{"id":118,"date":"2023-02-03T11:16:32","date_gmt":"2023-02-03T16:16:32","guid":{"rendered":"https:\/\/unsung.davidpogue.com\/?p=118"},"modified":"2023-11-16T13:42:49","modified_gmt":"2023-11-16T18:42:49","slug":"the-mars-helicopter-that-would-not-die","status":"publish","type":"post","link":"https:\/\/www.unsungscience.com\/index.php\/2023\/02\/03\/the-mars-helicopter-that-would-not-die\/","title":{"rendered":"The Mars Helicopter That Would Not Die"},"content":{"rendered":"\n<h3 class=\"wp-block-heading\">Season 2 \u2022&nbsp;Episode 5<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The star attraction of NASA\u2019s Mars 2020 mission is the Perseverance rover. But bolted to its underside was a stowaway: A tiny, 19-inch helicopter called Ingenuity.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">She was intended to fly five times on Mars, as a wild experiment to see if anything could fly in Mars\u2019s incredibly thin atmosphere. But as the speed, altitude, length, and usefulness of Ingenuity\u2019s flights improved, her mission was extended indefinitely. Ingenuity is still flying, nearly a year after its original mission was to end\u2014and now, NASA is designing a new generation of Mars helicopters, based on her unlikely success. In this episode, meet the three engineers who created Ingenuity\u2014and kept her flying against all physical, planetary, and managerial odds.&nbsp;&nbsp;&nbsp;<\/p>\n\n\n\n<figure class=\"wp-block-audio\"><audio controls src=\"https:\/\/unsung.davidpogue.com\/wp-content\/uploads\/2023\/10\/unsungscience-20230203.mp3\"><\/audio><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">Episode Transcript<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Season 2, Episode 5: The Mars Helicopter That Would Not Die.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>Intro<\/strong><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><em>Theme begins.<\/em><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In 2013, a splinter faction of NASA engineers had the bizarre idea to build a helicopter\u2026 and send it to Mars, attached to the belly of the Mars 2020 rover. Not everybody loved the idea.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">BOB: [00:04:37] \/ There were more than a handful of people who would be very happy to just get this stupid distraction off the rover. You know, it was a nuisance.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">TEDDY: [00:11:52] Yeah. \/ there were a lot of \/ skeptics within the engineering community at large.\/&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Today, the skeptics have become cheerleaders. Today, NASA is designing&nbsp;<em>more&nbsp;<\/em>Mars helicopters. Bigger ones. Better ones. This may be the most amazing Cinderella story in space-engineering history.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">I\u2019m David Pogue, and this is \u201cUnsung Science.\u201d<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>First Ad<\/strong><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">In July 2020, NASA sent a helicopter to Mars.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">You\u2019d be forgiven for having some questions about that line. First of all, NASA made a helicopter? Second of all\u2026for Mars?<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">I mean, how? And why?&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">I mean\u2014a helicopter\u2019s propellers work by spinning through air, right? But how are they supposed to work on Mars, where there\u2019s practically<em>&nbsp;<\/em>no air at all? There\u2019s an atmosphere, but it\u2019s&nbsp;<em>really&nbsp;<\/em>thin.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">TEDDY: [00:09:52] \/ The density is 1% that of Earth\u2019s, right? \/&nbsp; It\u2019s such a tiny fraction when it comes to air density.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">And now you have to think, okay, the rotor blades as they\u2019re spinning, there\u2019s almost nothing, right? How on earth\u2014how on Mars\u2014could they spin fast enough to actually produce enough upwards lift force, right? It sounds impossible and it is almost impossible.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Meet Teddy Tzanetos, NASA\u2019s Mars helicopter team lead.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">TEDDY: (cont\u2019d) \/ to stand any sort of chance of doing that, right, there\u2019s kind of the three hallmarks of a Mars helicopter.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">One is it\u2019s got to be very, very light, right? \/ So you got to be very light.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">You have to have large rotor blades. The larger you are, the more air \/ you can push off of against.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">And you need to spin those blades very, very quickly. \/ we\u2019re spinning at around 2800 revolutions per minute, right? Incredibly fast. Whereas helicopters here on Earth, they\u2019re, you know, around 500 and higher, \/ but they\u2019re hundreds of RPM. But on Mars, you need to spin that much faster \/.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">POGUE: [00:17:40] \/ So \/ the thin atmosphere made it harder to fly.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">TEDDY: Yeah.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">POGUE: But presumably the lesser gravity&nbsp;<em>helped<\/em>&nbsp;you to fly.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">TEDDY: It\u2019s a bad trade. Oh, you are correct, you are correct. But it\u2019s a bad trade overall.&nbsp;&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">So it\u2019s about one-third the gravity of earth, right? So all of us could jump higher. You know, we could probably stand a good chance of dunking on Mars, if we could hold our breath long enough.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">But it\u2019s a bad trade overall because of how difficult the 1% the density makes flying. \/<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">OK, so that\u2019s the \u201chow.\u201d But how about why? NASA already has a rover, and it\u2019s already got a rocket. So what value does the chopper add?<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">AUNG: 13:35:09 So first, if you allow me to state the obvious, we as human beings have never flown in the atmosphere of Mars, right? So this is like the Wright brothers equivalent, right, on Mars. \/ this would be the very first flight.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This is Mimi Aung, who was the project manager for the helicopter. I met her in 2018, while the chopper was still under construction. I was working on a \u201cCBS Sunday Morning\u201d story about plans to get to Mars. the Mars race.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">AUNG: 13:35:50 \/ there are two major\u2013 important\u2013 contributions from adding the aerial dimension. The first is forward reconnaissance. So having a helicopter go kilometers ahead of a rover and \/to see \/ where you\u2019re going will make tremendous contributions for rovers\/.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">13:36:17 And the second part is, there are parts of Mars that we simply cannot get to with rovers, or even when humans get there. For example, sides of very steep cliffs. Very steep volcanoes. You would need an aerial platform that can take you there to get close up to those targets.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">So that was the original sales pitch: \u201cIf this test works, then someday, a helicopter could serve as a scout.\u201d It could look ahead, to see if this mountain or that crater is even worth driving to, so we don\u2019t waste our time puttering over to a dead end.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">We were having this conversation at the Jet Propulsion Lab in Pasadena, California. Better known as JPL, because everything at NASA winds up with a TLA. You know\u2014a three-letter acronym.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Anyway, JPL is NASA\u2019s robotic-spacecraft facility. It\u2019s also where the Mars helicopter story begins. In 2013, JPL\u2019s director Charles Elachi saw a talk.