Michael Hecht

Chapter 1 · 1980s – 2001 Thirty years at JPL, the explorers’ dust

Michael Hecht grew up in the Boston area. Before returning to Massachusetts, he spent thirty years at the Jet Propulsion Laboratory in California, preparing for what future explorers of Mars would find under their feet.

A Boston childhood

He tells it himself when explaining the name of his best-known instrument: when he was growing up in the Boston area, the soft drink of choice was called Moxie. It had been invented in Lowell, a few miles from the observatory where he works today. The word “moxie” came to mean pluck and spirit.

MECA, a laboratory for humans

At JPL, where he spent thirty years, he led in the late 1990s the design of MECA, the Mars Environmental Compatibility Assessment, planned for the Mars Surveyor Program 2001 lander. The instrument was sponsored by NASA’s human exploration enterprise: its primary goal was to evaluate the chemical and environmental hazards that Martian soil and dust might pose to future explorers, and to help make realistic Mars soil simulants on Earth. It combined a small wet-chemistry laboratory, which mixes soil with water to analyze its composition, a microscopy station meant to take the first microscopic images of Martian soil, an electrometer to measure static electricity, and arrays of material patches to study abrasion and dust adhesion. He designed it with Thomas Meloy of West Virginia University.

The 2001 lander never went to Mars. But MECA’s heritage would be, as he wrote in 1999, all-important for future low-cost missions.

Sources: NASA, “Small Steps, Giant Leaps” podcast, episode 71, October 20, 2021 (the Boston area, the Moxie drink invented in Lowell, thirty years at JPL); M. H. Hecht (JPL) and T. P. Meloy (West Virginia University), “The MSP 2001 Mars Environmental Compatibility Assessment (MECA),” 1999 (NTRS 20000110352 and 20000025371: human exploration sponsorship, hazards to explorers, simulants, wet chemistry, microscopy, electrometer, patches); same authors, “Soil Analysis Micro-Mission Concepts…,” 1999 (NTRS 20000025372: heritage). The cancellation of the 2001 lander is recounted in Steve Squyres’s biography in this collection.

Chapter 2 · 2007 – 2008 Two teaspoons of soil and perchlorates

MECA came back to life on the Phoenix lander, which touched down near the north pole of Mars in May 2008. Michael Hecht was its principal investigator. There he would make a discovery that changed how people think about life on Mars.

Phoenix’s laboratory

On Phoenix, the instrument became the Microscopy, Electrochemistry, and Conductivity Analyzer. Alongside the wet-chemistry lab and the microscopes, it included a probe stuck into the soil to measure its temperature, thermal conductivity and heat capacity, and to detect any mobile water molecules throughout the polar summer.

An “intimate” mission

He remembers Phoenix as a “small intimate” mission: half a billion dollars, he admits, does not sound small to most people, but it was a small team co-located in one place, with somewhat looser rules and very focused goals. His greatest excitement, he said at the time, came from the wet-chemistry experiment.

Perchlorates

The lab dissolves soil in water brought from Earth and “tastes” the ions with electrodes. On June 25, 2008, and again on July 6, in two samples from different trenches, it detected an unexpected signal: perchlorate, an ion made of one chlorine atom surrounded by four oxygen atoms. On Earth it is found in Chile’s Atacama Desert, and in rocket fuel and fireworks. On August 5, 2008, Hecht presented the discovery cautiously. “Finding perchlorates is neither good nor bad for life, but it does make us reassess how we think about life on Mars.” The result is exciting, he added, if “our two teaspoons of soil” are representative of all of Mars. These very stable salts do not destroy organic material under normal conditions.

Sources: A. P. Zent and M. H. Hecht, “The Thermal Electrical Conductivity Probe (TECP) for Phoenix,” 2009 (NTRS 20090033138: instrument name, probe measurements); NASA Ames, biography for the February 11, 2021 lecture (MECA principal investigator on Phoenix in 2008); NASA, “Small Steps, Giant Leaps” podcast, episode 71, October 20, 2021 (“small intimate missions,” half a billion dollars, co-located team); NASA/JPL, “Phoenix Mars Team Opens Window on Scientific Process,” August 5, 2008 (samples of June 25 and July 6, Dodo-Goldilocks and Snow White, definition of perchlorate, Atacama, fuel and fireworks, quotations, stability); NASA, “NASA Selects ‘MAVEN’ Mission to Study Mars Atmosphere,” September 2008 (Phoenix landed May 25, 2008, near the north pole); contemporary press summarized by a web search (“My greatest excitement came from the wet chemistry experiment,” the electrode method).

Chapter 3 · 2012 – 2021 Making oxygen from Martian air

In 2012, Michael Hecht left JPL for the Massachusetts Institute of Technology’s Haystack Observatory. Two years later he was chosen to lead a new kind of instrument on Perseverance: not a science instrument, but a small factory.

A local name

On July 31, 2014, NASA presented the principal investigators of the Mars 2020 instruments; he was one of them. His instrument was called MOXIE, for Mars Oxygen ISRU Experiment. The acronym contains another: ISRU, in-situ resource utilization, essentially living off the land. And Moxie was also the drink of his childhood.

