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By NASA
5 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
It’s a new year on Mars, and while New Year’s means winter in Earth’s northern hemisphere, it’s the start of spring in the same region of the Red Planet. And that means ice is thawing, leading to all sorts of interesting things. JPL research scientist Serina Diniega explains. NASA/JPL-Caltech Instead of a winter wonderland, the Red Planet’s northern hemisphere goes through an active — even explosive — spring thaw.
While New Year’s Eve is around the corner here on Earth, Mars scientists are ahead of the game: The Red Planet completed a trip around the Sun on Nov. 12, 2024, prompting a few researchers to raise a toast.
But the Martian year, which is 687 Earth days, ends in a very different way in the planet’s northern hemisphere than it does in Earth’s northern hemisphere: While winter’s kicking in here, spring is starting there. That means temperatures are rising and ice is thinning, leading to frost avalanches crashing down cliffsides, carbon dioxide gas exploding from the ground, and powerful winds helping reshape the north pole.
“Springtime on Earth has lots of trickling as water ice gradually melts. But on Mars, everything happens with a bang,” said Serina Diniega, who studies planetary surfaces at NASA’s Jet Propulsion Laboratory in Southern California.
Mars’ wispy atmosphere doesn’t allow liquids to pool on the surface, like on Earth. Instead of melting, ice sublimates, turning directly into a gas. The sudden transition in spring means a lot of violent changes as both water ice and carbon dioxide ice — dry ice, which is much more plentiful on Mars than frozen water — weaken and break.
“You get lots of cracks and explosions instead of melting,” Diniega said. “I imagine it gets really noisy.”
Using the cameras and other sensors aboard NASA’s Mars Reconnaissance Orbiter (MRO), which launched in 2005, scientists study all this activity to improve their understanding of the forces shaping the dynamic Martian surface. Here’s some of what they track.
Frost Avalanches
In 2015, MRO’s High-Resolution Imaging Science Experiment (HiRISE) camera captured a 66-foot-wide (20-meter-wide) chunk of carbon dioxide frost in freefall. Chance observations like this are reminders of just how different Mars is from Earth, Diniega said, especially in springtime, when these surface changes are most noticeable.
Martian spring involves lots of cracking ice, which led to this 66-foot-wide (20-meter-wide) chunk of carbon dioxide frost captured in freefall by the HiRISE camera aboard NASA’s Mars Reconnaissance Orbiter in 2015NASA/JPL-Caltech/University of Arizona “We’re lucky we’ve had a spacecraft like MRO observing Mars for as long as it has,” Diniega said. “Watching for almost 20 years has let us catch dramatic moments like these avalanches.”
Gas Geysers
Diniega has relied on HiRISE to study another quirk of Martian springtime: gas geysers that blast out of the surface, throwing out dark fans of sand and dust. These explosive jets form due to energetic sublimation of carbon dioxide ice. As sunlight shines through the ice, its bottom layers turn to gas, building pressure until it bursts into the air, creating those dark fans of material.
As light shines through carbon dioxide ice on Mars, it heats up its bottom layers, which, rather than melting into a liquid, turn into gas. The buildup gas eventually results in explosive geysers that toss dark fans of debris on to the surface.light shines through carbon dioxide ice on Mars But to see the best examples of the newest fans, researchers will have to wait until December 2025, when spring starts in the southern hemisphere. There, the fans are bigger and more clearly defined.
Spiders
Another difference between ice-related action in the two hemispheres: Once all the ice around some northern geysers has sublimated in summer, what’s left behind in the dirt are scour marks that, from space, look like giant spider legs. Researchers recently re-created this process in a JPL lab.
Sometimes, after carbon dioxide geysers have erupted from ice-covered areas on Mars, they leave scour marks on the surface. When the ice is all gone by summer, these long scour marks look like the legs of giant spiders.NASA/JPL-Caltech/University of Arizona Powerful Winds
For Isaac Smith of Toronto’s York University, one of the most fascinating subjects in springtime is the Texas-size ice cap at Mars’ north pole. Etched into the icy dome are swirling troughs, revealing traces of the red surface below. The effect is like a swirl of milk in a café latte.
“These things are enormous,” Smith said, noting that some are a long as California. “You can find similar troughs in Antarctica but nothing at this scale.”
