The Planetary Entry Systems Synthesis Tool: A conceptual design and analysis tool for EDL systems

Conceptual design of entry, descent, and landing (EDL) systems requires models over several disciplines as well as knowledge regarding the interactions between these disciplines. To ease the conceptual development of an EDL mission segment and to explore the mission design space, the Planetary Entry Systems Synthesis Tool (PESST) was created. The PESST framework estimates the performance and mass of an entry system using user-defined geometry, aerodynamics, flight mechanics, terminal descent guidance, thermal response and mass estimation models. Trade studies can be performed by parameter sweeps to gain an understanding of the design space for conceptual studies. Several standard atmospheres are available, and either a user-defined or GRAM atmospheric model may be used. In its present form, PESST may be applied to entry studies for Earth, Mars and Venus missions. This framework is broadly applicable to the conceptual study of EDL systems. A detailed presentation of the PESST tool and each discipline model is provided along with comparisons to historical entry missions for Earth, Mars and Venus. The PESST framework for system level sizing and synthesis allows for the impact of technologies such as inflatable aerodynamic decelerators and guided terminal descent propulsion to be examined at the mission design level. Closing conceptual designs about these major discipline analyses models the effects of design changes on entry mass, peak deceleration, propellant mass, payload mass, and other mission level design constraints.