I was a NASA mission operations systems engineer on the Mars 2020 project, which means I was responsible for designing and testing the health and safety of the Perseverance rover (Percy) before she left for Mars. Once she landed on Mars, I managed the rover’s well-being by implementing daily activities and quickly solving problems during the mission. For nine years, Percy and I were intimate friends. It’s my pleasure to give you a first-hand and behind-the-scenes account of her Mars mission and our friendship.
“Good Night Oppy” (https://www.youtube.com/watch?v=W4t58Yruhds) is a documentary that tells the story of Opportunity, one of NASA’s twin Mars exploration rovers (the other being Spirit) and the grandmother of Percy. I started my NASA career working on the Opportunity rover as a Tactical Downlink Lead and Testbed Lead. They were designed to last only 90 days on Mars; Opportunity lasted 15 years. Each Mars rover was built upon the one before. Sojourner landed on Mars in 1997 as a demonstration project to determine if landing a rover on Mars was possible. Following that successful landing, we built two Mars rovers—Spirit and Opportunity—for redundancy in case one failed to land or failed to operate shortly thereafter.
Launched in July 2003, one month after its twin rover Spirit departed for Mars, Opportunity landed in the Meridiani Planum region of the planet on January 24, 2004. Designed to function for 90 Martian days (or sols) and travel 1,100 yards (1,000 meters), Opportunity surpassed all expectations with its endurance, scientific value, and longevity. Exceeding its life expectancy 60 times over, the six-wheeled, golf-cart-sized rover traveled 28 miles (45 kilometers)—farther than any previous wheeled rover—before ceasing communication with Earth in June 2018.
All along, Opportunity sought out evidence of water at sites where conditions may have once been favorable for the emergence of Martian life. Opportunity’s discoveries implied that conditions at Meridiani Planum may have been habitable for some period of time in the planet’s history.
The next mission sent the Curiosity rover to answer the question, “Did Mars ever have the right environmental conditions to support small life forms (i.e., microbes)?” Curiosity was the largest and most capable rover sent to Mars when it launched in November 2011 and landed in August 2012. Early in its mission, Curiosity’s scientific tools found chemical and mineral evidence of past habitable environments on Mars. Even now, in November 2024, it continues to explore the rock record from a time when Mars could have been home to microbial life.
From the Spirit, Opportunity, and Curiosity rovers, we learned that Mars once had a considerably wetter climate with lakes, indicating that the planet was much more habitable billions of years ago, with evidence suggesting these lakes existed around 2 billion years ago.
To establish habitability—as we know it on Earth—it is important to establish the presence of water, specific elements (e.g., carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur), and an energy source. The latter could be a sun or come from within the planet (i.e., a molten core, as is found on the Europa moon that circles Jupiter). Lastly, life requires a suitable climate—neither too hot nor too cold—and time to evolve. To advance NASA’s quest to explore the past habitability of Mars, the 2020 Perseverance rover is currently searching for signs of ancient microbial life. In addition to on-site analysis, Perseverance is collecting core samples of Martian rock and regolith (broken rock and dust) for potential pickup by a future mission that would deliver them to Earth for detailed study.
Designing a Mars rover to look for ancient life requires careful consideration about where to land the vehicle, which determines the specific instruments and engineering components needed to ensure success of the mission. Perseverance landed in Jezero Crater on Mars, which was once a giant lake fed by a river delta. Seven scientific instruments were selected from proposals and scientists from around the world (e.g., Norway, Spain, France, and the United States). Following five years of construction, Perseverance was launched on July 30, 2020. After a six and one-half-month journey, she landed on Mars on February 18, 2021. Six trajectory maneuvers during the flight ensured she landed precisely in Jezero Crater. This mission was akin to directing a golf ball from here to Buckingham Palace to land on one of its doorknobs.
