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Season 1Episode 153Jul 17, 2020

Luther Beegle, Deputy Division Manager for Science at NASA’s Jet Propulsion Laboratory, takes us through the history of previous landers we have sent to Mars and highlights Perseverance, the most sophisticated rover NASA has ever sent to the Red Planet. HWHAP Episode 153.



If you’re fascinated by the idea of humans traveling through space and curious about how that all works, you’ve come to the right place.

“Houston We Have a Podcast” is the official podcast of the NASA Johnson Space Center from Houston, Texas, home for NASA’s astronauts and Mission Control Center. Listen to the brightest minds of America’s space agency – astronauts, engineers, scientists and program leaders – discuss exciting topics in engineering, science and technology, sharing their personal stories and expertise on every aspect of human spaceflight. Learn more about how the work being done will help send humans forward to the Moon and on to Mars in the Artemis program.

On Episode 153, Luther Beegle, Deputy Division Manager for Science at NASA’s Jet Propulsion Laboratory, takes us through the history of previous landers we have sent to Mars and highlights Perseverance, the most sophisticated rover NASA has ever sent to the Red Planet. This episode was recorded on June 10, 2020.

Houston, we have a podcast


Gary Jordan (Host): Houston, we have a podcast. Welcome to the official podcast of the NASA Johnson Space Center Episode 153, “Perseverance.” I’m Gary Jordan, and I’ll be your host today. On this podcast, we bring in the experts, scientists, engineers, astronauts, all to let you know what’s going on in the world of human spaceflight. NASA is paving the way towards a sustainable presence on the Moon and on to Mars. Though humans have never set foot on the red planet, we’ve been there many times. Most recently, the Mars InSight Lander that went to the surface of Mars to understand the planets quote unquote “vital signs”, its seismology and heat flow and whether the planet’s core is solid or liquid. Before that, the Curiosity Rover landed on Mars to explore the surface for chemical and mineral evidence of past habitable environments on Mars, searching for environments where microbes could have survived billions of years ago. Or these habitable environments. I remember watching Curiosity’s landing live, and man, what a thrill. NASA’s Jet Propulsion Laboratory is sending a new rover to Mars. It looks a lot like Curiosity but with a whole new suite of incredible instruments, many of which are in direct preparation for human exploration on Mars. We’re talking instruments to test the production of oxygen from the Martian atmosphere, identifying valuable resources such as subsurface water, improving landing techniques, and characterizing Martian weather in a way that could help future astronauts that are living and working in the environment. So, here to go into detail on this new Mars 2020 rover called Perseverance is Luther Beegle, Deputy Division Manager for Science at NASA’s Jet Propulsion Laboratory. Luther is also the Principal Investigator of the [Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals] SHERLOC instrument, one of the scientific instruments on Perseverance. Note that this episode was recorded prior to the most recent change to the launch date of Perseverance. For the latest information please visit So, here we go. The Mars Perseverance Rover with Luther Beegle. Enjoy.

[ Music]

Host: Luther Beegle, thank you so much for coming on the podcast today.

Luther Beegle: Thank you very much for having me. I really appreciate it.

Host: This is a very exciting topic. I love — this is a very exciting mission, one of the top priorities for NASA this year, and it’s coming up, you know, we’re releasing this episode on July 17th, fingers crossed that we’re still looking for that launch day. This is a big mission. I want to start, before we dive deep into Perseverance in this mission, I want to start with you, your interest in astrophysics. You have many degrees in astrophysics, and I want to understand kind of where that all began. Where did this spark, something that you wanted to dedicate your career to?

Luther Beegle: So, I think that, like most people, at least in my generation, basically “Star Wars” itself had a really big influence on me, not only from the perspective of entertainment, but from the perspective of what could possibly be out there. I watched science fiction movies in the past, and I think everybody had grown up wanting to be a spaceman. We’ve — I’ve seen this — I’m just old enough to remember one of the last Moon missions and watched movies about Mars and things like that. But when you start thinking about all of the permutations of what could possibly be out in the universe, it’s really fascinating, and my interest went beyond just life. It went to what the stars are like and what the planets are like, but I always kept coming back to what was life like, and that’s one of the reasons I am where I am.

Host: And that’s got to be the genesis of why you pursued physics and astronomy first with a bachelor’s, right? Physics is, I mean, I’ve heard it described as just like the language of the universe.

Luther Beegle: Yeah, and physics really is why things are the way they are, and a lot of it is problem solving, and I like problem solving. Physics, you’re given an incomplete information, and you try to figure things out, and it really is — it’s very hard, very simple. All of electricity and magnetism really can be boiled down to four equations, Maxwell’s equations, and then from there, you can build on everything else up there. And I always found that fascinating that there are things that you can, you know, figure things out with incomplete knowledge, and that was always fascinating from a problem-solving perspective. And it also fed into my interest in astrophysics and astrobiology later on, in that being a problem solver at heart, physics allows you to go into other things and try to solve problems in those fields as well. And it’s — it was a fascinating education.

Host: That’s got to be where your interest in astrophysics, just understanding how the universe works, how that intersects with Mars, which is the — really the topic of today is, is that’s what this Perseverance rover is going to be doing. We want to understand more about Mars. So, how does that intersect here, your love of astrophysics and Mars?

Luther Beegle: So, Mars is the closest planet we have, and it’s also the most Earth-like planet. So, we started thinking about where, you know, understanding of where we came from, you know, from an origin of life and origin of species perspective, Mars is it. Mars, we are close to it, we’re able to access it, we’re able to go down to the surface and touch it, we can see it, we know what it was like in the past, because you can see evidence all over the surface of different processes that happen. So, when you go thinking about looking for life, Mars is the first stepping stone of a lot of that, and it also enables us to try to start thinking for the first time of what actually is life-like and what — how do we go look for it? Those are questions that have come up a lot over the past 30 years of my career that people have asked, and we continue to talk about them, and that’s why Mars is special.

