Engineering topics

Kerry J Johnson

Publications and source records attributed to Kerry J Johnson.

3 records

NASA NTRS2023

RF Metrology of Lunar Highlands Regolith Simulant NU-LHT-2M

Understanding the electrical properties of lunar regolith is vital to modeling radiofrequency(RF) propagation on the lunar surface a fundamental step in planning lunar surface missions. Near the lunar south pole, the regolith has yet to be directly sampled and thus there remains uncertainty in the electrical properties of the regolith. The regolith simulant NU-LHT-2M is a highlands simulant that is representative of the expected chemical composition of the regolith near the lunar south pole. Previous studies have investigated properties of NU-LHT at UHF and S-band[1]. Future missions to the lunar south pole are expected to utilize X and Ka-band for direct-to-Earth links and UHF, S-band, C-band, and Ka-band for lunar surface communication[2]. As a result, it is necessary to electrically characterize the lunar regolith at these frequencies. In this paper, coaxial impedance dielectric reflectometry is performed on the NU-LHT-2M simulant using a commercially available soil permittivity measurement device. This study serves as a preliminary measurement of the simulant and may lead to enhanced efficacy of the measurement hardware for future applications.

simulant↗

NASA NTRS2023

Lunar LTE Studies DRATS 2022 Report

In October 2022, the Lunar LTE Studies (LunarLiTES) team from the National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) conducted a series of communications field test measurements through the NASA Desert Research and Technology Studies (DRATS) campaign held near Flagstaff, Arizona. The objective of the NASA DRATS outings are to provide analog mission testing of candidate technologies for space exploration, especially those technologies applicable to human exploration of extraterrestrial rocky bodies. These activities are performed at locations with similarities to extraterrestrial conditions, such as the dry, volcanic landscape north of Flagstaff. This report describes the surface-to-surface communications testing performed by LunarLiTES as part of the 2022 NASA DRATS experiments. The objectives of this testing were to collect data for the development and refinement of radio frequency (RF) propagation models and emulation techniques, as well as to evaluate the application of terrestrial cellular communication technologies to lunar surface exploration.

lunar communication↗

NASA NTRSDate not supplied

RF Metrology of Lunar Highlands Regolith Simulant NU-LHT-2M

*Presentation for the publication* Understanding the electrical properties of lunar regolith is vital to modeling radiofrequency (RF) propagation on the lunar surface, a fundamental step in planning lunar surface missions. Near the lunar south pole, the regolith has yet to be directly sampled and thus there remains uncertainty in the electrical properties of the regolith. The regolith simulant NU-LHT-2M is a highlands simulant that is representative of the expected chemical composition of the regolith near the lunar south pole. Previous studies have investigated properties of NU-LHT at UHF and S-band[1]. Future missions to the lunar south pole are expected to utilize X and Ka-band for direct-to-Earth links and UHF, S-band, C-band, and Ka-band for lunar surface communication [2]. As a result, it is necessary to electrically characterize the lunar regolith at these frequencies. In this paper, coaxial impedance dielectric reflectometry is performed on the NU-LHT-2M simulant using a commercially available soil permittivity measurement device. This study serves as a preliminary measurement of the simulant and may lead to enhanced efficacy of the measurement hardware for future applications.

simulant↗