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By NASA
4 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
The mystery of why life uses molecules with specific orientations has deepened with a NASA-funded discovery that RNA — a key molecule thought to have potentially held the instructions for life before DNA emerged — can favor making the building blocks of proteins in either the left-hand or the right-hand orientation. Resolving this mystery could provide clues to the origin of life. The findings appear in research recently published in Nature Communications.
Proteins are the workhorse molecules of life, used in everything from structures like hair to enzymes (catalysts that speed up or regulate chemical reactions). Just as the 26 letters of the alphabet are arranged in limitless combinations to make words, life uses 20 different amino acid building blocks in a huge variety of arrangements to make millions of different proteins. Some amino acid molecules can be built in two ways, such that mirror-image versions exist, like your hands, and life uses the left-handed variety of these amino acids. Although life based on right-handed amino acids would presumably work fine, the two mirror images are rarely mixed in biology, a characteristic of life called homochirality. It is a mystery to scientists why life chose the left-handed variety over the right-handed one.
A diagram of left-handed and right-handed versions of the amino acid isovaline, found in the Murchison meteorite.NASA DNA (deoxyribonucleic acid) is the molecule that holds the instructions for building and running a living organism. However, DNA is complex and specialized; it “subcontracts” the work of reading the instructions to RNA (ribonucleic acid) molecules and building proteins to ribosome molecules. DNA’s specialization and complexity lead scientists to think that something simpler should have preceded it billions of years ago during the early evolution of life. A leading candidate for this is RNA, which can both store genetic information and build proteins. The hypothesis that RNA may have preceded DNA is called the “RNA world” hypothesis.
If the RNA world proposition is correct, then perhaps something about RNA caused it to favor building left-handed proteins over right-handed ones. However, the new work did not support this idea, deepening the mystery of why life went with left-handed proteins.
The experiment tested RNA molecules that act like enzymes to build proteins, called ribozymes. “The experiment demonstrated that ribozymes can favor either left- or right-handed amino acids, indicating that RNA worlds, in general, would not necessarily have a strong bias for the form of amino acids we observe in biology now,” said Irene Chen, of the University of California, Los Angeles (UCLA) Samueli School of Engineering, corresponding author of the Nature Communications paper.
In the experiment, the researchers simulated what could have been early-Earth conditions of the RNA world. They incubated a solution containing ribozymes and amino acid precursors to see the relative percentages of the right-handed and left-handed amino acid, phenylalanine, that it would help produce. They tested 15 different ribozyme combinations and found that ribozymes can favor either left-handed or right-handed amino acids. This suggested that RNA did not initially have a predisposed chemical bias for one form of amino acids. This lack of preference challenges the notion that early life was predisposed to select left-handed-amino acids, which dominate in modern proteins.
“The findings suggest that life’s eventual homochirality might not be a result of chemical determinism but could have emerged through later evolutionary pressures,” said co-author Alberto Vázquez-Salazar, a UCLA postdoctoral scholar and member of Chen’s research group.
Earth’s prebiotic history lies beyond the oldest part of the fossil record, which has been erased by plate tectonics, the slow churning of Earth’s crust. During that time, the planet was likely bombarded by asteroids, which may have delivered some of life’s building blocks, such as amino acids. In parallel to chemical experiments, other origin-of-life researchers have been looking at molecular evidence from meteorites and asteroids.
“Understanding the chemical properties of life helps us know what to look for in our search for life across the solar system,” said co-author Jason Dworkin, senior scientist for astrobiology at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and director of Goddard’s Astrobiology Analytical Laboratory.
Dworkin is the project scientist on NASA’s OSIRIS-REx mission, which extracted samples from the asteroid Bennu and delivered them to Earth last year for further study.
“We are analyzing OSIRIS-REx samples for the chirality (handedness) of individual amino acids, and in the future, samples from Mars will also be tested in laboratories for evidence of life including ribozymes and proteins,” said Dworkin.
The research was supported by grants from NASA, the Simons Foundation Collaboration on the Origin of Life, and the National Science Foundation. Vázquez-Salazar acknowledges support through the NASA Postdoctoral Program, which is administered by Oak Ridge Associated Universities under contract with NASA.
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Last Updated Nov 21, 2024 EditorWilliam SteigerwaldContactNancy N. Jonesnancy.n.jones@nasa.govLocationGoddard Space Flight Center Related Terms
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By NASA
1 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
ESI24 Li Quadchart
Wei Li
University of Texas at Dallas
Internal defects are always formed in laser welding process due to the keyhole instability, molten pool collapse, and rapid solidification. The extreme lunar environment complicates the reliable implementation of welding, thereby enhancing the welding defects formation. The welding defects are critical material barriers preventing the metal components from Moon exploration. Professor Wei Li’s team will establish an integrated computational materials modelling framework to study the process-structure-property linkage of laser welding under the lunar conditions. The research is emphasized on modelling the internal defects (void, lack of fusion) formed in the lunar laser welding by fully considering the reduced gravity, large temperature change, and extreme vacuum on the Moon surface, and predicting the influence of internal defects on the material and mechanical properties of welding joint.
