Emily Lakdawalla: "The Design and Engineering of Curiosity: How the Mars [...]" | Talks at Google

All. Right so so, Emily this is your first book it is you. Didn't want to start with something simply a. Brief, history of time maybe I mean I know that's been done but, but. But. As. You write in the book this, is the most complicated, robot ever sent to another planet in fact ever sent off earth why did you why. Do you want to write about this and and and why do you say that it's the most complicated well, I think it's fair, to admit that I didn't realize what I was getting into and I started writing this book in, fact. As I explained in the introduction it's not actually, the book that I meant, to write to begin with it's a I, was approached by Springer, to write a book about the curiosity, mission and I. Wrote and I wrote and, I wrote and I, wasn't finishing, and I couldn't I with. A tremendous. Quantity of material, and wasn't able to wrap it up and I finally figured out that the reason I was having so much trouble was because I had accidentally, written two books and so. This, is actually just the first of a pair of books on curiosity the. Second one is going to be coming out next year and will be about the science missions so I kind of was able to partition the. Engineering, stuff into. One book science, to another book and basically. This is the book that I needed in order to be able to understand, the rover well enough to be able to write about its science mission and, so now, I'm writing about the science I'm actually I've got a copy on my desk and I keep on referring to it all the time how many of this thing does it have and how long did it and when did this fail and it's, all in there. So. So so, tell us a little more about why it is the most but what makes it the most complicated robot we've ever sent off this planet it's, a. It's. Sort of the culmination of a long history, of NASA's. Exploration of, Mars and, I. Think, that the key to its complexity, is that as you, NASA. Builds, on from one mission to the next you begin with a very basic broad set of questions what is Mars and you map it and you, find out some more things about what it is and then you ask more detailed questions was water ever important, on Mars and Spirit, and Opportunity were, sent with this mantra follow, the water try to understand, how, more water, was active on Mars in the past curiosity's. Quest are more subtle than that we, know that there was water on Mars but did they ever have a habitable environment that, microorganisms, might have been able to live in and so as the questions get subtler, the, investigations. That you have to do to try to answer those questions get more, detailed more complicated, it's, not enough just to snap pictures anymore you have to have much, more detailed kinds of data and curiosity, has these two highly. Sophisticated laboratory, instruments. That are designed to ingest solid, samples, and perform. X-ray. Diffraction, and x-ray, fluorescence. State performs, gas chromatograph, mass spectrometry. With a tunable. Laser spectrometer and. A quadrupole mass spectrometer it's. Got like all of these laboratory. Instruments, that have been miniaturized to, fit inside the rover and so, just, supporting. That hardware requires. A host of subsystems. That are, necessary. To keep the thing alive you, also have to have a mission that lasts a lot longer. The, warranty. On Spirit and Opportunity is, famously, only ninety days and of course opportunity. Is still going after five thousand, and something Sol's, do you know off the top of your head, let. Me check my Mars time app why it's 5107. Sol's today Emily all right very good so yeah, curiosity. Has not lasted, nearly so long yet, and. In fact it's, quite likely that, curiosity. Will, not last as many salsas as opportunity, does it's almost certain. But. Anyway the point is that that, the opportunity. Was only warranted to last 90 days it was supposed to be able to accomplish its prime mission in that amount of time curiosity's. Warranty ran out after a first year and so, you have to build a much more robust. Year so systems. First Martian yeah first Martian yes right. You. Have to build much more robust systems, to be able to support all of that and so that also, made it more complex because you have a lot of redundancy and other things, built in to make it just last so long and.

Famously, The the, one of those two labs you were talking about the the sample analysis at Mars our Sam instrument I think was rich brick Welch you pointed out that that instrument, alone is larger, than the entire chassis, of the Mars exploration, Rovers that's right yeah and it's big it's heavier than the Sojourner Rover was, I mean it's the size of a microwave which you, know in earth terms for a laboratory instrument, it's amazingly, miniature, but, in terms of what a mobile. / has to support on the surface of another planet its enormous, and has high power demands, it has exacting. Temperature requirements, and it's just it's a very complicated, piece of machinery I think, that might be the size of the entire first Rover that we said yeah so Turner is what Sam is the size of sojourner bigger than the chassis of the Mars exploration Rovers. So. You. You did an enormous amount of research it shows. And it pays off fairly well in this book this by the way is the first technically, or I've read a lot of technically or technically, oriented books in my life and this is the first technically oriented book that I've read that, uses terms like stubborn gunk I think it does a very good job of kind of like making making, these very complicated things accessible to a lay audience. And. That's kind of an outgrowth of the work that you do you're the senior planetary senior. Editor and Planetary evangelist at the Planetary Society do you see this as kind of an outgrowth of that work oh absolutely yes, oh yeah so I, see, what I do at the Planetary, Society as, kind, of a translation, function there's, so many exciting things happening, in science and engineering and space exploration right, now and. While. I was a grad student exploring. These things I thought you, know this stuff is really cool but nobody learns about it and one of the main reasons that nobody learns about is that the the, ways that scientists, and engineers communicate. With each other are really frankly, kind of horrible science. Papers are just bad they're, they're. Boringly, written, they're. Difficult to understand, but. When you train as a scientist or engineer you learn that language and you become capable of reading it and understanding, it and, you. Learn to use a whole new vocabulary of, terms that have very specific and precise meanings, but, when you use that same language to speak to a member of the public you are basically. Speaking a language that's foreign to that member of the public so you have to translate and it's, not one, of the phrases that I hate the most in public communication, is dumbing down because. You are not you're.