As temperatures rise, powerful winds kick up that carve deep troughs into the ice cap of Mars’ north pole. Some of these troughs are as long as California, and give the Martian north pole its trademark swirls. This image was captured by NASA’s now-inactive Mars Global Surveyor.NASA/JPL-Caltech/MSSS Fast, warm wind has carved the spiral shapes over eons, and the troughs act as channels for springtime wind gusts that become more powerful as ice at the north pole starts to thaw. Just like the Santa Ana winds in Southern California or the Chinook winds in the Rocky Mountains, these gusts pick up speed and temperature as they ride down the troughs — what’s called an adiabatic process.
Wandering Dunes
The winds that carve the north pole’s troughs also reshape Mars’ sand dunes, causing sand to pile up on one side while removing sand from the other side. Over time, the process causes dunes to migrate, just as it does with dunes on Earth.
This past September, Smith coauthored a paper detailing how carbon dioxide frost settles on top of polar sand dunes during winter, freezing them in place. When the frost all thaws away in the spring, the dunes begin migrating again.
Surrounded by frost, these Martian dunes in Mars’ northern hemisphere were captured from above by NASA’s Mars Reconnaissance Orbiter using its HiRISE camera on Sept. 8, 2022. NASA/JPL-Caltech/University of Arizona Each northern spring is a little different, with variations leading to ice sublimating faster or slower, controlling the pace of all these phenomena on the surface. And these strange phenomena are just part of the seasonal changes on Mars: the southern hemisphere has its own unique activity.
More About MRO
The University of Arizona, in Tucson, operates HiRISE, which was built by Ball Aerospace & Technologies Corp., in Boulder, Colorado. NASA’s Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, manages the Mars Reconnaissance Orbiter Project for NASA’s Science Mission Directorate, Washington.
For more information, visit:
https://science.nasa.gov/mission/mars-reconnaissance-orbiter
News Media Contacts
Andrew Good
Jet Propulsion Laboratory, Pasadena, Calif.
818-393-2433
andrew.c.good@jpl.nasa.gov
Karen Fox / Molly Wasser
NASA Headquarters, Washington
202-358-1600
karen.c.fox@nasa.gov / molly.l.wasser@nasa.gov
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Last Updated Dec 20, 2024 Related Terms
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By NASA
A rendering of Firefly’s Blue Ghost lunar lander and a rover developed for the company’s third mission to the Moon as part of NASA’s CLPS (Commercial Lunar Payload Services) initiative.Credit: Firefly Aerospace NASA continues to advance its campaign to explore more of the Moon than ever before, awarding Firefly Aerospace $179 million to deliver six experiments to the lunar surface. This fourth task order for Firefly will target landing in the Gruithuisen Domes on the near side of the Moon in 2028.
As part of the agency’s broader Artemis campaign, Firefly will deliver a group of science experiments and technology demonstrations under NASA’s CLPS initiative, or Commercial Lunar Payload Services, to these lunar domes, an area of ancient lava flows, to better understand planetary processes and evolution. Through CLPS, NASA is furthering our understanding of the Moon’s environment and helping prepare for future human missions to the lunar surface, as part of the agency’s Moon to Mars exploration approach.
“The CLPS initiative carries out U.S. scientific and technical studies on the surface of the Moon by robot explorers. As NASA prepares for future human exploration of the Moon, the CLPS initiative continues to support a growing lunar economy with American companies,” said Joel Kearns, deputy associate administrator for exploration, Science Mission Directorate, NASA Headquarters in Washington. “Understanding the formation of the Gruithuisen Domes, as well as the ancient lava flows surrounding the landing site, will help the U.S. answer important questions about the lunar surface.”
Firefly’s first lunar delivery is scheduled to launch no earlier than mid-January 2025 and will land near a volcanic feature called Mons Latreille within Mare Crisium, on the northeast quadrant of the Moon’s near side. Firefly’s second lunar mission includes two task orders: a lunar orbit drop-off of a satellite combined with a delivery to the lunar surface on the far side and a delivery of a lunar orbital calibration source, scheduled in 2026.
This new delivery in 2028 will send payloads to the Gruithuisen Domes and the nearby Sinus Viscositatus. The Gruithuisen Domes have long been suspected to be formed by a magma rich in silica, similar in composition to granite. Granitic rocks form easily on Earth due to plate tectonics and oceans of water. The Moon lacks these key ingredients, so lunar scientists have been left to wonder how these domes formed and evolved over time. For the first time, as part of this task order, NASA also has contracted to provide “mobility,” or roving, for some of the scientific instruments on the lunar surface after landing. This will enable new types of U.S. scientific investigations from CLPS.