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">BOB: [00:03:37] \/ there was a presentation about what was then the hot new thing, about drones. And he came back to the lab and he said, like, \u201cHey, can we do this on Mars?\u201d<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Bob Balaram is the helicopter\u2019s designer and chief engineer. He and a small team put together a proposal for this helicopter idea.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Very few people thought it was a&nbsp;<em>good<\/em>&nbsp;idea.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">BOB: (cont\u2019d) \/at every stage of the game, you know, \/ we could always have been canceled at any step, right?<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">[00:10:16] \/there are dimensions to this which are not just, \/ \u201ccan it fly?\u201d&nbsp;&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">[00:08:48] \/ it\u2019s not just an aircraft flying on Mars, it also happens to be a spacecraft. So everything that goes with the space business\u2014vibration testing, \/ shock testing, radiation, temperature extremes\/\u2014that was\/ a much bigger add-on than just the fundamental\/ feasibility of, can you spin something fast enough to have it generate lift.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">[00:10:16 cont\u2019d] \/ Like, you don\u2019t want to be this thing that breaks apart and, you know, damages the main rover. You don\u2019t want to be this thing that has batteries exploding. You don\u2019t want to be this embarrassment that goes there and fizzles.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">[00:13:21] \/ So the scientists \/ hated us in the beginning.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">[00:13:21 (out of order)] \/ They were upset because we were taking away precious time from the science campaign.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">(cont\u2019d from earlier) \/ I think if we had failed somewhere along the way, it would\u2019ve been a footnote and they\u2019d have been perfectly happy. \/&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">But Balaram pacified the doubters by reassuring them that the project would be small and limited. The helicopter would fly five times, tops, within a period of 30 days, max.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">And after five flights? End of project. NASA\u2019s focus would fully return to the rover\u2019s primary mission: digging up samples and looking for signs of ancient life.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">BOB: [00:16:45] \/\u2026 and then you guys can get on. There\u2019s not going to be this mission creep where it\u2019s going to be one more flight, one more flight.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">So the helicopter idea got some funding and a small staff. It was classified as a \u201ctechnology demo,\u201d a NASA category meaning, \u201ctech ideas that may one day become useful to our main missions, but for now, are just experiments.\u201d Here\u2019s how Teddy Tzanetos explains it:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">TEDDY: [00:25:59] \/ We do not have mission-critical goals that we must execute, like the rover, for example, right? The Perseverance Rover, its goal is to collect samples so that the next mission \/, can bring samples back to Earth. That must succeed. Ingenuity did not need to succeed.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">To manage the project, Balaram teamed up with our friend Mimi Aung.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">BOB: [00:56:39] \/ MiMi Aung is a force of nature that no programmatic, financial, political thing could withstand, right? And she was, you know, the sharp point of the spear, \/ that was just able to push through all the obstacles.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Mimi Aung taught me what a balancing act it is to create a Mars copter. I mean, you\u2019re limited in its size\u2014to what can fit underneath the rover, because that\u2019s how the chopper was going to get to Mars.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The limited space limited the size of the propellers, to about four feet long. And&nbsp;<em>that&nbsp;<\/em>meant that this thing couldn\u2019t be designed like a regular consumer drones, with four propellers at the corners. There just wasn\u2019t room. The propellers would have to be stacked, one above the other. Mimi Aung walked me through the design in JPL\u2019s kind of noisy facility.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">POGUE: 13:02:16 I would imagine that it\u2019s a very fine line you\u2019re walking, right? I mean, you could put a bigger battery in there, but that would make it heavier\u2013 too heavy to fly. So you could make the wings smaller, but that would make it not powerful enough to fly, you know? \/<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">AUNG: 13:02:33 You\u2013 you have nailed it. (LAUGH) This is the ultimate exercise in system engineering. \/<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">POGUE: 13:10:08 Was there ever anyone who said, \u201cForget it, Mimi. We\u2019re not\u2013 (LAUGH) we\u2019re not gonna walk that tightrope. It\u2019s not gonna work\u201d?<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">AUNG: \/11:10:38 So, yes, there were difficult moments. (LAUGH) More than moments. (LAUGHTER) \/<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">POGUE: 13:03:47 \/ when you add it all up with that amount of power, that amount of weight, this amount of\u2013 of rotor span, what\u2019s the total flight time, and flight distance, and flight altitude?<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">AUNG: 13:04:01 So this particular helicopter is designed now to fly up to 90 seconds. And\u2013<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">POGUE: 13:04:09 Ninety seconds!? $23 million for a drone (LAUGH) that can fly 90 sec\u2013 it doesn\u2019t sound like very much!<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">We\u2019ll come back to my reaction there. Let\u2019s just say that it was not my finest moment as a forward-thinking journalist.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">AUNG: 13:05:00 \/ So it sounds modest, as you say, but it\u2019s an extraordinarily important\u2013 demonstration. Look, this is the first time ever that we\u2019re flying\u2013 in an\u2013 on another planet. Flying a helicopter on another planet outside of our own earth\u2019s atmosphere, okay?&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">13:05:49 \/ And that\u2013 I don\u2019t think you can put a price on that. (LAUGH) Because\u2013 ba\u2013 basically this forms the basis of the fundamental principles of flying in very thin air.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Now, this helicopter doesn\u2019t look like a helicopter. A chopper that carries&nbsp;<em>people&nbsp;<\/em>is horizontal, with a tail.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><em>This<\/em>&nbsp;machine looks more like the Apollo lunar module, but with two propellers on top. It\u2019s 19 inches tall, all vertically stacked components. At the top, there\u2019s a rectangular solar panel; below it are the two stacked propellers. They rotate in opposite directions for the same reason that a traditional helicopter has a rotor on the tail: To prevent the torque from making the&nbsp;<em>body&nbsp;<\/em>of the helicopter spin around.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">And you cannot&nbsp;<em>believe&nbsp;<\/em>how light these propellers are.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">AUNG: 13:44:34 \/ So I want you to hold it.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">POGUE: 13:44:39 Oh my gosh! It\u2019s like a dead leaf! I mean, I\u2019m not kidding! This thing\u2014 I could blow this thing like a Kleenex. That\u2019s amazing. And that\u2019s strong enough?