Not Making. Things. Stupider. You are translating. To a language, that you can use to communicate with other people and so it's perfectly, possible to, get across. Complicated. Concepts, you just have to use the words that people can understand, so when I need to write about stubborn, gunk I write about stubborn, gunk because that's exactly, what we're talking about we're talking about material, that is sticking to the sides of an instrument that you can't get even, by shaking it and that's, that's what the Phoenix lander was dealing with in the section that I wrote that about and, it you know you've all dealt with that problem in your own homes and lives I'm quite sure and and it's just it's better to write about it in that way it's, more exciting, it is, just, as effective at communicating as saying I don't know high viscosity, material. That. Has adsorbed, onto the walls of the sample collection device or something like that you know you could say it that way but why I wonder, if instead of dumbing, down we could say that this is a smarting, down. Just. A translation it's a translation, of how, everything. Works to make it more accessible to a to. The speaker's of to to people who are non-native speakers, of science right and you're in your well position to do that having trained as a scientist yourself that's that's also your background yes yes I'm a planetary geologist, by training so I as, an, as. An undergrad I did field geology, I got to walk around on mountains and whack, things with rock hammers and draw a pencil and colored, colored. Pencil maps and things and then in. Grad school I studied geology. On Venus using radar images from the Magellan orbiter which, is, just it's such an underappreciated, mission. It's it ended in the early 90s, it mapped, all of Venus in in. Radar wavelengths, and Venus is a fascinating, looking planet I really wish NASA would get a mission back there sometime soon but it's hard it's, hard to study because of the insanely, high temperatures, and the sulfuric.

Acid Clouds and, the temperate the pressure at the surface is the same is that a mile beneath the ocean so it's, tough to build hardware that survives for very long on Venus yeah I wouldn't want to be the guy who'd has to design the rover, that can Rove around where temperatures. Will melt lead yes that doesn't seem like fun yeah solder is not going to work right yes right and the russians succeeded, in exploring, the surface of Venus by essentially, building. I mean, it's no exaggeration but, they were basically clockwork, spacecraft, I mean they were a mechanical. Spacecraft. Because you can build mechanical, components, that can work at very high temperatures, electronics. Especially, in the 1970s, were not ready to. Operate at those kinds of conditions and the Russians being, the Russians built these big robust, spacecraft, that basically worked with. These mechanical, systems and were able to take. Measurements, after landing on the surface for a matter of minutes, to an hour or so before the spacecraft, failed and that's how we know anything about the surface of Venus. So. So, so returning our attention to Mars one. Of the things I think you do really, well in this book, which. Which I greatly enjoyed reading and enthusiastically, recommend by the way. One. Of things I think you will really do well in this book is you you you don't just translate, all of the technical, jargon in terms and people can understand, but you also recognize and this is again part of your work at the Planetary Society I think, that. You can't talk about this Rover just as a machine it's, not just that the rover as a machine it's that there were over like, carries, with it a lot of human hopes and ambitions and, I think you kind of communicate, that as well as is what we're we're, hoping and dreaming to, explore on surface, of Mars yeah. There's a there's, a book that was written actually by a sociologist. By name, Janet vertice who has embedded with several, of. NASA's. JPL's. Operations, teams on space missions and she studies the sociology, of how teams work when. They work on these missions and one of the most striking things that she observed that really made me sit back in Doha is the, the pronoun, that. That. JPL, engineers and scientists use when they refer to the rover you know it's sometimes, some, people do say it it, can be traditional to, call ships, of exploration she. Like you know ocean-going, ships are often referred to as she but, that's it's, not actually very common to use that pronoun for curiosity. The most common pronoun is we and, so. Think about that for a for a minute what it means to be referring to this machine as we it, means that you know we are exploring, Mars we drilled today we are driving across that hill it's, it's, not just one, machine it's, the embodiment, of all of the people participating together, on this mission and it's, it's such a team. Thing especially, because of the way that there, are all these operational, roles on the mission and many, different people who can fill those operational, roles on any on any given day so it feels more like I, don't. Know I feel it feels kind of like being. On a ship on the ocean in a way where there is a captain, but there there's all, these other commanders, and everything else and every person has their part to contribute to make it going and together, you're, on this great ship of exploration, that's what curiosity feels, like and so. It. Kind. Of feels, like there's. A false dichotomy between, human, and robotic exploration because, this is human exploration, right we are seeing the, surface of Mars we're exploring places that humans could never go at least not now and, we're. Doing it through the eyes of robots and I think that you. Know as as virtual, reality gets. More commonplace as. We. Decreased. The separation. Between humans, and the machines, and the software that we use we're. Actually gonna see a merging of human and robotic exploration where. We may have, human, exploration of the surface of Venus except, that it'll be humans in an orbiting spacecraft using. Robotic avatars to, explore the surface and it sounds science fictiony but it's not it's really not that far-fetched, given, current technology, and would. Be a much more efficient, way for us to get human, brains in to, serve, and to rope into environments.

