Engineers just designed a better ‘shock absorber’ for spacecraft

Rocket launches are among the most violent ways humans have devised to travel. They generate millions of pounds of thrust and subject passengers to intense g-forces. Humans must undergo serious training to withstand those forces, while machines must be designed to survive them. If a delicate mirror or solder joint cracks before a multibillion-dollar satellite even begins its mission, the years of effort that went into its design and assembly could be lost. Now, researchers in Switzerland have come up with an ingenious way to make that less likely.

During a rocket launch, a satellite doesn’t just sit loosely inside the rocket’s nose cone (also called its fairing). It bolts directly onto an interface known as a payload adapter. Usually, these are rigid mechanical mounts designed to make sure the spacecraft doesn’t move during flight. But because they are so stiff, they are also excellent at transmitting vibrations—especially longitudinal vibrations that shake the satellite straight up and down along with the rocket.

That is exactly the kind of stress that could cause those failures, so engineers have long sought ways to lessen the impact of the vibrations. However, their solutions were less than ideal: giant rubber cushions (which have their own history of space-based failures) or motorized dampeners that added more weight to the rocket’s payload.

Swiss researchers from the Swiss Federal Laboratories for Materials Science and Technology (Empa) and aerospace supplier Beyond Gravity turned to a completely different technology for their novel payload adapter—phononic crystals. These metamaterials are designed to control, bend or completely block mechanical waves, similar to how photonic crystals manipulate light.

The researchers built a prototype that redirects sharp vertical shocks into rotational motion, transferring that kinetic energy from the shaking rocket body into a set of movable aluminum rings. After the energy is transferred, the shocks lose force, lowering the stress on the satellites’ internal systems.

Satellites are designed to survive the extreme conditions of a rocket launch, so any technology that reduces their need for structural reinforcement is a welcome development. That, in turn, frees up payload capacity, either cutting launch costs or allowing more useful payload on the satellite itself. It also allows scientists to fly even more fragile instruments, such as thinner optics or sensitive quantum computer sensors that would otherwise be destroyed by launch vibrations.

There’s still a lot of work to do before these adapters find their way into mainstream use. Beyond Gravity has filed for a patent on the system, which has passed its computer simulation and lab-bench stress tests. But that still only puts it at TRL 4–5 on NASA’s Technology Readiness Level scale. So while it might be a while before phononic crystal payload adapters see regular use, their advantages over traditional mechanical systems seem clear-cut. Assuming the technology doesn’t hit any further development hurdles, it’s only a matter of time before satellites have a much smoother, less weighed-down ride to the stars.

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Gaby Clark

MA in English, copy editor since 2021 with experience in higher education and health content. Dedicated to trustworthy science news.

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Andrew Zinin

Master’s in physics with research experience. Long-time science news enthusiast. Plays key role in Science X’s editorial success.

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