A Framework for Utilization of DAVINCI+ Measurements to Study Physical State of Venus Near Surface Environment

Abstract:

The atmosphere of Venus has been explored by many probes and lander missions, which investigated different regions of the atmosphere, including chemical composition, dynamics and thermal structure. However, the repeatability and accuracy of measurements of the near-surface environments provided by the missions of previous decades is lacking, and there is a need for more accurate and precise measurements to study the near surface environment and its physical state. Vega 2 measurements are regarded as the most reliable temperature measurements for the deep atmosphere with an error bar of 0.5 K. Recent analyses of Vega 2 measurements indicate presence of a supercritical fluid state in the last few kilometers above the Venus surface, an increasing concentration of nitrogen with altitude. The DAVINCI+ deep atmosphere chemistry probe, now in Phase A led by Principal Investigator Dr. James B. Garvin and NASA GSFC will study the atmospheric structure and chemical composition of Venus’ lower atmosphere. The Venus Atmospheric Structure Investigation (VASI) payload will provide temperature and pressure measurements during the entry and descent stages, while the Venus Mass Spectrometer (VMS) payload will provide measurements for nitrogen isotope abundances. We will present a framework for the deep atmosphere chemistry probe measurements to study the physical state and thermodynamic properties of the deep atmosphere of Venus based on the knowledge and principles of thermodynamic properties of states and previous atmosphere probes. The goal of the framework is to investigate the supercritical state of Venus atmosphere, check the possibility of existence of a concentration gradient, and to take advantage of proposed DAVINCI+ probe synergistic measurements.