For space missions to either the Moon or Mars, protecting mechanical moving parts from the abrasive effects of prevailing surface dust is crucial. This paper compares the abrasive effects of two lunar and two Martian simulant regoliths using special pin-on-disc tests on a stainless steel/polytetrafluoroethylene (PTFE) sealing material pair. Due to the regolith particles entering the contact zone, a three-body abrasion mechanism took place. We found that friction coefficients stabilised between 0.2 and 0.4 for all simulants. Wear curves, surface roughness measurements, and microscopic images all suggest a significantly lower abrasion effect of the Martian regoliths than that of the lunar ones. It applies not only to steel surfaces but also to the PTFE pins. The dominant abrasive micro-mechanism of the disc surface is micro-ploughing in the case of all tests, while the transformation of the counterface is mixed. The surface of pin material is plastically transformed through micro-ploughing, while the material is removed through micro-cutting due to the slide over hard soil particles.
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http://dx.doi.org/10.3390/ma17174240 | DOI Listing |
An Acad Bras Cienc
January 2025
Universidade de Brasília, Laboratório de Criptógamas, Departamento de Botânica, Campus Universitário Darcy Ribeiro, Bloco D, 1° Andar, 70910-900 Brasília, DF, Brazil.
The exploration of extraterrestrial environments has become a focal point of scientific inquiry, driven by advancements in technology and a growing interest in the potential for life beyond Earth. This study investigates the adaptability of Antarctic nematodes, known for thriving in extreme cold and isolation, to simulated Martian (MGS-1) and Lunar (LMS-1) soils. The experiment revealed differential responses in nematode survivability to the two simulants, with Lunar soil demonstrating better adaptability compared to Martian soil.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Division of Space, Ecological, Arctic, and Resource-limited (SPEAR) Medicine, Department of Emergency Medicine, Massachusetts General Hospital, Boston, MA 02114.
One of the most surprising and important findings of the first human landings on the Moon was the discovery of a very fine layer of lunar dust covering the entire surface of Moon along with the negative impacts of this dust on the well-being and operational effectiveness of the astronauts, their equipment, and instrumentation. The United States is now planning for human missions to Mars, a planet where dust can also be expected to be ubiquitous for many or most landing sites. For these missions, the design and operations of key hardware systems must take this dust into account, especially when related to crew health and safety.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Cosmochemistry and Isotope Signatures Group Nuclear and Chemical Sciences Division Lawrence Livermore National Laboratory, Livermore, CA 94550.
The radiogenic isotopic compositions of basaltic Martian meteorites (shergottites) and clinopyroxene/olivine cumulate meteorites (nakhlite/chassignites) are used to define the global evolution of Mars. However, the two main groups of meteorites demonstrate that their sources underwent divergent styles of magmatic evolution. The shergottites portray a planet that differentiated ~4.
View Article and Find Full Text PDFAn Acad Bras Cienc
December 2024
Universidade do Estado do Rio de Janeiro, Departamento de Biofísica e Biometria, Núcleo de Genética Molecular Ambiental e Astrobiologia, Rua São Francisco Xavier, 524, Pavilhão Reitor Haroldo Lisboa da Cunha, Subsolo, Maracanã, 20550-013 Rio de Janeiro, RJ, Brazil.
Extremophile organisms have been largely studied in Astrobiology. Among them, two antarctic plants emerge as good candidates to become colonizers of other celestial bodies, such as Mars and the Moon. The present research aimed to evaluate survival and growing capacity of Sanionia uncinata and Colobanthus quitensis on Martian (MGS-1) and Lunar (LMS-1) regolith simulants, under terrestrial conditions.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
December 2024
Center for Stable Isotopes, Northrup Hall, University of New Mexico, Albuquerque, NM 87131.
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