Host: That’s a perfect lead into this next topic. You talk about there’s evidence all over the surface of this, and it’s worth noting that this is not the first time we’re going to Mars. We’ve been to Mars, not exactly humans, but we’ve sent a lot of things to Mars to investigate that. Give us a brief history of what has been — how we’ve gone to Mars in the past through various missions.

Luther Beegle: So, Mars is probably the most visited and really understood planet we have other than the Earth. Actually, it is the most visited and understood planet that we have behind the Earth. We’ve gone there since space age. We’ve looked at it through telescopes. You know, we’ve all heard the stories about the canals of Mars Percival Lowell and people like that, and we understand that we’ve been looking at Mars for, you know, hundreds of years and the ancients knew about it. We started sending spacecraft as soon as the space age started. We sent the Mariner spacecraft to Mars. We thought, we weren’t exactly sure what we were going to see, and when we sent Mariner there, we found a cold dead planet. There wasn’t life on it, like people would assume there would or there might be in the past, but Mariner did see things like dry riverbeds and other things that could only have been made through water processes. So, we started to figure out very quickly from Mariner, the Mariner series, that Mars at one point had to have liquid water on the surface, and now it was no longer possible. So, that brought Viking, and Viking was launched in 1976, and the Viking consisted of two landers and two orbiters, and what Viking did was Viking took a map of the planet, the orbiters took maps of the planets and the Viking orbiter — Viking landers went down, landed on the surface, scooped up some material and tried to see if there was actual life associated with them. And we learned a lot from those experiments. We learned one, you really have to understand the geology and chemistry before you do a biology experiment, which was a big deal at the time. But we also learned how to operate in another planet, which was very important. And from there, there wasn’t anything on Mars till about — till 1996 when we launched Pathfinder, which was a small rover and a lander, [inaudible] station lander. That was the first time we’ve roved on another planet other than the Moon. Pathfinder went out and looked at a big dry rock to try to get the elemental abundance of that rock. From there, the 2003 mission, the MER, Mars Exploration Rover mission, which sent Spirit and Opportunity. These really were two feel robotic geologists, and what their job was, is their job was to go out and understand the geology of Mars. So, one of the things we’ve learned from Viking is, when the Viking tried to do the biology experiment, it came up with a result that we weren’t 100% sure what to make of it. Some people thought it indicated that there was life there. The vast majority of people thought it was just a chemical reaction, but what we learned was is that we had to really understand geology and to understand chemistry in order to understand biology. And so, Spirit and Opportunity were two missions that went there to two different locations and started looking at the geology, let’s understand the geology, and what they found was they found a planet. They found minerals, and they found environments that were aqueous in nature, so that there was liquid water at both those landing sites at some time in the past, and that’s important, because now we know that Mars, you know, we can see different places on Mars that all have the same aqueous process associated with it. We sent Mars Reconnaissance Orbiter in 2005. That was taking high resolution images of the planet and did some spectroscopy of the planet as well, so we can understand from orbit where different mineral deposits were. We’ve sent [Mars Atmosphere and Volatile Evolution] MAVEN, that was a scout mission, and InSight, they were two smaller class missions to look for whether Mars had earthquakes. That was InSight. MAVEN looked at — was looking at the atmosphere, trying to understand what happened to the atmosphere. We know Mars’ atmosphere now does — can’t support liquid water on the surface, but we know in the past it had liquid water on the surface. So, what MAVEN did was MAVEN tried to figure out what happened to that atmosphere and what were the processes that moved forward with that, which was really cool. And then Curiosity, which was the biggest rover we’d sent to date in two-thousa… it landed in 2012, and that really was looking at chemistry and looking for organic molecules and trying to determine whether the planet was habitable in the past, and by that we mean whether or not the condition existed on the surface of Mars that life as we know it could exist. And Curiosity has found that at Gale Crater, and that’s pretty much the history. So, that leaves us to Perseverance, which is going to go to basically look for potential bio signatures and try to cache samples to return to Earth later on.

Host: Yeah, that’s a huge milestone of — and a difference really with Perseverance. You went through this beautiful history of all these different rovers and landers and orbiters. I mean, we’ve been sending all these crazy instruments to really, as you said, this is the most studied planet other than Earth, and you can see why. I mean, we’re looking at all these different elements that are really diving deep into the history of how this planet works, what’s on it, the history of it. It’s absolutely fascinating, and it sounds like Perseverance is just taking those next steps.

Luther Beegle: Yeah. If you look, there’s been a thought process for the whole program, right? It’s not just let’s go send a biology mission and a very complicated biology mission, but it’s — we’re going to build blocks, we’re going to understand this, we’re going to understand that, we’re going to understand, you know, geology and chemistry, then understand the internal dynamics of the planet, understand some of the history of the planet, and we build along the way. So, it’s a — and we look at different sites along the way as well. So, what happens is, is that you start adding all of these things together, and then what you’re left with is you’re left with a really interesting — history of the planet and a better understanding of the planet.

Host: Wonderful. Well, let’s dive into Perseverance, because you ended it when you were going through this history of the different orbiters, land rovers, all those, you talked about Curiosity. I understand a lot of Perseverance is modeled after Curiosity. In fact, if you look at pictures of the two of them, they look very similar.

