A TPS Design Analysis of Entry Probe Delivery from Orbit for Ice Giant Missions
Previous investigation of direct delivery of a probe into Neptune’s atmosphere showed said approach to be challenging due to high stagnation pressures and heat loads. Entering at a high entry flight path angle (EFPA) results in stagnation pressure beyond current Heatshield for Extreme Entry Environment Technology (HEEET) qualification, while entering at a lower EFPA results in higher heat loads, leading to required HEEET thicknesses beyond manufacturing capabilities. Aerocapture is an enticing alternative entry scenario because it enables a fast trip and the placement of a payload in orbit around Neptune that can also reach Triton. Here, we investigate entry conditions associated with delivering a probe from orbit to assess feasibility. We consider whether 1) this entry scenario results in reasonable conditions, and 2) HEEET single insulating layer (mid-density carbon phenolic, 3MDCP) can be used to decrease mass, risk, and cost.