Ephemeris: A TSTO Space Rescue Vehicle Conceptual Design

With the increasing interest in commercial space activities, it is inevitable that a catastrophe will occur in space again. To address this scenario, the Ephemeris Space Rescue Vehicle (SRV) is designed as a fully reusable, vertical-launch / horizontal-landing based, Two-Stage-To-Orbit (TSTO) vehicle. Ephemeris seats seven and uses air-breathing engines to maneuver within the upper atmosphere, allowing for cruise of greater cross-range capability prior to orbital insertion. By using airbreathing propulsion, we can cruise 300-500 miles range any direction prior to orbital insertion, increasing the range of orbit providing the ability to cover a larger degree of inclination. This in turn increases the launch windows, which is critical for rescue, and provides more flexibility to rendezvous with distressed spacecraft in a variety of orbits. Ephemeris’s high characteristic L/D provides flexibility during reentry and landing, permits choosing multiple landing sites. To optimize the Ephemeris concept, a rapid simulation capability is needed to generate the propulsion and aerodynamic databases needed for the vehicle trajectories, and to determine the vehicle’s aerothermal environment needed to design the thermal protection system. Tip-to-tail aerodynamic and propulsion simulation of the entire vehicle over its trajectory is used. This effort is the first attempt known to the author(s) to use distributed and exascale supercomputing for hypersonic vehicle design.