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Krystal L. Acosta

Publications and source records attributed to Krystal L. Acosta.

6 records
All sourcesNASA NTRSDOE OSTI
NASA NTRSDate not supplied

Electrostatic Regolith Interaction Experiment (ERIE) Electrometer Initial Flight Results

The Electrostatic Regolith Interaction Experiment (ERIE) is a suborbital flight payload studying electrostatically charged dust particle dynamics under microgravity, jointly developed by University of Central Florida (UCF) and NASA Kennedy Space Center (KSC). ERIE combines components from two systems, the COLLisions Into Dust Experiment (COLLIDE) from UCF and the Wheel Electrostatic Spectrometer (WES) from NASA KSC, to advance understanding of charged grain behavior on low gravity bodies such as the Moon and asteroids. ERIE slides a door containing an electrometer system monitoring various insulating disks across the surface of a regolith simulant bed. The experiment is activated when the payload enters the microgravity potion of the flight. The grains in the simulant bed tribocharge via agitation during launch as well as through frictional interactions with the door and its protruding insulators. As the retention door retracts, particles are allowed to loft into an open volume, achieving motion due to electrostatic repulsion. The electrometer system measures the charge transfer between the granular material and the insulators. As the charged grains exit the bed, they travel through an applied electric field and a camera observes the kinematics of the individual grains whose trajectories are determined by their net charges. The design of the ERIE electrometer instrument and initial results from the first flight was presented at the 2021 AGU Fall Meeting under P55E-2002. Shortly after microgravity was achieved and the retaining door began to open, the rate of charge acquisition measured by the electrometer increased, indicating the insulators were accumulating triboelectric charge. Charged grains were observed in the video data to traverse across the external electric field and become deflected from a linear path due to their charges. Pairs of grains were also observed to orbit one another as expected from two oppositely charged bodies in proximity to one another. Improvements to the design of the instrument and preliminary results obtained from the second flight scheduled for Q3 2022 will be presented at this meeting.

Electrostatics↗
NASA NTRSDate not supplied

Evaluation of Coatings for the Electrodynamic Dust Shield Application on Thermal Radiators

Space dust acts as a blackbody, becoming hot if left in direct sunlight. This is a problem for thermal radiators used in space missions, where the main function is to radiate heat away from an object. If dust lands on the thermal radiator, the unit will less effectively reject heat, and it will overheat, leading to electrical or system failure. The current state-of-the-art in active dust mitigation is the Electrodynamic Dust Shield (EDS) which uses an electric field generated by alternating high positive and negative voltages (low current) to eject the charged dust off surfaces. An EDS made from copper coated Kapton is an ideal candidate to be bonded to a thermal radiator and coated with a low solar absorptance, high heat-emitter coating. This work compares the dust removal of copper-Kapton EDSs covered with different thermal radiator coatings in air and vacuum environments. The coatings include AZ-93 paint, Thermal Bright, and Solar White, a coating developed by the Applied Physics Lab (APL) at NASA Kennedy Space Center (KSC). The resistance and the thickness of the various coatings impact how well it works as an insulative layer for the EDS. Preliminary results indicate that Solar White may have better properties for dust removal and thermal rejection than the other coatings.

Krystal L. Acosta↗
NASA NTRSDate not supplied

Electrostatic Regolith Interaction Experiment (ERIE) Electrometer Initial Flight Results

The Electrostatic Regolith Interaction Experiment (ERIE) is a suborbital flight payload studying electrostatically charged dust particle dynamics under microgravity, jointly developed by University of Central Florida (UCF) and NASA Kennedy Space Center (KSC). ERIE combines components from two systems, the COLLisions Into Dust Experiment (COLLIDE) from UCF and the Wheel Electrostatic Spectrometer (WES) from NASA KSC, to advance understanding of charged grain behavior on low gravity bodies such as the Moon and asteroids. ERIE slides a door containing an electrometer system monitoring various insulating disks across the surface of a regolith simulant bed. The experiment is activated when the payload enters the microgravity potion of the flight. The grains in the simulant bed tribocharge via agitation during launch as well as through frictional interactions with the door and its protruding insulators. As the retention door retracts, particles are allowed to loft into an open volume, achieving motion due to electrostatic repulsion. The electrometer system measures the charge transfer between the granular material and the insulators. As the charged grains exit the bed, they travel through an applied electric field and a camera observes the kinematics of the individual grains whose trajectories are determined by their net charges. The design of the ERIE electrometer instrument and initial results from the first flight was presented at the 2021 AGU Fall Meeting under P55E-2002. Shortly after microgravity was achieved and the retaining door began to open, the rate of charge acquisition measured by the electrometer increased, indicating the insulators were accumulating triboelectric charge. Charged grains were observed in the video data to traverse across the external electric field and become deflected from a linear path due to their charges. Pairs of grains were also observed to orbit one another as expected from two oppositely charged bodies in proximity to one another. Improvements to the design of the instrument and preliminary results obtained from the second flight scheduled for Q3 2022 will be presented at this meeting.

