Background

Human exploration of Mars will expose crews to a persistent, fine particulate environment whose physicochemical properties and health implications remain only partly understood. Because no samples of authentic Martian airborne dust have been returned to Earth, NASA must rely on lunar dust toxicology, Martian regolith simulants, and extensive rover/lander geochemical and mineralogical datasets to develop an initial, risk‑informed Permissible Exposure Limit (PEL). The Johnson Space Center (JSC) Lunar and Martian Dust Risk Custodian, the JSC Toxicology group, and the OCHMO Standards team worked together to draft a preliminary standard for incorporation into NASA-STD-3001 NASA Spaceflight Human-System Standard, Volume 2: Human Factors, Habitability, and Environmental Health.

The Martian Dust Limit Working Group was assembled to review this draft standard and associated evidence. Across two working sessions in February 2026, panel members reviewed mission architecture drivers, the current scientific understanding of Martian dust composition, and the toxicological evidence base supporting the establishment of a Mars dust PEL. Discussions emphasized the critical interplay between dust standards and Mars mission design elements including Extravehicular Activity (EVA) cadence, dust ingress characteristics, and the performance of habitat environmental control systems; these features highlight the need for a limit that is conservative, verifiable, and adaptable as the Mars architecture evolves. Panel members for the Working Group were David Damby, Claire Horwell, Brian Hynek, Shaunna Morrison, and Joyce Tsuji; NASA presenters were Katie Borremans, Elizabeth Rampe, and Torin McCoy; the OCHMO organizers/moderators were Douglas Ebert, David Francisco, and Kim Lowe. The Working Group meetings were also attended by members of Space Medicine and Operations group and JSC Toxicology.

The Martian Dust Limit Working Group Primary Goals

Evaluate NASA’s proposed derivation of this initial standard

The panel concluded that NASA’s approach to deriving a 30‑day continuous PEL of 0.1 mg/m³ is reasonable and appropriately conservative for early short‑stay missions. This value originates from the established lunar 30‑day PEL (0.4 mg/m³), reduced by a 3x database uncertainty factor to account for knowledge gaps in Martian dust toxicity, higher iron content, amorphous constituents, and differences between simulants and actual dust. Members supported this framework, noting that a continuous limit applied using measured time‑weighted averages is more practical than making assumptions tied to fixed dust clearance rates given the diversity of spacecraft designs. They also acknowledged that near‑term exposures will be peak‑driven (e.g., post‑EVA suit ingress) and therefore recommended that the standard explicitly address the need to manage short‑duration spikes.

Identify chemical constituents requiring further scrutiny

The panel affirmed that overall dust mass remains the primary near‑term engineering concern, but several chemical constituents warrant attention. Chromium 6⁺, manganese, and perchlorate were all considered low‑risk in the context of inhaled Martian dust, provided the overall dust PEL is applied (see below). However, perchlorate was recommended for broader agency‑level exposure management across multiple intake routes (e.g., ingestion due to in situ crop growth). Iron was discussed in detail due to its high abundance in Martian regolith and its potential to generate Reactive Oxygen Species (ROS), though current toxicology shows no clear link between iron‑driven ROS and pulmonary harm; still, knowledge gaps led the panel to prioritize iron for further study and potential Spacecraft Maximum Allowable Concentration (SMAC) development. Arsenic was judged unlikely to pose meaningful risk at present.

Weigh the merits of an overall dust limit versus separate SMACs

Chemical constituents embedded within Martian dust were evaluated with respect to whether independent SMACs are warranted. Based on rover observations indicating predominantly trivalent chromium, low airborne perchlorate, and manganese concentrations well below conservative SMAC thresholds at the proposed PEL, the group agreed that the overall dust limit is likely sufficiently protective for expected 30‑day missions. However, panel members advised that SMACs be maintained for select constituents such as perchlorate and manganese for mission‑planning crosschecks. From the requirement perspective, an overall Martian dust PEL approach was favored for practicality and clarity, with constituent-specific SMACs retained or developed only where they add tangible operational value.

Refine the standard’s technical language for operational use

The working group also refined the standard language to ensure clarity and consistency in implementation. Members recommended that the limit apply to a specified time‑weighted average measurement period but also making it explicit that the requirement is for protection during continuous exposure. They encouraged incorporation of peak‑exposure management within the rationale, and highlighted uncertainties related to iron content, nanophase iron, and oxidative potential so that future revisions can incorporate emerging scientific insight.

Martian Dust Contamination Limits

The new requirement established for NASA-STD-3001 is as follows:

[V2 6253] The system shall limit the concentrations of Martian dust particles less than 10 μm in size in the habitable atmosphere below a 24-hour time-weighted average of 0.1 mg/m3 during exposure scenarios lasting up to 30 days in duration.