That Are really hard to for, humans to survive, terrible. Radiation, environments, terrible heat crushing. Pressure you. Know all of those things we just put robot bodies down there and we'd so if we can manage use our human brains effectively, then that's, I think the future of exploration right, and then you haven't gone down into the gravity well and so you know I have to get the people boosted, back off the pulse of that yes we can even land the humans on like Fobus or something and have them you, know tele, operating, a mission, on the surface below them so, yeah it turns out to be harder to do Aereo synchronous, orbits that's Mars geosynchronous, orbits, the earth, geosynchronous, orbits, because Mars. Has gravity, field is a lot lumpier and so, it's hard to keep you to do stations keeping with your spacecraft to keep it positioned, over the one. Over. A single. Spot, on Mars but there are like two stable, positions, in. Longitude, or metastable positions so you have to like really want to explore the part of Mars that's underneath a stable, positions, yeah. So, you were talking about the way that that. We embody, the rover right that, we are the rover and the the language that's used but another thing that Janet. Pratesi pointed out was that that in, the same way as we embody the rover. We also use our bodies to communicate, about the rover and so like for example what Spirit and Opportunity will, talk about the solar panels by you, bend your body forward you splay your arms backward in this position because that's what the solar panels look like and that's when you talk about the solar paleis you do that when you talk about the mobility system you kind of move your arms in this characteristic, way right and steer the wheels like this and. And you when you talk about the robotic arm you use your arm and it's always the left arm because they're left armed, did. You find yourself doing that when you're writing this book did you kind of inhabit, there over the rover's body that way I did, that a little bit but I actually find myself doing it a lot less with curiosity than I do a spirit and opportunity everybody else does too yeah so spare, an opportunity, have this they're. Much more human, scale and they're, symmetrical. It's much more easy to, imagine them as having the body plan of a person or a donkey, or a dog or whatever you want to imagine it curiosity. Is um it's. A you. Know it's not nearly, as symmetrical, it's not nearly as pretty and to be honest I really didn't like the appearance of curiosity, when I first started. Doing the research on this book I often, feel like you know there's these three generations, of Rovers there's a. Sojourner. Spirit and opportunity and curiosity and I feel like Sojourner, was sort of a loyal little dog that it, couldn't ever go any farther out of sight of the lander because it didn't have its own communication, skills so it just kind of you know poked around a rock so you could even see these images of it like lifting its leg on a rock because it like drives up and it kept driving and it and there's actually an image of the rover like perched almost, sideways on a rock like this and. Then Spirit and Opportunity are, much more sure-footed, they're bigger they're more human scale so, I in, my extended, animal metaphor, they're the burrows that used to are the donkeys that used to accompany the Western geologists, as they explore the geology, in the American West and then, so what does that make curiosity, well it's the animal designed by committee it's, a camel ship. Of the desert it moves, slowly, and, steadily across the desert landscape you, know carrying, its load lumbering, load with it and and. That's what curiosity is like and like I said I didn't really love, it when I first saw the design but that changed. Actually. The. JPL, had a moment, had. An opportunity for the media to come into the clean room and see curiosity. Before it got shipped to Florida for launch and. I was actually able to put on all the they call it a bunny suit the the white suit and the cap and everything else and go, in and see curiosity, fate face to face and I have to say that I kind of fell in love with curiosity when I had the opportunity to sit there and, and meet it face to face but, yeah I don't I don't feel, like I, embody. Curiosity. Nearly as much because it's it's so ungainly, it's a different, kind of creature from. Spirit, and Opportunity and, and. That. Seems to be kind of widespread on the project to Washington Vasavada talks about about that about how people have you have he feels like people have emotionally, connected with curiosity less, than with spirit opportunity, I. Think. Also it's it, may partly be because of the way that the, spirit. And opportunity are much more.

Responsive. In a way they you, come in on a morning you plan the day and then that's it whereas curiosity. Has to be planned by committees as well where you have. As. Many as four parallel. Planning. Processes, that are happening at the same time operating. On different timescales, you do have a tactical, operations, team that, is planning every day of operations, but, then there's a look ahead planning, team that is planning a couple days of operations, there's, a long-term planning, team that's looking at months, and then there's a project science group that is kind of keeping, track of all of the the mission requirements. And. Unlike. Spirit and Opportunity most. Of the decisions, for curiosity, get made many. More days in advance so. It's it's much less responsive. So it feels in a way a lot more like some of the other big NASA missions, like Cassini, or. These. Other things that need to be planned and much longer, in advance yeah it's, kind of this weird hybrid right where that where for that and for also for project management reasons because it has like lots of pies for the different instruments instead of one VI overseeing, them all as. On Spirit and Opportunity and, so there's there's this kind of Council, of monarchs. Who. Are kind of qualitative so it's all of elders yeah, it's it they're all men by the way which I hate yeah. Really bad so, there's this group of like 12. Pis. And they're all men there's a lot of awesome women working on this team but yeah a lot of a lot of great engineers working on the team and I'm working on operations, as well and, in fact that was one of the things I was going to ask you about was. You. Know you you, cite some of those women in the book some, of the one, who designed the saucepot for exams yeah a sample, acquisition and handling system are. You hoping that a you know as as. You are well known for your kind, of science outreach you're also well known as being an advocate of women in science and engineering and are you hoping that you, know one of the many effects of this book will be to encourage women to go into science and engineering to see that there's a role for them I know it's gonna work I don't think that that's, something. That I see coming as an outcome of this book I think the book is you know designed to feed people's. Insatiable, curiosity about, what curiosity is right and. Honestly. You know as a parent of two daughters I don't see any problems with the number of women who want to go into science yeah, sure it's whether science and engineering wants to keep them there really ultimately it's. These missions are really hard because. They. Operate. When, you first land on, Mars the amount of time you, spend. Just. Continuous, hours working on these missions it's just it's kind of nightmarish and I don't really go that into that that much in this book if, you're interested, in books where kind, of the life of being on a mission is central. You can read there's another recently published book by Allen Stern a David Grinspoon called chasing new horizons, it's about the New Horizons mission to Pluto and at every stage of that mission it was like we, thought we were all in before but we had to get even more all in and then I started, working 16, hours a day and getting by on three hours of sleep and it's like the four Yorkshiremen schedule, right from, Bonnie, Python it just keeps on getting worse and worse and you wonder, how people can last like this and people.