New technology called Terrain Relative Navigation helped land the rover at a precise spot in Jezero Crater. Essentially, the rover took pictures as it descended, compared them to an onboard orbital map to determine the rover’s precise location, and then fired jets to maneuver the vehicle to the exact spot in the landing ellipse. If a hazard had been detected (e.g., a boulder), the vehicle would have been maneuvered away from it to a safe landing spot.
One of the remarkable behind-the-scenes stories was that the launch and landing took place during the global COVID pandemic. Since a trip to Mars can only be launched once every two years, we either pressed forward or delayed the space mission. During the rover flight and landing, NASA had strict isolation rules for employees. On February 18, 2021, the day of the Mars landing, three teams were assembled in different mission rooms in Pasadena, California. Each crew team handed responsibilities off to the next team for the three phases of Cruise, EDL (Entry, Decent, and Landing), and Surface operations. The EDL phase only lasted seven minutes total but is arguably the most critical time for the rover—we call it the seven minutes of terror. The EDL team handed off to the Surface team for which I was on console as the “Systems” lead. After >five years of construction on this multibillion-dollar asset (with no backup) and a space flight of >six months, an emotional but muted celebration marked this successful landing. Team members were masked and spaced three feet apart, and no high-fiving or hugging was allowed. Despite the contained excitement, it was a remarkable day. The first pictures transmitted from the surface of Mars were simply amazing!
Source: NASA/JPL-Caltech
Shortly after landing, we started surface operations. This is when my team took over. We brought along a sidekick, a quadcopter named Ingenuity, to see if we could fly a rotorcraft on Mars. The Martian atmosphere is about 1% of Earth’s. So, flying something on Mars requires substantially more lift than what is required on Earth. Ingenuity was designed with two rotor blades to provide sufficient lift for flight. Two months after Percy landed, Ingenuity took her first of five flights as a technology demonstration. She became the first aircraft to achieve powered, controlled flight on another planet and was subsequently used to scout driving locations for the rover. Ingenuity flew for the last time on January 18, 2024, and completed her mission on January 25, 2024, after nearly three years of aerial exploration and 72 historic flights.
Source: NASA/JPL-Caltech/MSSS
Since Ingenuity’s antenna was only strong enough to transmit the data to Perseverance, all the flight data and images were transmitted to Perseverance, then to the orbiters, and then down to Earth. Once a day, we gave Perseverance a list of instructions on what to do for that single day, and she talked back to us about four times a day. Since our instructions to Perseverance were small, we sent them directly from Earth to her antenna, but what she collected was much bigger (e.g., movies, pictures, and sound bites). Because the files were too big to send to Earth directly, they were transmitted from Percy to the orbiter and from there back down to Earth.
Several exciting instruments were placed on Perseverance in 2017. Twenty-three total cameras populated the vehicle, with 19 mounted on the rover and four mounted to the entry vehicle. These included seven entry, descent, and landing cameras; nine engineering cameras; and seven science cameras. The engineering cameras served as eyes for driving—binocular cameras provided depth perception and wide-angle features allowed 360-degree observation—while the science cameras made scientific observations and helped collect and analyze samples.
Six hazard detection cameras (HazCams)—four in front and two on the rear—detected hazards, such as large rocks, trenches, and sand dunes, to the front and back pathways of the rover. When driving, the rover stopped frequently to take new stereo images of the path ahead to evaluate potential hazards. The 3D views allowed the rover to make its own decisions about where to drive without consulting on every move with the rover team on Earth. Two color stereo Navigation Cameras (Navcams) located on the mast of the rover helped engineers navigate Perseverance safely, particularly when the rover navigated autonomously. These cameras can see an object as small as a golf ball from 82 feet (25 meters) away. Before Percy “drove blind,” the cameras ensured a safe path. Blind-drive mode occurs when engineers command the rover to drive a certain distance in a certain direction, and the rover’s computer “brains” calculate distance from wheel rotations without looking or checking for wheel slippage.
Seven instruments on the rover were dedicated to specific scientific investigations.