Conclusions

Taken together, the working group’s deliberations reinforce that an initial Martian dust standard must balance conservatism with operational feasibility while accommodating architectural and scientific uncertainty. The proposed requirement provides a defensible, evidence‑informed foundation for design, verification, and risk communication. As additional Martian data and toxicological research become available, this standard should be periodically revisited to ensure continued protection of crew health during human exploration of Mars.

For more information on the results of the working group, see link to the special publication below:

NASA and its partners will discuss the upcoming crew rotation mission to the International Space Station during a pair of news conferences on Monday, Aug. 3, from the agency’s Johnson Space Center in Houston.

Mission leadership will provide an overview of NASA’s SpaceX Crew‑13 mission at 12 p.m. EDT. Next, crew members will discuss their training and mission preparations at 2 p.m. This is Crew-13’s final media availability prior to traveling to the agency’s Kennedy Space Center in Florida for launch.

NASA will stream these events live. Learn where to watch online:

https://www.nasa.gov/live

The Crew-13 mission will carry NASA astronauts Jessica Watkins and Luke Delaney, CSA (Canadian Space Agency) astronaut Joshua Kutryk, and Roscosmos cosmonaut Sergey Teteryatnikov to the orbiting laboratory. The crew will launch aboard a SpaceX Dragon spacecraft on the company’s Falcon 9 rocket from Space Launch Complex 40 at Cape Canaveral Space Force Station in Florida no earlier than mid-September.

International media attending in person must email the NASA Johnson newsroom at jsccommu@mail.nasa.gov by 5 p.m., Tuesday, July 21. United States-based media attending in person must respond by 5 p.m., Thursday, July 30. Media joining virtually must respond by 10 a.m. the day of the event. NASA’s media accreditation policy is available online.

Briefing participants are as follows (all times Eastern and subject to change based on real-time operations):

12 p.m.: Mission Overview News Conference

• Joel Montalbano, deputy associate administrator, Human Spaceflight Mission Directorate, NASA Headquarters
• Dana Weigel, manager, Low Earth Orbit Program, NASA Johnson
• Mathieu Caron, director, Astronauts, Life Sciences, and Space Medicine, CSA
• Julianna Scheiman, director, NASA Science and Dragon Programs, SpaceX

2 p.m.: Crew-13 News Conference

• Jessica Watkins, commander, NASA
• Luke Delaney, pilot, NASA
• Joshua Kutryk, mission specialist, CSA
• Sergey Teteryatnikov, mission specialist, Roscosmos

Following the news conference, crew members will be available for limited media interviews. All interview requests must be submitted by 5 p.m. on July 30, to the NASA Johnson newsroom at: jsccommu@mail.nasa.gov.

This will be the second flight to the space station for Watkins, who was selected as a NASA astronaut in 2017. Watkins grew up in Lafayette, Colorado, and earned an undergraduate degree in geological and environmental sciences from Stanford University, as well as a doctorate in geology from the University of California, Los Angeles. As a geologist, she studied the Martian surface and was a member of the Curiosity rover science team at NASA’s Jet Propulsion Laboratory in Southern California. Watkins first launched to the space station as a crew member aboard NASA’s SpaceX Crew-4 mission, spending a total of 170 days in space across space station Expeditions 67/68 in 2022. She will be the first NASA astronaut to launch aboard a SpaceX Dragon spacecraft twice.

Selected as a NASA astronaut in 2021, Delaney earned a bachelor’s degree in mechanical engineering at the University of North Florida and a master’s degree in aerospace engineering at the Naval Postgraduate School. The Florida native is a distinguished naval aviator who participated in exercises throughout the Asia Pacific region and conducted missions in support of Operation Enduring Freedom. As a test pilot, Delaney evaluated developmental aircraft systems and served as a test pilot instructor. He also worked as a research pilot at NASA’s Langley Research Center in Hampton, Virginia, where he supported airborne science missions. This is the first spaceflight for Delaney.

The Crew-13 mission also is the first spaceflight for Kutryk. Prior to his selection as a CSA astronaut in 2017, he served as a CF-18 fighter pilot, flying missions in support of Canada’s NATO, U.N., and North American Aerospace Defense Command commitments. A native of Fort Saskatchewan, Alberta, Kutryk also worked as an experimental and operational test pilot at the Aerospace Engineering Test Establishment in Cold Lake, Alberta. Kutryk received a bachelor’s degree in mechanical engineering from the Royal Military College of Canada in Kingston, Ontario, and he is a distinguished graduate of the United States Air Force Test Pilot school in Edwards, California. He has master’s degrees in space studies, flight test engineering, and defense studies.

