Pridwen est un nouveau bouclier thermique à base d’origami conçu pour la rentrée atmosphérique depuis l’espace. La conception réutilisable de Pridwen, nommée d’après le bouclier légendaire du roi Arthur, devrait protéger le vaisseau spatial des brûlures lors de la rentrée en distribuant un flux de chaleur élevé sur sa surface en alliage à haute température, lui permettant d’évacuer progressivement la chaleur. Crédit : Space Forge
L’ESA est sur le point de tester Pridwen, un bouclier thermique innovant et réutilisable à base d’origami qui utilise le rayonnement au lieu de l’ablation pour protéger les engins spatiaux lors de la rentrée atmosphérique. Développé par Space Forge, Pridwen vise à permettre aux satellites d’atterrir sans parachutes, à soutenir les plans de fabrication en orbite et les retours de routine sur Terre. La première mission, ForgeStar-1A, est prévue pour plus tard cette année.
Un nouveau bouclier thermique à base d’origami développé avec[{ » attribute= » »>European Space Agency (ESA) support is planned to be tested with an actual atmospheric reentry from space. Named Pridwen, after the legendary shield of King Arthur, this reusable design will spring out before a spacecraft reenters the atmosphere.
As a spacecraft commences its return to Earth and encounters the atmosphere its orbital velocity gets converted into such high heat fluxes that an unprotected spacecraft will simply burn up. Which is where heat shields come in.
Standard ‘ablative’ heat shields remove unwanted heat by having pieces of the shield gradually burn off. Instead of ablation, Pridwen relies on radiation: its high-temperature alloy fabric has a sufficiently high surface area that the heat flux can spread evenly across it to gradually radiate away.
The shuttlecock-style Pridwen shield will also serve to slow down a satellite sufficiently so that it can survive landing without a parachute. Its maker, Space Forge in Cardiff, UK, plans to capture satellites with a hover net.
The heat shield has undergone multiple drop tests from as high as 17 km and practiced net captures of test items falling at terminal velocity. The company has developed Pridwen as part of a larger vision of in-orbit manufacturing of high-value goods such as pharmaceuticals, superconductors and super alloys, to be returned to Earth on a routine basis.
The first Pridwen heat shield is planned for flight aboard the company’s inaugural ForgeStar-1A mission later this year.
The project has been supported through ESA’s General Support Technology Programme – readying promising technologies for space and commercial markets – as well as the UK Space Agency.