<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">AUNG: 13:44:51 Yes. So\u2013it had to be built for strength, as well as for the stiffness and the light weight. So when we talk about having to fit in a four-pound bag, it is not an exaggeration. \/<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">These blades are not just made of carbon fiber, which already has one of the best strength-to-weight ratios known to man. It\u2019s&nbsp;<em>hollow&nbsp;<\/em>carbon fiber. There\u2019s foam inside to make it even lighter.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Then, below the propellers, a cube, known as the fuselage.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">POGUE: 13:40:15 And so what all is in that box? So camera, electronics, batteries\u2026?<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">AUNG: Uh-huh (AFFIRM). 13:40:48 \/ So if you open, take out the outer shell of it, you will see\u2013 circuit boards surrounding a battery pack.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">And that\u2019s an ingenious design decision. It gets&nbsp;<em>bitterly&nbsp;<\/em>cold at night on Mars. So NASA assembled the circuit boards&nbsp;<em>around&nbsp;<\/em>the battery, because a battery gives off heat. The hope was that it could keep the circuitry warm at night.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">AUNG: 13:43:11 \/ And there are\u2013 two cameras that are on there. \/It\u2019s a side-looking\u2013 color camera to take images of the terrain\u2014<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">POGUE: Uh-huh (AFFIRM).<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">AUNG: \u2014But on the bottom is the black and white camera for navigation. 13:41:24 \/ And then we have landing gears, which are legs. Again, designed to be strong but light, and with some play, you know, for landing.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">POGUE: Nice! I\u2019ll take two. (LAUGHTER)<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">AUNG: Okay.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Part of what makes this chopper project so complicated, by the way, is that you can\u2019t control its flight in real time. It takes anywhere from 20 minutes to four hours for a signal from the Earth to reach Mars, depending on the planets\u2019 positions<em>.&nbsp;<\/em><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">POGUE: 13:17:28 \/ so you can\u2019t be like, \u201cWatch out for that mountain!\u201d It\u2019s not like that.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">AUNG: 13:17:32 \u2013absolutely not. (LAUGH) No, no. 13:18:02 \/ Definitely not a real-time (LAUGH) control of\u2013 or joysticking of any sources possible, simply due to the distance\u2013 \/between earth and Mars.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Instead, the plan was for NASA to pre-script each helicopter flight on earth, and transmit those instructions well in advance.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">But, to me, the scariest aspect of building a Mars helicopter on earth must have been that it\u2019s a one-off. It\u2019s not based on any previous design. There isn\u2019t a series of them that NASA could steadily improve.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">And there\u2019s no spare.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">And you\u2019re going to send this machine on a 300-million-mile journey, to a place where you\u2019ll never be able to touch it again? No repairs, no spare parts, no shelter, no adjustments?<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">To make matters worse, you have to do all your testing here on earth\u2014where the atmosphere, temperatures, solar patterns, and gravity are all different from Mars.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">So you know what NASA did?&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">They used their space simulator.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">AUNG: 00:00:51 We use the JPL 25-foot space simulator here.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">It\u2019s a massive, cylindrical, stainless-steel chamber, 25 feet across and 85 feet high. It\u2019s got an enormous door, 15 by 25 feet, big enough to accommodate the various spacecraft prototypes that NASA has tested inside since 1961, when the thing was built.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">I asked Teddy Tzenetos about it.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><s>Here\u2019s Teddy Tzanetos.<\/s><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">POGUE: [00:46:36] \/ how close can the chamber come to simulating Mars?&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">TEDDY: [00:46:53] \/ Pretty close. \/ What it provides us is the ability to suck the air out. \/ And you can carefully adjust the amount of air that you want to match the density or the pressure at Mars. So that takes care of one part of the equation, is the air density.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">What he\u2019s calling air, by the way, is basically carbon dioxide. CO2 is 95% of the Mars atmosphere.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">TEDDY (cont\u2019d) The second part is the temperature. \/ Around the perimeter, along the inside edge are all of these fins that run the entire height of the chamber. Those fins can carry inside of them liquid nitrogen to chill the chamber down, right? So that takes care of the second part of of feeling like Mars, right?<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">[00:48:36] \/ So, so the third part is \/ the solar actual energy that\u2019s reaching your solar panels. This chamber has a set of large powerful bulbs outside of the chamber. \/ you can beam down onto your spacecraft whatever sort of energy that you want. So you could simulate doing a near, near bypass the sun. \/ And you can dial in that energy to match and test your solar panels, test your recharge capability.&nbsp;&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">POGUE: [00:48:35,&nbsp;<em>moved from above:]<\/em>&nbsp;But you can\u2019t do gravity.&nbsp;&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">TEDDY: (cont\u2019d) \/ you hit the nail on the head. You can\u2019t do gravity. We don\u2019t, we don\u2019t have an anti-gravity system figured out. \/ The closest thing that we were able to think up was a gravity offload system, right? And it\u2019s a fancy name for effectively what is a pulley with a bunch of fishing line rolled around, it attached to a motor and a torque sensor.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\/ so this was at the top of the chamber. \/ So we brought the fishing line all the way down to the helicopter. And we had a little\u2014we had a little eyelet and we tied a very secure and very well-reviewed knot, a series of knots.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">I almost named this episode, \u201cA Very Well-Reviewed Knot.\u201d I mean, they\u2019ve got this helicopter, which eventually cost 80 million dollars, hanging from a piece of fishing line! I guess you really would check that knot carefully!<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">TEDDY: [00:50:28] \/ It\u2019s like, you have the best engineers on the planet here debating knot strategy, right, on a fishing line, right? \/ it sounds clich\u00e9, but the entire project was hanging on the thread of a string at some point, right? If that knot failed, the helicopter would fall, hit the ground and be destroyed.&nbsp;&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In any case, the fishing line was designed to pull gently&nbsp;<em>upward&nbsp;<\/em>on the helicopter, continuously, always exactly enough to&nbsp;<em>subtract&nbsp;<\/em>two-thirds its weight as it flies around. Because Mars gravity is about one-third Earth gravity.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">POGUE: [00:51:57] \/I guess you can\u2019t use the, the swimming pools that the astronauts use, that\u2014&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">TEDDY: [00:52:01] That would have been a little tough. That would have been a little tough on the electronics. \/<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Now, if I learned anything from the movie \u201cThe Martian,\u201d it\u2019s that you have to watch out for windstorms on Mars. Just ask Matt Damon\u2019s character.