This mission will be Teteryatnikov’s first trip to the orbiting laboratory. He graduated from the Naval Academy, St. Petersburg, Russia, in 2011 as an engineer specializing in ship power plant operations. Before his selection as a test cosmonaut, Teteryatnikov served in various naval engineering roles, including undersea vessels and specialized engine room operations. He was selected for the Gagarin Research and Test Cosmonaut Training Center Cosmonaut Corps in 2021 and has served as a test cosmonaut since 2023.

For more information about the mission, visit:

https://www.nasa.gov/mission/nasas-spacex-crew-13

-end-

Joshua Finch / Jimi Russell
Headquarters, Washington
202-358-1100
joshua.a.finch@nasa.gov / james.j.russell@nasa.gov

Leah Cheshier / Anna Schneider
Johnson Space Center, Houston
281-483-5111
leah.d.cheshier@nasa.gov / anna.c.schneider@nasa.gov

A meteorite recovered immediately upon its fall to Earth on July 16, 2024, is helping NASA scientists uncover new clues about ancient water, the chemical evolution of primitive asteroids, and the ingredients that may have helped make life possible throughout the early solar system.

This rapid recovery began when an amateur astronomer in New Jersey quickly recognized that a newly fallen meteorite had landed on his property. Recognizing its scientific value and wearing protective gloves, he collected the fragments and stored them in aluminum foil and glass containers, which preserved delicate minerals and organic compounds that are often altered by moisture, weather, and contamination.

As the meteorite fell to Earth, cameras across New Jersey captured its fiery passage through the atmosphere. Scientists used these observations to reconstruct the fireball’s trajectory and, after recovering the meteorite, combined this data with laboratory analyses to determine where in the solar system the rock most likely originated. In a study published Wednesday in the journal Science Advances, researchers found evidence that ancient salty water altered minerals within the meteorite’s parent asteroid, preserving unique minerals and a rich inventory of organic compounds.

“When we have both a documented fireball and a quick recovery of its meteorite, we can learn not only what the rock is made of, but where it came from in the asteroid belt,” said Peter Jenniskens, meteor astronomer at both NASA’s Ames Research Center in California’s Silicon Valley and the SETI Institute, and lead author of the study.

Named for the township where it was recovered, the Hillsborough meteorite belongs to a class of carbon-rich meteorites known as CM carbonaceous chondrites. These primitive rocks preserve some of the oldest materials in the solar system, recording the chemical processes that shaped asteroids more than 4.5 billion years ago.

While examining the unusually pristine meteorite, researchers found a mosaic of tiny broken-up rocks and noticed that some contained unusually high concentrations of sodium — an unexpected finding for this type of meteorite. The surprising signal prompted a closer investigation using powerful electron microscopes that allowed scientists to examine the meteorite from the millimeter scale down to individual atoms. By combining observations across multiple scales, researchers reconstructed the history of the minerals and the fluids that once flowed through them.

These analyses revealed microscopic fractures filled with sodium-rich material left behind by ancient brines. Unlike pure water, brines contain dissolved salts that allow them to transport elements and chemically alter the rocks they move through. In the case of the Hillsborough sample, those ancient fluids altered the asteroid’s minerals and left behind chemical evidence that remained preserved for billions of years.

Scientists were also able to detect fragile sodium-carbonate salts that normally react with moisture in Earth’s atmosphere before they can be studied. Jangmi Han, a paper co-author and mineralogist at NASA’s Johnson Space Center in Houston, identified evidence of ancient brines preserved within microscopic fractures. Similar salts were identified in samples returned from the asteroids Bennu and Ryugu by NASA’s OSIRIS-REx mission and JAXA’s (Japan Aerospace Exploration Agency) Hayabusa2 mission. However,Hillsborough marks the first time the salts have been identified in a CM carbonaceous chondrite meteorite, offering a new glimpse into the surfaces of the primitive asteroids that produced these meteorites.

Together, these findings suggest that ancient, salt-rich brines were more widespread among primitive asteroids than previously recognized, and provide scientists with new opportunities to compare how water altered different asteroid bodies across the early solar system.

“The chips of the most salt-rich bits of this meteorite are quite comparable to the samples returned by the Hayabusa2 and OSIRIS-REx missions,” said Mike Zolensky, a meteorite researcher at NASA Johnson and co-author of the study. “They’re not identical. They’re different in some very interesting ways, but they’ve seen very similar processes.”

Scientists expected Hillsborough to contain a rich suite of organic compounds because it is a CM carbonaceous chondrite. What made the meteorite exceptional was how quickly it was recovered, allowing researchers to study those compounds before prolonged exposure to Earth’s environment could contaminate the sample.

