COSSTA-PL - Low-pressure sensor for Dragonfly entry capsule

NASA's upcoming Dragonfly rotorcraft mission is planned to be deployed to the surface of Saturn’s moon Titan [1]. As part of the Dragonfly Entry Aerosciences Measurements (DrEAM) suite [2], the Dragonfly entry capsule will include a subsystem known as the COmbined Sensor System for Titan Atmosphere (COSSTA). This subsystem is being developed by the Supersonic and Hypersonic Technologies Department at the DLR Institute of Aerodynamics and Flow Technology, in collaboration with NASA. One of the components of COSSTA is a pressure sensor developed by the Finnish Meteorological Institute (FMI). This sensor, named COSSTA-PL, is designed to measure static pressure on the entry capsule's backshell.

The sensor is based on FMI’s pressure sensors previously developed for Mars landers, mostly sharing its design with MEDA PS [3], the pressure sensor of the Perseverance rover. Its core components, the Barocap® pressure sensor heads, are developed by Vaisala. The optimal measurement range of COSSTA-PL is up to about 10 hPa, but it has a capability to measure pressures up to at least 20 hPa.

Due to possible exposure to extremely cold temperatures during the long cruise, several tests have been performed with a prototype model and individual components to confirm that the sensor endures temperatures down to -150 °C. The pressure calibration is planned to be performed mainly at FMI in the 0 to 20 hPa pressure range and -70 to +55 °C temperature range, and calibration down to -150 °C (TBC) is continued at the COSSTA level.

References

[1] Lorenz, R. D. et al. (2018). Dragonfly: A Rotorcraft Lander Concept for Scientific Exploration at Titan, Johns Hopkins APL Technical Digest 34(3), pp. 374-387.

[2] Brandis, A. et al. (2022). Summary of Dragonfly’s Aerothermal Design and DrEAM Instrumentation Suite, 9th International Workshop on Radiation of High Temperature Gases for Space Missions, 12 – 16 Sep 2022, Santa Maria, Azores, Portugal.

[3] Jaakonaho, I. et al. (2023). Pressure sensor for the Mars 2020 Perseverance rover, Planetary and Space Science 239, 105815, https://doi.org/10.1016/j.pss.2023.105815.