Granular Materials and the Risks They Pose for Success on the Moon and Mars

Working with soil, sand, powders, ores, cement and sintered bricks, excavating, grading construction sites, driving off-road, transporting granules in chutes and pipes, sifting gravel, separating solids from gases, and using hoppers are so routine that it seems straightforward to do it on the Moon and Mars as we do it on Earth. This paper brings to the fore how little these processes are understood and the millennia-long trial-and-error practices that lead to today's massive over-design, high failure rate, and extensive incremental scaling up of industrial processes because of the inadequate predictive tools for design. We present a number of pragmatic scenarios where granular materials play a role, the risks involved, and what understanding is needed to greatly reduce the risks

ISS Microgravity Experiments: Data Analysis

Please cite as: Sahoo, Shilpa, Michel Y. Louge, and Oliver Desjardines (2021). ISS Microgravity Experiments: Data Analysis [Dataset]. Cornell University eCommons Repository. https://doi.org/10.7298/kfej-df78.To study imbibition on Earth, time and distance must be shrunk to mitigate gravity-induced distortion. These small scales make it impossible to observe the inertial and pinning processes in detail. Therefore, the microgravity on the International Space Station (ISS) was exploited to study the imbibition of water into a network of hydrophilic cylindrical capillaries on time and length scales long enough to observe details hitherto inaccessible under Earth gravity. To investigate the role of contact pinning, a text matrix needed to be produced which consisted nine kinds of porous capillary plates made of gold-coated brass treated with Self-Assembled Monolayers (SAM) that fixed advancing and receding contact angles to known values. In the ISS, astronaut Luca Parmitano slowly extruded water spheres until they touched any of nine capillary plates. The 12mm diameter droplets were large enough for high-speed GX1050C video cameras on top and side to visualize details near individual capillaries, and long enough to observe dynamics of the entire imbibition process. The high-speed videos of spreading and imbibition on the capillary plates were obtained and analyzed. The data analysis is presented here. This contains .mp4translations of the original NASA-generated .avi videos in https://doi.org/10.7298/MKBW-KF79; spreadsheets and Matlab programs for data reduction and the PhD thesis of Shilpa Sahoo explaining the data and their analysis.National Science Foundation Grant CBET 1637531 and User Agreement UA‐2017‐228 from the Center for the Advancement of Science in Space under NASA Cooperative Agreement NNH11CD70A

ISS Microgravity Experiments: Raw Data from NASA

Please cite as: Sahoo, Shilpa, Louge, Michel Y. , & Desjardins, Oliver. (2021). ISS Microgravity Experiments: Raw Data from NASA [Dataset]. Cornell University eCommons Repository. https://doi.org/10.7298/MKBW-KF79To study imbibition on Earth, time and distance must be shrunk to mitigate gravity-induced distortion. These small scales make it impossible to observe the inertial and pinning processes in detail. Therefore, the microgravity on the International Space Station (ISS) was exploited to study the imbibition of water into a network of hydrophilic cylindrical capillaries on time and length scales long enough to observe details hitherto inaccessible under Earth gravity. To investigate the role of contact pinning, a text matrix was produced which consisted nine kinds of porous capillary plates made of gold-coated brass treated with Self-Assembled Monolayers (SAM) that fixed advancing and receding contact angles to known values. In the ISS, astronaut Luca Parmitano slowly extruded water spheres until they touched any of nine capillary plates. The 12mm diameter droplets were large enough for high-speed GX1050C video cameras on top and side to visualize details near individual capillaries, and long enough to observe dynamics of the entire imbibition process. The high-speed videos of spreading and imbibition on the capillary plates were obtained and are presented here.National Science Foundation Grant CBET 1637531 and User Agreement UA‐2017‐228 from the Center for the Advancement of Science in Space under NASA Cooperative Agreement NNH11CD70

ISS Microgravity Experiments: Preparation Work

To study imbibition on Earth, time and distance must be shrunk to mitigate gravity-induced distortion. These small scales make it impossible to observe the inertial and pinning processes in detail. Therefore, the microgravity on the International Space Station (ISS) was exploited to study the imbibition of water into a network of hydrophilic cylindrical capillaries on time and length scales long enough to observe details hitherto inaccessible under Earth gravity. To investigate the role of contact pinning, a text matrix needed to be produced which consisted nine kinds of porous capillary plates made of gold-coated brass treated with Self-Assembled Monolayers (SAM) that fixed advancing and receding contact angles to known values. On Earth, flat, 25% surface fraction and 50% surface fraction brass plates were designed and manufactured. The CAD files of these are presented here. Then they were electrolessly gold-deposited with the help of the group of Prof. Sadik Omowunmi at the University of Binghamton (now at the New Jersey Institute of Technology). The SEM images of these brass and gold-plated samples are also shown here. Then they were coated with SAMs, the MSDS of each chemical are presented here. Additionally, the contact angle measured by goniometry on these plates after SAM coating are exhibited here. Finally, the excerpts of the original NSF proposal for this project; crew procedures for set up, execution and stowage of the ISS experiment and PI science requirements forming the basis of the design by Zin-Technologies has also been presented here.This work was supported by: National Science Foundation Grant CBET 1637531 and User Agreement UA‐2017‐228 from the Center for the Advancement of Science in Space under NASA Cooperative Agreement NNH11CD70A

Microgravity spreading of water spheres on hydrophobic capillary plates

We create nearly perfect centimetric spheres of water by splitting a cavity consisting of two metal hemispheres coated with a hydrophobic paint and under-filled with liquid, while releasing the apparatus in free-fall. A high-speed camera captures how water spread on hydrophobic aluminum and polycarbonate plates perforated with cylindrical capillaries. We compare observations at the ZARM drop tower in Bremen with Lattice-Boltzmann numerical simulations of Frank, Perré and Li for the inertial phase of imbibition

Microgravity spreading of water spheres on hydrophobic capillary plates

We create nearly perfect centimetric spheres of water by splitting a cavity consisting of two metal hemispheres coated with a hydrophobic paint and under-filled with liquid, while releasing the apparatus in free-fall. A high-speed camera captures how water spread on hydrophobic aluminum and polycarbonate plates perforated with cylindrical capillaries. We compare observations at the ZARM drop tower in Bremen with Lattice-Boltzmann numerical simulations of Frank, Perré and Li for the inertial phase of imbibition