The LA Musician Who Helped Design a Microphone for Mars

How an obsession with space led to a partnership on the Perseverance rover—and the chance we could finally hear what our planetary neighbor sounds like.
jason mezilis
Jason Achilles Mezilis, a rock musician, composer, and lifelong space enthusiast, in his Los Angeles studio.Photograph: Phuc Pham

It’s called the "seven minutes of terror." As the 2,300-pound, six-wheeled, nuclear-powered Perseverance rover approaches Mars on Thursday, a supersonic parachute will slow the descent vehicle to 200 mph. About 70 feet above the landing site, retrorockets will settle it into a hover, then a “sky crane” will lower NASA’s newest rock-crawler to the rust-colored dirt below. As Perseverance touches down, the descent ship will boost itself clear and crash-land nearby.

Don’t worry, it’s going to be fine: Perseverance, which will explore martian geology and search for evidence of ancient microbial life there, is using known landing strategies, many from the 2012 Curiosity mission. What is new, though, is that earthlings will be able to hear much of the seven-minute drama. Embedded on the rover is a small microphone that, if all goes well, will record the sounds of the descent and, later, the martian environment itself, something no Mars probe has yet achieved.

Given the breadth of hypersensitive hardware humans have been shooting at planets for the past 60-odd years, it's startling that we’ve never been able to listen in. Sure, there have been attempts: In the early 1980s, two Soviet Venera probes to Venus carried microphones for estimating wind speed. But the recordings were staticky and incoherent. NASA’s Mars Polar Lander mission in 1999 included a mic, but the probe crashed into pieces on arrival. NASA tried again in 2008 with the Phoenix Mars mission, but the mic was nixed before takeoff. Space agencies have many thousands of images of planetary exploration but precious little in the way of alien soundtracks.

So if modern equipment could finally capture the rush of wind and the staccato sandblasting of dust that will accompany video of the descent and landing and, yes, the clicks and whirrs of a robotic probe as it crawls over the sandy surface of Jezero Crater day in and day out (OK, sol in and sol out)—wouldn't you want to hear that?

Jason Achilles Mezilis, a Los Angeles–based rock musician, composer, and lifelong space enthusiast, certainly did. In 2016, he was having drinks on a diner patio with his friend Joseph Carsten, who worked in robotics at NASA’s Jet Propulsion Laboratory nearby in Pasadena. They were talking about the Curiosity rover’s dramatic landing strategy, and Mezilis was curious what it would sound like. Would it be possible to mount a microphone on the upcoming Perseverance lander to capture the aural drama to accompany NASA’s video feed? “How cool would that be?” he mused.

Mezilis' dogged pursuit of this query catapulted him toward a rendezvous with NASA. It's a story that reminds us that innovation can come from surprising places.

Mezilis, a youthful 46-year-old with an unruly mop-top, was something of a late bloomer as a musician. He didn’t take up guitar until just before his senior year of high school, which caused his grades to plummet and his focus to drift. As a result, he flubbed a piano audition—he was unprepared and nervous—for the music school at UCLA, and UC San Diego rescinded his acceptance to its program. He made his way to De Anza College in Cupertino, his hometown, where a teacher taught him theory—performance, harmonic structure, musical analysis. This, it turned out, was the framework he needed. The instructor helped Mezilis prepare for music school placement tests, so when he applied to UC Berkeley’s music department, he got in handily. By the time he graduated, he was adept at guitar, bass, and piano, along with other keyboard instruments.

A few years after college, Mezilis, who uses the stage name Jason Achilles, headed to Los Angeles, and over the next years played in rock bands—Black Belt Karate, Your Horrible Smile, Owl—and did recording and production work. He has his own studio in the sprawling warehouse Downtown Rehearsal, where he recorded his first solo album, Comedown. He has since collaborated with Hungarian and Czechoslovakian symphony orchestras to record his compositions, and he’s now helping Guns N' Roses keyboardist Dizzy Reed produce his next album. In other words, he’s had a bright and diverse career, but it ain’t rocket science, at least not the kind JPL looks for.