Electrostatics↗
NASA NTRSDate not supplied

NASA’s Handheld Ionizer Tool for Astronauts

NASA’s next human lunar mission will require handheld tools to eliminate dust accumulation as well as electrostatic charge for the upcoming manned missions to the moon in the Artemis Program. The Moon’s lack of substantial atmosphere means the lunar surface is directly exposed to the solar wind, solar UV radiation, and cosmic rays which can cause dielectric charging of the lunar regolith via the photoelectric effect. The result is a layer of highly charged dust that is levitated and transported about a meter off the surface called the “horizon glow” as seen by the Apollo astronauts. The complex lunar electrostatic environment coupled with the surface dust behavior poses a concern for the longevity of surface infrastructures. The Electrostatics and Surface Physics Laboratory at NASA’S Kennedy Space Center retrofitted a commercial ionizer and successfully demonstrated that air ionizers are effective at removing dust particles and the static charge in high vacuum. Additional work is planned to establish the optimal voltage and flow characteristic to develop a high-fidelity ground prototype for future flight certification.

Electrostatics↗
NASA NTRSDate not supplied

Design of Electrostatic Dust Lofting Suborbital Flight Experiment Examining Photoionization under Lunar Gravity

Dust on the lunar surface electrostatically charges due to the plasma environment surrounding the Moon, causing grains to become lofted and adhere to nearby surfaces including landers and astronauts. Studying the behaviors of these charged particles in the lunar environment is essential to plan around the deleterious effects of dust to future Moon missions. Models attempt to predict the amount of dust loading that can be expected in many of these scenarios, but they require experimental validation to be predictive. This physics cannot be fully studied on Earth due to the six times larger gravitational force obscuring the electrostatic interactions, so it is necessary to run experiments in a more relevant environment, including vacuum and near-lunar gravitational effects. An experiment has been designed to fly on the Lunar Gravity Acceleration (LGA) mission aboard the Blue Origin New Shepard suborbital rocket. This experiment will perform photoionization charging of lunar regolith simulant grains under the illumination of an ultraviolet (UV) source. As a result, the charged grains will then electrostatically repel one another and loft in the reduced gravity environment; their trajectories will be imaged via a high-speed camera. Preliminary laboratory results influencing the design of this experiment will be presented, including characterization of several UV sources, measurements of photoionization currents under various vacuum conditions, and examination of lunar simulant dust lofting under terrestrial gravity. Results from this flight will be compared with ground-based testing and the laboratory results outlined above to examine the dependence on gravity and will be fed into the dust charging and lofting models currently under development.

electrostatics↗
NASA NTRSDate not supplied

Charge Deposition/Neutralization and Dust Removal via Plasma Interactions

Electrically charged and chemically reactive lunar dust can cause serious problems to spacecraft, surface equipment, and astronaut health, so understanding its interaction with and transport through the lunar plasma environment is important to dust mitigation efforts. We explore the charging of granular material in the natural environment of the Moon, recreate those conditions in the laboratory under high vacuum, and examine dust transport and charge neutralization for application in future lunar missions. Phenomena such as charge deposition via electron and ion beams, photoionization through ultraviolet light exposure, neutralization of charge through impingement by an ionized compressed gas, and tribocharging during dust liberation from surfaces will be presented. Surface materials of interest such as floating/grounded conductors and orthofabric for spacesuits are the preliminary focus of this effort. An electrometer is used to characterize currents interacting with the surfaces in the case of the electron/ion/UV source exposure, an electrostatic voltmeter is used to measure the potential on the surfaces without inadvertently discharging them, and a charge plate monitor is used to verify the efficiency of discharging the surfaces via ionized gas impingement. After setup of the initial charge conditions on the surfaces, a quick burst of high-pressure gas is used to overcome adhesion forces and initially dislodge the dust from the surfaces, followed by a low flow of gas that is ionized via application of a strong electric field. The gas is released in a high vacuum environment so as the pressure drops from the initial compressed state through to the vacuum state, the mean free path reaches a point where ionization can occur before all the gas disperses into the vacuum. This ionized gas can then neutralize both the dust and the surface to ensure minimal resettling. Several parameters such as gas composition, electrode geometry, high voltage waveform shape/polarity, and pulse timing have been explored and will be presented here.

electrostatics↗