With Families can't last like that for very long you know so you have primarily, young people working on missions at. Least on tactical operations, it's just it's difficult, now over time on a mission like this they, did what, they were able to change the operational, structure so first after, about. After. 90 days they went off of Mars time so. Mars time is where you. Set your clock to the rotational, rate, of Mars which has days forty minutes longer than Earth days and Scott, you're always my example, of the weirdo who loves Mars time because. Like, if you are a person who's like a night owl with no children you have children now of course but if you are a night owl with no children and you love to sleep in what's, not to love about sleeping, in 40 minutes later every day it sounds great but like if you have any connection, with the rest of humanity which. I totally don't miserable. If, you have children who have or a spouse, or partner who, has who wants to like see you during ordinary daylight hours it's absolutely miserable it's also kind of dangerous you know I was on Mars time with. Spirit and Opportunity for, a little while and because, the schedule slips around the clock you wind up. Sleep-deprived. Driving, home after being up all night during, morning rush hour, order. On empty, highways, and you fall asleep while driving and get into a wreck and Steve Squyres is actually really concerned about this and did all kinds of training for the operations, team before the mission started but, anyway after 90 days they. Knew this mission was a marathon not a sprint they. Quickly went off of Mars time, after. 180, days they stopped working on Sundays, after. Another 90 days they stopped working on Saturdays and what that means is that it really builds up your Friday you have to produce a three-song plan a three-day, plan on a Friday and sometimes. It means you're not taking advantage of the full capability, of the rover but, they did do they. Do clever things like some of these instruments, like the Sam instrument has, to cook samples. In an oven that is tremendously. Powered demanding, so, you might say cook them in an oven on a Saturday and just take sunday off to let the batteries recharge, because the rover would have to do that anyway so you might as well do it at a time when you don't want to double up on your planning and so. Over time they have actually managed to get the operations, requirement. Down to about nine hours a day it's, still a little bit long workday, they. Still do kind of play with a calendar a bit so sometimes, you have to come in and work at like 6 7 a.m. because that's when you. Need to get the commands up to the rover before, 2 p.m. or whatever it is sometimes. You have to come in late but they still now they allow everybody to have a, good, night's sleep except. For the poor chemcam team, chemcam, is one of the instruments and it's operated from France, so, now that they're on earth. Time, the. Poor Kim camp team primarily works overnight and it's kind of misery for them but they trade, off there's only they, work in two operational, roles over time like they might have two days on ops per week and, the, rest of the week they're not on ops and they don't have to do that schedule and, so I find, that as these missions. Go on you'll find a lot of older. A lot. More women people. Coming in to operations.

Because The the what, the work time. Is much more predictable, and it's, much easier to balance it with all the other obligations, you may have in your daily life, so. Do your point about families on Mars time you'll remember that when. A curiosity, landed, there was an engineer David, oh-hoo. He, and his wife and their two kids all went on Mars time together, because. The kids didn't have to be back in school, for a month or something, like that and so they all just all went on Mars I mean they were all living it the whole family was living on Mars time which is the first of those that I've heard of yeah, but. Your point is well-taken about that doesn't work for everybody all the time it was actually great they talked about what can you do in Los Angeles with two children, children, at midnight. And. They found all kinds of interesting walk walks they could do with lights and things like that was actually a pretty cool by going to the beach and you. Know overnight is really interesting and so they, had a good time they saw lots of interesting wildlife, they. They went to various all-night restaurants, that the kids loved so they actually had a good time with that so. Um so you studied all the instruments, on curiosity, in, excruciating. Detail for, this book. In. That process did you come out with a favorite what's your favorite instrumental I never have favorites. Matt Shiel I'd go. Ahead I do have to say that that Molly is pretty cool well that's a really cool instrument so Molly stands for the Mars hand lens imager it's mah, Li it's, the camera that's on the end of the robotic arm and. For. Reasons that I go into exhaustive. Detail on in the book it turns out to be the widest angle camp color camera also that the rover has so, I can take the broadest views, and because. It's on the arm you know they can the whole point of it is to take images of. Targets. That they do they're, institutes. And so they'll, use Molly to take an image from about a foot away and then they'll zoom in and take one from about five centimeters, away and then another one from about two one, or two centimeters, away and that gets you a nested, set of images. At. Increasing. Resolution that. Helps you see what's, going on in the rocks. But. Because. It's a focusable, camera, it can also focus at infinity, so you can take long distance views and, of course you can turn it back and look at the rover and so this. Is its the first Mars rover, to. Demonstrate, capability of, taking a self-portrait, on Mars although notably, opportunity. Recently took a self-portrait, on Mars it too has a arm. Mounted camera, it's camera is not focusing so.

