A small composite fuel tank fabricated by Boeing with funding from the “game-changing” program of NASA’s Space Technology Mission Directorate contained 2,091 gal. of liquid hydrogen through a series of shifts in its internal pressure and three temperature cycles ranging from ambient down to minus 423F.
The June 25 test at Marshall Space Flight Center with a 2.4-meter-dia. composite fuel tank paves the way for more tests next spring. That test will subject a 5.5-meter tank to flight-like mechanical loads as well as temperature and pressure cycles.
So far it appears the project is achieving its goal of reducing the cost of building tanks by at least 25% from that of conventional aluminum-lithium tanks, while cutting the weight of tanks made from the lightweight aluminum alloy by at least 30%.
“This is a very difficult problem,” says Mike Gazarik, associate administrator for space technology. “Composites and cryos don’t work well together, and these guys have done incredible work in figuring out how to design and how to fabricate these tanks.”