business will participate in a consortium led by Shell that will develop liquid hydrogen storage technology for tanks ranging from 20,000 to 100,000 cubic meters used at import and export ports. A $6 million DOE funding, as well as $3 million from Shell and CB&I, are supporting this endeavor, which also includes the University of Houston, NASA, and GenH2.
NASA’s study on liquid hydrogen
Several NASA laboratories are striving to enhance liquid hydrogen technology for both commercial and household use. For example, the Glenn Research Center in Cleveland is developing new insulation methods to ensure technology for storing liquid hydrogen with minimal boil-off. The Marshall Space Flight Center in Alabama is investigating the strength of materials exposed to hydrogen, while the Stennis Space Center in Mississippi is assisting in the development of liquid hydrogen barges that might be used to deliver fuel for rocket engine tests.
But, as NASA Technical Fellow for Cryogenics Michael Meyer pointed out at the session, storage isn’t the only area where the agency is investing in research.
According to him, the agency is working on a design for a spacecraft that might go to Mars and return using onboard liquid hydrogen pumped to a nuclear reactor. As the hydrogen passes through the reactor, it heats up before being expanded into a nozzle to create thrust. It would be twice as efficient as an oxygen-hydrogen rocket engine, such as the one used by the SLS rocket.
“There’s a lot of interest in liquid hydrogen-fueled aircraft all across the world,” Meyer added. “NASA is thinking about how that may be incorporated into programmatic efforts.”
