Light-weight carbon fiber strengthened plastic gas tanks cross a crucial check and will take a variety of weight out of a missile’s dry matter
Materials science is still the unsung hero of space exploration. Rockets are more noticeable and control systems more precise, but they are useless without materials that can withstand the immense temperatures of the forces required to free people and things from the planet. Now a team at MT Aerospace, working on an ESA grant, has developed a new type of material that will be immensely useful in one of the most important parts of a rocket engine – the fuel tanks.
The material itself is not new – known as Carbon Fiber Reinforced Plastic (CFRP), the technology has been around for decades and is widely used in the automotive, aerospace and construction industries. However, no one has yet succeeded in turning it into a rocket fuel tank.
External test of a small composite tank.
Credit – MT Aerospace
First, it had to overcome a few challenges – it had to be sealed and then had to withstand the extreme cryogenic pressures that come with storing rocket fuel. Hydrogen and oxygen combined in a rocket engine are notoriously difficult to store. Existing field tanks, including those made primarily of composite materials, had an inner metal liner to ensure that the highly reactive gas did not escape from the tank.
However, metallic linings have one disadvantage – they are heavy and require many more parts and manufacturing steps than a pure CFRP tank. Since launch costs are one of the main cost drivers in space exploration and weight is directly linked to launch costs, it is attractive for rocket manufacturers to reduce both the weight and the number of components.
Not only ESA came up with this idea – NASA and Boeing also jointly developed a composite tank, as seen in 2014.
Photo credit: NASA / MSFC / Emmett Given
This attraction has long been known, and so ESA spent some research funding on projects to develop a novel, lightweight fuel tank. The new technology developed by MT Aerospace was one of the results of this funding.
This wasn’t the only result, however – other technologies were supported by ESA’s preparation program for the Future Launcher. These technologies will culminate in a large-scale demonstrator project called Phoebus in 2023. The CFRP tanks developed by MT are applied to both the Phoebus fuel tanks and the supporting infrastructure between the oxygen and hydrogen tanks.
Artistic conception of Phoebus, the ESA Upper Stage Test Module.
Credit – Ariane Group
When it is ready in 2023, Phoebus will deliver the first full-size, full-size cryogenic test of a CFRP system. But before that there is an intermediate step for “small” stand-alone tanks that use the technology. If CFRP technology proves to be just as effective on a larger scale as it is on a smaller scale, CFRP technology has the potential to save up to two tons in weight on future rocket launches. That’s a lot of extra load-bearing capacity for the more eye-catching space exploration technologies.
ESA – rocket tanks made of carbon fiber reinforced plastic verifiably possible
Composite World – carbon fiber in pressure vessels for hydrogen
UT – NASA tanks: Not just heavy metal anymore
Prototype CFRP tank in a pressure chamber
Credit – MT Aerospace