Mezilis was searching for another anchor. “The music side is very detached from the more intellectual side that my father passed on,” he says. (His dad, a computer systems analyst in Silicon Valley, was also a musician.) Mezilis had grown infatuated with space science. He read popular science magazines, peppered scientists with questions and ideas, and attended lectures and outreach events—in fact, he met Carsten at an open house program for JPL. At one point he sent a note to planetary scientist Alan Stern, the principal investigator for NASA’s New Horizons mission to Pluto, asking if probes with multiple small landers could help analyze the wildly varied surfaces New Horizons had discovered. He received a thoughtful reply. He sent back some of his music, in case Stern needed a break from his work.

As an audio engineer, Mezilis' goal was to coax a coherent, realistic recording from the equipment instead of creating one tuned for specific scientific qualities.

Photograph: Phuc Pham

Over drinks with Carsten that evening in 2016, Mezilis asked his friend what it would take to get a microphone, as well as a second idea he had for a novel camera system, on board Perseverance. The payload decisions for the new rover had been pretty much settled already—you can’t just squeak bonus hardware like that onto a billion-dollar scientific mission—but Carsten, a rover driver who will help navigate Perseverance across the martian surface, didn’t exactly nix the notion of Mezilis being able to convince NASA to put a mic on board. Nor did the engineer think his ideas were, as Mezilis paraphrases, “batshit crazy.” Absent any formal invitation from NASA or any reasonable expectation that his work would be seriously considered, Mezilis dug into the challenge.

As an audio engineer, he had a broad knowledge of microphones. Now, Mezilis began to read up on how they might be used in space: Carl Sagan had championed the concept decades earlier, and there were those NASA and Soviet efforts. What was clear, though, was that space acoustics haven’t been a priority. Every extra ounce on a vehicle requires additional fuel at takeoff and landing, and saps precious electrical power during the mission. “Besides,” says David Gruel, the Perseverance assembly, test, and launch operations manager at JPL, who oversaw the microphone effort, “in the space business we don't do a lot with microphones and sound, since most of our research is done in a vacuum.”

As he built his pitch, Mezilis focused on reasons NASA might consider a mic on Perseverance: public outreach potential, for one, giving space science fans something new to latch onto; and it could be a diagnostic tool for the rover, even an early warning system for mechanical faults. “We take for granted how often sound is used in our latent perceptions,” he says. “The first time you can tell when your car or your refrigerator is acting up is when you hear something wonky.” He then tackled the engineering challenges. The microphone would need to survive the launch and the seven-month journey to Mars, along with the 120-degree heat swings on the planet itself. Mezilis studied how the analog-to-digital converter should be designed, what sort of sensitivity the device should possess, which parts should be mounted on the outside of the vehicle and which could be protected inside, what sort of testing and calibrations would be needed, how the final recordings would need to be processed.

A few months into his research, however, Mezilis received a note from Carsten. Mars 2020—the official name for the mission that includes the Perseverance rover—would indeed include a mic. NASA was, coincidentally, on a very similar wavelength. The mic would be scientifically focused, and it would sit in an instrument called SuperCam to help study what happens to rocks when they get zapped with a laser. It could also record ambient sound. Soon after, Mezilis found an article announcing a second experimental mic, an idea that came up late in the planning when managers realized they could squeeze such a thing on board.

The Edmund Scientific Astroscan telescope was a popular instrument for beginners in the 1980s. Mezilis has owned this one for as long as he can remember.