A fuel cell in reverse

Mars’s air is very thin, about 1 percent of Earth’s, but more than 95 percent carbon dioxide. MOXIE draws it in, compresses it, then passes it through a ceramic heated to 800 degrees Celsius, a solid oxide electrolysis cell. “The technology is actually very similar — it may be identical — to that of a fuel cell,” he explains. “You just run the voltage in the opposite direction and the whole reaction reverses itself.” The cell pulls one oxygen atom off each carbon dioxide molecule and leaves carbon monoxide behind. It must not go too far: if both oxygen atoms were removed, carbon would remain and coat the ceramic.

To build it, he chose two companies that had never built anything for flight: the company now called OxEon Energy, for the cell, and Air Squared, for the compressor. Better, he believes, to take people who know the technology and teach them how to make a space instrument than the other way around.

What a rocket needs

“What people typically ask me is whether MOXIE is being developed so astronauts have something to breathe,” he said in 2020. “But rockets breathe millions of times as much oxygen as people.” To lift four astronauts off Mars would take about seven metric tons of fuel and twenty-five metric tons of oxygen; a crew spending a year on the surface might use one ton. Bringing all that oxygen from Earth would be, he says, horrendously complicated and horrendously costly.

April 20, 2021

Perseverance landed on February 18, 2021. On April 20, its sixtieth Martian day, MOXIE ran for the first time on Mars: after a two-hour warm-up, it produced about 5.4 grams of oxygen in an hour, enough to keep an astronaut breathing for about ten minutes. It was the first time an instrument had produced oxygen on another world.

Sources: NASA Ames, biography for the February 11, 2021 lecture (MIT since 2012, Haystack Observatory, thirty years at JPL); NASA, “NASA Hosts 3 p.m. EDT Teleconference with Mars 2020 Principal Investigators,” July 31, 2014; NASA, “Small Steps, Giant Leaps” podcast, episode 71, October 20, 2021 (the name, ISRU, 1 percent, over 95 percent, the reversed fuel cell and quotation, 800 degrees, carbon, OxEon Energy and Air Squared, “horrendously complicated, horrendously costly”); NASA, “MOXIE Could Help Future Rockets Launch Off Mars,” November 24, 2020 (quotation); NASA, “NASA’s Perseverance Mars Rover Extracts First Oxygen from Red Planet,” April 21, 2021 (April 20, sol 60, two-hour warm-up, 5.4 grams, ten minutes, 7 and 25 metric tons, one metric ton).

Chapter 4 · 2021 – 2026 Sixteen runs and what comes next

MOXIE cannot run all the time. Each test drains the rover’s batteries. Michael Hecht and his team had to learn as much as possible from every session.

Once a month

When MOXIE runs, he explained in October 2021, nothing else runs that day; the rover then has to recharge its batteries. So the team ran it about once a month, each time in somewhat harsher conditions: at night, then in daytime when the air is even thinner, at different temperatures, with different compressor speeds. Each heat-up to 800 degrees followed by a cool-down wears the ceramic; a real plant, running continuously, would have an easier job.

He also drew management lessons. The requirement was to produce six grams of oxygen per hour, which calls for constant current; yet the safety of the ceramic would rather call for constant voltage. “Design your instrument for operations, and don’t design it for requirements”: he remembers being taught that a long time ago.

Twice the goal

On August 7, 2023, MOXIE ran for the sixteenth and final time and produced 9.8 grams of oxygen. In all it made 122 grams, about what a small dog breathes in ten hours. At its best it reached 12 grams per hour, twice NASA’s original goal, at 98 percent purity or better. “MOXIE has clearly served as inspiration to the ISRU community,” Hecht said. “It showed NASA is willing to invest in these kinds of future technologies.” The next step, in his view, is not a MOXIE 2.0 but a full-scale system that produces oxygen, liquefies it and stores it. That will take 25 to 30 kilowatts of power, needed for a human base anyway, and a unit of about a ton, the size of a small chest freezer.

Other horizons

For most of 2020 he also served as deputy director of the Event Horizon Telescope, which revealed the first image of a black hole in April 2019. In 2025, NASA selected for a study in its innovative concepts program his project to explore Venus with electrolysis. Having always considered himself a planetary scientist, he finds it “exhilarating” to work toward human exploration, and to imagine perhaps one day his grandchildren landing on Mars.

Sources: NASA, “Small Steps, Giant Leaps” podcast, episode 71, October 20, 2021 (once a month, batteries, conditions, thermal cycles, six grams per hour, current and voltage, quotation, 25 to 30 kilowatts, one ton, the chest freezer, planetary scientist, “exhilarating,” grandchildren); NASA, “NASA’s Oxygen-Generating Experiment MOXIE Completes Mars Mission,” September 6, 2023 (16th run on August 7, 9.8 g, 122 g, the small dog, 12 g/h, 98 percent, quotation, full-scale system); NASA Ames, biography for the February 11, 2021 lecture (Event Horizon Telescope deputy director in 2020, April 2019 image); NASA, “NIAC 2025 Phase I and Phase II Selections,” January 10, 2025 (“Exploring Venus with Electrolysis”).