Bonus episode: InSights Insights


Atmospheric entry on my mark three two one mark on November twenty six two thousand eighteen. The insight mission arrived at Mars after a six month journey of over three hundred million miles. Tom Hoffman is the project manager for the mission on Landing Day for inside is in the Mission Control Center here at the Jet Propulsion Laboratory. Being the project manager. I was sitting in the back all the management from both JPL and NASA were sitting back there with me. It was a little bit nerve wracking. Because they're all looking at me for what's going on and you know I I don't don't know any better than what the call is in the room at any given time mission control is a complete misnomer in that particular situation because the reality is our planned time. Mm for entry descent and landing was a little over six minutes and one way light time at that. Point was eight minutes so whatever happened on Mars had already happened and we were observing serving the past. I wanted to actually have scenes of kittens. Put up on their monitors to keep everybody calm. But that was voted. Down in fact should now be experiencing the peak heating rates portions of the heat. Shield may reach nearly three thousand degrees Fahrenheit as it protects the lander from the heating environments as insight barrel down through the planet's atmosphere atmosphere. It had to perform every aspect of the landing maneuvers perfectly in order to arrive safely on the Martian surface inside his now traveling at one thousand meters per second insight rose to about four hundred meters per second it will deploy twelve meter diameter supersonic parachute. SUSHMITA CAR deputy project scientist for for insight was also in mission control that day hoping this mission would succeed where others had failed seen many disasters in my day and did not want to see one more unfold in front of me out to play out that tragedy and in front of the camera. You can help it. I'm not that that's the most important factor but it adds an extra element of anxiety once the radar locked on the ground and insight is about one kilometer above the surface. The lander will separate from on the back show and began terminal. Defense using twelve descent and Bruce Banner is the lead scientist on the mission. I was in the back row of the quote control room. We're all just watching and listening and hoping of nervous obviously but was pretty hopeful that everything would go well well. It's always the nagging fear back there. That things just blink out and you'd never hear from it again but we were getting to a tree and every time something good happens. That's one less thing or one hundred fifty fewer things that can go wrong and so she keeps on ticking off okay. Well that went well. There's fewer things that can go wrong now. Lander under seperation commanded out the two hundred meters gravity turn altitude four hundred meter three hundred written meters two hundred meters eighty meter sixty meters fifty meters confident philosophy. Thirty seven meters thirty meters twenty meters seventeen meters. Standing by for touchdown touchdown confirmed welcome to on a mission a podcast of NASA's Jet Propulsion Laboratory. I'm Leslie Mullen back with a bonus episode for our first season. We're going to find out. What the insight missions been up to since it landed on Mars incites landing on the Monday after Thanksgiving gave the scientists a lot to be thankful for the mission they dreamed about and sweated over for so many years was was finally on Mars? Tom Says they even set a new record for the fastest successful landing. We came in at five minutes fifty three seconds so it was about thirty seconds seconds faster than we had planned. We spent a lot of time trying to figure out exactly why that was in. The short answer is the upper atmosphere of Mars was a little bit different than we had predicted. We came in a little bit quicker because it was a little less dense. As much as we've studied Mars and done things Mars we've only landed just a couple of handfuls at times understanding the atmosphere is still something we're trying to grapple with two suitcase sized spacecraft named Marco had flown behind inside all the way to Mars and and they played a vital role on landing day insight and the other landers and Rovers on the Martian surface generally can't send data back to Earth directly instead they send signals nose up to satellites that orbit. Mars says Mars Odyssey which then relay that information back to us for insights. Landing the MAR- satellites weren't positioned to the sentence that data right away so the Marquez acted as temporary relay stations as they flew past the planet Bruce says he was on the edge of his seat. Waiting for the mark is to send the first photo that insight took of its landing site on Mars within a couple of minutes. We started getting back that I picture from our ICCPR instrument context camera and that was super exciting. We've already jumped up and down in high five in hugged and stuff like that and then hustle back over to the console for the Image Processing Lead Highly Angle Justin mackey and I were hanging over her shoulder. And she was plugged into the feed for Marco which was still communicating mutating up to seven eight minutes after landing and then we started to get the image down it starts to fill in on one edge of the image and kind of moves across as they get a little a bit more a little bit more data and got sort of like the first tenth of the image and was just reddish muddy looking