Photograph: Phuc Pham

Mezilis was both thrilled and panicked. He might have a shot at the experimental mic, but if NASA was already moving forward with its own plan, it would likely start seeking ideas elsewhere too. He’d have to hustle to get his offer on the table. “I freaked out because I realized this is a very rare opportunity to actually do this, and I risked missing it,” the musician recalled from the porch of his house in LA, overlooking the San Fernando Valley. (In classic LA music scene fashion, his neighbor and close friend is Anthony Hudson, an artist and the father of Guns N' Roses lead guitarist Slash.) He had just shown me around, and I noted an equal mix of vintage musical instruments and space exploration memorabilia. In one cabinet he has a collection of sci-fi films on VHS—alphabetized, no less, though some friends once shuffled all the tapes inside their boxes as a prank. (They remain shuffled.) Sitting on a bookshelf in the same room as a century-old piano is an iconic artifact of amateur astronomy: a bulbous, red Edmund Scientific Astroscan telescope, which was a popular instrument for beginners in the 1980s. Mezilis also owns a patch of fabric from the space suit worn by Space Shuttle astronaut Bruce McCandless during the first untethered space walk in 1984, and an autographed photo of Bob Moog, inventor of the first commercial synthesizer.

On the porch, Mezilis nursed a glass of scotch as he talked about his pursuit of the Mars mic: “I knew I wanted to get into that world, so my sense of urgency magnified 10 times. How do I get onto that mission? I felt it was mine to lose.”

Honestly, he shouldn’t have had much of a chance. His only contact with NASA was the casual friendship he’d built up with Carsten. That was it. And NASA isn’t an organization known for its open-door policies. The tentacles of space exploration extend globally, and universities, research groups, and space agencies collaborate closely under airtight contracts led by highly credentialed engineers. A guitar-toting gig musician and symphony composer who hangs out in the Viper Room and pals around with Slash’s dad was not likely to have a realistic shot at creating a martian microphone for NASA.

Turns out, he actually kind of did. In August 2016, three months after hearing about NASA’s plans, Mezilis submitted his pitch to JPL, offering to assist with the development of the microphone. It quickly found its way to Gruel. Mezilis included white papers he’d written on the microphone’s design, calibrating the final product, and post-processing the raw data files. He’d even hired an acoustical science engineer named Caesar Garcia to help hone the pitch. In short, he was rigorous and methodical. He did it right.

In October, Mezilis got a message. Gruel wanted to talk. Mezilis and Garcia got on a call, and Gruel caught them up on details of the effort, noting that he was convinced by the work the pair had done. Mezilis would need to form a company to make the arrangement compatible with NASA’s contracting policies, but then they could get started. When Gruel hung up, Mezilis said to Garcia, “Wait, what just happened here?” Garcia responded: “I think you just got a job.”

Mezilis went to work. The “Entry, Descent, and Landing” microphone would be oriented toward capturing sounds for a broader audience than the science-oriented SuperCam mic. Though official specifications for the microphone stipulated only that the device last through the rover's journey to the planet, it could well remain functional long into the mission—a planned two years. (Mars probes can last long beyond their expected lifespan; Curiosity is still going strong nine years in.) The microphone would pick up sounds to be sent back to Earth with a few days’ delay; the sounds would also be used to accompany videos taken during the landing

Mezilis' “notional” sketch of an enclosure that would protect the Perseverance microphone from the harsh martian atmosphere.

Illustration: Jason Mezilis

When Mezilis focused on public outreach in his proposal, it was prescient. Instead of, say, designing a camera to point straight at the ground for the benefit of geologists alone, you’d make one that captures a vast, striking panorama of what that world is like. Mezilis’ goal was similar, to coax a coherent, realistic recording from the equipment instead of creating one tuned for specific, highly esoteric qualities. “I started thinking of all the possible considerations you could have for audio—including all the problems in my world and how they’d apply to NASA’s world,” he says. For example, Mezilis created a filter that would, in processing the files, cancel out the effects of sound on the rover’s own body. In other words, it would eliminate echoes or vibrations the surrounding metal might introduce. To do that, he built a rough model of a section of Perseverance in his backyard.