“Firefly will deliver six instruments to understand the landing site and surrounding vicinity,” said Chris Culbert, manager of the CLPS initiative at NASA’s Johnson Space Center in Houston. “These instruments will study geologic processes and lunar regolith, test solar cells, and characterize the neutron radiation environment, supplying invaluable information as NASA works to establish a long-term presence on the Moon.”
The instruments, collectively expected to be about 215 pounds (97 kilograms) in mass, include:
Lunar Vulkan Imaging and Spectroscopy Explorer, which consists of two stationary and three mobile instruments, will study rocks and regoliths on the summit of one of the domes to determine their origin and better understand geologic processes of early planetary bodies. The principal investigator is Dr. Kerri Donaldson Hanna of the University of Central Florida, Orlando. Heimdall is a flexible camera system that will be used to take pictures of the landing site from above the horizon to the ground directly below the lander. The principal investigator is Dr. R. Aileen Yingst of the Planetary Science Institute, Tucson, Arizona. Sample Acquisition, Morphology Filtering, and Probing of Lunar Regolith is a robotic arm that will collect samples of lunar regolith and use a robotic scoop to filter and isolate particles of different sizes. The sampling technology will use a flight spare from the Mars Exploration Rover project. The principal investigator is Sean Dougherty of Maxar Technologies, Westminster, Colorado. Low-frequency Radio Observations from the Near Side Lunar Surface is designed to observe the Moon’s surface environment in radio frequencies, to determine whether natural and human-generated activity near the surface interferes with science. The project is headed up by Natchimuthuk Gopalswamy of NASA’s Goddard Space Flight Center in Greenbelt, Maryland. Photovoltaic Investigation on the Lunar Surface will carry a set of the latest solar cells for a technology demonstration of light-to-electricity power conversion for future missions. The experiment will also collect data on the electrical charging environment of the lunar surface using a small array of solar cells. The principal investigator is Jeremiah McNatt from NASA’s Glenn Research Center in Cleveland. Neutron Measurements at the Lunar Surface is a neutron spectrometer that will characterize the surface neutron radiation environment, monitor hydrogen, and provide constraints on elemental composition. The principal investigator is Dr. Heidi Haviland of NASA’s Marshall Spaceflight Center in Huntsville, Alabama. Through the CLPS initiative, NASA purchases lunar landing and surface operations services from American companies. The agency uses CLPS to send scientific instruments and technology demonstrations to advance capabilities for science, exploration, or commercial development of the Moon. By supporting a robust cadence of lunar deliveries, NASA will continue to enable a growing lunar economy while leveraging the entrepreneurial innovation of the commercial space industry. Two upcoming CLPS flights scheduled to launch in early 2025 will deliver NASA payloads to the Moon’s near side and south polar region, respectively.
Learn more about CLPS and Artemis at:
https://www.nasa.gov/clps
-end-
Alise Fisher
Headquarters, Washington
202-358-2546
alise.m.fisher@nasa.gov
Natalia Riusech / Nilufar Ramji
Johnson Space Center, Houston
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natalia.s.riusech@nasa.gov / nilufar.ramji@nasa.gov
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Last Updated Dec 18, 2024 LocationNASA Headquarters Related Terms
Commercial Lunar Payload Services (CLPS) Artemis View the full article
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By Space Force
During the keynote remarks, Gen. Stephen Whiting emphasized the joint functions and the importance of operating across the joint team using a common playbook to enable joint force commanders to synchronize, integrate, and execute joint operations.
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By European Space Agency
Image: These summer images from the Copernicus Sentinel-2 and Sentinel-1 missions showcase different satellite views of Greenland’s west coast. View the full article
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By NASA
This article is from the 2024 Technical Update.
The NESC evaluated material compatibility of some common aerospace metals in monomethylhydrazine (MMH) and nitrogen tetroxide (MON-3). Previous work had identified a lack of quantitative compatibility data for nickel alloy 718, 300 series stainless steel, and titanium Ti-6Al-4V in MMH and MON-3 to support the use of zero-failure-tolerant, thin-walled pressure barriers in these propellants. Static (i.e., not flowing) general corrosion and electrochemistry testing was conducted, evaluating varied processing forms and heat treatment of the metals, water content of propellant, and exposure duration. Corrosion-rate data for all tested product forms, fluids, and durations were on the order of 1 x 10–6 inch per year rather than the previously documented “less than 1 x 10–3 inch per year”. The majority of the corrosion products were seen in the first 20 days of exposure, with an overall corrosion rate decreasing with time due to the increased divisor (time). It is therefore recommended that corrosion testing be performed at multiple short-term durations to inform the need for longer-duration testing.
