Heating and Sampling Efficiency Evaluation for the Nephele Venus Cloud Sampling Mission Concept
Nephele is a descent probe concept with a unique combination of entry (3D-CC+HEEET), sampling (flow-through passive impactors), and optics (laser-induced breakdown spectroscopy, or LIBS, and surface-enhanced Raman spectroscopy, or SERS), technologies with two key innovations. The first is the integration of the aerosol sampling inlet into the aeroshell body, allowing the possibility of sampling during passive descent without separation. The second is the use of the aerosol capture surface as an optical analysis substrate, allowing fast-cadence aerosol analysis via a dual optical spectrometer instead of mass spectrometry. Although this concept shares some features with other efforts such as Cupid’s Arrow (single-body sample capture system), DAVINCI and Venera-D (use of an optical spectrometer), Nephele is unique in its physical integration of the sonde body, aerosol and gas sampler, and analysis instrumentation. This innovation is designed to eliminate the need for a controlled descent to achieve a detailed atmospheric aerosol transect, which offers in situ planetary science in a small spacecraft envelope. Aeroshell designs with inlets for free-falling sondes are well-understood, though not yet assessed for aerosol capture efficiency. A HEEET aeroshell with a specialized nose inlet material comprised of Carbon-Carbon is proposed for this mission concept.