Luther Beegle: They do. [Mars Science Laboratory] MSL, Mars Curiosity is a rover that’s about 900 kilograms. It’s about the size of a Mini Cooper. It has a scientific payload that’s very complex. Perseverance is more complex than Curiosity in several ways, but it’s built on this. The nuts and bolts and skeletons are the same from Perseverance as they are on Curiosity. So, whenever we go do a new mission, we have to learn from scratch how to do a lot of things. For example, you know, wheels, how the wheels work, how tools interact, how the robotic arm interacts. So, what we did with Perseverance is we took all of the stuff we learned from MSL and all of the stuff we learned from MER and added to it to make a more complex mission. But we used the same type of skeleton to actually do this. So, from the outside, it looks the same. It has six wheels; the wheels are very large. I think they’re 65 centimeters in diameter. It has a robotic arm. It has a mask — the kind of the mask looks kind of the same, the robotic arm kind of looks the same, except it’s much more complicated. So, our robotic arm on Perseverance is much bigger than the robotic arm, and it’s much more capable than the robotic arm on MSL, but we had to learn how to do all of that with MSL, so that we can do go to the next step and learn on what we’re doing on Perseverance. The other thing Perseverance has that MSL did not have is we have the capability of caching samples. So, the robotic arm has a core on it, and that core will go out to different spots that we decide to pick depending on the diversity of sites and things like that and how much scientifically interesting the sample has or sample is, and we will basically be able to capture some of that sample, put it in the tube, seal that tube up, and then basically go back and pick it up later with a different mission. And so, Perseverance does the science, my instrument SHERLOC, [Planetary Instrument for X-ray Lithochemistry] PIXL, SuperCam, Mastcam-Z, RIMFAX, and [Mars Oxygen in-Situ Resource Utilization Experiment] MOXIE and MEDA. We all are doing great science to characterize the sample, and then we’re going to be able to bring that sample back. So, that’s the next step in Mars’ exploration is the sample return aspect of this particular mission.

Host: That’s perfect. That’s one of the new objectives of Perseverance, but what I’m hearing with this skeleton, the framework that you were talking about, it sounds like it’s just — what Curiosity did beyond its own scientific missions was prove that the hardware was right. It had to deal with maybe a sense of that this technology — the way that you rove across the surface of Mars was proven, and then you just take the different scientific instruments and objectives you want to do and rove across the Martian surface, just doing — meeting those objectives. Is that the idea?

Luther Beegle: That is the idea, and what happens is, is that you have — it’s a learning process the entire way. You had to learn to walk before you could run, you had to run before you could fly, and that’s exactly what we’re doing here. The — I used to work on Curiosity, and I was part of the, we called ourselves the Surface Sampling System Scientists, and what we did is we tried to figure out whether it was possible to drill on Mars and what type of materials could you drill into and could you not drill into, because this is all stuff we’ve done for the very first time, and that is really scary. If you send something to Mars, if it breaks, it breaks. There’s no way to fix it. There’s nobody — tape duct tape for the spacecraft we used to joke about all the time that could just basically tape themselves off, fix the hardware and just basically go back on. You’re stuck with what you have, and so you’re really trying to figure things out along the way and by learning all of these things, learning how the rover operates in this particular environment, the sand environment versus a rock environment, now we understand all of that we can design things better. One of the things that MSL did do is we had a wheel issue. At a certain point, we realized that the wheels were degrading faster than they were designed to. So, we learned from that, and Perseverance has a new set of wheels, and you could only do that by in situ the testing of that. We understood how the robotic arm placement can be, so how we put a drill down, what if the drill interacts with the rest of the rover in a bad way? So, now we can do a core, which is a more complicated piece of equipment. So, you keep learning along the way, and you keep becoming more and more sophisticated. I think that MSL was the most complicated mission ever flown, robotic mission ever flown, and Perseverance is more complicated than that. So, we keep adding and we keep getting better, which is what we at NASA tend to want to do is always do is always push the envelope.

Host: That’s incredible. Yeah, there’s been a lot of strides in that, and I can totally see the logic of wanting to — you — it’s the ultimate test, right? Those wheels on Mars is the ultimate test for the wheels. You learn from them, and you make them better for the next mission. It’s perfect. Talk about some of the just general design features of, I guess, a little bit of Curiosity, a little bit of Perseverance, things that make this the right type of rover. I know, I know, just, you know, and I was really into Curiosity in 2012 with landing it was just such a such a big event for me, and I was really fascinated by the wheels and just this tradeoff of torque and speed and wanting to get over some of those rocks and stuff like, so some of those engineering-like design elements of how Perseverance will do the roving on Mars.

Luther Beegle: So, the way Perseverance is going to do it is much like Curiosity did with some added exceptions, which I’m not 100% sure are actually going to work, not work, but be implemented, because working is a different concept. We have the large wheels and what the large wheels will enable you to do is not worry about the number of really reducing the number of hazards in a particular site. As you get closer to the ground, bigger rocks become problematic. If anybody’s ever driven a Jeep versus a car that’s very low to the ground, you’ll know that if you go over a speed bump, you kind of sometimes scrape against the ground. By having the bigger wheels than MER did, you’re able to go over a lot more of those particular rocks and not have to worry about them. They become less of a problem. We’ve learned on Curiosity we had problems — gap of getting over sand, getting up and over a sand patch. So, we kind of understand that we can’t get over that. Those wheels, we learned how to drive backwards with the same wheels on MSL that we will learn on Curiosity, I mean, excuse me, Perseverance. The wheels themselves will go actually very relatively slow. I don’t — I’m not sure what the speed limit is, but we end up going on Curiosity 80 to 100 meters a day, I think, as an average is a good day for Curiosity. And hopefully, we’ll be able to push that a little bit on Perseverance. We have a proven landing system on Perseverance. We’re using the Sky Crane, exact same design as we used on Curiosity. Hopefully, that will enable us to get to within a smaller and smaller place of where we want to go on the ground. So, what happens is, is that the original landing systems were — it had a landing ellipse, which is basically where you land that were very large, hundreds of kilometers. We’ve now lowered that down into the tens of kilometers range, because the landing systems have become better and better and better, and if you’re going to send humans, you really need to even reduce that even further. But the landing system now has enabled us to go to Jezero Crater, which we would not have been able to go under old landing systems, because it’s too hazardous, but we’ve reduced the error, the where we can land greatly. You — and we use a lot of the same parts to do that. It’s been — the design is solid and been tested. So, it enabled us to take a little, you know, go do things that we haven’t been able to do before.

Host: So, this is, just to confirm, this is the same landing system, but it sounds like was there a few upgrades to make it a little bit more precise too?

Luther Beegle: There is a different feature on this landing system called terrain navigation.

Host: Cool.

