Calibration of COSSTA-PL low-pressure sensor of the Dragonfly entry capsule

NASA is preparing to launch the Dragonfly mission, a rotorcraft lander destined for the surface of Saturn’s moon Titan [1]. As part of this mission, the entry vehicle will carry the Dragonfly Entry Aerosciences Measurements (DrEAM) payload [2], which includes a sensor suite known as the COmbined Sensor System for Titan Atmosphere (COSSTA). This instrumentation package is being co-developed by NASA and the Supersonic and Hypersonic Technologies Department at the DLR Institute of Aerodynamics and Flow Technology. One component of COSSTA is a low-pressure sensor, COSSTA-PL, developed by the Finnish Meteorological Institute (FMI) to capture static pressure data on the backshell of the entry capsule. 

COSSTA-PL builds on FMI’s experience with Mars missions, closely following the design of previous pressure sensors such as MEDA PS on the Perseverance rover [3]. FMI has pressure calibration facilities specifically developed for the low-pressure range characteristic of Mars’ surface conditions, as well as the pressures expected in the upper atmosphere of Titan during the beginning of entry. The sensor is calibrated at FMI’s facilities over a pressure range of 0 to 20 hPa and a temperature range of -70 to +55 °C. Since the sensor may be exposed to extremely cold temperatures in the backshell, additional calibration measurements down to -150 °C are also performed at 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.