Composites are taking off as a key material for outer space applications.
From the first heavier-than-air human flight in 1903 to the first manned lunar landing just 66 years after and today’s new Orion spacecraft, the aerospace industry has a history of rapid growth. Composite materials have been integral to this growth, playing an increasingly greater role in pushing the boundaries of space travel. Some of the latest applications that show the breadth of composites usage are cryogenic tanks, deep-space observatories and launch vehicles.
Cryogenic Tanks Fuel Exploration
Composite cryogenic tanks – or “cryotanks” – are so important to new deep space missions that Northrop Grumman, Lockheed Martin and Boeing are all developing them. Cryotanks are often used in outer space as rocket fuel tanks to contain liquid hydrogen or liquid oxygen fuels at cryogenic temperatures (below -238 F). The tanks, previously made from metals, provide high-energy propellant solutions required for extended human exploration missions beyond low-Earth orbit.
Recently, NASA and Boeing successfully tested a 5.5-meter diameter all-composite cryotank as part of the Composite Cryogenic Technology Demonstration Project, funded by the NASA Space Technology Mission Directorate within the Game Changing Program Office. The tank, one of the largest and lightest cryogenic liquid hydrogen fuel tanks ever manufactured, is the latest step toward the planned 8.4-meter tank that could reduce the weight of rocket tanks by 30 percent and cut launch costs by at least 25 percent.
Weight and cost savings are critical because the cryogenic tank is intended to eventually help bring humans to Mars on NASA’s Space Launch System, America’s new rocket for deep space exploration. “We’re looking at an application that’s for the upper stage [of the rocket engine], so any pound you save can be directly transferrable to an additional pound of payload capability,” says Dan Rivera, Boeing program manager for the cryotank project.
NASA and Boeing designed the cryotank for out-of-autoclave (OOA) manufacturing. The team chose OOA primarily because there is not an autoclave large enough to mold a one-piece 8.4-meter cryotank, says Jim Sutter, a senior research chemical engineer at NASA. The cryotank uses Hexcel’s HexTow® IM7 carbon fiber and Cytec’s CYCOM® 5320-1 epoxy prepreg resin.