Two Mastcam-Z cameras mounted on the rover mast were designed to take high-definition video, panoramic color, and 3D images of the Martian surface and features in the atmosphere with a zoom lens to magnify distant targets.
The SuperCam camera located on the rover mast was a suite of instruments—a camera, two lasers, and four spectrometers—that performed remote analyses of rocks and soils to seek organic compounds that might hold biosignatures of past microbial life on Mars. It could identify the chemical and mineral makeup of areas on Mars as small as a pencil point, from a distance >20 feet (7 meters). For the first time, a microphone mounted on the rover body and used in collaboration with the SuperCam provided “ears on the ground.” Not only did it record ambient sounds on the Martian surface, but it also listened to mechanism movements (i.e., wheel motions and coring operations) to make certain the rover was operating correctly.
The Planetary Instrument for X-ray Lithochemistry (PIXL) instrument was mounted on the robotic arm and acquired high spatial resolution observations of rock and soil chemistry, rapidly analyzing the elemental chemistry of a target surface in 10 seconds.
The Radar Imager for Mars’ subsurface experiment (RIMFAX) was a ground-penetrating radar mounted on the belly of the rover. It used radar waves to see geologic features under the surface. This device could make detections dozens of meters/yards underneath ground, such as buried sand dunes or lava features, different ground densities, structural layers, buried rocks, and meteorites. Some scientists believe that aquifers exist beneath the surface of Mars, which would be important for humans going to Mars one day to have a source of water. RIMAX can detect underground water ice and salty brine at a depth of 10 meters (33 feet).
The Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals (SHERLOC) instrument was mounted on the robotic arm and contained two cameras: the Advanced Context Imager (ACI) for context imaging and the Wide Angle Topographic Sensor for Operations and eNgineering (WATSON) for general documentation and context. SHERLOC used cameras, spectrometers, and a laser to search for organics and minerals that have been altered by watery environments and may be signs of past microbial life. In addition to its black-and-white context camera, SHERLOC was assisted by WATSON, a color camera for taking close-up images of rock grains and surface textures. Since WATSON was mounted on the rover arm, it conveniently provided “selfies” of Percy.
Source: NASA/JPL-Caltech/MSSS
The robotic arm of the rover was seven feet long and had five motorized articulating joints that allowed for a full range of motion. In addition to the three scientific cameras (SHERLOC, WATSON, and PIXL), the robotic arm had a variety of sampling tools. Since the environment on Mars’ surface can dramatically change the exterior of a rock, Perseverance created abraded patches on the exterior of surface rocks to allow examination of the interior which may hold important clues to the history of the area.
Accordingly, the “hand” or turret at the end of the robotic arm had a coring drill, a ground contact sensor, and a dust removal tool. A rotary percussive drill extracted rock core samples from the surface of Mars, while a force-torque sensor at the end of the arm helped it apply the right amount of force during sampling. Finally, a suite of interchangeable bits, including coring bits, a regolith bit, and an abrader, allowed the scientific cameras to examine the interior of the rock. The newly abraded patch was full of dust generated by drilling that could obscure what the scientists were interested in seeing (i.e., the color and shape of individual grains in the abrasion). So, Percy removed the cuttings using a Gaseous Dust Removal Tool (GDRT). The GDRT had a tank of nitrogen gas and used four short puffs to blow the cuttings away and reveal the fresh rock surface underneath.
The Mars Oxygen In-Situ Resource Utilization Experiment, or MOXIE, located inside the rover (front, right side) helped NASA prepare for human exploration of Mars. MOXIE was testing a way for future explorers to produce oxygen from the carbon-dioxide rich Martian atmosphere to be used for burning fuel and breathing.
The last instrument was the Mars Environmental Dynamics Analyzer (MEDA), which made weather measurements including wind speed and direction, temperature, and humidity. MEDA also measured the amount and size of dust particles in the Martian atmosphere. MEDA sent us daily weather reports. A typical summer day on Mars might include a high temperature of 19 degrees Fahrenheit—so you’re definitely going to need a warm jacket if you go out for a stroll—and a low temperature of minus 115 degrees Fahrenheit. A thick space suit might be a better choice for an evening walk.