it just looked like static. And we're going now. Yeah well maybe this is going to be such a great picture and then the next strike came down and suddenly you can see the ghosts of the rock at the bottom of his and suzy saw that. Then we knew yes. This was real image. We have a picture from Mars and then the rest of it started filling in faster and faster than we could see the horizon and it was funny because just like I. We're kind of hanging over Halley's shoulder and as far as I knew everybody was off doing their thing in the room but later there's actually a photo that ended up in a lot of papers across that's the world and there's like a dozen people you'll crowded around behind us and I had no idea anybody else was there. It was just that little bubble with the three of US sitting here looking at a figure things Out But I think half the room was huddled behind us and I had no idea some would say the hardest part was over but the mission still had many hurdles to overcome for one thing. The solar panels had to open. We had to wait for about six or eight hours before we had confirmation to the solar panels was out now is the last nerve racking thing were on Mars safely safely but our batteries are only going to last for twenty four hours or so we went into a radio blackout. Once the Markos went out of range. We had to wait for Odyssey. Talk come back around for its communication passing over the lander to see whether the solar panels had deployed and so we had a little bit of a break where you had our press conference and AH also missed the press conference because my family was viewing the landing with the science team and then once we finished up at the mission control and I went and grabbed them. Bring them over the press conference. And and the Guard's going. Oh wait they don't have a press badge the can't let them in. I said well if they're not going going they're just doing their job but I wasn't in the mood to deal with bureaucracy at that point and so I kept on there looking around for somebody with the Authority to let these dangerous family we members into pressroom and I finally found one of the lab managers. Richard Cook. I said Richard. Can I bring my family and says well. Yeah of course so I actually walked in about three minutes minutes. I think before we had our press conference which was a big party in Bruce. Mannered is our principal investigator and we have been working together for the last seven years to make this a reality Jay. Bruce has been working for decades. And I'm so excited for him. They finally start getting his science back that he's been working so long. And so hard for so bruce. Well I can't tell you what a privilege it is to be up here today. People keep talking about my science and my my mission but this is really something that we're doing. Science team for the world after the solar panels opened inside could sit back and admire the view but the first photo from the ACC camera on the underside of the lander was heavily clotted with dirt or just the high pressure from the blast. Last of the landing rockets was enough to kind of force them dirt under the dust cover and so it was still almost as dirty when we opened the covers four which was a surprise. Ah disappointment but fortunately over the last months almost all that dirt come off the cameras. Now Gimme a really clear picture. Insights landing rockets also pushed a rock about about three feet or one meter that's the farthest we've seen a rock roll while landing spacecraft on another planet team members nicknamed the Golf Ball Sized Rock Rolling Links Stones Rock after the rock band. Sue says the blast of the landing rockets did more than just dirty a camera in Iraq the rockets doug some fairly deep holes on the lander they are about twenty centimeters so about eight inches but nothing actually out of the ordinary and it gives us a little window into the surface. What we saw was a layer an inch or so thick? It's commonly called d'Or crust and it's basically a region near the surface where there's been kind of cemented the grains together you see this of the desert too often because As you have a day night cycle atmospheres cycling in and out of the soil right and it helps introduce minute amounts of water things that can chemically cement things together so so. It's a common thing on Mars. We came down in exactly the terrain that had been predicted. Matt Golombek put another notch on his belt that he got a safe lander under down. And of course one of the first things you do when you start looking at the surface what we get right and what we get wrong. That's the Mars landing site dude. Himself Matt Golombek for me. Is the landing site dude. It's not just the knowledge that you landed safely. I need to see the picture as fast as possible to see whether or not the surface looks some semblance of what we expected until like and everybody else was jumping up and down when they got the telemetry that said that it had landed safely but I was waiting for the first picture which took a little bit later. And that's what I jumped up and down because it was pretty much what we expected insight needed a flat landing site that was relatively free of large rocks. The landing ellipse the area area were insight could possibly come down. Given all the uncertainties of parachuting through the atmosphere was a huge one hundred and thirty kilometers across about the size of Los Angeles Angeles. Exactly where you wind up in that giant ellipse matters. There are some big craters in that ellipse and not