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><em>Sound clip of \u201cThe Martian\u201d windstorm<\/em><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">So JPL rigged the testing chamber to generate its own wind, too. They bought a bunch of computer fans\u2014the ones inside PCs\u2014about 900 of them\u2014and arrayed them in a giant wall of 25-mile-an-hour wind.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">But&nbsp;<em>not&nbsp;<\/em>because they were worried about windstorms knocking things over, like in \u201cThe Martian.\u201d<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">TEDDY: [00:52:26] \/ I love the movie. A big fan of the movie. \/But most films \/ about dust storms \/ tend to overplay it. You know, it made for a great film. But you got to keep in mind, the air density is 1%. So even if you have fast gusts, fast gusts of very thin air is not imparting a lot of momentum, right? \/ If you have very thin air, you\u2019re not going to have a lot of momentum, you know, transfer when the wind hit you.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\/ That just means that we\u2019re not worried about being tipped over. Wind is a big concern when it comes to flying. \/ We do care about winds, you know, from a stability or controls perspective. \/&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">By early 2020, the Mars helicopter was flying well in the test chamber\u2014noisily, but well\u2014<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><em>Use sound from: https:\/\/youtu.be\/Pd2271JaMeg?t=21<\/em><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u2014and it now had a name. As is its custom, NASA opened up a naming contest to American school students\u2014and the winner was 14-year-old Vaneeza Rupani.<\/p>\n\n\n\n<figure class=\"wp-block-embed is-type-video is-provider-youtube wp-block-embed-youtube wp-embed-aspect-16-9 wp-has-aspect-ratio\"><div class=\"wp-block-embed__wrapper\">\n<iframe loading=\"lazy\" title=\"High School Student Names NASA\u2019s Mars Helicopter\" width=\"782\" height=\"440\" src=\"https:\/\/www.youtube.com\/embed\/6i-UOl9yTJE?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" allowfullscreen><\/iframe>\n<\/div><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">RUPANI: Ingenuity represents the most remarkable things that humanity is capable of.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Ingenuity is a great name, but what have we learned about NASA? That\u2019s right. They shorten all terminology. So Ingenuity soon had a nickname: Ginny.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Another kid\u2019s essay won naming rights to the rover\u2014Perseverance. Wanna guess its nickname? Yup. Percy.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Finally, on July 30, 2020, everything was ready. The Mars 2020 mission lifted off. It was like a set of Russian nesting dolls: The helicopter was nestled beneath the rover, which itself was inside a landing jetpack, which was packed into a landing capsule, which was stored at the top of an Atlas 5 rocket.&nbsp;<\/p>\n\n\n\n<figure class=\"wp-block-embed is-type-video is-provider-youtube wp-block-embed-youtube wp-embed-aspect-16-9 wp-has-aspect-ratio\"><div class=\"wp-block-embed__wrapper\">\n<iframe loading=\"lazy\" title=\"Mars 2020 launch\" width=\"782\" height=\"440\" src=\"https:\/\/www.youtube.com\/embed\/K-UKgePczbY?start=183&#038;feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" allowfullscreen><\/iframe>\n<\/div><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\"><em>Audio of takeoff\u2026 let it play under the following<\/em><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Somehow, the Mars helicopter had made it past the bean counters and the skeptics, the physics problems and the political ones. One executive joked that the&nbsp;<em>helicopter&nbsp;<\/em>should have been called Perseverance!<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">I think that this much of the story has been pretty cool\u2014but it\u2019s nothing compared to what happened after Ingenuity reached Mars. Up next, the part where Ingenuity\u2019s flying blew everyone away. The part where it got frozen to death 200 times. The part of the three miracles. The part you\u2019ll hear after the ads.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>Ad break<\/strong><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Last time you heard from me, the Perseverance rover was lifting off for its 7-month journey to Mars. And it had a stowaway: The first helicopter ever to leave the earth. It was bolted to the belly of the rover, on its side, protected by a cover that, once you take it off, looks kinda like a guitar case with the lid missing.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The whole package arrived at Mars going 12,000 miles an hour. How NASA got from there to setting the rover down onto the Mars surface gently, without stirring up any dust that would have gotten on its cameras, is a story in itself\u2014and an episode of \u201cUnsung Science\u201d in itself, from last season.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><em>{{{{{{{From the Mars Landing episode\u2014a super truncated version of the landing sequence:<\/em><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><em>BEEP!<\/em><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\/ Parachute opens.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><em>BEEP!&nbsp;<\/em><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\/\u2026and the jetpack\u2019s eight engines light up\/.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><em>F jetpack.aiff<\/em><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\/ The rover drops out of the jetpack on its nylon ropes. \/<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><em>5 touchdown.aiff<\/em><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">NASA: Touchdown confirmed! Perseverance safely on the surface of Mars! Ready to begin seeking the signs of past life.&nbsp;<em>(cheers)<\/em><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><em>Let the applause continue.) }}}}}}}}}}}<\/em><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">That was February 18, 2021. It took a month for the rover to wake up, get its bearings, and undergo testing before NASA was ready to drop Ingenuity.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The first step was kicking off the debris shield\u2014that guitar-case thing\u2014on March 21. Here\u2019s integration lead Farah Alibay, giving a press conference.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Farah:<strong>&nbsp;<\/strong>\/ And what you\u2019re looking at here is the debris shield on the ground. \/ But what\u2019s the coolest thing is you can see ingenuity there, all tucked in below the rover, doing okay. \/ Everything is all in place.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The rover, with the helicopter still underneath, spent a couple of days driving to the spot that NASA had picked out for\u2026the copter drop.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">FARAH (cont\u2019d) \/ And then when we get there, we\u2019re going to go through a series of steps to get the helicopter from its current horizontal position all the way to being vertical and then being dropped on the ground. \/<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Finally, the bottom of the helicopter was allowed to swing down 90 degrees, into an upright position. The connecting bolt blew off with a small explosive, and Ginny dropped a couple of inches to the ground.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><em>bolt noise<\/em><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">At this point, the rover drove a hundred yards away, leaving the copter alone and shivering.