Activities at a European Planetary Simulation Facility

Activities at a European Planetary Simulation Facility

 

J. P. Merrison, J.J. Iversen, K.R. Rasmussen, A. Waza

¹Institute of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus  C, Denmark (merrison@phys.au.dk/ Fax: +45-86120740)

 

Abstract

This unique and now improved planetary simulation facility is capable of re-creating extreme terrestrial, Martian and other planetary environments. It is supported by EU activities including Europlanet 2024 RI here the latest research and networking activities will be presented. This facility is also used as a test facility by ESA and NASA Mars missions. Specifically it is capable of recreating the key physical parameters such as temperature, pressure (gas composition), wind flow and importantly the suspension/transport of dust, sand or ice particulates. This facility is available both to the scientific and Industrial communities.  

• Europlanet Transnational Access

 

This environmental simulator facility is utilized for a broad range of research programs including; the study of other planets (such as Mars), for recreating extreme terrestrial environments, or in specific investigations involving aerosols and other forms of Aeolian particulate transport. The facility is also involved in the Europlanet 2024 Research Infrastructure through which a trans-national access program is allowing numerous research groups access to this facility. Some selected recent and upcoming projects are listed below;

• Polar CO₂ ice on Mars (USA) [5]
• LIBS system on Mars2020 (ISAE France) [3]
• Sand transport and ripples on Mars (P. Claudin, B. Andreotti, et al. 2019)
• Dust aerosols at low pressure. INGV, I [6]
• Flow Testing of a Sonic Anemometer for the Martian Environment (USA) [4]
• In-situ utilization on Mars2020 and dust loading. Imperial College UK [7]

Other activities include the development, testing and calibration of sensor and planetary lander systems, both for ESA and NASA. Testing for missions ExoMars 2020 and Mars Perseverance were carried out.

 

 

Figure 1 The main Planetary Simulation Facility 2022 carrying out a Europlanet2022RI funded experiments involving sand transport under Marian conditions and guests;

 

• Design and operation

 

The simulator consists of a 38m³ environmental (thermal-vacuum) chamber within which a re-circulating wind tunnel is housed [1]. The wind is generated by a set of two fans which draw flow down the 2m×1m tunnel section and return it above and below. Wind speeds in the range 1-40 m/s have been demonstrated. Cooling is achieved by a novel liquid nitrogen flow system which has achieved temperatures below -160ºC. The inner chamber is thermally isolated from the vacuum chamber. An atmospheric cooling system allowing independent control of the air temperature (tested to -50°C) and a range of particle imaging, microscopy and laser based techniques allow study of aerosols [2].

Improved functionalities of this facility (funded by Europlanet 2024RI) include the implementation of; improved pumping capabilities to lower pressure (<10-4mbar) and improved aeroslization systems for dust and ice studies. Additional recent sensor systems include a new Laser Doppler Velocimeter system and an optical transmission (opacity) sensor for studying aerosol properties.

 

 

Figure 2 studying resuspended dust using a Laser Doppler Velocimeter and a light transmission (opacity) system.

 

• Sand, dust and ices on Mars

 

With control of wind flow at low pressure and temperature this facility is well suited for recreating the environment at the surfaces of terrestrial type planets such as Mars, Earth and Titan. The interaction of wind and the planetary surface, specifically the transport of sand and dust is fundamental to understanding the evolution of the planets’ surface and atmosphere. Laboratory studies of the entrainment, flow, deposition and erosion are scarce and empirical in nature. The effects of low atmospheric pressure, composition, temperature can now be studied in detail.

This laboratory is part of an EU supported European collaboration called ROADMAP including groups from BIRA in Belgium, CSIC in Spain and UDE in Germany, to study dust aerosols on Mars [Home (aeronomie.be)]

Recently Martian Aeolian ripples have been recreated in experiments to investigate the behaviour of wind-driven sand transport under decreasing pressures, from the ambient (1 bar) towards Martian atmospheric conditions, and even to lower pressures than on Mars (2 mbar). In comparison to terrestrial conditions, sand transport at Martian pressures is significantly modified by viscous effects. However, centimeter-scale ripples nevertheless emerge (fig. 2), which match observations made by NASA’s rover Opportunity on the surface of Martian dunes.

 

Fig. 3 Ripples created at low pressure (P. Claudin, B. Andreotti, et al.).

 

• Conclusion

 

This planetary simulation facility has many unique and recently improved features which make it well suited for both planetary research applications and the development/testing of instrumentation. Details of some of the most recent and upcoming collaborative research activities will be summarized. For information on access to this facility please contact the author.

Acknowledgements

This laboratory is a member of Europlanet 2024 RI which has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 871149.

The laboratory is also a member of the ROADMAP  project which has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 101004052.

References

[1] C. Holstein-Rathlou, et al., American Meteorological Society, 31, 447 (2014)

[2] S. Alois et al., J. Aerosol Science 106, 1, (2017)

[3] Murdoch, N., et al., Planet and Space Sci, 165 (2019) 260-271

[4] White, R. D. et al. AIAA Scitech 2020. AIAA2020-0712

[5] G. Portyankina et al., Icarus 322, 210–220 (2019)

[6] E. del Bello, et al., Scientific Reports, 8, 14509 (2018)

[7] Andreotti and Claudin et al.. PNAS 5, 118 (2021)