Safe escape for hypersonic passengers
The capsule is the outcome of work on the project HYPMOCES (Hypersonic morphing for a cabin escape system). The EU-funded project was part of the European Space Agency's (ESA) FAST20XX suborbital-spaceplane study, and also linked with the SpaceLiner project aiming to design a hypersonic airliner capable of flying 50 passengers. SpaceLiner will take off vertically, powered by a liquid oxygen/hydrogen rocket booster that would separate above 70-km altitude and fly back. The orbiter stage will continue to accelerate up to a Mach number of 25. After engine cutoff, SpaceLiner glides on to its destination. Because such a hypersonic airliner will operate over a wide range of Mach numbers, passengers may need to escape in unexpected conditions. The HYPMOCES team, therefore, designed a capsule with morphing surfaces to adapt its shape to the phase of flight. Specifically, two different concepts were developed. The baseline has sidewalls on the lower fuselage that inflate to give the capsule a lifting-body shape. At the same time, small rudders deploy for directional stability and a pair of body flaps on the rear fuselage provides flight control. On the other hand, the backup design has narrow wings that deploy from the fuselage bottom. The inflatable design was preferred because it is compact and lighter. The inflatable sidewalls are flexible but stiff enough to form a robust and stable thermal protection barrier. The shape-changing cabin escape system also offers aerodynamic control and robust navigation for safe return to the ground by non-trained persons. HYPMOCES has achieved a breakthrough in technologies to help hypersonic passenger spacecraft take flight. Furthermore, the inflatable technology explored in HYPMOCES could find applications to the National Aeronautics and Space Administration's (NASA) hypersonic inflatable aerodynamic decelerator (HIAD) designed to land payloads on the surface of Mars.
Keywords
Hypersonic airliner, flight abort, shape-changing capsule, HYPMOCES, SpaceLiner
