Speaker 1: Get in touch with technology with tech Stuff from how
Speaker 1: stuff works dot com. Hey there, and welcome to tech Stuff.
Speaker 1: I'm your host, Jonathan Strickland. I'm an executive producer with
Speaker 1: House to Parks and I heart radio and I love
Speaker 1: all things tech. And On November two, eighteen, after traveling
Speaker 1: four hundred fifty eight million kilometers or three hundred million
Speaker 1: miles on a trip that lasted nearly seven months, the
Speaker 1: robot platform Insight touched down on the surface of Mars.
Speaker 1: They marked the eighth time the United States has managed
Speaker 1: to land a mission on Mars successfully. So we're gonna
Speaker 1: take a look at this lander, what it does, and
Speaker 1: what it's mission parameters are. Before I get into Insights specifically,
Speaker 1: it's a good time to chat about the logistics of
Speaker 1: just getting to Mars in general. You may have heard
Speaker 1: that if we were to send people to Mars, they
Speaker 1: need to stay there for about two years before they
Speaker 1: could return. So why is that, Well, it's because of
Speaker 1: the respective orbits of Earth and Mars. Mars is further
Speaker 1: out from the Sun than the Earth is, and a
Speaker 1: Martian year lasts six hundred eighty seven Earth days or
Speaker 1: six hundred sixty nine souls or Martian days compared to
Speaker 1: an Earth year, which has of course three hundred sixty
Speaker 1: five days, unless it's a leap year. So there are
Speaker 1: times when Earth and Mars are relatively close, and by
Speaker 1: relatively I mean nearly thirty five million miles or fifty
Speaker 1: six million kilometers apart, and there are other times when
Speaker 1: they are opposite each other with the Sun in the center,
Speaker 1: they're bout as far apart as they possibly can be.
Speaker 1: Space travel is expensive and it requires a lot of fuel.
Speaker 1: Fuel ways a lot, and the heavier year spacecraft gets,
Speaker 1: the more fuel you need, so you end up in
Speaker 1: this sort of cycle up to a point where you
Speaker 1: have to keep adding fuel to lift not just the
Speaker 1: spacecraft but the fuel you are already have in it.
Speaker 1: So that means you get to be super careful with
Speaker 1: how heavy your spacecraft is so that you can be
Speaker 1: very efficient with the amount of fuel you're going to
Speaker 1: need to get to your destination. So that includes playing
Speaker 1: your trips so that you travel the shortest possible distance
Speaker 1: between two points, taking the least amount of time to
Speaker 1: get from point A to point B. So you want
Speaker 1: to set a launch date in advance of a time
Speaker 1: when Earth and Mars are going to be relatively close
Speaker 1: to each other. That's the launch window we want to
Speaker 1: look at. But of course Mars is moving the whole
Speaker 1: time as his Earth. So really you're setting a launch
Speaker 1: window to aim at the point in space where Mars
Speaker 1: is going to be in several months after the launch.
Speaker 1: It's actually pretty complicated stuff. I mean, they do call
Speaker 1: it rocket science. Even when you take advantage of orbital paths,
Speaker 1: you're still talking about a trip that will take between
Speaker 1: six and eight months using conventional rockets, So you have
Speaker 1: to settle in for a long trip. Now, once you
Speaker 1: get to Mars, you won't be able to leave right
Speaker 1: away if you have a method of leaving in the
Speaker 1: first place, you would have to wait around for Earth
Speaker 1: and Mars to be nearing one another again. And a
Speaker 1: launch window for the minimal amount of energy needed to
Speaker 1: get between the two comes around only every two Earth
Speaker 1: years and two Earth months, So you need enough fuel
Speaker 1: to make the trip home, or you need some way
Speaker 1: to make the fuel at your destination, such as Mars,
Speaker 1: so that you can make the return trip. Now, you
Speaker 1: could make going to Mars a one way trip, and
Speaker 1: considering how hostile the planet is and how hard it
Speaker 1: would be to get back. That's probably not entirely unrealistic,
Speaker 1: if I'm being honest. We'll talk more about that in
Speaker 1: our next episode, but before we decide to shove someone
Speaker 1: off into space for a life sentence on Mars, we
Speaker 1: can send other craft to the red planet, and in
Speaker 1: fact we have that includes orbiters, which, as the name suggests,
Speaker 1: orbits the planet and gathers information about it. Landers, which
Speaker 1: has the name suggests, lands on the planet and gathers
Speaker 1: information about it. And rovers, which, again the name tells
Speaker 1: you everything you need to know. It roves about on
Speaker 1: the planet, gathering information and you know, doing sick donuts,
Speaker 1: and the name is pretty much tell you everything you
Speaker 1: need to know about them, at least in a general sense.