The next planned mission is Mars Sample Return, a joint campaign being planned by NASA and the European Space Agency (ESA). Mars Sample Return will involve multiple missions and components, with the goal of bringing Mars rock, loose surface material, and gas samples to Earth for detailed laboratory analysis. The Perseverance rover’s job was to collect and cache samples on Mars, which was the first leg of this international, interplanetary relay team. The current plan is for a Sample Retrieval Lander to land near or in Jezero Crater and to bring a small rocket on which the samples collected by Perseverance will be loaded. The Mars Ascent Vehicle (MAV) would be the first rocket ever to launch off the surface of another planet and would transport the sample tubes containing Martian rock, atmosphere, and loose surface material into orbit around Mars. Sample Recovery Helicopters (SRH), modeled after the successful Ingenuity Mars helicopter, could be a secondary method of sample retrieval for the campaign. Once the sample cache is launched from Mars, another spacecraft—the Earth Return Orbiter (ERO)—will capture it in Mars orbit and bring it to Earth safely. This would be the first interplanetary spacecraft to capture an object in orbit around another planet and make a full round trip to Mars and back.
We are requesting sufficient funding to ensure that Mars Sample Return is a successful mission with hopes that those Mars surface rock samples will be delivered to Earth in the mid-2030s. These first collected and returned samples could answer a key question: Did life ever exist on Mars? We think only by bringing the samples to Earth can we truly answer the question by using the most sophisticated, state-of-the-art labs, at a time when future generations can study them using techniques yet to be invented.
DISCUSSION
Paterson, Little Rock: Bekah, that was fantastic. We’re all proud of the work that you and your team have done. Elon Musk has issued statements that SpaceX plans to colonize Mars. Since you no longer work for NASA, maybe you can speak your mind. Who will be first to transport humans to Mars: NASA or Musk?
Siegfriedt, Austin: That’s an excellent question and one that I can’t answer. Elon is a very interesting person, so we’ll see what he has in store for the world.
Carethers, San Diego: Fantastic talk. I learned a lot. You mentioned MOXIE. I assume that is just a demonstration, because there was no need for the rover to have oxygen.
Siegfriedt, Austin: That’s exactly right. The rover did not need oxygen. In fact, now that oxygen has been successfully extracted from CO2 in Mars’ atmosphere, scientists are planning for the next MOXIE to be much bigger. The current-sized version didn’t produce enough oxygen to sustain a human being.
Lane, Sacramento: I had the opportunity to be involved with a NASA project tasked with keeping people alive on Mars for about three years. Accordingly, we had to produce food, medicines, and hormones (e.g., PTH out of lettuce leaves). Where’s that sort of dome going to sit on Mars?
Siegfriedt, Austin: Human beings need to be located along the equator, which is the warmest place with the narrowest temperature extremes. Precisely where the dome habitat is placed may depend on what we see in the surface samples that come home.
Gladwin, Baltimore: Can you tell us quickly about your personal journey? How did you become the leader of the ground game on Mars? Also, you never told us how Mars transitioned from an aquatic world to the current world. What are the theories for that?
Siegfriedt, Austin: I grew up in a small town. My dad was in the military, so I moved around frequently. We ultimately settled in Fredericksburg, Texas. Although now famous for its wineries, then it was a small town of 900 people. The night skies were extremely dark so I would lay out on a blanket when I was young and look up astonished at the stars. I saw the Spirit and Opportunity rovers land when I was in 8th grade, but I was not a very studious student. I was rebellious and did not want to attend school. My parents didn’t think I was being responsible, so they took away all my privileges and picked my class schedule when I was a sophomore in high school. They signed me up for a rocket class. It was all boys, and I did not want to be in this rocket class. I stood in the class with my arms folded and pouted for the first couple of months. Ultimately, I started to listen and fell in love with rockets. So long story short, I became obsessed with rockets in high school and determined to study aerospace engineering at the University of Texas (UT). I thought it was a long shot, but it turns out they needed women in the aerospace industry. So, I was admitted to the UT aerospace program despite a very low SAT score. Then I became a huge nerd in college and really studied hard. I knew it was what I wanted to do so it became a lot easier to study. I interned at SpaceX and that’s a whole other story about Elon and when I met him with his snow cone.