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Now it was time for Ingenuity\u2019s first big test. No, not zooming off into the ruddy Mars sky. According to Teddy Tzanetos, the first big challenge\u2014<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">TEDDY: [00:20:17] \/\u2026is surviving the first night, okay? Mars is so cold that the sheer problem of just, hey, keep enough heat in the system and make sure you have enough energy in your battery tanks to warm the battery overnight, right, is a huge\u2014was a huge challenge. It still is a huge challenge.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">During the day, summertime on Mars is nice\u2014in the 60s or 70s Fahrenheit. But at night\u2014hoo boy. We\u2019re talking negative 130. And those temperature swings are a big problem for delicate machinery.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">TEDDY: [00:22:19] \/ every time you thermal cycle something, heat something up and then cool it down, everything expands and then contracts, expands and contracts. And just like if you were to take a metal spoon and bend it back and forth, you do that five, ten, 30 times, eventually it\u2019ll snap. Think of now all of the electrical joints inside of Ingenuity, expanding and contracting, expanding and contracting, right? And that, that kind of gets to the core of, of one of these big milestones, is surviving the night \/.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">POGUE: [00:23:14] \/ And we all know that, you know, electric car batteries, cell phone batteries, they all are horrible in the cold. \/<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">TEDDY: [00:23:36] Exactly.&nbsp; \/so what do we do, is we conserve as much as we can. \/ Throughout the night, we would use a little bit of the battery energy to keep that temperature at around -20. \/ And then once sunrise happens, then the SOC starts climbing again.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">SOC\u2014that\u2019s the state of charge. Meaning how full the battery is.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">All told,&nbsp;<em>two-thirds&nbsp;<\/em>of Ingenuity\u2019s battery power goes to keeping the thing warm at night. Only one-third is actually used for flying!<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Anyway, Ginny&nbsp;<em>did&nbsp;<\/em>survive the first night. And the first two months of nights. Finally, on April 19, it was ready to take its first flight. The plan was to spin the rotors up to over 2500 rpm, fast enough to lift the whole machine slowly, majestically, into the sky!&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Well, OK\u2014slowly, majestically 10 feet off the ground.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">And there it was supposed to hover for a magnificent 39 seconds, take a couple of pictures, and then land.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The thing is, at this point, Mars was so far away from the earth that it would take any messages from the helicopter&nbsp;<em>four hours&nbsp;<\/em>to arrive!&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">So for four hours after the flight, the NASA team had no idea whether or not its $80 million drone had even flown. For all they knew, it was a pile of twisted metal in the dust.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><em>First flight 1.aiff<\/em><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Tim: Earlier today, the helicopter flew. As it was flying and after it landed, it transferred its data to the base station. When it shows up, our team can take that data and decode it, and see what happened during that flight.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This is how the live YouTube broadcast went from JPL, as Mimi Aung, Teddy Tzanetos, Bob Balaram, and their team waited for the news from Mars.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><em>First flight 2.aiff (continue through the VO below)<\/em><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">ANN: We\u2019re moments away from getting that all-important data, and the anticipation\u2019s definitely building in the room.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Down: This is downlink. We are beginning to fetch the data from Mars 2020.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Flight: This is flight control. Ingenuity is reporting having performed spinup, takeoff, climb, hover, descent, landing, touchdown, and spindown.&nbsp;<em>(applause)<\/em>&nbsp;Confirmed that Ingenuity has performed its first flight of a powered aircraft on another planet!<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">That data was pretty cool\u2014but not as cool as the data that showed up next: a picture.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><em>(crowd roars)<\/em><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Terr: So the image we\u2019re looking at on the screen is\/ showing us hovering above the surface of Mars. How incredible! The onboard navigation camera points straight down, so we\u2019re seeing its shadow right now.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">ANN: I can just hear Mimi in the background, \u201cThis is real! This is real!\u201d It\u2019s so amazing!<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">TERR: We\u2019re gonna wait for the Perseverance rover image of us.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">That would be\u2026 a photo taken by the rover, of the helicopter in flight.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><em>Crowd loses its mind<\/em><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">It was actually a bunch of frames, kind of like a GIF\u2014a jerky little movie of the first flight.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">And that\u2026 was the first time a human-made aircraft had ever flown under its own power on a distant world.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">On Flight #2, three days later, Ginny went a little higher\u201416 feet\u2014and flew sideways for the first time. 7 feet out, then 7 feet back to the start. Flawless.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Flight #3: 4.5 mph, 328 feet.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Flight #4: 887 feet. This time, another first: the rover\u2019s microphones recorded the&nbsp;<em>sound&nbsp;<\/em>of Ingenuity.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><em>Copter sounds.aiff<\/em><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Flight #5: Ingenuity flew to a new landing spot for the first time, 430 feet away.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Clearly, something spectacular was happening. There\u2019d been a couple of little glitches, which NASA fixed with software upgrades\u2014but otherwise, this thing was performing like a champ. Didn\u2019t crash, didn\u2019t fall over, survived the frigid Mars nights.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The skeptics around Bob Balaram had begun to soften.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">BOB: [00:16:45] \/ in those five flights, we proved our merit. We proved our worth, right? And that\u2019s when things started changing, right? And that\u2019s when the scientists said, \u201cOh, this thing actually works. Oh, those images are pretty darn cool. We can actually infer some geology from them, and we can decide where to send the rover.\u201d&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">One scientist, who\u2019d publicly slammed the helicopter as a waste of time and money, actually approached Balaram at JPL.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">BOB: [00:13:21] \/ he was man enough to just say, you know, \u201cyou guys proved me wrong.\u201d \/<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Ingenuity\u2019s mission was to fly five times and then shut up forever. Go off and crash somewhere. But suddenly, that seemed like a waste.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In fact, the scientists wondered if maybe Ingenuity could do some real scouting for the rover? They wanted to know if a region known as Seitah (SAY-ta) would be worth rovering over to. Answering that question would mean flying Ginny much faster and farther than ever before.