Luther Beegle: And so, what we’re able to do is we’re able to, when we hit, when we go down through and we’re in the final stage of descent, the rover has onboard images of what the landing ellipse looks like, and it can tell whether it’s in a spot where this might not be the best place to land on, so let’s move over a little bit. And that’s a new feature with this rover that we didn’t have on the last one. The last one, we, you know, we could go down and then lower everything down to the surface and landing on all four wheels or six wheels and just move off. This one allows us to go to a spot that we wouldn’t have been able to go. Because we have the terrain, we’re able to avoid terrain that we can’t get to in the past. The [Entry, Descent and Landing] EDL system operates — you’re going 17 — it’s about 17,000 miles an hour when you hit the top of the atmosphere, and seven minutes later you’ve got to be going zero miles an hour. There’s a great video online of describing this all called the “7 Minutes of Terror” that describes the entire EDL system, and it’s all automated, and it happens all — we just turn it on, and we let it go. And we find out whether or not we landed or not, but it’s the Sky Crane configuration. We hit the top of the atmosphere going 17,000 miles an hour, and there’s a heat shield. That heat shield dissipates heat in the atmosphere. It slows us down to, I’m not sure what the miles an hour is, but we then lose the heat shield, and we open up a parachute. That’s a supersonic parachute. It’s a very large parachute, which then dumps more energy, we slow down even further, but we get to about a couple of kilometers above the surface, and then we’re on retrorockets. So, the landing system itself takes over this active landing system, and the Sky Crane itself, it’s kind of like a landing system, and it’s all over the rover, and basically, the rover gets lowered to the ground by a rope, and then the rover hits the ground and then moves off on its own power. It’s really cool to watch. It’s a really cool video to see how it all works.

Host: I loved that video, “7 Minutes of Terror,” especially back in 2012, when I was following Curiosity, I watched that over and over and over. It was just fascinating. Is this landing system the one you’re describing for Perseverance? Are there elements of this, because I know when I was reading the description of Perseverance and some of its objectives, one of the things was improving the techniques for landing? Is this one of those things that might actually help us — the landing of Perseverance might actually help us understand how eventually to land humans on Mars?

Luther Beegle: The answer to that question is I don’t really know. I do know what it does do is it’s completely instrumented, and so it understands the nature of the Martian atmosphere better, and by that we can design better landing systems. I think there’s probably an upper limit to how much this landing system can land. In fact, I know there is, because I’ve read some of the mission architectures for potential humans to Mars, and so they all have different landing systems associated with it, but giving — this gives us information on what that atmosphere is like in the higher — above the surface, and so we can get — take that information and design better systems, and that’s the important part of the EDL system for potential humans to Mars. I don’t know whether or not the scales to full human activities, and that’s a lot more mass.

Host: Yeah, no, yeah, sure, not necessarily designed, but understanding what the environment is that you’re dealing with, that’s got to help for sure.

Luther Beegle: Yeah, it does, and, in fact, it basically flows all into that, and we, every time we land, we learn something new, and it’s good.

Host: Perfect. You mentioned some supersonic parachutes. There’s a lot of crazy engineering that’s going into the landing here, and I know just from Curiosity, a lot of it is familiar to me, but for Perseverance specifically, some of the development of testing of some of those things to make sure Perseverance is going to survive the journey.

Luther Beegle: Yeah, testing is we joke all the time that testing is always nerve-racking, because you’ve spent four years building something, and then all of a sudden, you go in to test it, and you just hope that it works the way everything is supposed to work, because it’s put the — it really puts the needle to the test. There’s better act — there’s a better description than that. So, what happens is that we have to test everything, and so if you remember back to when I was talking about what the Mars Exploration Rovers, everybody talks about the fact they were only supposed to exist for 90 days. But really, what that means is, is that all of the instruments and all of the hardware was — were tested out to about three times life. So, we test, we test, we test, we test, and we test for three times what the eventual life is going to be. We don’t test things till they die. We test things to make sure that they work for three times what the nominal lifetime is, and what that means is that Mars is a very difficult place. Mars, every day on Mars, the temperature swings are about 100 degrees centigrade, which is about 200 degrees Fahrenheit. So, imagine going from ice freezing to boiling, freezing to boiling, freezing to boiling every single day, and all of the hardware has to work through those environments. It’s also a very, very dusty place. It’s very — there’s — dust gets into everything. You can see pictures of Curiosity now, and I have one in my office where there’s dust just littered across the deck of everything there. It’s also got a very low atmospheric pressure, which change — which adds some complexity to things like high voltage and other things that we try to do. So, what happens is you make the hardware, you put it in through these tests, the hardware has to go through these [inaudible] cycles, basically zero to, you know, from zero to minus 100, zero to minus 100. It’s got to go through 3,000 cycles of that, and it’s got to work, and it’s got to work every single time, and it’s — everything has to — and everything is tested under relevant Martian conditions. It’s — principle here called test as you fly, and so we’ve tested our hardware down to minus 110 degrees — SHERLOC hardware down to minus 110 degrees. We’ve tested it up to 50 degrees C, because when it’s flying in space and it’s flying in that – the that, that heating, the backshell, it does get — it gets much hotter than it ever will on the surface, but you have to make sure that the instrument can survive those conditions as well. So, it’s test, test, test to make sure that you take everything that Mars can and throw at you and continue to make sure that everything works that way. It also has to go undergo shock and vibe that, you know, in the launch conditions, everything gets shaken up during launch. There’s a shock when it hits the atmosphere. So, everything gets, you know, really hit hard with a shock and every — all hardware has to work through all of those conditions, and you continue to test, and you just, you know, you go into a test and you just pray, and you pray, and you pray, and it’s funny, because then sometimes when things don’t work, you have to figure, you have to go back and figure out why it didn’t work, whether it was a problem with the test setup, whether it was a problem with the test design, whether it was a problem with the hardware, and then you’ve got to redesign the hardware to make sure that it works in those particular tests. And it’s nerve racking, it’s very nerve racking, because you’re going to be working on hardware for four years, and you put it through a test and it doesn’t function the way it’s supposed to function, and all of a sudden you’re like, wow, we’re back at, you know, we’re not back at square one, but, you know, god, how do I fix this?

