Comparative Analysis of Planetary Entry Probe Missions

Abstract

Since the beginning of robotic exploration nearly six decades ago, successful planetary probe entry has been accomplished at Venus, Earth, Mars, Jupiter, and Saturns moon Titan. More probe missions are under implementation or planned to Venus, Titan, and Uranus in the next decade. During entry, the probe is subject to rapid deceleration and aerothermal loads which the vehicle must be designed for, to deliver the robotic instruments inside the atmosphere. The design of planetary probes and their mission architecture is complex, and involves various engineering constraints such as peak deceleration, heating rate, heating load, and communications. These must be satisfied within the budget and schedule of cost constrained mission opportunities. Engineering design and flight data from previous probe missions serve as an invaluable reference for future missions. The present study compiles a historical entry probe dataset spanning a wide range of planets, performs a comparative analysis of the entry conditions, and provides engineering rules of thumb for design of future missions. Using the dataset, the study proposes a new empirical relationship which aims to more accurately predict the thermal protection system mass fraction for high heat load conditions during entry and aerocapture at Uranus and Neptune.