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">BOB: [00:18:14] \/ it was a calculated risk on my part, because my take on it was if we succeeded in that flight, that would seal the science case once and for all. And we did that. We did that long flight. \/ we went across the region of Seitah and we did the forward scouting for them.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">[00:19:22] \/ once the scientists saw those images, they were completely on our side, you know, and then they started asking us to go here, go there. \/ [00:13:21] \/&nbsp; We kept succeeding, so they couldn\u2019t get rid of us!&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Suddenly this little black-sheep technology demo found its classification upgraded\u2014to an&nbsp;<em>operational&nbsp;<\/em>demo. And its 30-day lease on life was upgraded, too\u2014now the project was extended seven months, to at least September 2021. It was going to participate in the actual mission of exploring Mars!&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">TEDDY: [01:01:34] \/ there was an area called Raised Ridges \/ that the rover team was potentially interested in exploring, but they weren\u2019t quite sure. And we flew out there. We took some images and we found out, no, it wasn\u2019t as interesting as they thought it was. That\u2019s a win. That\u2019s time saved from the rover. \/Flight 13, we were able to fly around an outcrop called Faillefeu and generate a three\u2014beautiful three-dimensional map that you can look up online and you can zoom around in in three dimensions\/.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Little Ginny was no longer a freak, an orphan, a nuisance.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">TEDDY: [01:04:51] now we\u2019re for real, right? Now we have real mission objectives and the stakes are much higher.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For Ingenuity, it was a miracle\u2014the first of three.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Ingenuity kept flying through the summer, getting better and doing more. On Flight 12, it flew for nearly 3 minutes\u2014so much for that 90-second thing.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">On Flight 18, it flew farther and faster than ever before: almost half a mile, at 12.3 miles an hour.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Throughout these flights, Ginny sent a steady stream of photos back to earth: Of craters, of deltas, of the parachute and other landing gear from Mars 2020 itself. The team kept improving its software with updates\u2014for example, to allow it to fly higher, to let it change speed in mid-flight, and to understand the terrain below it better.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Now, remember: NASA had designed the helicopter to survive for only 30 sols. A sol, S-O-L, is one Mars day. See, a Mars day is about 24 and a&nbsp;<em>half<\/em>&nbsp;hours, so we can\u2019t really use the word \u201cday\u201d; we\u2019d get that confused with&nbsp;<em>earth&nbsp;<\/em>days. So the word is \u201csol.\u201d&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">As the May sols flowed into the warmer sols of June, warmer weather just made it easier for Ingenuity to stay warm.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">TEDDY: [00:31:44] We would charge during the morning and then, hey, we\u2019d be at 100% state of charge by 1:00 in the afternoon. Great.&nbsp;&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">As the mission progressed, we went into the summer. Things got even better in the summer. We had excess energy. \/ We call it Leaving Energy on the panel.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">But everybody knew it couldn\u2019t last.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">TEDDY: [00:25:59] no one designed for winter ops on Mars. She was designed to operate in spring and, and nowhere outside. \/<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In winter, the sun is lower in the sky, which means less light falling onto the solar panel \u2026and on Mars, there\u2019s more dust in the atmosphere in winter, which&nbsp;<em>also&nbsp;<\/em>means less sunlight hitting the panel.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">TEDDY: [00:33:02] \/&nbsp; So we\u2019re not charging as much. And because it\u2019s colder, we\u2019re using more energy to stay at the same temperature, right?&nbsp;&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\/ we knew that we were going to run into a problem here where we might reach our limit. And on sol 426, we hit that limit. We went to sleep on sol 426 with about 70% state of charge in our battery. It was so cold that night. \/ And we were burning energy, burning energy, burning energy. \/ And the battery drained all the way to zero. We stopped heating ourselves. \/ In the Ingenuity mission on sol 427, we tried talking to her, and she didn\u2019t reply.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">So that was it. The copter was unresponsive and frozen. After a spectacular 427 Mars days and 28 flights, little Ingenuity was dead.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">POGUE: [00:44:32] So did you do any, like, little micro-mourning, like, \u201cWell, that\u2019s it. It was a good run\u201d? Or are you trained not to get emotionally involved?&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">TEDDY: [00:44:42] \/ There\u2019s always that question in the back of your mind, you know, did we get to the end of the mission? \/ [00:36:07] \/There\u2019s a part of you that\u2019s always emotionally prepared in the background, right, to \u2026to call it. \/OK, let\u2019s assess. Let\u2019s analyze, let\u2019s find out what happened, let\u2019s see what we can learn from it.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For three days, the team threw themselves into studying what went wrong.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">TEDDY: [00:36:07] \/ pulling up the schematics, pulling up the designs, and trying to come up with any explanation, any reasonable explanation that we could to to explain what was happening.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">You know how, in movies, there\u2019s that trope where the hero starts frantically giving CPR to revive his best friend, who\u2019s been shot? But the hero\u2019s so overcome with grief that he keeps CPR-ing way too long, way past the point where everyone else realizes the buddy is dead?&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><em>Scene like that.<\/em><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">It was kinda like that. The comms team spent day after day frantically pinging their baby on Mars, desperately hoping for a response.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">And then\u2026on the third day\u2026<em>they got one.&nbsp;<\/em><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Ingenuity responded. Somehow, it was alive\u2014and taking commands again.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">TEDDY: [00:36:07] \/ We wiggled our blades. We did a high speed spin just to confirm that everything was still healthy.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">It was the most incredible thing\u2014and eventually, they figured out what was happening.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Each night, Ingenuity really was freezing. The battery really was dead, so there was no longer anything to keep the electronics warm.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">But each morning, the solar panel started collecting energy, and Ingenuity thawed out.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">TEDDY: [00:36:07] \/ What was happening is that every morning it was like Groundhog Day. The sun would rise. She\u2019d have 0% state of charge in her batteries.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">But by pure luck\u2014or pure design brilliance\u2014Ingenuity has a little circuit that directs the first trickle of energy to the battery. Bob Balaram calls it the Lazarus circuit.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">BOB: [00:21:14] \/ So the piece of circuitry that we call the Lazarus circuits, which divert this solar power to first warm up the battery and thaw it out, and when the battery gets to about \/ -13 degrees Fahrenheit, roughly, it then starts charging of the battery.