Your second question: we actually don’t quite know how Mars transitioned from an aquatic world to the current world. But we do know it involved greenhouse gases very similar to what’s happening on Earth.
Firestein, La Jolla: The primary mission was to determine if there was evidence of life. But you didn’t comment on any of the results.
Siegfriedt, Austin: I did not.
Firestein, La Jolla: Right. So, there are leopard spots on red rocks in Cheyava Falls.
Siegfriedt, Austin: Yeah!! You saw that.
Firestein, La Jolla: Yes, and where are we with regard to understanding if there’s life there?
Siegfriedt, Austin: Depending on what scientist you ask, you’ll get a different answer. To definitively answer this question, we need to analyze the samples with instrumentation on Earth. Even if we were 99.9% sure that we found evidence that life existed on Mars, we must be 110% certain it is true before we announce anything. Once we do make an announcement, it will completely change the way that humanity looks at life. We need to get those samples back home to really determine if life ever existed on Mars.
Firestein, La Jolla: Based on analysis conducted on-site, some of the building blocks of life appear to be present. Is there more that can be said about that?
Siegfriedt, Austin: In the last year, several discoveries have been made regarding the existence of the building blocks of life. However, I can’t say any more about that. We’ll have to wait until we hear it from NASA.
Bray, Salt Lake City: What is gravity like on Mars? We know damage occurs when people are in space for a long time. Maybe you can speculate a little bit about that.
Siegfriedt, Austin: Gravity on Mars is about a third of what it is on Earth. For comparison, gravity on our moon is an eighth or a ninth of that experienced on Earth. So, if you were to jump on Mars, you would jump higher, but you would still land on the ground.
We are very close to being ready to send humans to Mars, and I personally think it’s a great thing that there’s competition. Artemis, which is NASA, is trying to get to Mars, and SpaceX is trying to get to Mars. Competition speeds up the pace of the mission and keeps the public eye on it. There are different thoughts about the human journey. For example, travelers could be put into a deep sleep for a while and awakened intermittently for exercise. The biggest issue is water. It’s heavy, and you have to take enough to keep three astronauts alive for nine months on a mission. Could you dehydrate water and add water back to hydrate it again? Figure that out, and you’ll become a bazillionaire.
Bishopric, Washington, DC: I was wondering if I could get around the things you can’t talk about by talking about the atmosphere on Mars. My limited understanding of Earth’s atmosphere is that there wasn’t any oxygen for the first billion or two years. Then plants—basically cyanobacteria—began to produce oxygen through photosynthesis. Is there any atmospheric evidence of oxygen that might lead you to believe that there had been cyanobacteria on the surface of Mars or something that could photosynthesize?
Siegfriedt, Austin: We’re looking for microbial mats that might have been deposited. Unfortunately, I’m an engineer, and I don’t know the answer to your scientific question.
Mackowiak, Baltimore: When Wayne Gretzky, one of the greatest ice hockey players of all time, was asked what made him so great, he said, “Because I skate where the puck is going to be.” I want to ask the obvious question. Where are we going with this? Why would we spend these billions and billions of dollars?
Siegfriedt, Austin: Here’s how I think of it. Human beings have this incredible ability to ask questions. We’re very curious people. The only way we drive technology and ourselves as a species forward and figure out how to live on this planet is by asking and answering questions. I think it’s worth spending a little bit of money to answer these incredible questions because we don’t know what we don’t know.
Zabner, Iowa City: As researchers, we’ve lost the ability to communicate to the public the importance of the things we do. Do you think NASA could communicate better?
