An inflatable re-entry thermal protection system that is cooled by gas release is being studied by Seattle-based Andrews Space under a NASA contract. The ballute, which inflates to provide a large, high-drag surface for aerobraking, would be transpiration-cooled by gas flowing out through the flexible membrane.
Using gas from within the ballute to absorb and carry away some of the heat from re-entry could allow it to be made of thinner material. “[Inflatable] ballutes offer significant advantages over rigid shells for aerocapture and re-entry of spacecraft by providing simpler packaging and lower total weight,” says Andrews Space. The study results will be used to develop a concept for an operational system.
Source: Flight International