all that far away that that we could not have survived in if we had landed on the inner slope of one of those big craters. That would have been death for the lander when you select the site you say well that percent area covered by those dangerous places is less than one percent out of the total. And then you say okay we. We have a ninety nine percent chance of success. And that's kind of as good as you can do. So there's always gonna be things in the ellipse that are worse than others so then the question is how lucky were way right. It turns out. We came down in a rougher part of the ellipse and a rockier part part of the ellipse then. Most of the average of the elapsed bought the individual location where we came down. Was this smooth terrain which is like most of the rest of the ellipse. There was less than a degree slope at all on the surface in the area that we're most interested in there was no rock the bigger than a pebble. I mean they were teeny. It almost didn't matter so we're we lucky that we hit smooth terrain. No that was ninety percent of the ellipse. Were we lucky to have hit smooth terrain gene and that particular portion okay. But you know as they say if you're good then you're more likely to be lucky using using a robotic arm. The insight lander had a place instruments on the surface of Mars. A seismometers to listen for Mars quakes a windshield to cover the size monitor and and a heat flow probe to take the planet's temperature part of mats job was to figure out the best places to put them because insight landed in such a good spot with no big Iraq or slopes to complicate things that was relatively easy. It turned out we could put the instruments in the places that the instrument people most wanted them to be which was away from the landers and away from each other's to have minimal noise moving the instruments off the lander was a slow and careful process. Here's Tom Hoffman. Hoffman again before we can get to that step we have to test that so we have a testbed here at JPL that we set up to look pretty much exactly like Mars or so. We practiced make sure or that. We actually fully understood redoing before we try to Mars. Because you don't really get a second attempt so did it up taking us about eighty seven. Sol's we call days on Marhsall. Seems like taking three elements and putting onto the surface. Mars shouldn't take eighty seven days. We wanted to be sure that we're doing things safely at carefully. So it did take us a fair amount of time to get that done. Their robot arms grapple hand was designed to pick up each instrument by a small lollipop shape structure sticking up out of their tops. We we call those. The grapple hooks basically there the point where the robotic arms grapple grabs and. That's what we have to lift it within is not a very large structure. I'm sure it's pretty thin. It's thinner than a pencil but it is made out of titanium so it's pretty strong but after we had launched we had brought a flight spare seismometers so something that's built exactly like the flight unit but we didn't fly here to jpl in the process of doing some very simple testing we snapped off the scrapple Apple Hook and so that was a big scare for us. Because we're thinking if that happens on Mars mission isn't going to work and and that that would be a total disaster having this ten dollar part caused the whole mission not to work after months of investigations. They were able to figure out what caused the thin stem grapple grapple hook to break in the testbed. We actually had a little bit of a nick in it from some of the tooling and that created a stress point and stress. Point is what broke and we're able to show by looking looking at the procedure and talking to the person who built all of them that that one was a little bit different than the other one and then we went through the process of building a whole bunch more of them using both processes processes and tried to break them and it turns out that I think the one that broke was just really really bad because even the other ones where we tried to make them bad and break and we couldn't break. I mean we Kinda got got lucky that we had one bad one in. That was the one that didn't fly. It ended up not being that big of a deal but we did spend a couple of months thinking really hard about it between the time we launched in the time we landed and trying to prove to ourselves at everything was okay and thinking well even if it isn't okay. There's not much we can do other than try anyway anyway. There's any number of other problems that we have had to. Each of the devices are secured to the deck with basically little bolts that have to activate in release. It's like a phase change material basically thermal expansion reheat it and it expands and then breaks it and then you can lift up the device. Even though we've done lots of testing of making making sure that they release every time you just never know something could get cockeyed in there. We did a lot of testing on earth but earth is not Mars. You always hold your breath whenever you do something for the first first time for sure but in the end dale worked great. One of the most delicate operations was placing the seismometers the sensitive instrument that would measure even the slightest vibrations nations caused by quakes on Mars. When we put the seismometers down one of the things that we needed to do was activate this mechanism which allowed the tether to be we've released from holding onto the seismometers? Both the seismometers and the heat flow physical