Speaker 1: So landing on Mars, particularly if you want to do
Speaker 1: a soft landing, is pretty challenging as well. That's because
Speaker 1: of several factors. One is that the Martian atmosphere is
Speaker 1: much thinner than Earth's, so stuff like parachutes are less effective.
Speaker 1: They do work, but they don't slow down to scent
Speaker 1: quite as effectively as they would if you were using
Speaker 1: them on Earth. However, the atmosphere is thick enough to
Speaker 1: cause heating problems. Upon entry of the atmosphere, the spacecraft
Speaker 1: starts to come in at a very high speed, it
Speaker 1: hits the atmosphere, starts to compress the atmosphere in front
Speaker 1: of it, and it begins to heat up rapidly. So
Speaker 1: whatever your spacecraft is, you need some really good heat
Speaker 1: shielding to take care of that problem. That of course
Speaker 1: adds to the weight of the spacecraft. And while gravity
Speaker 1: on Mars is less intense than on Earth, the gravity
Speaker 1: on Mars is about point three eight times out of
Speaker 1: Earth's gravity. Descending from Martian orbit still means you're going
Speaker 1: at a speed that's plenty fast enough to cause serious
Speaker 1: damage when you hit the ground, So you have to
Speaker 1: have a way to slow your descent. One way to
Speaker 1: offset that incredibly fast descent is to have special retro
Speaker 1: rockets on the landing craft and to fire those before
Speaker 1: you land so that you have a nice and gentle touchdown.
Speaker 1: That really would help slow the descent. But here's the
Speaker 1: thing with these craft that we're sending the landers and
Speaker 1: the rovers. For the ones that we're using for a
Speaker 1: soft landing, they have to rely upon a fully automated system.
Speaker 1: Because the distance between Mars and Earth is such that
Speaker 1: it takes several minutes for radio signals to pass back
Speaker 1: and forth between the two. Radio signals move at the
Speaker 1: speed of light, but the distances involved are so great
Speaker 1: that even light requires a few minutes to get the
Speaker 1: job done. So if you were looking at a video
Speaker 1: feed from the spacecraft, let's say that there's a live
Speaker 1: camera feed and it's able to send video back to Earth.
Speaker 1: This would be unrealistic, But let's say it's happening. What
Speaker 1: you would actually be looking at would be video from
Speaker 1: several minutes ago. The video footage would be several minutes old,
Speaker 1: because that's how long it took for the information to
Speaker 1: travel from the the lander or rover on Mars to
Speaker 1: get to you on Earth. Sending a message to the
Speaker 1: lander would obviously take more time. So let's say you
Speaker 1: see a picture and you think, oh, well, that's that
Speaker 1: rock over there is interesting. I want this thing to
Speaker 1: go grab that rock, and you send a command to
Speaker 1: the device. Well, keep in mind the picture you're looking
Speaker 1: at it several minutes old. When you send the message,
Speaker 1: it takes several more minutes for it to get back.