The, Images, that it took of itself were very blurry but it's still unmistakably. The rover and it was really quite a thrill to see that yeah it's become part of standard operating procedure, for curiosity. To take a selfie whenever. It's at a drill site and so we have these self-portraits. Of curiosity, across the surface of Mars and you can see it getting increasingly, dusty, the. One that you're seeing on the screen up here is a special, one where. The. The first self-portrait. Actually that curiosity, took was just of the wheels on the surface and you want to do that so that you can check. And see how the wheels are contacting, the surface check, and see the condition of the wheels after the landing, and. They. You. Know after they did that they in, order to do that they have to have the arm very low obviously underneath, the undercarriage or they're over most, of the selfies, are shot at an altitude, that's, similar to the altitude of the mastcam cameras so, that there it's you, know taking, a self-portrait but, this one they were actually at a drill site where the ground sloped, downward, which, made life actually quite difficult for the drill. Team but. Because the ground was sloping downward away from the rover they were able to turn the turret and take a full selfie, from that low perspective. So, that's what gives you this. Very low perspective, on the rover and, those self-portraits. Are cool and it the, some. People on the science team or on the, engineering, team we're dubious but when the the Molly principal. Investigator. And. A couple of the workers on that mission, simulated. What it could look like and showed it to the engineering team they were like oh my god we have to do this and so, like with everything they have to do it on earth before they can do it on Mars and so the first selfie was actually taken by the earth. Copy the earth twin of curiosity. Inside. Its little garage in the, Mars yard at JPL and you can see there's two engineers, in the one of them is Vandy for us she's like the, corner and so as. The camera, images, being taken it's pretty cool yeah I was, I was, I am surprised, that you said the Molly was your favorite because everybody, when they when a when you asked what their favorite instrument on the on. Curiosity is everybody always says the laser OS. Pew pew pew come on. It's, a rover with a freaking laser beam on it say exactly what's, not to love about that, exactly, and actually so the it is kind of fun there's there's very imaginative. Artworks. Of you know curiosity, zapping various things my favorite one actually is one that, I first saw in a chemcam teen chemcam, is the instrument that has a laser, they, were doing a team presentation. At a, science, meeting and they, had a photo, of curiosity. Shooting, a laser and a full-on michaelbay explosion. Happening. At the end of the laser. So. No, it's um I just, I like pictures what can I say pictures tell the stories and I really like the Molly pictures, one, thing camp camp has though is it does have a camera, on it for. To take context, images of where these up with their laser and later. On in the mission they trained to the camera to be able to focus, at infinity, so that you can take long, distance photos and the, camera has this circular, baffle, so, it's.

The Highest resolution camera, can take the most distant photos so it's just like taking a spyglass and, like, seeing these long distance features ahoy. There's that you. Know Valley, Network that we were going to visit in the future and, so I always kind of feel like a ship's captain every time I see those chemcam pictures. Just. So it's clear I didn't mean to disagree with you about the Molly because I think it's a very strong choice if Molly also has a flashlight, yeah. Which is which is Kim, my wife who, works on the Rovers on curiosity. That's, her favorite is the flashlight oh yeah yeah, there's. Actually two flashlights, and the reason for that is because if you're a geologist working, in the field with your rock hammer you smash off a piece of fresh rock to look at the crystals inside and try to identify what, minerals are present you. You'll do this with the rock sample, to try to catch glints, from the Sun to see if there's reflective, surfaces, and what the angles are to each other well curiosity, can't do that but, what I can do is take its two little flashlights, on Molly and go blink-blink-blink blink-blink-blink to. Do lights, coming from two different directions and so that's does to try to to, catch crystal glints I don't know that it's ever worked that way but, they do use the flashlights, at night because, that way they have a light source of known illumination, properties, and so, all the night images, that they've taken of all of their drill sites they can compare, the color to each other because they're all taken under exactly the same illumination, conditions, so. In addition to the the, laser on the rover I actually. Learned from your book there's not a thing I realized before reading your book but I learned, from your book that Dan the Dan of the dynamic, albedo of neutrons experiment, has, an ion cannon yes, we've got a laser and an ion cannon now all we need is a Rover with a lightsaber we've got the trifecta. Yeah. Another. Another really, cool thing I learned about the, science instruments from reading the book was about. The rad which has a scintillating, plastic detector, yes which, I love that name I've decided that scintillating, plastic detector is the name of my muse cover band. Yeah. It's, there's all kinds of fun, terms and, they tend to squeeze. All of these terms into, acronyms. And so you, talk about Sam's, TLS, and QMS and doing GCMs and all of the samples and and I think it's actually a lot more fun to say gas chromatographs, mass spectrometer. It sounds like it, sounds like startstart Trekkies you know and let's, send those let's fire things up in our oven and send them through the, what.

Is It the manifolds, that there are many manifolds, inside sam and you send it with your helium carrier gas through manifold. A and send it off to the tunable laser spectrometer and. See what that's it's just fun it's there's a lot of a lot of fun terms. So. So, again having studied all the instruments, and like this exhaustive. Detail as you say which. Which of them do you think was the the most complicated instrument. Of. All of them on the were over that one's easy to answer but the first thing, I want to answer is is like when he says exhaustive, detail exhaustive, is the most, common adjectives used to describe my, book and I'm just glad that it's not exhausting, right. So. Yeah so it's fascinating by, the exhaustive, right, so. Definitely. Without question, the most complicated instrument, is the Sam instruments, so Sam means sample analysis at Mars it's one of two laboratory, instruments, and it's interesting that the two laboratory, instruments, one of them is really very simple and that's, it's, a that's an instrument, that it has a it. Has a laser that, it shines through a little sample of powder and it, it shakes the powder so that those crystals, all, toss around in various different, orientations, and the crystals scatter the light and you get a diffraction plot, it's the same kind of technology, that rosalind. Franklin used to figure out the structure of DNA you're, doing x-ray crystallography, basically, and it's. And, that's all it is you take a picture of the, of, the diffraction and then you download that picture and you can say oh these minerals, are present and, that's it and that's, one of the two. Laboratory. Instruments, but then there's Sam and sim, is, ridiculous. I cannot believe they actually built this instrument, and put it on a rover on Mars it has. It. Has a carousel.