Mezilis used this identical second sample microphone for testing and to calibrate filters to process the final audio files.

Photograph: Phuc Pham

As Mezilis zeroed in on solutions for the mic, including pitching a custom build and a more affordable alternative using off-the-shelf components—NASA ultimately chose the latter—the agency explored the potential payoffs. In addition to helping monitor and diagnose problems on the rover (knowing how the hardware sounds will help with troubleshooting), the mic could also help NASA better understand the martian environment. Researchers could compare how sounds transmit on the Red Planet against the same sounds on Earth, allowing them to add detail to their models. Air density on Mars is much lower than on Earth, which will likely make some things sound muffled; and the atmosphere’s heavy carbon dioxide composition might mute higher-frequency noises, so we’ll hear lower pitches more easily. This intel could also help writers and directors get their stories just a little more right when speculating about—if Elon Musk’s dreams come true—what life will be like when humans move in.

The microphone could also deliver powerful moments on Earth. Gruel remembers an encounter he had with a visitor to JPL soon after hiring Mezilis. She’d asked him if NASA was ever going to put a microphone on another planet. When he told her their plans, she was delighted. Gruel asked her why she was so interested. “Her sister was blind,” he says. “She can't see the images that come back from Mars, and no matter how hard her sister tries to explain how amazing they are, she just can't see it—she gets her senses in a different manner.”

Gruel had never thought of the microphone the way his guest had. “I got super excited about this in a way we've never done before,” he says. “You’ll hear the retrorockets roaring, then maybe the wheels actually crunching down onto the surface. Then, when the descent stage cuts free and flies off into the distance, it’ll get quieter and quieter.” He pauses: “What's left behind at that point will be the ambient noises of Mars, whatever they are.”

In the summer of 2017, NASA approved Mezilis’ suggestions and assembled the components based on his specifications—including a high-grade commercial microphone and preamplifier combo from DPA Microphones, an analog-to-digital converter, and a custom dust-protection screen. The mic is positioned externally on the chassis just above the middle wheel, on the left; the preamplifier sits inside the rover itself. All told, the components add 102 grams to the payload. It’s part of an array of seven cameras known as the EDLCAM system (“entry, descent, and landing”), which will collect 40 gigabytes of visual and acoustic data during the “seven minutes of terror.” 

At JPL, the microphone was tested in a vacuum chamber filled with a gas that simulated the martian atmosphere.

Courtesy of JPL/NASA

The mic will record from just before the parachute deploys, through the descent and landing process, and then stop shortly after touchdown. About 287 seconds, or just under five minutes. If it survives the landing, the mic can be reactivated to record additional sounds for as long as it continues to function. 

This set of sounds from the surface of Mars were recorded by the microphone on the side of NASA’s Perseverance Rover on Feb. 20, 2021. In this set, sounds from the rover itself dominate. 

Credit: NASA/JPL-Caltech

In this set, the sound was filtered to make sounds from Mars more audible, and you can hear a little wind. 

Credit: NASA/JPL-Caltech

JPL is also exploring the possibility, at Mezilis' suggestion, of using both the SuperCam and EDLCAM mics together, to create a stereo recording from the surface of the planet. "It's the final step in making a fully immersive sensory experience," Mezilis says. In other words, it's not for the scientists. It's for you.

Buzz Aldrin’s iconic photo of a boot print on the moon, the Hubble Space Telescope’s Pillars of Creation image of cosmic dust and gas, a picture of McCandless’ untethered space walk—all are stunning moments captured serendipitously. Now, in this era of strangely captivating TikTok skits and cleverly sampled sounds, Perseverance could insinuate itself into the culture in ways NASA hasn’t yet considered.