Speaker 1: The device then has to react to it, and it
Speaker 1: will take even more minutes for you to know that
Speaker 1: anything actually happened, so there's no way to make any
Speaker 1: adjustments in real time at all. So that's why the
Speaker 1: system has to be fully automated. When it's landing, there's
Speaker 1: no way to step in and take control of it
Speaker 1: as a remote pilot, because the distances are so great
Speaker 1: that by the time you're sending commands, the thing you're
Speaker 1: trying to command has already crashed into Mars. So you
Speaker 1: have to create this automated system. The landing process for
Speaker 1: this lander would take about six and a half minutes
Speaker 1: from the point it enters the Martian atmosphere to the
Speaker 1: point that it landed on the surface. NASA would call
Speaker 1: this the seven minutes of Terror. That six and a
Speaker 1: half minutes would include every single thing that would have
Speaker 1: to happen in this process of entering the atmosphere all
Speaker 1: the way to the point of firing the retro gets
Speaker 1: at settling down on the surface of Mars. If anything
Speaker 1: were to go wrong at any stage there, whether it
Speaker 1: maybe it's a parachute that fails to deploy, a thruster
Speaker 1: that fires a second too late, whatever it would be,
Speaker 1: all would be lost. Chances are you would have a
Speaker 1: total loss of the spacecraft. In addition, that distance between
Speaker 1: Earth and Mars would mean we wouldn't even know that
Speaker 1: something had gone wrong until about eight minutes after it
Speaker 1: had gone wrong, So if the lander were to crash
Speaker 1: and be destroyed, it would have been destroyed for eight
Speaker 1: minutes before we knew about it. Also, it meant that
Speaker 1: picking a landing site is incredibly important. You want to
Speaker 1: find the best possible site to target so that your
Speaker 1: lander or rover, whatever it may be, has the best
Speaker 1: possible chance of survival. NASA had to find a spot
Speaker 1: that not only would be optimal for whatever the mission
Speaker 1: objectives happened to be. In this case, it's all about
Speaker 1: measuring various uh features of Mars, but it also has
Speaker 1: to be geographically favorable for that successful landing and for
Speaker 1: a continued operation. Sou with the case of the Insight,
Speaker 1: it also meant that having to pick a spot that
Speaker 1: would be favorable for solar panels, because that's how the
Speaker 1: the Insight lander recharges its batteries. So for that reason,
Speaker 1: they chose a spot near the equator because that would
Speaker 1: maximize solar exposure, and because you're relying upon automated systems
Speaker 1: to guide the landing craft to the surface. You also
Speaker 1: have to pick a location that's relatively flat and free
Speaker 1: of large rocks or boulders that could cause the craft
Speaker 1: to topple over after touchdown. That is a tough thing
Speaker 1: to look for on Mars. Mars is very very rocky
Speaker 1: and uneven in many places, but the team in NASA
Speaker 1: eventually chose a region of Mars called the Elysium Planetia.
Speaker 1: That was way back in when they made that choice.
Speaker 1: That first, NASA had more than twenty potential landing sites
Speaker 1: identify light. Then the team directed the Mars Reconnaissance orbiter
Speaker 1: to gather images of those sites so that they could
Speaker 1: choose the best candidates. Each potential site measured eighty one
Speaker 1: miles by seventeen miles in an elliptical shape. That's a
Speaker 1: hundred thirty kilometers by twenty seven kilometers. The insight landing
Speaker 1: location is about three d seventy miles or six hundred
Speaker 1: kilometers away from where the curiosity rover is, so it's
Speaker 1: probably not going to get a visit from its fellow
Speaker 1: robot anytime soon, and a monitor the progress of the
Speaker 1: actual landing. NASA sent up a pair of small satellites
Speaker 1: called cube SATs. Along with the Insight These were the
Speaker 1: first two cubes AT spacecraft to journey into deep space.