properties package tied back to the lander with these tethers. And the tethers. There's are what provide the power to each of those instruments and then in turn send commands and then also received the data coming back from the instrument so tether there is a little bit of a misnomer there actually fairly thick heavy and hard to move almost printed circuit boards so pretty stiff. They're not at all flexible. People like your iphone tether. They're much much bigger lot more signals and kind of a little bit of a pain. I frankly because even the little bit of perturbation of the tether shaking in the wind or just even expanding temperature-wise dislike nanometer creates a huge huge annoy source on our seismometers. So you create this whole system to make the tether so that wouldn't be pushing against the size monitor. We have a little loop in there. That's basically annoy shunt. Dont instead of pushing directly on the seismometers any little vibrations or thermal noise or whatever it is pushing against a spring and so one of the things we had to do is actually pull all the tether away from the size. Modern towards the lander which was not particularly easy. took us a bunch of tries to get just pulled back enough because the problem that we had is if we pulled it too much. There's no way to push it back. We kind of had to sneak up on pulling it a little bit in fact the very first time we try to pull it. We didn't move at all second any time we try to pull it. We moved at like barely and then the third time we moved at just about enough in the end that ended up taking us about two weeks all told it took about two months to stat up all the elements of the size Mamata. Bruce says it took another month to make sure it was working correctly. We were busy that whole time. There's a handful of things you have to do. Each thing takes preparation. And then you have to check it out afterwards and we're always trying to make sure everything is safe. We don't WANNA be swinging robotic arm around run into the antenna or punch a hole in the thermal protection of the seismometers so we checked everything in the test faciliate. JPL each one of those was round the clock preparation and work by the team to get it done and so that was an exhausting three months to get the seismometers working. It was worth every minute because the seismometers seismometers has been performing amazingly. Well I mean we're getting seismic data at a precision that is in some parts of their frequency bands. Thousand Thousand Times better than anything has been done on the earth because of the background noise on the earth. No matter where you go on the earth you have a certain amount of vibration just from the storms and the ocean and the waves beating against the shoreline. You can go to the center of Kansas and you're still getting a pretty big signal from ocean turbulence but we don't have any oceans on March so we're actually seeing vibrations that have never been seen on the earth because I can never get that quiet on the earth and so this is new territory for seismology in a technical sense as well as in a geographical sense as has noted in episode two Apollo astronauts had put seismometers on the moon which also doesn't have oceans. The Moon seismometers were very similar. But that was using sixties and seventies technology so they actually got some noise that was as low as ours but over much more narrow frequency band seismic signals have information at all different frequencies and all the different frequency bands have different kinds of information higher frequencies tend to die out with distance. Just like certain sounds you hear from long distance like if you hear thunder from a long distance away is just a rumble. If you hear thunder up close you hear the crack. You hear the high frequencies as well so the hyphen season Seismology Allergy. Tell you about things that are close in but for more distant quakes several hundred miles to several thousand miles away. You're seeing lower and lower lower frequencies as the dominant contributor. And so you want size. MOMBER that measures all the different frequencies all the way down to some frequencies that may be takes almost. Listen our for an oscillation to finish. which is the frequencies that which the whole planet vibrates or rings in episode? Two Bruce had explained how quakes cause earth to ring like a clear clear bell but the moon to crash like a Gong Guests that Mars would have more of a bell ring like Earth. There's the ring. But there's still some of that scattered Kinda hissy stuff going on the signals. That we're looking at are kind of halfway in between so on the Earth if you get a fault fault or get a crack and then just leave it alone. For a few hundred million years there's water that seeps through at minerals crystallize in the cracks and you get a kneeling healing of these cracks and so after some amount of time another wave goes through there. It doesn't even see that crack anymore. Just passes passes through on the moon. It's very dry. And so those cracks maintain sells for hundreds of millions or even billions of years. There's and so there's lots of things that reflect and scatter the seismic waves and so when you scatter a wave instead of going straight from point A. to point it be it bounces around takes drunken walk and finally you know maybe ends up back at point B but instead of going one hundred miles in a direct route it may have taken to three hundred miles to get to where you are and so it comes in really late. So we've got moon quake