At ASMS 2025, National Aeronautics and Space Administration (NASA) research scientist Melissa Trainer discussed how the agency is using advanced mass spectrometry tools to investigate some of the most intriguing environments in the solar system.
Trainer, based at NASA’s Goddard Space Flight Center, leads the development of mass spectrometers for three planetary missions:
Dragonfly to Titan
DAVINCI to Venus
The Curiosity rover’s continuing work on Mars
"Designing instruments for these environments means confronting engineering and scientific challenges at the same time," she notes.
Studying these vastly different worlds in parallel allows scientists to compare how planetary atmospheres and surfaces evolve under dramatically different conditions. This comparative approach connects Titan’s dense, cold atmosphere with the hot, chemically active atmosphere of Venus and the dynamic seasonal cycles of Mars.
Trainer emphasizes that planetary exploration requires the same precision and adaptability as Earth-based separation science, but applied in far harsher, more unforgiving environments.
Dragonfly: Mass Spectrometry on Titan
Titan, Saturn’s largest moon, is shrouded in a dense nitrogen-rich atmosphere and covered with hydrocarbon lakes, dunes, and icy plains. With a surface temperature of 94 K (−190°C), Titan’s stable environment may preserve complex organic compounds, offering critical insights into prebiotic chemistry.
As Trainer explains, "We know there are organics there, from Cassini–Huygens, but we don’t know exactly what they are. I want to know: are they just baseline organics, or have they been processed into something more—maybe even prebiotic molecules?"
The Dragonfly Mass Spectrometer (DraMS) is central to this investigation, designed to analyze drilled surface samples for both baseline organics and potential prebiotic molecules such as amino acids and nucleobases.
For Trainer’s team, maintaining sample integrity at low temperatures while operating a warm instrument posed significant thermal engineering challenges. "The sample wants to stay cold; the instrument wants to be warm," she notes.
To overcome this challenge, DraMS uses a ‘cold zone’ carousel (maintaining ~150–170 K) to preserve samples, separated from room-temperature electronics by a thin thermal barrier.
This enables two complementary analysis modes:
Ultraviolet (UV) laser desorption/ionization for high-mass organic molecules
Gas chromatography with mass spectrometry (GC–MS) after controlled heating to 600 °C for targeted separations
Dragonfly must also maintain operating temperatures in Titan’s extreme cold, and is powered by a multi-mission radioisotope thermoelectric generator (MMRTG). Waste heat from the MMRTG is circulated through the lander in a system similar to HVAC ducting, helping to keep critical components within stable operating ranges.
DAVINCI: A One-Hour Descent Through Venus’ Atmosphere
Venus presents a rare opportunity to sample a dense, chemically complex atmosphere and investigate a planetary evolution path that may have diverged significantly from Earth’s. Understanding its atmospheric composition and history can shed light on planetary formation, climate evolution, and habitability across the solar system.
As Trainer notes, "Noble gases are like molecular fossils. They tell you about the origin and evolution of the planet."
The DAVINCI mission’s quadrupole mass spectrometer—a heritage design drawing on instruments flown on past missions such as the Galileo and Huygens probes—is built for mechanical robustness, calibration stability, and high-precision isotope analysis under rapidly changing pressures and temperatures during a single one-hour descent. It includes enrichment cells for noble gas concentration and a tunable laser spectrometer for complementary isotope measurements.
Targets include atmospheric gases, sulfur compounds, and noble gases such as argon, xenon, krypton, helium, and neon. "By measuring their abundances and isotopes, we can compare Venus directly to Earth and Mars," Trainer explains. These measurements will reconstruct Venus’s origin and evolution and enable direct comparisons with Earth and Mars.
Curiosity: Long-Term Atmospheric Monitoring on Mars
Shifting from brief atmospheric descents to Venus, NASA takes a long-term approach to studying Mars.
Mars’s accessible surface and atmosphere make it an ideal natural laboratory for studying climate variability, geological processes, and potential past habitability. Long-term atmospheric monitoring can reveal whether Mars still has active processes shaping its environment.
"Mars is a lot more active and alive than people were thinking,” observes Trainer. “There’s still a lot going on between the subsurface, the surface, and the atmosphere. One of the surprises we found in the Mars atmosphere was how oxygen varied relative to argon in a way we didn’t expect from our models."
Curiosity’s Sample Analysis at Mars (SAM) suite is a collection of instruments that includes a quadrupole mass spectrometer, a tunable laser spectrometer, and a gas chromatograph designed to analyze gases, isotopes, and organic molecules in the Martian atmosphere and soil. SAM has revealed seasonal variations in oxygen and methane that defy current atmospheric models.
"Oxygen should behave almost inertly, like argon," Trainer explains. "Instead, we saw it rising before the big argon bump each spring." This suggests unrecognized surface–atmosphere interactions and highlights the complexity of Martian atmospheric chemistry.
Implications for Separation Science
Across these missions, several principles resonate with Earth-based analytical science:
- Sample preservation under extreme conditions.
- Multi-modal analysis for complex mixtures.
- Instrument ruggedness for field or mobile applications.
- Long-term monitoring to reveal trends and anomalies.
As Trainer concludes, "These are the same fundamentals we use on Earth, but pushed to the limits by the environments we’re working in."
Future Directions
Trainer sees the future of planetary mass spectrometry in flexible sample introduction systems and onboard AI for data triage. "Ultimately, data is power. The more we can process onboard, the more science we can return."
By processing data before transmission, missions can conserve power and bandwidth while maximizing scientific return—an approach equally relevant to high-throughput labs on Earth.
"Mass spectrometry is one of the key instruments we’ll continue to send on planetary missions because it’s so adaptable," Trainer emphasizes. The same analytical rigor that drives separation science on Earth is enabling NASA to explore and better understand some of the most extreme environments in our solar system.