Background
Nickel alloy 718, 300 series stainless steel, and Ti-6Al-4V are commonly used in storable propulsion systems (i.e., MMH/MON-3), but a concern was raised regarding what quantitative compatibility data were available for proposed zero-failure-tolerant, thin-walled (~0.005 to 0.010 inch thickness) pressure barrier designs. A literature search found that limited and conflicting data were available for commonly used aerospace metals in MMH and MON-3. For example, corrosion behavior was listed qualitatively (e.g., “A” rating), data on materials and fluids tested were imprecise, fluids were identified as contaminated without describing how they were contaminated, no compatibility data were found on relevant geometry specimens (i.e., very thin-walled or convoluted), and limited data were available to quantify differences between tested materials and flight components. When corrosion data were quantified, documented sensitivity was “1 x 10–3 inch per year or less”, which is insufficient for assessing long-duration, thin-walled, flight-weight applications.
Discussion
General corrosion testing was performed with a static/non-flowing configuration based on NASA-STD-6001, Test 15 [1]. Design of experiments methods were used to develop a test matrix varying material, propellant, propellant water content, and tested duration. Materials tested were nickel alloy 718 (solution annealed sheet, aged sheet, aged/welded sheet, and hydroformed bellows), 300 series stainless steel (low carbon sheet, titanium stabilized sheet, and hydroformed bellows), and Ti 6Al-4V sheet. Samples were tested in sealed test tubes in MMH and MON-3 with water content ranging from as-received (“dry”) up to specification allowable limits [2,3]. Tested durations ranged from 20 to 365 days. Measurements included inductively coupled plasma mass spectrometry (ICPMS) to identify corrosion products and their concentrations in test fluid, gravimetric (i.e., scale) measurements pre- and post-exposure, and visual inspection. Bimetallic pairs (titanium stabilized 300 series stainless steel: Ti 6Al-4V and nickel alloy 718: Ti 6Al-4V) were tested for up to 65 days in both MMH and MON-3. The test setup incorporated important features of the test standard (e.g., electrode spacing and finish) and adapted the configuration for MMH/MON-3 operation. Measurements included potential difference and current flow between samples. Figure 1 shows images of the general corrosion and bimetallic pair test setups.
Test Results
For all tested materials and product forms, corrosion rates were on the order of 1 x 10–6 inch per year in MMH or MON-3, three orders of magnitude lower than historically reported. Corrosion products were generated in the first 20 days of exposure, and corrosion rate decreased with time due to the increase in divisor (i.e., time). Corrosion products increased as the water content of the propellants increased but remained in the same order of magnitude between the as-received dry propellant and propellant containing the maximum water content allowed by specification. Figure 2 illustrates test results for corrosion rate, mass loss with duration, and mass loss with water content. It is important to note that water has been demonstrated to contribute to flow decay even when water is within the specification allowable limit, and previous NASA-STD-6001 Test 15 data have demonstrated susceptibility of some nickel alloys to crevice-type corrosion attack [4]. Therefore, these results do not reduce the importance of considering the system impact of water content and evaluating for crevice corrosion behavior. Finally, in the bimetallic pair testing, tested materials did not measurably corrode in MON-3 and MMH within specification-allowable water content, as evidenced by no visual indications of corrosion and very low electrical interaction (i.e., corrosion rates derived to be less than 1 microinch per year from electrical interaction).
Recommendations
It is recommended that corrosion testing be performed at multiple shortterm durations to inform the need for longer-duration testing.
References
NASA-STD-6001 Flammability, Odor, Offgassing, and Compatibility Requirements
and Test Procedures for Materials In Environments that Support Combustion MIL-PRF-27404 Performance Specification: Propellant, Monomethylhydrazine MIL-PRF-26539 Performance Specification: Propellants, Dinitrogen Tetroxide WSTF Test 15 Report 12-45708 and WSTF Test 15 Report 13-46207 View the full article
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