signals that last four an hour or more whereas the same size quake on the earth with last four maybe fifteen or twenty seconds and so we're seeing some of the same type of scattering processes we think on Mars as we saw the moon and especially for the close events so we think that the outer portions of the Martian crust maybe the upper ten or twenty miles might be more fractured and less a kneeled than the earth. which tells us that? Possibly the Martian crust is drier than the Earth's crust. Although that's still speculative at this point the few events we've had from farther away don't seem to be quite so scattered a few events from a over a thousand kilometers away. Those words are dipping down into the upper mantle. So we think that deeper into the crust or into the mantle. Things don't seem to be so fractured up Marzieh's between the Earth and the moon a lot of different ways and it looks like this is just one more way see that it really lies on that line. Even the picture of Mars is just starting to emerge bruce's happy to be seeing even small Mars. Quakes again we. We didn't start measuring at a level that we could detect them until about saul one hundred and then we went for another month with seeing nothing. which was it's a little concerning so we started watching and we're waiting for our first Mars quake and we're waiting? We're waiting after after about a month was kind of looking are watching sing. And when you're going for weeks without seeing anything you start to get a little bit fearful earful that well do. We really know what we're doing here or really gonNA see something. So First Mars quake that we saw was on Sol. One Twenty eight and it turns out. It's very unusual Joie. We haven't seen another one quite like that. Since most of the energy was at high frequencies and since then most of our quakes have been much lower frequency. Since then we've been getting about one or two seismic events per week. Most of very small earth they would probably be magnitude wonder. `and to were actually only able to see very small Mars quake signals for part of the day. There's a lot of wind activity and so the small quakes get drowned out by that north. We've found out very early on bet. The pattern of atmospheric noise is very repeatable every day eh so about six o'clock at night it gets very quiet and then around midnight. The wind comes up in from midnight to about six or seven in the morning. The wind's blowing very steadily. Then the sun comes up and you start getting turbulence and the noise just goes up quite a bit and then it just keeps on going until about sundown again and we can see that each and every day so now we know the window to spend our time watching Paul Mars quakes one of the Nice things about Earth's seismology. Is You get dozens of Nice earthquakes every day. We get all excited when an earthquake happens. But most of the earth is unpopulated. There's oceans there's wilderness and when earthquakes occur out there nobody but seismologists knows about and so- seismologists can spend a few months collecting being data. And you'll have a few hundred signals to work. From in lots of information there on Mars the activity is probably something like a factor of thousand and less so instead of having several hundred quakes over the course of a month. We have a handful of maybe a half a dozen and so so we have to wait a lot longer for the number of quakes. You have this giant thousand piece jigsaw puzzle and every week we get one piece so we have after. You've really really patient and we have all these pieces that don't fit together yet and just have to assume that as we get more pieces will be able to start making the connection. It's funny I start thinking about what it must have. been like to be a seismologist back in the early nineteen hundreds when people were first starting to piece together you know what was going on the earth but for those first ten or twenty years of the twentieth century you look at Seismic Graham and just scratch your head. What's going on underneath there and we sort of take take it for granted you open up a textbook? There's a cross there's a mantle. There's a core. And they show you nice clean seismic grand with all these wiggles than this corresponds to this path. But somebody had to figure that out from scratch and we're having to do that on Mars now in. It's not as easy as it looks. The weather station on insight helps rule out how a breeze or an air pressure event shakes the seismometers by amplifying the vibration of insight shaking in the wind. You can get a sense of the weather on Mars. Plus as kind of a bonus were actually able to see dust devils in the weather the data we have the pressure data and steering slowly during the day and suddenly it'll drop about several Pascal and interpret that as a dust devil passing very close to us and it's like a hurricane when you have super low pressures in the eye of a hurricane. You have very low pressures in the center of industrial because it's essentially little vacuum cleaner. Where the air from the surface of being sucked up higher into the atmosphere and we can actually see that in the seismic data as well because as the dust devil is sucking up the air is actually like a vacuum cleaner pulling on the ground as well and so we can actually see the tilt of the ground as a double goes by and so we've seen hundreds of those things now and by doing that? We actually get some information about the surface of Mars because the amount that a tilts is related to how Steph off the