Siegfriedt, Austin: I think we could all do better at that. I started at NASA in 2013, and it has done much more in the last 10 or 15 years for public outreach and engagement. NASA encourages all of us to do public outreach and engagement. So, I’ve done a ton of talks to elementary schools and middle schools. It’s important that we continue to speak, not only to people like us and scientists and engineers but to kids. The only reason I became who I am is that I saw three women on the television screen in NASA mission control when the Spirit and Opportunity rovers were landing. I was like, “A woman in mission control—maybe I can do that too.” I think it’s all very important, so we should all continue to keep talking about it.
Reiser, Galveston: Biosafety level 4 is our highest level of containment on Earth. Where will these Mars samples go?
Siegfriedt, Austin: We have this concept called planetary protection, and NASA is extremely concerned about the purity of the samples. As we were constructing the rover, we had to be super, super, super, super secure in the clean room because NASA didn’t want our DNA to get onto the rover, travel all the way to Mars, and find life that really originated on Earth. So, strict rules applied. We couldn’t wear deodorant. We couldn’t wear makeup. It was a whole ordeal. When those samples come back, NASA is discussing how it is going to process and protect them. It’s a new thing NASA is trying to figure out.
Arthur, Little Rock: In 1962, Kennedy announced we would go to the moon, and in 1969, we put a man on the moon. Why does it take so much longer to go to Mars?
Siegfriedt, Austin: Money.
Rice, Providence: It’s about money? Okay.
Siegfriedt, Austin: When Kennedy gave his speech that we do things not because they’re easy but because they are hard, the whole nation rallied behind NASA. The NASA budget was much bigger back then than it is now. We can do things a lot faster. We have the ability to do that. SpaceX launched a capsule to the international space station with humans on board in a matter of a couple of years. If the NASA budget were bigger, we could do things a lot faster.
Greenspan, Boston: Is there research into how to get there faster? Do you see yourself up there some day?
Siegfriedt, Austin: We got Percy to Mars in six and a half months, but that time frame is determined by orbital dynamics and orbital mechanics (i.e., the distance between Earth and Mars and surrounding planets and their gravitational pulls). In the future, we might develop a propulsion system that could get us to Mars quicker. Mission launchings sometimes wait years for the perfect timing to achieve speedy interplanetary travel. Will I ever go to Mars? I went to summer camp a couple of times, and I got very home sick for my parents. I still get very home sick. The only way I would go to Mars is if Gordon (my husband) and Milo and Luna (our children) came with me.
Sacher, Cincinnati: What are radiation levels like up there, and what are the implications for long- or short-term human habitation?
Siegfriedt, Austin: Radiation levels are extreme. The Martian atmosphere is very thin, so radiation exposure to people and devices is more than on Earth. Space suits have to be different, and the habitats have to be different because of that.
Wilson, Durham: Why are you calling the rovers “she”? I think I agree that’s the best pronoun.
Siegfriedt, Austin: It all goes back to the Navy. Its boats all have female names. Scientists wanted to continue that so all the rovers are also female. They are all “she’s.” Yes, go women!
Lange, El Paso: Bekah, I’m so proud of you. So, let’s hear about snow cones.
Siegfriedt, Austin: I interned at SpaceX in 2011 when it was a pretty small company. It was just getting public attention by docking an uncrewed vehicle to the international space station. I was a test propulsion engineer working on Grasshopper—a concept for a vertical takeoff, vertical landing—because Elon had this “crazy” idea that we could land a booster and reuse it. And here we are doing that now. Elon wanted to thank us for getting to the international space station so he threw a picnic and rented a snow cone truck. We all got snow cones, and Elon picked a blue one. There were approximately 100 people attending, and I thought this might be my only chance to talk to the CEO of the company. I asked him a question that I don’t even recall. When he answered, his mouth was bright blue as he was talking to me. I remember his answer was strange, but his blue mouth was even stranger. I will never ever get that out of my mind.