Of More. Than 70 little quartz cups it can rotate this carousel under two different inlets, to receive samples, then. It rotates the carousel, and lifts a cup into an oven in. The oven it can heat things up to 500 degrees it. Can heat it in steps it can heat it with a ramp it can heat it for a little bit then hold it or not it can, heat it all the way it can heat it part way it, can take it down and do it bring, it back up again and, then, there is a little, helium tank that takes all of the gases that come off of the oven and sends them into one. Of numerous, possible, different instruments, but before that it sends them into these little chambers, called manifolds, which. Are you know a manifold is a place where you have lots of things. Intersecting, and by. Opening and closing one, of dozens of different valves, they can send the material, on to different getters, and scrubbers, which take. Certain stuff out of out of the the. Gases they. Can turn, turn on a getter for a little while and then heat the getter to release the stuff again and then they send that into one of three different instruments, so, there's all these valves, there's, all these different ways that all these knobs to turn. They. Actually developed a basically, a programming. Language that they can that the Sam team can use to, send. Things through the Sam instrument one of the wackiest things I think is that the the, P I on the Sam instrument was very proud of the fact that it's that he can he programs it in basic, right. I was. Like I know. And I know very little about programming, languages, but I know enough to know that that's not something to be proud of it's. Not widely used at Google that's yeah. So. Anyway, it's um it's incredibly, complicated and to most people it's just a box that, you that. The Sam team asks. For knobs, to be turned and they turn the knobs and data comes out and then even. Once you have the data you still don't have answers because. The. Kinds of things that they're trying to figure out are so complex, that the only way to be sure that you've figured it out right is to. Create. A sample, of known composition. And put, it through a duplicate. Of the instrument, in a lab on earth under Martian conditions so, that's temperature and vacuum and it's, so, Sam. Results there's actually going to be a press, conference. Tomorrow, concerning. A science paper that, is. One. Of the main people on the press panel is Paul Mahaffey who is the principal investigator on this instrument and so, I'm.

Sure That the paper concerns, data that was taken at least six months ago probably years ago because, that's just how long, it takes to understand. The results from this instrument. Fortunately. There are other instruments that produce much more rapid results and, make things a little more interesting for those of us following along in the mission so, the Sam instrument has another talent if there were a talent show on Mars. Curiosity's. Entry would be singing that's. Right Sam famously, sang happy birthday to itself, using its AM instrument I actually don't know the details, of what was. Vibrating, or making noise it was it like an FPGA or something the heavenly I don't. Know the details my wife is the instrument engineer, for the Sam instrument show so she could probably tell us about that exhausting. At detail so. So, anyway but this story does surface once a year yeah right, but I am. Here to tell you it does not sing happy birthday to itself every year that once on Mars it was a cute little stunt and and. That's uh that's, it, so. We've, been talking for about 40 minutes what's. What's thrown out for audience questions. As well, and. Kind of while we're getting so oh have you seen our microphone this is really cool the microphone is in a little box and a soft box and they can just throw the box around the room but. While, we're while we're waiting for that let me ask you you were saying the Sam instrument is complicated, instrument was it also the hardest to explain it, was absolutely by, far the hardest to explain to find about 50 pages of this book on the same instrument and I I warp. All Mahaffey out asking, questions, about because. You know when I first started writing this I envisioned. You. Know you you you have. You heat stuff up you get a gas and it, goes through the machine comes out and but that's not how it works at all you keep you, heat it up you get a gas and goes into one place then you open a valve and it goes into this place then you might be turning on something that pumps slightly but not too much and you get like a gradient going that it's, so, incredibly. Complicated that, the the main comment that I get from people on the mission who are not on the Sam team is thank. God somebody finally explained, this to me because I have no idea. So. I was wondering how does the delay. Between. Earth and Mars like affect the teams that operate the rover like is it a lot easier to do work when Earth and Mars are close together ah so, no actually, that's a good question so Mars, and Earth have widely. Differing, distance. To each other which affects the the, communications, lag but the, fact of the matter is that because. The, lag is many minutes regardless of, the relative distances, there's. No real time commanding, so you are always doing, a, full, saw worth of sequencing, at a minimum you, send the rover receives its commands at 10 a.m. every, morning Mars. Time and so. The, reason that they do that is because Earth is always, up in Mars's, sky at 10 a.m. local time earth, is closer to the Sun than Mars is so it's always somewhere, relatively, close to the Sun and so if you're doing your commanding at 10 a.m.. Earth will always be up in the sky although sometimes it can be a little low on the horizon and so, the, rover executes, it's 1, Sol's worth of commands, and then, in the afternoon. There are over flights by two Mars, orbiters Mars Odyssey and, Mars Reconnaissance Orbiter, and it. Sends, its data through. A UHF, connection. Up to the orbiter which receives, the data and then relays it on to earth and so, there's also overnight passes, by the orbiters, and so you. Wind up having the command, in these at minimum. Once all increments, and so, it really doesn't matter, how close Mars is except. That. It is, you. Can get much higher bandwidth. In your transmissions. Between Mars and Earth when Mars is closer so, you do get more data returned from the orbiter because, it can communicate faster, you, can use a higher data rate when, they're close and so you'll see these like seasonal, spikes and data rate that are not actually, seasonal, they happen when Mars is near opposition, when Earth and Mars are close to each other and then, on the opposite side when when Mars gets into conjunction, with the Sun you actually have three weeks where you're not, allowed to talk to the rover at all because if there were a problem you couldn't be sure that your message, would get through unguarded. To be able to save the rover so they all the spacecraft, kind of hunker down and go into a fairly low activity mode during conjunction. I. Have a question. Are. There pieces of the rover that it, can, separate. From itself, like in the selfie, picture I don't, see how there's something attached to it that would take the selfie right so, this. The question of who took the picture and how the selfie works is one that pops up every single time I post a selfie the, issue is, that although.