surfaces that this very stiff. It doesn't tilt very much if it's relatively bendable it tilts a lot and so we're actually starting to measure the elastic nick properties of the upper few meters of the Martian surface by looking at these dust devil signals if a Martian dust devil flew right on top of insight. What are the odds? It would mess up the lander. We were actually worried about that. We have our solar panels out there and they're relatively fragile. They're on pretty skinny. Little spars than actually if you look at the biggest dust devils that have been seen on Mars and you combine them with the highest winds that you see that would actually. That'd be enough to rip the panels right off our spacecraft but statistically that's extremely unlikely and so we beat up our solar panels channels as much as we could within the limitations of mass and volume that we had to work with and we believe that we can survive any likely lead dust devil or even some pretty unlikely ones and so far none of them have bothered small but that's always one of the worries in the back of my mind that some really big dust devil comes by and aw off our solar panels go to some place you know. We're not in Kansas City. Another other instrument on insight called rise is measuring how much Mars wobbles as it orbits the Sun. The wobble of the Martian poll is tied very closely. He to the activity of the core will amount that it actually wobbles back and forth depends on how much mass there is in the core sloshing around we do at least the outer part of the cores ars liquid. So that's working together. With seismology to look at the deep structure of the planet all the instruments on inside aim to help figure out what Mars is like deep inside quakes wake said the result of underground activity a Mars. We think that probably the basic process is shrinkage of the planet as cools. But it's it's more complex because there's volcanoes going on there may be a convection in the mantle that's pushing up some areas and pulling down some other areas and maybe even dragging some things laterally on the earth we have plate tectonics that her moving the plates around either moving past each other at places. Like the Sandra's fault sown or moving them apart from each other at spreading ridges or together at mid ocean trenches in the end even on the earth the forces do plate tectonics talks are from the cooling of the planet plate tectonics driven by heat bringing up hot mantle material to the mid ocean ridges where it cools roles as it spreads and then the cold slab zinc back down into the earth cooling off interior. And so this is just the way that the earth gets rid of its heat. Every planet is a heat engine. What we're really trying to do is understand? The various different heat engines. That are going on. Earth has one that were pretty familiar with this. Got Lots of heat. It's a high performance zengin. The moon might be a car in the junk yard is not really running very well anymore and Mars might be a little bit more of a Volkswagen bug or something like about incites instrument to measure. The heat of Mars is engine got stopped in its tracks right out of the starting gate. Eight sue says the heat flow probe also known as the mole ran into trouble. The first day at tried hammering itself into the ground S.. Started going great guns for about ten to fifteen centimeters and then slowed noticeably thing that we noticed right away is that the sports structure that is holding holding them all in place until it gets underground moved which was a surprise. Wasn't just hammering itself vertically down into the ground at tipped tilted and was pushing against the side it's support structure. Scientists didn't see this happening in real time after the command to hammer had been sent to the mall. The results didn't come back until much later yet. Because we have to send the data up to an orbiter orbiter has ascended back to a deep space network station somewhere on the earth and then it has come Jesus so all that takes in the best possible case it would be a couple of hours almost never do get rapidly usually. It's the next day that you get the data that's in fact that's why everything takes so long because it's basically two days to upland commands execute them down link them and then analyze them on the earth to build new commands 'em cinema looking over the data from that first hour of drilling. It looked like the mole had run into trouble about fifteen minutes. Then we learned that it went down about thirty five centimeters and then it just stopped progressing. 'em We try to second hammering session as well because we weren't clear about what kind of resistance it was is actually meeting. We've of course tried to anticipate every possible scenario and test them out in the lab and among the scenarios we've tested is what if it encounters a small mall rock. And we've seen is that if it's a small rock if it keeps hammering it can effectively push it to the side and keep going have also big rocks and what happens then the case if Iraq has a slow from its top the Malkin actually kind of skipped her around the side. It has a big flat rock than we have no recourse. We were hopeful that perhaps it was a small rock that we can push aside or break as we've seen a lab so he's I try a second hammering session but that did did not progress any further. We basically went into problem solving mode. Chart figure out what could be causing us. One idea was the tether that connected the mole all to the lander had gotten bound up inside the