Speaker 1: They are communications relay satellites. These particular cube SAT satellites
Speaker 1: are the Jet Propulsion Laboratory designed and built them. The
Speaker 1: basic unit of a cube sat is a box about
Speaker 1: ten centimeters or four inches to a side, and CubeSats
Speaker 1: can be made up of multiple units, and the two
Speaker 1: that were hitching a ride with Insight were each six
Speaker 1: units large. The job of those two satellites involved flying
Speaker 1: by Mars and listening for Insights signal that would indicate
Speaker 1: a successful landing. The CubeSats both have UHF capabilities, though
Speaker 1: they can only receive UHF radio signals and X band capabilities,
Speaker 1: which meant they could receive and transmit over those frequencies. Interestingly,
Speaker 1: those satellites separated from the launch vehicle that was an
Speaker 1: Atlas five rocket, and they did so independently of the
Speaker 1: Insight cruise spacecraft, and so they flew to Mars on
Speaker 1: their own trajectories and with their own course adjustments in
Speaker 1: order to get to where they needed to be for
Speaker 1: the actual landing procedure. The satellites also served as a
Speaker 1: pilot program to test the viability of a bring your
Speaker 1: own communications relay with a short development cycle into deep space,
Speaker 1: and it worked. Now I have a lot more to
Speaker 1: say about INSIGHT and what it does, but before we
Speaker 1: get to that, take a quick break to thank our sponsor.
Speaker 1: The full name for INSIGHT is the Interior Exploration using
Speaker 1: Seismic Investigations, GEO Daisy and Heat Transport. And I have
Speaker 1: a sneaking suspicion. This is another case of a mission
Speaker 1: getting a fun name and then a project team tries
Speaker 1: to work backward to make that name into an acronym.
Speaker 1: But I don't know that for sure. The purpose of
Speaker 1: the mission is to deduce how celestial bodies that have
Speaker 1: a rocky surface are formed, how do they come to be.
Speaker 1: This would include planets like Earth, as well as satellites
Speaker 1: like our Moon, and of course planets like Mars. The
Speaker 1: Lander is going to do this by using several scientific
Speaker 1: instruments to study the deep interior of Mars, and then
Speaker 1: the team back on Earth is going to take the
Speaker 1: information and form hypotheses to explain the formation process. The
Speaker 1: Lander will also gather data that will allow scientists on
Speaker 1: Earth to make educated guesses about Mars's core. So this
Speaker 1: is really cool. This is all about observing planet's behavior
Speaker 1: in a way and then drawing conclusions about what that
Speaker 1: means for the planet, what how the planet is made up,
Speaker 1: you know, what sort of core it has, that kind
Speaker 1: of stuff, and it's all about working backward based upon
Speaker 1: these observations. I love this kind of science. Insight is
Speaker 1: kind of like the Phoenix Lander, and that both of
Speaker 1: those are stationary robotic platforms, so it's not like the Spirit,
Speaker 1: Opportunity or Curiosity rovers. Those are all robots with wheels
Speaker 1: that can move around the surface of Mars. Actually, the
Speaker 1: Opportunity and Curiosity rovers are still in operation to this day.
Speaker 1: Opportunity landed on Mars in two thousand four and Curiosity
Speaker 1: landed in two thousand twelve, and there's still kind of
Speaker 1: roaming around. But insights job is to monitor conditions from
Speaker 1: a set location over the course of a Martian year
Speaker 1: plus forty or so martian days. Insight is a pretty
Speaker 1: large lander. NASA describes it as being about the size
Speaker 1: of a big nineteen sixties convertible. That's a quote, but
Speaker 1: this is tech stuffs. Let's get technical. What are the
Speaker 1: specs for the Insight Lander, well, it is six ms long.
Speaker 1: That's about nineteen ft eight inches, assuming you're measuring it
Speaker 1: when it's solar panels are deployed. Again, we'll talk about
Speaker 1: the solar planel panels in just a minute. It's got
Speaker 1: a width of one point five six ms that's about
Speaker 1: five ft one inch. Uh. The deck height, so the
Speaker 1: the top surface of the main portion of the lander
Speaker 1: ranges from eighty three centimeters to one centimeters tall or
Speaker 1: thirty three to forty three inches. The whole thing weighs
Speaker 1: in at a smelt three d sixty ms. Technically that's
Speaker 1: its mass. Uh we If we're expressing it in pounds,
Speaker 1: it would be seven pounds here on Earth. Remember, on
Speaker 1: Mars the mass is the same, but it weighs less
Speaker 1: because again, mars Is gravity is a little more than
Speaker 1: one third that of Earth's gravity. The lander has a
Speaker 1: lot of cool gadgets attached to it. It draws power
Speaker 1: through batteries that are recharged by those solar panels I
Speaker 1: had mentioned. Those actually had to deploy after Insight touched down,
Speaker 1: before they were all folded up and tucked away on
Speaker 1: the sides of the platform for safety. About an hour
Speaker 1: after touchdown, they began the deployment phase and this involves
Speaker 1: unfolding and then they can start catching the sun's rays.