Mezilis thinks a lot about the way sound can tap our emotions. Even the resonant voice of his elementary school science teacher filled him with wonder. His work with NASA “has got that same sort of fascination and wonderment as music does, which opens the creative door for him,” says Andy Brick, a composer and conductor known for scoring films and video games, including The Sims, and who conducted the orchestral recordings of Mezilis’ work in Hungary and Czechoslovakia.

Mezilis is determined to keep opening more doors. As the microphone project wound down, he started exploring the other idea he had during his initial talk with Carsten: the Lunar ExoCam. It’s a spherical cage for a 360-degree camera that would be ejected by a lunar probe during its final descent to the surface. It would beat the craft down, land, bounce, and settle. It would transmit video of the landing to the probe and eventually back to Earth. Cool, yes, but also useful, as one of Mezilis’ collaborators, space systems engineer Rex Ridenoure, points out. “One of the biggest gaps in information about landing on the moon is what the spray of all the regolith does when the lander comes down,” he says, referring to the dust, gravel, and pebbles on the surface. “Everything goes supersonic in all directions.” Video could really help lunar base planners.

Work with the camera prototype will help confirm, say, that the release mechanism doesn’t throw the rocket off balance, or ensure the camera doesn’t land directly underneath the lander.

Photograph: Phuc Pham

Mezilis also discussed his moon-selfie-sphere idea with Jim Bell, a planetary scientist at Arizona State University, who has developed camera systems for several Mars rovers, including Perseverance. Because launching bouncing space cams from moon landers is new turf for Mezilis, at least compared to microphones, Bell helped him get through a cosmic case of imposter syndrome. “I basically had to twist his arm and talk him into giving a presentation at a scientific conference about this. I think he felt that he was an outsider, like he wasn't worthy in some way,” Bell says. “I'm like, dude, you have to understand that we're all making this stuff up as we go along. There's no book, no class you take on how to operate a rover.’”

Bell was right. Mezilis ultimately stood in front of conference attendees, sharing his ideas and absorbing their feedback. Speaking with him, it's hard to not notice his hard-won command of the subject matter. It’s as though there really is a fully formed PhD candidate lurking inside the good-natured guitar hero.

In October, NASA awarded Mezilis and his collaborators $650,000 to develop a functional prototype. Honeybee Robotics will do the mechanical engineering for the camera, and rocket company Masten Space Systems, which is planning several lunar missions, will conduct testing. The team will build a prototype to evaluate all the things that could go wrong: to confirm that the release mechanism doesn’t throw the rocket off balance; to ensure the camera doesn’t land directly underneath the lander; to test the effect of ejected debris on the view or the camera itself.

Mezilis’ vision is for both the mic and the ExoCam to become regular additions to future probes. Space launch startup Rocket Lab has already expressed formal interest in using his microphone work on an upcoming probe to Venus, and Mezilis hopes the camera will land on several lunar missions being planned—though he still has his sights set on Mars. “I want it to be as if you’re standing on the surface watching, like it’s straight out of a Ray Bradbury story,” he says. “It’s all about creating those moments, the ones where a 5-year-old is going to see that and just be like, ‘Holy shit, we’re doing that in space! It’s like magic, but real!’”

First, though, NASA has to crack the sound barrier. On Thursday, Mezilis—now a bona fide extraterrestrial audio engineer (a space roadie, if you like)—will be tuned in to the livestream from mission control right along with everybody else. It will take a few days for the video and audio files to be processed and released to the public. If all goes right, the world will experience a new dimension in space exploration, one that could be as haunting as anything Bradbury could dream of, or as comforting and familiar as a breezy day on Earth.


Update 2/22/2021, 5:30 EST: NASA released the first audio recordings from Mars using the EDLCAM system. Though the system didn’t capture the sound of the descent and landing phase, the mic is now functional and it successfully recorded ambient sounds from the planet’s surface, including several gusts of wind. Mezilis says he’s grateful for the gusts, because had they not arrived during that minute-long recording period, the success of the effort would still be uncertain. “That little gust of wind was definitely a gift,” he says.


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