“One of the big surprises for me when we analyzed a small chip of the Hillsborough meteorite was the complexity of amino acids and other organic compounds,” said Danny Glavin, senior scientist in the Astrobiology Analytical Laboratory at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and co-author of the study.

Its diversity of amino acids and other organic compounds is, comparable to the Murchison meteorite, a nearly 100-kilogram carbonaceous chondrite that fell in Australia in 1969 and became the benchmark for extraterrestrial organic chemistry.

“It’s just more proof that the chemical building blocks of life could have been delivered — and are still being delivered — to Earth today by these carbonaceous asteroid fragments,” said Glavin, who was a co-investigator on OSIRIS-REx, leading an international team that studied the organic composition of the samples delivered to Earth from asteroid Bennu in 2023.

Understanding the Hillsborough meteorite required expertise from multiple scientific disciplines.

Astronomers reconstructed the meteorite’s journey through space, finding evidence that it may have originated from the Erigone asteroid family in the inner asteroid belt, home to the asteroid Donaldjohanson, which was visited in 2025 by NASA’s Lucy spacecraft. Mineralogists identified evidence of ancient brines preserved within microscopic fractures, while organic chemists analyzed the meteorite’s inventory of amino acids and other organic compounds.

“Together, those complementary studies are helping scientists build one of the clearest pictures yet of how primitive asteroids such as the asteroid Erigone evolved chemically over billions of years,” said Jenniskens.

Researchers continue to study the Hillsborough meteorite, revealing new details about how water transformed primitive asteroids and shaped the early solar system.

By tracing the history of water on primitive asteroids, scientists are learning how water and the chemical ingredients for life were distributed throughout the early solar system.

“If you follow the water through the solar system, you’re actually following life,” Zolensky said. “Following the history of water through the solar system is an essential part of understanding the origin of life.”

For more information on NASA’s astromaterials research and exploration, visit:

https://science.nasa.gov/astromaterials

Karen Fox / Molly Wasser
Headquarters, Washington
240-285-5155 / 240-419-1732
karen.c.fox@nasa.gov / molly.l.wasser@nasa.gov

Victoria Segovia
NASA’s Johnson Space Center, Houston 281-483-5111
victoria.segovia@nasa.gov

NASA is recruiting research participants for the agency’s next simulated deep space mission. Beginning no earlier than August 2027, research volunteers will spend one year living and working in interplanetary environments at the agency’s Johnson Space Center in Houston, operating under isolated conditions expected during crewed missions to the Moon or Red Planet.
 
Insights from this new, yearlong experience, called the Moon and Mars Exploration Analog, can be used to help keep astronauts safe and mission-ready during future planetary surface operations. The results also could inform plans for a sustained lunar presence through the agency’s Moon Base and future Artemis missions.
 
NASA is looking for applicants for the approximately year-long mission simulation, which will take place in two confined habitats. In addition to specific physical and education requirements, volunteers must be willing to take part in a multi-day selection process and pass NASA’s physical and psychological assessments, found on the Moon and Mars Exploration Analog web page. Candidates also should have a strong desire for unique, rewarding experiences, and interest in contributing to NASA’s work to prepare for extended stays on the lunar surface and the first crewed mission to Mars.
 
The Moon and Mars Exploration Analog evolves elements of the agency’s HERA (Human Exploration Research Analog) and CHAPEA (Crew Health And Performance Exploration Analog) missions into a single, integrated mission to streamline how researchers evaluate astronaut adaptation across the full range of potential mission scenarios. Using the HERA habitat as a spacecraft and the CHAPEA habitat as a base, the volunteers will live and work in confined, isolated environments that simulate months-long flights to and from other planetary surfaces. They also will mimic surface operations, including mock Mars walks and using a rover to travel to exploration sites located beyond the main habitat.
 
Throughout the Moon and Mars Exploration Analog mission, researchers will study crew health and performance under resource limitations and mission demands. These missions also help NASA assess and validate hardware, technologies, protocols, requirements, and other systems designed to support crew health and performance on long-duration deep space missions, all without leaving Earth. The effort will provide valuable data for NASA’s Human Research Program, which innovates ways to keep astronauts healthy and mission-ready.
 
To apply, visit:

 NASA Analogs Recruiting

As part of the Golden Age of innovation and exploration, NASA will send astronauts on increasingly difficult missions to explore more of the Moon for scientific discovery, economic benefits, establish an enduring human presence on the lunar surface, and to build on the foundation for the first crewed missions to Mars.
 
For more about NASA’s Human Research Program, visit:

https://www.nasa.gov/hrp/