The The field of view of the Mali camera is fairly wide it's not anywhere near as wide as the kind of camera you have on your cell phone it's actually very narrow so, in order to take a selfie. The rover actually takes about, 70, pictures of itself in kind, of a matrix, sort, of way, and it. Repositions, the arm to keep the arm out of you you know it would never be able to photograph its whole arm regardless, and so. You wind up mosaicing. And image together. Like. This out of out of multiple different images, and they, just they. Do it in a way so that the the arm is not constantly, poking into view from all these different directions because when. When. You do take the selfie, you do see. You. Know you you will see the arm in in multiple images, and so you have to come up with a way of, neatly. Cutting, it off you actually see more of the arm in this picture than you see in most of the self-portraits, usually, they chop it off at the shoulder, because, otherwise, it would be crossing, the front of the, rover. But because of all those multiple pictures you wind up being able to get the arm out of it and there's, no real sensible. One, of the more disconcerting, images, that I've seen was a self-portrait, taken, by the mastcam, which. Is the, only way that opportunity, and spirit can take self-portraits, as you take a you, can get a mosaic. Of the deck of the rover by, shooting multiple images with the mastcam and in, those images of course the mast is missing because. It can't photograph the mass camp it can't photograph its own mast and so you, wind up you get a great view of the arm but the rover's headless and it's really kind of disturbing. This. Wasn't, this the one that had the like really difficult. Landing like, it was really complicated and, they were really worried about it, well. If you guys didn't a lot of detail about that in the book by the way it's really fascinating yeah, so, it's. Kind of fun it was a really complicated landing, it's a Rube Goldberg II, and landing, so it has the. Problem with landing on Mars is that it has enough atmosphere. To burn you up but not enough atmosphere to slow you down so, it's easier, to land on the moon it's easier, to land on Earth on. The moon no atmosphere, you just streak in blast with retro rockets boom you're on the surface and a problem on earth, parachute.

And Heat shield slows you down enough where you just kind of Coast into a landing that's what the space, shuttles did that's what all the Apollo, capsules, did on Mars, you have to combine all of those things so, you have a heat shield that, takes you from interplanetary. Travel, speeds down to supersonic speeds then, you have a parachute, that takes you from supersonic, to subsonic, then. You have rockets that slow you down from subs from subsonic to still. And then, you have to touchdown and, different, missions, have accomplished this in different ways most. Mars missions are Landers and so what the Landers typically, do is they get down úrsula Vander's as opposed your world as opposed to Rovers yeah sorry so. They get pretty close to the surface and, then usually, they, cut off their rockets right, above the surface, because. You don't want to be blasting, the surface with a lot of rocket, exhaust and so, they'll have like crushable, legs, that's. What Fenix and insight have they have legs that can take up that last bit of drop or, you'll have what Spirit and Opportunity had, which are the airbags, surrounding, and it actually bounced, to a halt which I think is, I mean. Ridiculously. Expensive machine, and racket, on the surface multiple, times, that's, what spirit and opportunity and pathways and, so. Curiosity's. Approach. Curiosity. Was already too big to have any extra Lander hardware and so it said it had a rocket assisted backpack, that, it lowered, the rover on a rope and, the. Rover and then gently let the the, rover touch the surface and there's slack on the cables and once, the machine detected. That there slack on the cables it cuts the cables and flies the jetpack away which, like you can just imagine it's, just like in a wily coyote, car. Like. A big explosion that we, got a picture of which we actually got a picture that was amazing, the first curiosity, image from the surface of Mars was taken by its rear has cam and you see this plume of dust on the horizon, and they later figured out that that was probably the, the plume from the explosion, of the jetpack when it crashed on the surface which i think is just great so, yeah so it was it's an incredibly, complicated. Landing, but as I explained in the book it's actually not really out of family from what had been done before. Hanging. The rover on a rope was, actually exactly what they did was spear at an opportunity that airbag thingy was. Descent was hanging, on a rope off of the, retrorockets. And so. The. Landing, looked, ridiculous. But. It was very well modeled and after. They had the the, two-year launch delay I have, never seen engineers as confident, as I saw I mean engineers as a rule are not confident people they're like well it might work if all the conditions are right you know they're they, don't want to tell you what's absolutely going to work because like as, they say in the rocket business there's a thousand.

Ways For a launch to go wrong only one way for it to go right and so. But. When they were, they. Had the last two years to really prepare, and throw all kinds, of, situations. At it you know dust storms, and and bad. Navigation. And, failure. One of the rockets and all kinds of stuff and the machine in their simulations, performed. With flying colors and in the in the final event it was just straight down the middle everything was nominal, nominal nominal. Except. For one little detail that maybe I'll let you guys read the book for. So software people while the mic is going to the next person software people like us understand, the concept of, Easter. Eggs a, little hidden things and you know maybe your web browser you hit ctrl alt shift S and it pops up a flight simulator or something like that and, curiosity, has one of those Easter. Eggs as well in in the wheels, before. They before they had not on purpose wheels in them they had on purpose holes in them that's. Right so if you look at, the the wheels of the rover you can see that there are deliberately, a whole bunch of holes punched in them this, is kind of a callback to Spirit and Opportunity which. They were connected, to their Lander with these bolts that were fired and, separated, after landing and so, there are holes on spirit and opportunities wheels that are there just as an artifact, of the method. By which they are attached to the lander but they turned out to be really useful for the science team because, you can see the little mark that the holes left in the wheel tracks to actually measure distances. You. Can also use it to see how much the rover wheels slipped, during driving so you can kind of measure distances, in one way and then in a different way and see how, long or short it was and the rover, actually, got to where it was using this for odometry, it could actually use its own wheel tracks to help understand. How far to travel so. They wanted to include some kind of, odometry. Marking, on the wheels on curiosity, to. Make sure that it would be easy to tell how. Many wheel, turns there had been in the rover tracks and so, the first thing they did was that they actually machined, the letters JPL, into the wheels into the treads and. So there's a picture in my book of the of the early, set of wheels that has JPL, on it so it left tracks JPL, JPL JPL knows what was going and that's was like you guys you can't do that so they. Came up with another plan which was to put the letters JPL, in the wheels in Morse code so. That's what you see there's three rows there and they have like narrower, and wider gaps and that's the letters JPL in Morse code.

