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Carlos I Calle

Publications and source records attributed to Carlos I Calle.

6 records
All sourcesNASA NTRSDOE OSTI
NASA NTRSDate not supplied

Electrodynamic Dust Shield Testing on the Materials on International Space Station Experiment 11

Dust is a major concern for lunar exploration. To combat the effects of dust, NASA, academia, and industry are developing solutions to the dust problem. One potential technology solution for this problem is the Electrodynamic Dust Shield (EDS). Many years of research and development have gone into this technology. The Materials on International Space Station Experiment – 11 (MISSE-11) provides a long term space exposure platform for this technology to verify compatibility of materials and manufacturing processes to the space environment. The MISSE-11 EDS experiment consists of 12 EDS panels. These panels are made of glass, polyimide, or prototype spacesuit fabric. Some panels are covered with a lotus leaf coating while others are covered with thermal paint. They are flown in the wake position of the ISS to simulate the lunar environment. Two panels are in an active configuration and are energized with a high voltage power supply, which generates high-voltage pulses to activate the dust shields. Current and voltage data are recovered from each of these trials to compare to baseline data. Also, each of the EDS panels are imaged on a monthly basis to track any changes with time that may occur with the EDS variants. In this paper, we report preliminary data and analysis from this spaceflight experiment.

Electrostatics↗
NASA NTRSDate not supplied

Passive Dust Mitigation Technologies Being Developed for Demonstration Under Patch Plate Materials Compatibility Analysis Task

With the Artemis program, we are planning longer stays on the surface, with more activities that have the potential to put the astronauts and equipment in contact with greater quantities of lunar dust. The success of these missions will depend on our understanding of material interactions with lunar dust and the development of ways to mitigate dust effects in cases where exposure to dust will lead to failure of components, unacceptable loss of power or thermal control, unacceptable loss of visibility, or health issues. Passive dust mitigation by coating or surface alteration is one method that is being developed and demonstrated under the Space Technology Mission Directorate’s Game Changing Technology, Dust Mitigation Program as part of the Patch Plate Materials Compatibility Assessment Task. The goal of the task is to alter the surfaces of materials in order to passively reduce the adhesion of dust, demonstrate their performance in relevant ground-based tests using lunar simulants, and prepare them for demonstration through experiment on the lunar surface. Optically transparent, sputter deposited, work function matching coatings are being developed to reduce adhesion of dust to windows, lenses and display panels by matching the minimum energy to remove an electron from the surface to that of lunar dust in order to reduce adhesion due to charge transfer. Low surface energy coatings and surfaces for thermal control are also being developed to reduce the bonding of dust with the surface enabling it to be removed more easily. Conductive coatings with the ability to shed dust more easily are being developed for use with the active Electrodynamic Dust Shield technology to help reduce the power needed to remove dust from the surface. Passive dust mitigation surfaces for metals such as aluminum, stainless steel, and titanium are being developed that reduce the area of dust contact with the surfaces through topographical modification using laser ablation patterning to impart hierarchical topographies with nanometer to micrometer length scales in a single step. Topographically modified polymeric materials, both those with extensive space heritage and those with lower technology readiness levels, are also being evaluated. Space suit fabric surfaces that can reduce dust penetration into and through the fabric are also being investigated as well as pristine and topographically modified ceramic materials that exhibit high wear resilience. An overview of the passive dust mitigation surfaces and coatings being developed under this task, ground testing being conducted using lunar simulants, characterization techniques, and materials preparation for flight sample delivery for integration into the Alpha Space Regolith Adherence Characterization experiment going to the lunar surface on a Commercial Lunar Payload Services (CLPS) lander in 2023 will be discussed.

Lunar dust, passive mitigation, lunar simulant, co↗
NASA NTRSDate not supplied

Electrostatic Charging of the Lunar Surface

Lunar regolith dust particles accumulate charge and interact electrostatically with rover wheels, astronaut boots, and equipment. We have developed instrumentation for in situ measurements of the electrostatic charge developed by the interactions of lunar regolith dust with the space-rated materials on these devices. This instrument is also capable of measuring the distribution of electric fields on or near the lunar surface and the ion currents present near the lunar surface. We also report on our efforts to characterize the charging behavior of lunar dust in low gravity environments. This behavior is nonintuitive due to complex interactions between individual dust grains. We are developing an experiment to study this interaction in a microgravity vacuum environment. Better understanding of this interaction will allow for improved dust mitigation on the lunar surface.

electrostatics↗