support structure that the mole was housed in. There are these friction springs and basically what their job is is to hold them all vertical while it's dropping out of the support structure and to give it resistance because has a hammer. You've hit a hammer. You know. Hammer has recoil right and so you might think that the hardest time is like when you get deep and you're pushing against more weight of soil but actually the hardest part is getting fully into the ground and that's because of this recoil. We rely on friction from the soil that it's moving through on the sides to stop it from bouncing back upwards and so these frictions brings assist with damping that recoil while the mole all is still in the support structure and so one idea was that may be the mole was tilting and it had somehow snagged the tether inside these friction brings if the Taylor wasn't holding them all back then. Perhaps the Martian soil was to blame another scenario is at the soil hadn't collapsed in around the mall and it made a a whole all and didn't have any resistance to that recoil so which is able to bounce freely backwards. We thought that the soil would just flow in based on our understanding understanding of the properties the Martian soil. So basically we got busy in the lab and brought out all the spare hardware that we had and tried out a whole bunch of things to try to assess assess what we thought was most likely and people pretty much ruled out. The idea of the tether. Getting snagged in these frictions brings eventually. We came to the conclusion vision that we really can't help the mole at all unless we lift the support structure and get a peek underneath to see what is going on. So in our test sped the practice picking up the sport structure with robotic arm and lifting it. We did it in series A. Steps because the risk was that we would on the tether and actually lift the more out of the ground that was fear right so we did it in little small steps. You know you send the man take pictures. The data back analyze slow process and and so it was clear that we will not pulling out of the ground which is good and so through a series of steps. We ended up placing sport structure off to the side of where the mole was stuck into the ground with a support structure off to the side. Insights camera could get a good look at what trouble the mole had gotten itself into so it revealed the pitch the malls roughly an inch in diameter. And there's a whole that several mole diameters wide. We've taken a ton of images at different time. Today's the lights at a different angle and so forth into the bottom of the pit and it's about five inches is not super deep clearly. The soil around the mole has gotten compressed. Because you know where's us well got that soil is patch it either at the bottom of the pit in front of them all off to the sides in the end what we decided to do who was tried to fill in that pit and try to increase the friction on the sides of the mall to damp out the recoil. See if that is the solution to getting it moving again so again took love testing and analysis to make sure we could carry out a push on the soil without hurting either the mole of the arm the scoop on the end of the arm and it has the knuckle the flat and the tip of the scoop so the first thing we did was push that flat scoop against the side of the pit so you just kind of pushing it would collapse it. Fortunately was not clouds it and the next attempt was to take the knuckle of the scoop and push that against the side and again not a lot of motion of the soil straightforward strategy would be to scoop up soil in dump it in the pit well in theory could kind of scrape soil. It's probably easier to do that then to push the soil but it's very challenging. Because when we he placed the support structure on the ground our goal was to put as far as way from the lander as we could because we wanted to keep the thermal affect of the lander as removed as possible so we really stretched the arm out as much as possible initially so to be able to reach beyond the pit Pitt and scoop in. That's super challenging just from the standpoint of the arm and also there's a juror crust who don't actually think it's that hard er be able to crumble it in your fingers. We're certainly hopeful that we can use scooped truncheon and kind of break it into pieces and allow it to start falling into the pit and getting some more of that looser material and her niece to start filling in the hole to the frustration of trying to get them. All going is magnified by how easy it could be to fix six. If we could just go stick a finger on the back of the mall you know it would probably be enough resistance to going again. Really doesn't take a huge amount of resistance the to help it move forward because a recall is much smaller than the forward motion. So it's mother possible scenarios are trying to put the scoop on the edge of the mole or on the back just pushing where the tether is pushing on the top where the other is the last last ditch effort because the tether never designed heavy pushed from the back and lows connections are they're not delegate but the interface interface between the tether and the mole has always been a challenge. Because you WANNA keep it sealed so that the dirt doesn't in there but you don't WanNa Pinch the tether and you don't want it to have too much force from the hammering point forward so that's kind of our Hail Mary. Let's just push in the back and see what happens and seeping begin to move forward. That simple act is tough