Host: So, we’re recording this in the middle of June now. Perseverance, I’m guessing, at this point made it through the wringer, survived all the tests?

Luther Beegle: Everything seems to survive. We did the thermal test here. We have a big, you know, these things go into big giant chambers. We take them — we take the whole thing down to minus 100 degrees. We pump all the atmosphere out. We see what’s going to happen. We test it on different rocks and things like that, and everything passed, it’s at the Cape right now. It’s all — it should be all buttoned up here shortly and getting ready to be put on the rocket to be launched, and it’s a very exciting time. But I, you know, we talked about the “7 Minutes of Terror,” and it’s funny, because when we were landing Opportunity, I mean, excuse me, Curiosity, one of the other engineers looked at me and said, “you know, I’ve been working on Curiosity for seven years, so they should really do a seven years of terror,” I just don’t believe that the video would be all that interesting, I’m just sitting around just panicking of all the things that could go wrong. And everything, you know, we think about everything that could go wrong for multiple times, so.

Host: Yeah, that’d be a long one to watch for sure.

Luther Beegle: Yeah, it’s not very interesting.

Host: Yeah. So, you talked about designing it, you know, when you’re talking about mission duration, you know, you talked about the Mars Exploration Rovers being designed for 90 days, I think it was like, you know, designing for three times the — I forget the phrasing exactly what you said. But I know the Perseverance is tested for one Martian year, 687 Earth days. Does that mean you tested it to make sure that it’s going to survive 387 Earth days at a minimum?

Luther Beegle: Yeah, no. So, if it’s six — if it’s 90 days, we test it for 270 days.

Host: Got it.

Luther Beegle: For Perseverance, it was close 700 days, so we test it for 2,100 days.

Host: That’s a lot of testing.

Luther Beegle: Yeah, it is a lot of testing.

Host: For sure.

Luther Beegle: And there’s a lot of worries, because every single one of those testing cycles you’re worried about what’s going to happen, but it’s good engineering, and it’s very good engineering practices. Not everything can be tested that way, because there are some things that are considered consumables, but so you have to really figure out what’s going on and make sure that you’ve thought of everything in those cases, and then you get waivers and get reviewed, but you — they take a really fine look at anything that doesn’t get tested for the 2,100 days on Perseverance.

Host: Very cool. So, before we go into the science, I did want to tackle the mission profile here for a second. Right now, we’re in the middle of June. It’s scheduled for a July 17th launch date. I know that there are constraints with making sure that Earth and Mars are aligned. So, July 17th, I’m assuming, was picked for a very specific reason.

Luther Beegle: It is. So, actually, I think as of this morning, the earliest launch is now the 20th. I think we’ve slipped three days because of an issue with the Cape, however, yeah, so what happens is that Mars and Earth are continually moving. And so, what you’re doing is you’re launching from Earth to Mars, they have to be in the right state in their orbits. So, you can only launch to Mars about every 26 months. So, there’s about a three to four-week period where that launch window opens depending on where exactly they are in the orbits. And so, you launch and your — the spacecraft itself, basically at Mars get to the same point at the same time, because it takes, you know, seven months for it to — seven to nine months for it to get there. So, Mars and that’s — so there’s a launch window where it opens up. As you saw on the 17th of July, and it ends like the first week in August. We are going to land, however, at the — at — on February 18th at a certain time, and you can plan that exactly, and you need to plan that exactly, because there’s a lot of orbital assets with the Mars Reconnaissance Orbiter, MRO, Mars Odyssey still, MAVEN, that will be taking measurements as the spacecraft is going in. And you need all of those orbital assets to be in the correct spot at the correct time, so you know exactly when it’s going to land, but you get like three to four weeks of when it can possibly launch.

Host: Got it, okay. So, that’s — we’re still within the window. We’ve, at this time, we’ve slipped through the 20th, but we’re still within that window. It is — you mentioned the Cape. We are launching from Cape Canaveral Air Force Station down in Florida. It’s going to be launching on a ULA Atlas V-541 rocket. It is going to be — well, actually, before I get to the landing site, I did want to ask about the profile of how it gets there. I mean, I don’t know if it does a couple orbits around the Earth before a Trans-Mars injection or if there’s anything fancy in between.

Luther Beegle: No, it’s a direct injection.

Host: Got it.

Luther Beegle: Type two or type three orbit. It just goes straight out from the Earth and straight into Mars.

Host: Perfect. Now, the landing site, you’ve already mentioned this before, was Jezero Crater, and you said that Jezero Crater is a bit more hazardous, but this new landing system is able to get us to this area. What’s so interesting and actually what’s so hazardous about Jezero Crater?

Luther Beegle: So, Jezero Crater, where we’re going to land is, we’re going to land really at the base of what looks like a river delta, and on all indications, it was a river delta. So, Jezero Crater is a crater in — near Northeast [inaudible] on Mars. And it’s — there’s ample evidence that there was liquid water in this crater. In fact, you can see the one riverbed come in. It’s got a beautiful delta, you know, dried up delta, where — at the base we’re going to land, and then at the other side of the crater, there’s a place where the water used to go out into another basin. So, we know that there was water, we know water came in, we know water was there for a while, and we know it flowed out. So, this is a really cool place to go look for life. Now the reason why it’s a little bit hazardous is that river deltas do have, you know, structure to them. So, you don’t want to land on the side of a cliff. You want to land on a nice flat surface, and so because we have the terrain navigation feature, we can move away from the cliffs and actually land on a flat surface, and we have that ability. And so, Jezero was — it’s really cool. It’s got a lot of mineral diversity as well. So, there’s a lot of different things on the bottom of the crater that we can go look at, and really, what we want to do is we want to get a — sample return and understanding what Mars was like in the past. We want to get a lot of diversity. We really don’t, you know, you think about how far we’ve actually driven on Mars and how far we’ve actually explored. We’ve sent a lot of spacecraft there, and we’ve spent a lot of missions there, but the longest mission that’s ever been there is 28 miles, and that’s the Opportunity. It drove 28 miles. Curiosity was up to 13 or 14 miles as of last summer. So, the total mileage that we’ve driven across the surface of Mars is only 50 miles, and, you know, you can only really go out and touch a couple meters on each side of the rover. So, if you think about that, if you think about what the Earth is like and the diversity of different places on the Earth, you need to get out and try different things that the Sahara Desert is much different than the Amazon, which is much different than Siberia, which is even different than the Mojave here in Los Angeles. And 50 miles is not even half the distance between, you know, Washington D.C. and Philadelphia, for example. So, it’s really looking at diverse sites, looking at different places in Mars, trying to figure out all of Mars history, and that’s really what we want to do. So, Jezero Crater has a lot of that stuff, and that’s why we’re going there.