&nbsp;&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">So basically there is a piece of old fashioned electronics, you know\u2014no digital, no computer, no nothing\u2014that brings the helicopter back from the dead every single morning.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Once the battery is warm enough, it begins to charge, and the electronics come to life.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">So why hadn\u2019t Ingenuity been responding to pings from earth? Because each night when it died of cold, its&nbsp;<em>clock&nbsp;<\/em>got reset to zero. So when NASA sent its morning commands at the usual time, the helicopter didn\u2019t know it was time to listen!&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">TEDDY: [00:36:07] \/ And that\u2019s what was happening, is that Ingenuity was waking up later on in the afternoon, \/ and \/ she was waiting, you know, for commands as if nothing had ever changed, right? It was just another day. Just happened to be later on in the afternoon than usual.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Once the team on Earth realized that, they tried reworking the timing of the commands.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Bob: (cont\u2019d) We catch the helicopter at that time, talk to it, set the clock. And then during the rest of the day, where it\u2019s still warm, we then schedule a flight for or any other activity for late in the afternoon. And it does its job, goes into the night thinking it\u2019s going to get through the night. But, you know, \/ we know that around midnight or something it\u2019s gonna die. And then it comes back to life every single morning. \/<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Ingenuity continued freezing to death every night\u2026and rising from the dead in the morning\u2026and it kept right on flying\u2026through the entire winter. For 150 days and nights\u2014until the weather began to warm up again.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Now, incredibly, Ingenuity is no longer freezing at night\u2014it\u2019s returned to its original heating and flying patterns! This chopper will\u2026not\u2026die!&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">It was Ingenuity\u2019s second miracle.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">But as promised, there is a third one. This technology demo, this dark horse, this waste of money\u2026has a third act.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">See, the primary mission of the Perseverance rover is collecting samples of dirt and rocks, and to put them into airtight tubes. But collecting the samples is only Number 1 of&nbsp;<em>three&nbsp;<\/em>missions that will get those samples back to earth.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Number 2, possibly launching in 2028, is called Mars SRL, the sample retrieval lander. That is, a spaceship that will land on the surface of Mars.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">BOB: [00:44:23] \/&nbsp; the Perseverance will trundle up to the lander, present the samples to a little robot arm on the lander, which will carefully take those tubes and stick them in a canister that will then be mounted into the Mars ascent vehicle. And then, you know, the Mars ascent vehicle eventually takes off.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">And Mars mission number 3 will be a ship in Mars orbit that intercepts those samples and flies them back to earth.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">But with a project this big and expensive and complicated, it\u2019s&nbsp;<em>really&nbsp;<\/em>scary to have it all lie on the shoulders of the Perseverance rover. I mean, it\u2019s a fantastic rover, and it\u2019s been performing like a champ. But by 2028, it will have been driving around in the rocks and the dust for eight years, and any number of things could have gone wrong. NASA needed a backup plan for getting those sample tubes onto the lander.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">And can you guess what the backup plan is? Two\u2026more\u2026&nbsp;helicopters.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">BOB: (cont\u2019) \/ So what\u2019s being designed right now, is a variant of Ingenuity that has the capability to do this. \/&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">[00:47:37] And you would have effectively a claw or an arm that would grab one tube at a time. So we are basically adding on four wheels. And a small robot arm to Ingenuity, that Ingenuity design.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">And we\u2019ll have two of those for redundancy \/. They\u2019re called sample recovery helicopters. SRH. I tend to think of them as \u2018Sarah.\u2019 It\u2019s\u2013the Ingenuity was Ginny. We\u2019re going to have two \u2018Sarahs\u2019 on Mars helping.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Even the Sarahs aren\u2019t the end of the Mars chopper line. Balaram is also working on a much bigger copter, capable of carrying ten pounds of science equipment into the air. It\u2019s currently called the Mars Science Helicopter.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">BOB: [00:41:48] \/ the JPL is interested in saying like, \u201cHow do we scale it up, okay? \/ And let\u2019s see what such a system design might look like.\u201d&nbsp; And I was leading a team that did that study and continues to do that study. \/ it would look effectively like a hexacopter, with effectively each of the six blades looking roughly the same size as in Ingenuity, blade diameter, okay? \/<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">So\u2026Three miracles.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The first miracle was that the Ingenuity helicopter, once mocked, cursed, and dismissed as a nuisance, wound up outliving its five-flight, 30-day mandate, and became an essential part of the Mars 2020 mission.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">I mean, I was the idiot who said to Mimi Aung,<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">POGUE: 13:04:09 Ninety seconds? $23 million for a drone (LAUGH) that can fly 90 sec\u2013 it doesn\u2019t sound like very much!<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">I played that recording for Bob Balaram. He was cool about it.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">BOB: [00:02:57] But that\u2019s okay. You can join the line, a long line, of people who are skeptics.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The second miracle was that Ingenuity refused to die, even when Mars froze it solid every single night for&nbsp;<em>hundreds<\/em>&nbsp;of nights.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">And the third miracle is\u2026 that Ingenuity now has descendants. Two will go to Mars on the sample-retrieval project, and could wind up saving the whole three-mission, multi-multi-billion-dollar arc\u2026and a big helicopter with six giant rotors could become a primary vehicle on a future mission.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">As for Ingenuity herself\u2026 she is still flying. She\u2019s survived two dust storms and one brutal, bitterly cold winter\u2014and she is still flying. And still breaking her own records. On December 3, 2022, she flew 46 feet off the ground.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">And nobody can see any reason why she\u2019ll ever stop.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">POGUE: [00:58:53] Is there any hard death day for Ingenuity?&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">TEDDY: No.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">POGUE: Somewhere, some consumable that will\u2014<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">TEDDY: [00:59:02] No, your guess is\u2014and I\u2019m very serious when I say this\u2014your guess is as good as mine. We\u2019re well outside of the manufacturer\u2019s original warranty window, right? That 30 sols really was the design point.