Um. So, this isn't actually, a curiosity question because. There's something else you mentioned earlier that's been bugging me you, said the Russian has landed a mostly, mechanical. Lander. On Venus and, the. Electronics wouldn't stand up to the surface temperatures how did they communicate the. Information off the. Planet to us well. I, don't actually know and about, the, about. How those missions worked I mean they they did have like a pressure vessel a temperature. Safe. Vessel, on the inside, that had the electron, the limited, electronics, that there were and they did do radio communications. Director. Earth they didn't have orbiter so they were doing it direct to earth but then Venus is actually relatively close to Earth so you don't have to have very powerful radio, to get that data back, I'm, afraid I'm not an electronics, person myself so I don't really know the answer to that question. I. We're. Kind of starting to run, a little low on time and. It kills me that we're not going to get get, to all the questions when I ask you maybe we should take one more audience question and I'll ask you kind of a wrap-up here okay so my. Question is uh what, happens if something mechanical, fails is there any self, repair, kind of ability, there. Is not, but, there's a lot of redundancy a, lot of redundant, capability so. There's, a lot of planning done to, figure. Out how the rover can still accomplish its mission even. If this that or another component fails. So. Like the computer systems are fully redundant, there's an a side and a b-side and various components are cross strapped to each other so when a computer fails as actually, happened 200 days into the mission they, can swap to the backup, and operate. On the back up while they repair the prime computer, and so they've done that with them with the main computer already it actually took them a long time to bring the backup back online which is kind of scary, there, have been mechanical, problems, like problems, with the wheels and so, you. Get through that through, robustness, basically. Any one, of the wheels the motors are powerful, enough to to. Raise the entire rover's, weight vertically. So like if you attached a rope to it you could wind a rope on one of the wheels and it would and the motor is strong enough to be able to lift the whole Rover. This. Actually became important, for Spirit and Opportunity because, both, of them have had different kinds of wheel failures and so, spirit in particular was dragging, one of its wheels for a long time but. The rover is still able to drive that way and it's a good thing because we made some science discoveries, because of that yeah and so the, biggest problem that curiosity, has been dealing with lately is a, as a major mechanical failure in the drill so. The drill used to operate with a pair of prongs that have pressed against a rock and then there's a feed mechanism that, pushed the drill into the rock while, there everything, else stayed still and the feed mechanism failed, almost. Completely, they it was very sticky they. Couldn't get it to move backward and forward which is critical, for drilling and so over. The period of more than a year now they've, managed. To get the bulky feed to extend, all the way so now the feed is permanently, extended, and they, just, a couple weeks ago for, the first time managed. To do what they call feet extended, drilling where instead of using the the feed mechanism which, no longer works they're now using arm. Motion. Motors so, it's like taking a drill and trying to drill into a wall like this so you can imagine it's, hard but but the curiosity's, arm is pretty strong and so they just kind of lean on the arm and they push the drill into the rock and it worked so it's. Taken them a long time to fix it but, these. Engineers. Are really, ingenious, at solving problems and so a. Lot of what you do on an extended, mission and extended. Extended mission which is what curiosity is on now is figure out how to make the most of an aging machine that, does have problems but can still do great science where it is and so. All. These people have a lot of experience, in making. Old. Grody, machines, work I mean I'd like to write a book about Galileo, about all the things they had to keep that thing going after, radiation, freighted, at Jupiter multiple times and, so, curiosity, still got a lot of life in it they'll, have problems. But. You, know they wish the problems weren't there but they like. Okay here's this is our new reality and we'll keep going that's. How it works so it's. It's killing me that I've got like 20 more questions here and we've got like three minutes so that's not enough time I'm thinking but. But. Maybe, we can end, on this note by, asking you like. What. Do you hope that readers will take away from this gorgeous, terrific book that I could not more highly recommend oh, gosh.

I Hope that they will I guess. I hope that people will take away the fact that they can understand, this. Is a very complicated machine but what it's doing why it's there and how it works are not, are, not inaccessible. To, everyone now, one of the great things about space exploration I, think is that it's, easy to explain why, we're doing it the fundamental questions, we're trying to answer was. There ever life. On Mars are we alone in the universe that kind of stuff and. It's and it's fairly easy to understand, how we're going about solving those problems we're, sending a robot with a drill that's like sampling rocks and we put them into a lab and and all of these things you can communicate, with children you can communicate, with science interested adults as well and, it's just very accessible, and. Everybody. Can kind of participate, in the adventure by following along with what they're doing they share, their raw images, straight from Mars directly on the internet so, that you can see everyday you can tune in at JPL. And see what they've been doing I highly, recommend, midnight. Planets, calm. As a it's. A enthusiasts. Built website. That aggregates all, of the images, from the different Rovers and and puts them up ways that are easy to see and it's a it's, just it's a fun adventure and, we're all part of it basically Emily. I'm so sad that we're at a time. But. I enthusiastically. Recommend this book the book is the design and engineering of curiosity, how the Mars rover. Performs its job all, the stuff you've heard us talk about today and a whole lot more stuff is in there it's really terrific I highly recommend it it's also on my blog at planetary org slash blog, you'll, find I write updates about every two or three months and what curiosity is doing I'll probably have a new one out in a couple of weeks I. Wish we had another hour to talk but maybe you'll be able to come back and we'll be able to do it then in, the meantime please join. Me in thanking our guest today Emily lacta Walla.

2018-07-01 20:53

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