Host: Yeah. You know, it’s funny you say 50 miles. My commute to and from work is more than 50 miles. So, to put it in perspective, the total amount of area we’ve covered on Mars is less than my daily commute. That’s definitely saying something, but even what you’re saying about Jezera Crater and the, you know, why we’re landing there and what is there, from a scientific perspective, that sounds so exciting.

Luther Beegle: Yeah, if there was a place on Mars that had ancient life, this is one of — this would be one of the, you know, places that you would actually go look if there’s — there’s evidence of hydrothermal activity on the floor of the crater, the fact that there’s water coming from different spots along the way. We like chemical gradients for life. We enjoy things, and we enjoy looking for things like that, and that’s really, really what makes Jezero a really fascinating place to go. And it’s going to be really interesting, and what’s really cool is that when we land, we — the plan is to go up to the delta. So, we’ll basically be going back in time, because the stuff or the rock will be younger than the stuff at the bottom. And so, we’ll go through different epochs of Mars, and eventually, we’re going to head to a place called Northeast [inaudible], which has a lot of really cool formations and mineralogy as well that we’ve seen from [Compact Reconnaissance Imaging Spectrometer for Mars] CRISM and the Mars Reconnaissance Orbiter. It’s a fascinating diverse place that we do a lot of really good scientific papers and understanding better of what Mars was like when it had water.

Host: For sure, so exciting. That’s just, that whole mission profile, you just want to follow along every step of the way and see what’s discovered along the way.

Luther Beegle: Yeah.

Host: Let’s get into the science, let’s get into the fun stuff. You’ve already said one of the objectives here for the scientific objectives, seek signs of ancient life, that seems to be one of the top ones.

Luther Beegle: Yeah, and that’s — it’s an interesting concept, seeking signs of ancient life. What we say a lot is we’re going to look for potential bio signatures, and we use these words very carefully. It’s very difficult. It’s easy to discover alien life if it looks like E.T. or Chewbacca or, you know, the aliens from Independence Day. That’s easy to see. What we expect Mars to have had is microbial life, and if it had microbial life, and it flourished on the surface, it was three, four billion years ago, when Mars had liquid water. If there’s life on the surface now, near surface, it’s exceedingly rare, and it would be very difficult to find. And when we look at what happened on the Earth in terms of ancient life and our understanding of what the Earth is like, there’s still a lot of arguments on when we go to different formations. For example, the Australian pool formation — in Australia, there’s evidence of 3.5-billion-year-old life and some other places, and there’s a lot of scientific debate on whether or not these are really bio signatures or whether they weren’t created by life or not, and we know life exists on the Earth. We don’t know that about Mars. So, we continue to say potential bio signatures, because we want to make sure that if we see something, we study it and we know that it was basically biotic in nature. And so, we want to go seek things that we look at and we go, well, that’s really fascinating, it’s very difficult to make that without bio — without bugs, without microbes doing the work, let’s bring that sample back to Earth and analyze it in the laboratory and analyze it with as much, with as many instruments as we possibly can to determine whether or not that was alive and get scientific consensus on that.

Host: So, what, sorry–

Luther Beegle: That’s really powerful.

Host: Yeah, yeah, I was going to ask, I was going to follow up with some of the instruments onboard Perseverance. What’s onboard Perseverance? What kinds of instruments to look for some of these bio signatures?

Luther Beegle: So, we have a few instruments on Perseverance that are not necessarily doing the biology part of it, but the potential bio signatures detection part of it, but they’re doing very valuable scientific research, because, like I said, before, you need to understand the geology of the site. You need to understand the chemistry of the site. You need to understand everything about it to understand the bigger picture, and so we have a few — we have the one instrument is RIMFAX, which is a ground-penetrating radar. It’ll let us know what’s in the subsurface. So, that’ll give us an idea of what this — what the history of this particular site was, because we’ll see structure in the subsurface that we’ve never seen before. So, as we’re moving along, where, in fact, it looks down and understands what’s going on in the subsurface. We have MEDA, which does — is the metric — meteorological station. It does temperature and pressure and wind speed and wind direction to understand the climate of Mars. So, we can understand better what’s going on in the whole surface of Mars. And then beyond that, we have Mastcam-Z, which is twin imagers on top of the mast that can look out, and it’ll pick — takes the great pictures of panorama where we are, you know, being able to see geologic features and understand where we are. We’ll be able to get a great picture of the — where we are at the base of the Delta. We have Mastcam SuperCam, which is a remote Raman spectrometer, lid spectrometer, and IR spectrometer, and it’ll tell us in the distance what’s the mineralogy like of the site where it — is that mineral, for example, is that rock over there, is that an aqueous rock, because it only could’ve formed under water, or is that rock basaltic, could it only have formed through a volcanic process and things like that. So, that’ll help us understand the entire site, and then we have two instruments on the arm, PIXL and SHERLOC. PIXL is a microscopic elemental abundance mapper. So, what it does is it looks at the elements in a particular sample, so we can tell the history of that sample a lot better. It can identify some potential bio signatures because of life-like certain elements over certain other elements, and then we have SHERLOC, which is on the Principal Investigator of, which then will go in and look for organic molecule distribution. It is an instrument on the robotic arm too. We’ll be able to look for organics. We’re going to look for minerals, but more importantly, than just looking for them, we’ll be able to put them in context. So, it will take an image, we’ll take a picture, and then we’ll be able to tell whether or not there’s layers of organics or there’s layers of minerals, and that helps us a lot understand the history of that sample. And all of these, all of these instruments together, because there’s so many imagers onboard, we can look at all of these results we’re getting back from the same sample and with multiple instruments, and that tells us a lot more about a sample than we would with just looking at one instrument at a time. And the last instrument that I haven’t mentioned yet is an instrument called MOXIE, which is a precursor for a In Situ Resource Utilization, ISRU instrument, which is going to take carbon dioxide out of the atmosphere, and it’s going to take that carbon dioxide and make oxygen out of it. And what that is going to show is we’re going to show for the first time that we have a — the ability to make rocket fuel, which is, oxygen is part of rocket fuel, and whether we can make something that the astronauts can actually breathe in when we get to the surface, and that’s really cool. That’s one of the of us sending humans there, and the last thing that I haven’t talked about is the helicopter, which is the first time we’re going to try a — quadcopter on the surface of Mars. It’s a tech demonstration, and so we’re going to see how that works in the first 60 or 90 sols on the Red Planet, and that’s going to be able to take off, fly for a couple minutes, take images, and then relay it back to the rover. And eventually, that’ll lead to a better way of roving around the red planet, but all of these instruments operating together is fascinating. This really is a payload that’s been thought out in terms of these — in terms of identifying bio signatures and what could potentially be a bio signature, what potentially can’t be a bio signature.

