Space Application and Low-gravity Research Symposium
Space-science and rheology have a lot to learn from each other. Rheology plays a crucial role in the planning and success of research conducted in low-gravity environments offers novel avenues for rheological experiments, some of which are simply not feasible on Earth. Conversely, rheology plays a crucial role in forthcoming space missions., from the behavior of granular flows on extraterrestrial planets, 3D printing of Lunar infrastructure, to astronauts’ physiology, fuel viscosity under different gravity, and 3D printing of Lunar infrastructure to astronauts’ well-being, rheological questions abound. Conversely, low-gravity environments offer novel avenues for rheological research, enabling experiments in parameter regimes relevant for building better models, but unattainable on Earth. A special symposium was organized by Olfa D’Angelo (ISAE-SUPAERO, University of Toulouse), Thomas Voigtmann (German Aerospace Center) and Norman Wagner (University of Delaware) to provide SoR members with information for opportunities in this growing area. This initiative was supported by the SoR Venture Fund.
The program started Monday morning with a plenary by Karen Daniels (North Carolina State University) and Doug Jerolmack (University of Pennsylvania), highlighting the critical role of granular rheology for both Earth and space science. This was followed by an invited session featuring a range of presenters discussing the impact of low gravity on rheological materials and systems, with each talk highlighting a unique aspect of space-based rheology research to a packed, overflowing room:
- Phillip Irace, Science Program Director for the International Space Station (ISS) National Lab, presented insights into microgravity rheology on the ISS, where gravity-induced forces are decoupled from other drivers. This allows for precise rheological measurements in complex fluids, particularly in systems like colloidal suspensions that tend to sediment under Earth’s gravity. He emphasized how microgravity enables studies on transport phenomena, including flame propagation, otherwise impossible in terrestrial labs.
- Katie Koube, Senior Materials Engineer at ICON 3D, discussed lunar regolith simulants and their role in additive manufacturing for lunar infrastructure. Her focus was on the kinematic viscosity of lunar regolith melts, which are essential for the in-situ resource utilization (ISRU) process. She highlighted the challenges of replicating the properties of actual lunar regolith on Earth and how understanding these differences is critical for future lunar construction.
- James Mantovani, Senior Physicist at NASA Swamp Works KSC, described his work on plume-surface interactions (PSI) during lunar landings. His work focused on gas permeability in lunar regolith and its effect on high-speed regolith ejecta, which poses a risk to surface and orbital assets. Mantovani presented data from permeability measurements of regolith simulants to improve PSI models for lander safety.
- Eric Furst, Professor at the University of Delaware and recipient of the NASA Exceptional Achievement Medal, presented experiments on paramagnetic colloidal suspensions in microgravity. He described how the absence of sedimentation on the ISS led to unexpected anisotropic domain structures in these suspensions, providing new insights into phase separation and the kinetic dynamics of colloidal gels under toggled magnetic fields.
- Thomas Voigtmann, Professor at the German Aerospace Center, stepping in for Laura Alvarez (University of Bordeaux), discussed the fluidity of biological membranes in microgravity. Using the sounding rocket program MAPHEUS, they found that giant unilamellar vesicles exhibited reduced fluidity in the absence of gravity, which could have implications for drug delivery systems during space missions.
- Mazi Jalaal, Assistant Professor at the University of Amsterdam, focused on plastocapillarity in microgravity, where droplets of yield-stress fluids can remain in the low Bond number regime -- regime of interest for technological applications like 3D printing. His work discussed theory, simulation and experiments conducted in space and how surface tension plays a dominant role in material behavior in low-gravity environments.
A Space Rheology Luncheon, with over 50 participants, immediately followed the symposium and gave a chance for lively discussions between speakers and audience members. After a welcome by SoR president Jonathan Rothstein, Professor Sachin Velankar (NSF Program Director for CBET) described funding opportunities for performing experiments on the ISS in conjunction with CASIS. This was followed by Philip Irace providing further technical information about conducting experiments on the ISS and the application process.
The final event of the Symposia was a poster competition during the Wednesday evening poster session, where two outstanding posters were identified: 1st place went to Sean Farrington for work on blood rheology, with application to astronauts’ health, and 2nd place went to Ted Egnaczyk for geopolymer rheology for Lunar construction.
The organizers were thrilled by the symposium’s success and the enthusiastic participation from the rheology community. Stay tuned for the next exciting developments!