&nbsp;&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">But I\u2019m very happy to say that our batteries are extremely healthy, \/ Our solar panels are doing well, our motors are still performing extremely well. \/ Our computer system, \/ is still performing just fine as it was on the first day. So there is no hard date, there is no key consumable. \/ But when that day does come and it will come, we\u2019re going to have a massive party.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">BOB: [00:34:00] If we had failed, no big deal, it would have been a footnote. You know, we would have been saying, \u201coh, yeah, they tried to fly a helicopter and it got two feet above the ground and tipped over and crashed, a ha ha,\u201d you know. And then maybe the social media would have had a field day for a few days and then they would have gone on to the next thing.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This may be a good time to reveal the secret of Ingenuity\u2019s ballast. A little Bob Balaram easter egg.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">BOB: [00:49:24] \/ when we were building Ingenuity, I wanted to have some kind of token of appreciation. A talisman \/&nbsp; paying homage to the pioneers who came before.&nbsp;&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">He learned that it was possible to buy a piece of cloth from the wing of the first airplane that ever flew on earth\u2014the Wright Brothers\u2019 Wright Flyer.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">BOB: \/ Apparently, the Wright brothers were, you know, they were auctioning pieces of fabric from the first flyer to raise money. You know, fundraising never goes away in this business.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">And so, so we got a piece of the fabric. \/&nbsp; and we basically cut out a small piece. \/ you know, half inch by half inch kind of swatch. And that\u2019s wrapped up in some tape and tied to a little cable bundle under the solar panel.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">[00:51:37&nbsp;<em>(moved up)<\/em>&nbsp;I had my engineers sworn to secrecy.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">(cont\u2019d) And so that same piece of fabric flew about a half a dozen times on Kitty Hawk \/, so it flew five times there and it\u2019s flown 33 times on Mars. That little piece of fabric. \/ there\u2019s a lot of parallels, by the way, between what our team had to face and what the Wright brothers faced. \/<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Balaram and Tzaentos are still at JPL, building insanely cool rotorcraft. But in the summer of 2021, Amazon poached Mimi Aung from NASA\u2026hired her to oversee its plan to launch a constellation of satellites\u2014over 3 thousand of them\u2014to provide internet service.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">But Balaram believes that cool, bold projects like Ingenuity are important to NASA\u2019s future\u2014and to its ability to attract young engineers.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">BOB: [01:00:17] \/ it\u2019s a very real issue, by the way, in terms of our retention of people, in terms of what we can offer. You know, kids, people, go to Amazon or here or there and they build some gadget to deliver a brown box into your doorstep, you know, but they get paid twice as much or something, right? And\u2014<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">POGUE: [01:01:05] Yeah. Yeah.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">BOB: [01:01:06] How do you compete with that? \/<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">POGUE: Well, the next time you\u2019re interviewing someone, you can say, \u201cDo you want to engineer something that drops off brown boxes on front porches, or do you want to deliver something to Mars, like I did?\u201d<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">BOB: [01:02:52] You know, it\u2019s\u2014it\u2019s\u2014it\u2019s true. [01:04:36] Packages to Mars versus packages to your front doorstep is still the hook. But it doesn\u2019t mean that\/ we should not be thinking about exciting, good ways of making that happen. \/Hopefully we\u2019ll learn some things from Ingenuity and take that into everything else we do.&nbsp;<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Reference information<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><a href=\"https:\/\/mars.nasa.gov\/technology\/helicopter\/status\/336\/2800-rpm-spin-a-success-but-flight-14-delayed-to-post-conjunction\/\">https:\/\/mars.nasa.gov\/technology\/helicopter\/status\/336\/2800-rpm-spin-a-success-but-flight-14-delayed-to-post-conjunction\/<\/a><\/li>\n<\/ul>\n<div class=\"powerpress_player\" id=\"powerpress_player_6551\"><audio class=\"wp-audio-shortcode\" id=\"audio-118-1\" preload=\"none\" style=\"width: 100%;\" controls=\"controls\"><source type=\"audio\/mpeg\" src=\"https:\/\/unsung.davidpogue.com\/wp-content\/uploads\/2023\/10\/unsungscience-20230203.mp3?_=1\" \/><a href=\"https:\/\/unsung.davidpogue.com\/wp-content\/uploads\/2023\/10\/unsungscience-20230203.mp3\">https:\/\/unsung.davidpogue.com\/wp-content\/uploads\/2023\/10\/unsungscience-20230203.mp3<\/a><\/audio><\/div><p class=\"powerpress_links powerpress_links_mp3\" style=\"margin-bottom: 1px !important;\">Podcast: <a href=\"https:\/\/unsung.davidpogue.com\/wp-content\/uploads\/2023\/10\/unsungscience-20230203.mp3\" class=\"powerpress_link_pinw\" target=\"_blank\" title=\"Play in new window\" onclick=\"return powerpress_pinw('https:\/\/www.unsungscience.com\/?powerpress_pinw=118-podcast');\" rel=\"nofollow\">Play in new window<\/a> | <a href=\"https:\/\/unsung.davidpogue.com\/wp-content\/uploads\/2023\/10\/unsungscience-20230203.mp3\" class=\"powerpress_link_d\" title=\"Download\" rel=\"nofollow\" download=\"unsungscience-20230203.mp3\">Download<\/a><\/p>","protected":false},"excerpt":{"rendered":"<p>The star attraction of NASA\u2019s Mars 2020 mission is the Perseverance rover. But bolted to its underside was a stowaway: A tiny, 19-inch helicopter called Ingenuity.\u00a0<span class=\"excerpt-more-link\"><a class=\"more-link\" href=\"https:\/\/www.unsungscience.com\/index.php\/2023\/02\/03\/the-mars-helicopter-that-would-not-die\/\">More <svg class=\"svg-icon\" width=\"24\" height=\"24\" aria-hidden=\"true\" role=\"img\" focusable=\"false\" viewBox=\"0 0 24 24\" fill=\"none\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path fill-rule=\"evenodd\" clip-rule=\"evenodd\" d=\"M6.96954 10.2804L11.9999 15.3107L17.0302 10.2804L15.9695 9.21973L11.9999 13.1894L8.0302 9.21973L6.96954 10.2804Z\" fill=\"currentColor\"\/><\/svg><\/a><\/span><\/p>\n<div class=\"excerpt-audio-block\">\n<figure class=\"wp-block-audio\"><audio controls src=\"https:\/\/unsung.davidpogue.com\/wp-content\/uploads\/2023\/10\/unsungscience-20230203.mp3\"><\/audio><\/figure>\n<\/div>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3,1],"tags":[],"class_list":["post-118","post","type-post","status-publish","format-standard","hentry","category-podcast","category-uncategorized","entry"],"_links":{"self":[{"href":"https:\/\/www.unsungscience.com\/index.php\/wp-json\/wp\/v2\/posts\/118","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.unsungscience.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.unsungscience.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.unsungscience.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.unsungscience.com\/index.php\/wp-json\/wp\/v2\/comments?post=118"}],"version-history":[{"count":5,"href":"https:\/\/www.unsungscience.com\/index.php\/wp-json\/wp\/v2\/posts\/118\/revisions"}],"predecessor-version":[{"id":282,"href":"https:\/\/www.unsungscience.com\/index.php\/wp-json\/wp\/v2\/posts\/118\/revisions\/282"}],"wp:attachment":[{"href":"https:\/\/www.unsungscience.com\/index.php\/wp-json\/wp\/v2\/media?parent=118"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.unsungscience.com\/index.php\/wp-json\/wp\/v2\/categories?post=118"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.unsungscience.com\/index.php\/wp-json\/wp\/v2\/tags?post=118"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}