The rockets of the future will fly with plastic tanks

In the coming years, rockets may be seen flying with tanks made of lightweight carbon fiber reinforced plastic thanks to pioneering research carried out within the European Space Agency’s (ESA) Future Launcher Preparatory Programme.

Thus, Germany’s MT Aerospace has demonstrated a novel design of a small-scale tank made of a carbon fiber reinforced plastic (CFRP) that is not only leak-proof with liquid hydrogen, but also compatible with oxygen. liquid, without the use of a metal lining.

The advantages of this material are weight. Carbon fiber reinforced plastic is lighter than metal and requires fewer parts, making it faster and cheaper to manufacture.

“This is a historic achievement, as normally, storage of cryogenic propellants like these that are cooled to -253˚C requires metal-lined tanks to make them leak-proof, with or without a composite wrap,” they explain from ESA. .

“Fuel tanks are safety-critical elements in any propulsion system,” explained Hans Steininger, CEO of MT Aerospace. “We have provided evidence that a high-performance pressure tank made from CFRP can withstand cryogenic stress. In the future, the use of CFRP high-performance tanks should not only enable the safe launch of rockets, but can also take advantage of significantly lower mass compared to metal tanks.”

“This is a tremendous step forward. We have found a very specific carbon composite and processing method that will allow us to consider new architectures and function combinations for rocket upper stages that are not possible with metal,” added Kate Underhill, Propulsion and Stage Demonstrators Project Manager. higher in the ESA Future Launcher Preparatory Program.

“Metal is airtight. To recreate the same property with carbon composite required a complex weave of black carbon fiber and a special resin. The material withstood cryogenic temperatures, pressure cycling and reactive substances during a separate series of tests,” Underhill commented.

After these tests, small-scale tank pilots with integrated thermal protection will be built for further testing. The data collected will feed into the development of a large-scale demonstrator of a highly optimized future upper stage, called Phoebus.

Phoebus will have 3.5 meter diameter hydrogen and oxygen tanks, thermal protection, structural mounting elements and will feature new technologies in avionics, structures and propulsion equipment. CFRP will be applied to the tanks, the interface structure between the two tanks, and the outer cylinder representative of the outer shell of the upper stage.

The Phoebus demonstrator will be tested with cryogenic fluids in 2023 to confirm the functional performance of the technologies and cost-effective new production methods as part of a new contract to advance the development of highly optimized upper stages.

“This is an excellent example of how ESA’s support for mature, cutting-edge technologies leads to breakthroughs. This new lightweight carbon-based material would enable the fabrication of a superior Ariane 6 platform that is two tonnes lighter, a free mass for payloads,” said Daniel Neuenschwander, Director of Space Transportation at ESA.