Host: And it sounds like it even goes beyond that, you know, potential bio signatures. It sounds like it’s understanding the environment. There’s — you talked about the MEDA instrument, understanding, you know, what’s going on with the weather and the dust. I love the aspect of human exploration and In-Situ Resource Utilization, that’s going to be huge. A precursor mission, sure, but that’s a that’s a huge step towards humans living and working on Mars. That’s big one.

Luther Beegle: Yeah and living off the land is really important. If you’re going to send humans, you can’t send everything with them. It’s way too volumetric, and it becomes very costly relatively quickly, but yeah, you — what we learned from Viking really was that you need a better understanding of everything to really understand what the biology is like. MEDA does a lot more things than just understanding the wind and everything else. We can look at the humidity levels, whether it’s changing with time, whether something from the subsurface might be, you know, influencing what’s going on in the near surface climate. That’s really huge. Understanding the amount of UV radiation, they’ll be able to measure that to a very precise level, and that goes back into what the chemistry is on the surface. So, you know, everything acts together, and we’re, you know, all of the payload elements works in a really good solid team, and what we can do, you know, is — SHERLOC does — adds onto what PIXL can do, which adds on to what SuperCam can do. And you get a lot more information when you’re looking at something with multiple instruments, which is why sample return is so fascinating. So, when you send something to Mars, you know, you’ve got — you send it, you design your instrument four, five years before you send it, and you — plan on what you’re going to go see. But you’re never 100% sure what you’re actually going to get when you get there, because if we knew what we were going to find, we wouldn’t send anything in the first place, because, you know, that would be dull and boring. But by finding — but by going out there and doing the exploration is when you see something, you know, most scientific — most great science discoveries are always, you know, you just never eureka, it’s wow, that’s really weird, let’s, what is that? What is — what’s going on there? And so, having all these instruments together enables us to do that, and what’s going to happen is we’re going to find something that looks kind of live, that might be alive, that we’re going to be able to capture that particular sample. We’ll seal it up, we’ll bring it back, and then we’ll use every instrument on Earth to look at that particular sample and then come to a scientific consensus, “hey, Mars did have life or no, there was no life associated with that,” and that’s the power of sample return. And we have a well characterized sample, which is even more important. It’s not just a random piece of Mars that just ended up in Antarctica, because we find pieces of Mars all the time in Antarctica, but this is a well-characterized not transformed sample that should revolutionize what we think of Mars and Mars history.

Host: This is fascinating. There are so many interesting instruments onboard looking at all these different aspects but man, that sample return is so exciting. It just makes you want to just let’s go to Mars and pick that thing up and bring it back, you know? I’m sure there’s like a ton of scientists that want to get their hands on that first, you know, sample return from Mars. That’s — that’ll be a big deal.

Luther Beegle: Yeah, it will be, and, you know, the funny thing is, depending on who I’m talking to, I get very excited about either the in-situ science. This is the first time. The in-situ science on this is fascinating as well.

Host: Yeah.

Luther Beegle: It’s the first time we’re actually looking at microscopic type samples on Mars. So, we have the ability on SHERLOC. We’re looking for organics and minerals in 100 micron, that’s the size of the human hair, scale, and what we’re doing is we’re able to take those — that data, and we’re able to look at a postage-sized stamp. So, we’re looking at every 100 microns, we’re looking at something that, you know, we’ll be able to map out and be able to look at a sample and say, look, there’s layering in a sample, and this particular organic matches with this particular mineral, and that’s fascinating. How could those have existed at the exact same time? And then we’ll take PIXL data on that particular sample and say, look that elemental abundance, elements abundance is really, really strange, I think that only biology could have done that, we’re definitely going to take this sample back, and we will learn a bunch of stuff on the surface. The science will be great on the surface, and then we’ll go take it another step by taking the samples back and then doing even more stuff with them on Earth. And that’s where all of the power comes in, because the more things — the more time — the more instruments you can look at a sample, the more you learn about that sample, the more you learn about history, and it just, it takes everything we want out of a mission and put – ties a nice big bow around it.

Host: Well, this is this is actually a perfect place to wrap up, because, you know, you talk about, you talk about all these things that we’re looking forward to learning. We started this conversation with thinking about all the different ways we visited Mars in the past, through all of these different missions, you know? I’m sure there’s folks out there thinking like, you know, why are we — why do we keep going back to Mars? What is there that’s so interesting about Mars that we need to go back and back and back and back? What would be your response to someone who’s asking that question, why it’s so important to go back and continue to learn new things?