to do with the robot arm. That's a tricky thing. The arm was never intended to be extremely precise in its measurements and it was never designed to push against anything you know and so basically you commanded to be against the ground and it will kind of keep that forced forced for a little while but it doesn't maintain a push it's just basically holding itself in that location is a different than in pushing right and so we think we can time and so there'll be some resistance. All the moles hammering but not for many hammer strokes so we can imagine. That's very painstaking. Plus his cousin does move forward than it to move the farm fourtou but more more and using the arm takes power. And as the season progresses que- have less solar power available. At some point we could get the Situation where using the arm is impacting our ability to take seismic data. We don't rush and do something that's going to damage them all and just ruin any chance of getting into the ground but at the same time we can't keep doing it forever to save the mole. They must bury the Mall. Tom says the engineers have relished coming to the malls rescue. All the engineers ears were really excited because engineers generally either want to build stuff or fix stuff and we'd already built something and it wasn't working so now he had a chance to fix it. We're GONNA try yeah to see if we can get some dirt into the whole. I called the mole hole or the pit of doom. We can get around almost anything including concrete as long as it's not flat so hopefully we're not hitting any flat concrete. It's a fun fascinating problem to work because if you think about it. You're trying to do something nobody's ever done before. Nobody's ever done anything other than scratched the surface this March literally. And we're trying to hammer into it and we have no idea where we're hammering into. We're trying to figure out okay. Having no idea. We're hammering into. How are you going to get around whatever it is? We don't know about and everybody who's ever dug a hole in their backyard and encountered rocks has infinite numbers of things that they can tell you about in terms of what you should be doing. But we don't have a shovel a we can't look in the hole that well with our one camera only limited things we can do with our arm which never intended do any of the things we're starting to do now in terms of breath scratching or punching or hacking or chopping the soil. Tom Says insight situation is the opposite of what they expected. The initial concern actually really was. Oh it's a filled in impact craters going to be just really loose sand for the seismometers concern. Was it's GonNa absorb a lot of the seismic energy because as it goes through the it's not nearly as good as being on concrete as it turns out. We're probably closer to like concrete than sand on the flip side. We thought Oh this is GonNa be Great Mole Vis GonNa go through this like nobody's business snus because it's just sand. It's going to be like a knife through better. Even the geologists looking at where we landed knowing what they know about the surface of Mars we now know we don't know that much about the surface ars and certainly we don't know that much about underneath the surface of Mars. That's the interesting part about exploration when you're on even earth or another planet but when you try to do something for the first first time somewhere else inevitably something is going to surprise you. Something's GonNa be different even if they can't get the mole to dig down into. Mars insight is learning learning a lot about the planet's interior and the team expects to do so for at least another year. Tom Says what we learn about. Mars is just the beginning even just thinking about how we dug on to Mars and it was different than we expected. Something as simple as that you can think about all the different ways other planets could be so different than what we expect because we look around on earth and there's lots of different places there's icy places there's all okay knows there's underwater trenches that doesn't mean that those are all the same everywhere in fact if anything. I think we've learned just from our little digging experiment that more likely played the not things are a lot more different than they are similar on other planets. There's so much out there we still want to explore. But for Bruce. He's been working for over thirty years this to send us is Mama to Mars. Nothing compares to incite. Even though you're working towards this in you're hoping for it on some level you think probably knuckle now while you gotta try but especially after years and years you have to come to terms with the possibility that just might not happen then it happens and here we are at Mars. I mean the things that I've been dreaming about as possibly happening here. They are and of course once. You're there it's exciting and it's amazing and you just walk walk outside and look at the sky and Fine Mars and think about your spacecraft up there and one way. Many of us are up there on Mars within sight. The lander has a microchip inscribed with two million names of people from all around the world. Go to Mars dot NASA Dot Gov for more details you can also visit that website to learn more about incite. I get Mars weather updates and see all the raw images from the mission. The next season of this podcast will be about a whole new topic. Come come join US soon on a mission a podcast of NASA's Jet Propulsion Laboratory

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