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By NASA
2 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
ESI24 Nam Quadchart
SungWoo Nam
University of California, Irvine
Lunar dust may seem unimposing, but it presents a significant challenge for space missions. Its abrasive and jagged particles can damage equipment, clog devices, and even pose health risks to astronauts. This project addresses such issues by developing advanced coatings composed of crumpled nano-balls made from atomically thin 2D materials such as MoS₂, graphene, and MXenes. By crumpling these nanosheets—much like crumpling a piece of paper—we create compression and aggregation resistant particles that can be dispersed in sprayable solutions. As a thin film coating, these crumpled nano-balls form corrugated structures that passively reduce dust adhesion and surface wear. The deformable crumpled nano-ball (DCN) coating works by minimizing the contact area between lunar dust and surfaces, thanks to its unique nano-engineered design. The 2D materials exhibit exceptional durability, withstanding extreme thermal and vacuum environments, as well as resisting radiation damage. Additionally, the flexoelectric and electrostatically dissipative properties of MoS₂, graphene, and MXenes allow the coating to neutralize and dissipate electrical charges, making them highly responsive to the charged lunar dust environment. The project will be executed in three phases, each designed to bring the technology closer to real-world space applications. First, we will synthesize the crumpled nano-balls and investigate their adhesion properties using advanced microscopy techniques. The second phase will focus on fundamental testing in simulated lunar environments, where the coating will be exposed to extreme temperatures, vacuum, radiation, and abrasion. Finally, the third phase will involve applying the coating to space-heritage materials and conducting comprehensive testing in a simulated lunar environment, targeting up to 90% dust clearance and verifying durability over repeated cycles of dust exposure. This research aligns with NASA’s goals for safer, more sustainable lunar missions by reducing maintenance requirements and extending equipment lifespan. Moreover, the potential applications extend beyond space exploration, with the technology offering promising advances in terrestrial industries such as aerospace and electronics by providing ultra-durable, wear-resistant surfaces. Ultimately, the project contributes to advancing materials science and paving the way for NASA’s long-term vision of sustainable space exploration.
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By NASA
1 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
ESI24 Zou Quadchart
Min Zou
University of Arkansas, Fayetteville
Lunar dust, with its highly abrasive and electrostatic properties, poses serious threats to the longevity and functionality of spacecraft, habitats, and equipment operating on the Moon. This project aims to develop advanced bioinspired surface textures that effectively repel lunar dust, targeting critical surfaces such as habitat exteriors, doors, and windows. By designing and fabricating innovative micro-/nano-hierarchical core-shell textures, we aim to significantly reduce dust adhesion, ultimately enhancing the performance and durability of lunar infrastructure. Using cutting-edge fabrication methods like two-photon lithography and atomic layer deposition, our team will create resilient, dust-repelling textures inspired by natural surfaces. We will also conduct in-situ testing with a scanning electron microscope to analyze individual particle adhesion and triboelectric effects, gaining critical insights into lunar dust behavior on engineered surfaces. These findings will guide the development of durable surfaces for long-lasting, low-maintenance lunar equipment, with broader applications for other dust-prone environments.
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By NASA
An artist’s concept of SpaceX’s Starship Human Landing System (HLS) on the Moon. NASA is working with SpaceX to develop the Starship HLS to carry astronauts from lunar orbit to the Moon’s surface and back for Artemis III and Artemis IV. Starship HLS is roughly 50 meters tall, or about the length of an Olympic swimming pool. SpaceX This artist’s concept depicts a SpaceX Starship tanker (bottom) transferring propellant to a Starship depot (top) in low Earth orbit. Before astronauts launch in Orion atop the agency’s SLS (Space Launch System) rocket, SpaceX will launch a storage depot to Earth orbit. For the Artemis III and Artemis IV missions, SpaceX plans to complete propellant loading operations in Earth orbit to send a fully fueled Starship Human Landing System (HLS) to the Moon. SpaceX An artist’s concept shows how a crewed Orion spacecraft will dock to SpaceX’s Starship Human Landing System (HLS) in lunar orbit for Artemis III. Starship HLS will dock directly to Orion so that two astronauts can transfer to the lander to descend to the Moon’s surface, while two others remain in Orion. Beginning with Artemis IV, NASA’s Gateway lunar space station will serve as the crew transfer point. SpaceX The artist’s concept shows two Artemis III astronauts preparing to step off the elevator at the bottom of SpaceX’s Starship HLS to the Moon’s surface. At about 164 feet (50 m), Starship HLS will be about the same height as a 15-story building. (SpaceX)The elevator will be used to transport crew and cargo between the lander and the surface. SpaceX NASA is working with U.S. industry to develop the human landing systems that will safely carry astronauts from lunar orbit to the surface of the Moon and back throughout the agency’s Artemis campaign.
For Artemis III, the first crewed return to the lunar surface in over 50 years, NASA is working with SpaceX to develop the company’s Starship Human Landing System (HLS). Newly updated artist’s conceptual renders show how Starship HLS will dock with NASA’s Orion spacecraft in lunar orbit, then two Artemis crew members will transfer from Orion to Starship and descend to the surface. There, astronauts will collect samples, perform science experiments, and observe the Moon’s environment before returning in Starship to Orion waiting in lunar orbit. Prior to the crewed Artemis III mission, SpaceX will perform an uncrewed landing demonstration mission on the Moon.
NASA is also working with SpaceX to further develop the company’s Starship lander to meet an extended set of requirements for Artemis IV. These requirements include landing more mass on the Moon and docking with the agency’s Gateway lunar space station for crew transfer.
The artist’s concept portrays SpaceX’s Starship HLS with two Raptor engines lit performing a braking burn prior to its Moon landing. The burn will occur after Starship HLS departs low lunar orbit to reduce the lander’s velocity prior to final descent to the lunar surface. SpaceX With Artemis, NASA will explore more of the Moon than ever before, learn how to live and work away from home, and prepare for future human exploration of Mars. NASA’s SLS (Space Launch System) rocket, exploration ground systems, and Orion spacecraft, along with the human landing system, next-generation spacesuits, Gateway lunar space station, and future rovers are NASA’s foundation for deep space exploration.
For more on HLS, visit:
https://www.nasa.gov/humans-in-space/human-landing-system
News Media Contact
Corinne Beckinger
Marshall Space Flight Center, Huntsville, Ala.
256.544.0034
corinne.m.beckinger@nasa.gov
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