Development of a Rugged Seismometer for Venus Surface Deployment

Goals & Objectives Understanding the seismicity and interior structure of Venus have been long-standing objectives of the scientific community. Venus Express observations of recently emplaced basalt on the surface and injected SO2 in the atmosphere—alongside new studies of plume-induced subduction at coronae—indicate that Venus likely hosts magmatic and tectonic activity. While seismological investigation from orbit or floating atmospheric platforms have been conceptualized for Venus, only a surface station can measure all three dimensions of ground motion as required to achieve high-priority science goals. The objective of this proposal is to develop a miniature seismometer that could be deployed on the surface which has sufficient sensitivity, frequency response, and environmental tolerance to address seismological activity for a timescale of 60 Earth-days or longer. The instrument will be compatible with the harsh surface environment of Venus and will have a low vertical profile which ensures that wind-induced noise is kept low enough to minimize interference with possible seismic signals from the crust and depths below. The goal of the work is to increase the TRL of individual components and the assembled seismometer from its current entry TRL 1 to exit TRL 4.

Approach & Methodology The proposed miniature seismometer is based on a liquid sensing body using a molecular electronic transducer (MET) mechanism. It has the advantages of high shock tolerance, arbitrary installation angle, high sensitivity and wide dynamic range, and high ability to withstand any strenuous environmental conditions. The high shock tolerance and arbitrary installation angle of the MET sensor provide advantages over conventional seismometers on sensor deployment and also the possibility of creating a seismic array via a single landing on a planet’s surface. In this proposal, we will build upon our success of developing MET based seismometers supported by NASA COLDTECH, and gear them towards Venus applications. The proposed specific tasks include: 1) development of MET senor components for Venus surface applications; 2) development of readout circuit; 3) sensor assembly, performance validation and pier testing.

Relevance to PICASSO The proposed work is within the scope of the PICASSO program since our seismometer has significant advantages over the traditional ones and shows promise for application in future Venus missions. The team, composed of scientists and engineers from Arizona State University and Wayne State University, anticipates demonstrating science objectives/instrumental capability relationships and the exit TRL 4. Our traceability between high-level goals from the decadal survey and the physical parameters measurable by one or more rugged seismometers demonstrates that our proposed instrument achieves the goal of the PICASSO program from the solicitation to “develop new proof-of concept instruments that enable new science by significantly improving instrument measurement capabilities for planetary science missions” and is responsive also to the additional selection criterion regarding “the extent to which [a rugged seismometer] addressees a priority science goal of the mission or missions for which it would be candidate for flight.” More »