Luther Beegle: It’s a great question, and the answer is, we know Mars had everything we needed, that is needed for life to begin back at the same time life started on the Earth. It had liquid water. It had energy sources in terms of both solar radiation and hydrothermal and volcanic activity and chemical energy on the surface, and it had organic molecules. We know all three of those things. So, the big question is, did life start on Mars, and if it didn’t, why didn’t it start on Mars? We’ve lost a lot of information on Earth on the conditions that we’re like back when Earth — when life started on Earth, because we have plate tectonics. Rocks get — rocks come and go, rocks get destroyed, they get remade. There’s not a lot of evidence of rocks that are 3.6 billion years old. Mars has no plate tectonics. So, Mars, the conditions of Mars, 3.6 billion years ago, have only undergone chemical alteration, not geologic alteration. So, if life started on Mars, that’s fascinating. If life didn’t start on Mars, that’s fascinating as well, because we might be able to figure out what was different and what stopped life from starting on Mars or what created life on Mars. Either way, it’s a fascinating answer, and the last thing is that, because Mars was like Earth and Venus probably was like Earth at one point, and it’s long in the past. Now, Venus is way, way too hot, and Mars is way, way too cold, and Earth is perfect. So, we’ve got three planets, all started in the same spot in the solar system relatively. One is too hot, one is too cold, one is just right. So, when we look out, we look at all of the exoplanets that we found, and we’re up to about 5,000 exoplanets, the question is, how many of those could possibly have life associated with them? In order to make that calculation, we really have to understand what’s the difference between Venus, Mars, and Earth, and this mission will help do that. This mission will help understand why Mars is different and what the differences are and what makes it important and what doesn’t make it important? Is life easy to start or is life hard to start? Either way, it’s a fascinating answer, and it really does tell us a lot about where we are and where we’ve come from and where we’re heading.

Host: That’s beautiful. You know, there’s probably so many and, there has to be so many people that you’re working with on a day to day basis, all contributing to Perseverance, yes, but to many other missions to Mars and truly believe all of these things. They have this passion, that, the same passion that I’m hearing from you about exploring Mars and understanding that, just, you know, what is it like working with the team at JPL and with all these PIs that are contributing and wanting to learn about Mars and that passion that exists in this community?

Luther Beegle: So, we — there are probably, I don’t know, 1,000 people that have worked either directly or indirectly on Perseverance, not just at JPL. We have Co-Is at JSC, we have Co-Is at [inaudible], we have Co-Is at Goddard. There are people all over the country that are working on this particular thing, but it is fascinating. And it’s not — at JPL, we just don’t think about Mars. We talk about how Mars is different than Europa, which is a satellite of Jupiter that has more water on it, liquid water than the Earth does. Is life there? Is life on Enceladus? So, we’ll talk about these things all the time, and it’s a fascinating place to be, because you can start asking questions that every — normal people look at you like you’re insane when you ask, but you’re like, well, no, no, that’s what Titan is like, you know, little hydrocarbon lakes of, you know, bubbly benzene and other things, and it’s 90 degrees Kelvin. Could life exist there, could life exist there, and you start thinking about these things in terms of all these different conditions, and there are some great conversations to be had and then great philosophical discussions. The, you know, going back to the Mars question, if Mars didn’t have life, that’s pretty big. If Mars did have life, that’s pretty big as well, and either way, you start figuring these things out, and you start thinking about what does this mean for us as a species? And it’s great, and the teamwork is also great. I can’t — on SHERLOC itself, we had, you know, 50 to 100 people working on it for all of our Co-Is and external partners, and every single one brings this really quite enthusiasm to the team, and it really worked as a great team. And I know that the other instruments feel the same way and other portions of the rope have felt the same way, like there were hundreds of different companies that contributed to the design and build of this in different states and different places, and you can always — you can — you call them up and you start talking to them, you realize how proud they are being able to help do this, and it’s a great experience.

Host: Well, Luther I’m sure a lot of people are feeling pride just even listening to you describe all the different contributions, and honestly, I, you know, I just wish the best to all the team that contributed so many different parts to this mission, whether the engineering, whether the science, and there’s just a lot to look forward to, and to you Luther, I really, you know, best of luck to you and to the SHERLOC team, and I really appreciate your time for coming on the podcast and explaining this fascinating rover and everything on it. It’s been super fun. I really appreciate your time.

Luther Beegle: I really appreciate being here. Anytime, any chance we get to talk about it is great, because it really helps us get enthusiastic about, you know, about doing the day to day job, because it’s fascinating to bring to the public. So, thank you very much for having me. I really appreciate it.

Host: Awesome. Let’s get this thing to Mars! [Applause]

Luther Beegle: Yeah, absolutely.

[ Music]

Host: Hey, thanks for sticking around. I really had a great time with Luther Beegle today. He was so passionate about the Perseverance rover, and I hope it gets you excited for the launch coming up here soon. Go to to find the latest details on how you can watch the launch. If you like podcasts, you can go to There are a lot of them. You can listen to any one of the Houston We Have A Podcast episodes in no particular order. We have a lot of those as well. If you’re interested to learn more about Perseverance or maybe one of the other rovers or landers or orbiters that are on or around Mars, you can go to to learn more. If you want to talk to us at Houston We Have A Podcast. We’re on the NASA Johnson Space Center pages of Facebook, Twitter, and Instagram. Use the hashtag #AskNASA on your favorite platform to submit an idea for the show. Just make sure to mention it’s for Houston We Have A Podcast. This episode was recorded on June 10th, 2020. Thanks to Alex Perryman, Pat Ryan, Norah Moran, Belinda Pulido, Jennifer Hernandez, Cheryl Warner, Grey Hautaluoma, David Agle, Mark Petrovich, and Andrew Good. Thanks again to Luther Beegle for taking the time to come on the show. Give us a rating and feedback on whatever platform you’re listening to us on and tell us how we did. We’ll be back next week.