Speaker 1: And there's a great website for the lander over at
Speaker 1: NASA's Jet Propulsion Laboratory that shows animations of the solar
Speaker 1: panels deploying as well as the other tools and how
Speaker 1: those get deployed. The animations are fantastic, they really help
Speaker 1: a lot, So I highly recommend if you're interested in
Speaker 1: the Insight Lander checking out the interactive web page over
Speaker 1: at the Jet Propulsion Laboratory because it's it's fantastic and
Speaker 1: it looks super cool. Uh. The panels, the solar panels
Speaker 1: are decagonal. That means they have ten straight sides and angles.
Speaker 1: You know, an octagon is eight sides and eight angles.
Speaker 1: A decagon is ten, so they're kind of circular in shape,
Speaker 1: but they have those flat edges. The panels measure about
Speaker 1: seven feet or two meters across, and there are two
Speaker 1: of them. Has a pair of these solar panels. According
Speaker 1: to one NASA web page, the combined surface area of
Speaker 1: the two solar panels is quote as large as a
Speaker 1: ping pong table end quote. So you know, some light
Speaker 1: recreation on Mars. If you if you decide that it's
Speaker 1: served its purpose, I guess they're able to generate about
Speaker 1: three thousand what hours of electricity every martian day. Another
Speaker 1: important component on this lander is its robot arm. The
Speaker 1: arm has three degrees of freedom and those roughly translate
Speaker 1: to a human shoulder, elbow, and wrist joint. The arm
Speaker 1: has four motors to control the movements of the arm
Speaker 1: and those joints. And at the end of the arm,
Speaker 1: instead of there being a hand or like a claw,
Speaker 1: there's actually a grapple. It's attached by a cable. It
Speaker 1: dangles at the end of the arm, and this is
Speaker 1: used to grasp the various tools on the platform deck
Speaker 1: in order to lift them up and deploy them onto Mars' surface.
Speaker 1: So it kind of looks like one of those claw
Speaker 1: games you see in arcades or in the Toy Story film.
Speaker 1: It kind of looks like that, except that the claw
Speaker 1: does not descend and ascend. The cable doesn't unwind and wind.
Speaker 1: It stays the same length, so the arm itself will
Speaker 1: tilt up or down. But the claw does dangle from
Speaker 1: a cable. It just the cable itself is stationary. It's
Speaker 1: also got a firm grip, which also means it's not
Speaker 1: really like a claw game because those things are rigged
Speaker 1: I tell you, stupid Teddy Bear. Anyway, it's a super
Speaker 1: cool way of manipulating objects on the lander, and again
Speaker 1: the animations are really fun to watch. There's a camera
Speaker 1: mounted on this arm it's actually between the elbow and
Speaker 1: wrist joints that can provide NASA images of Mars and
Speaker 1: help the team make sure that the instrumentation that's attached
Speaker 1: to the platform is properly deployed. In fact, it's called
Speaker 1: the Instrument Deployment Camera or i d C. So the
Speaker 1: main purpose for the arm is to place the two
Speaker 1: of the three main sensors on the platform, two of
Speaker 1: the three main scientific experiments really on the surface of Mars.
Speaker 1: More on those two experiments in just a moment. The
Speaker 1: lander actually has a second camera. That one is mounted
Speaker 1: just below the surface of the deck. This one is
Speaker 1: called the Instrument Context Camera or i C SEE, and
Speaker 1: it has a fish eye perspective with a field of
Speaker 1: view of about hundred twenty degrees. It's aimed at the
Speaker 1: ground near the lander that serves as the landers work space.
Speaker 1: So both cameras have a resolution of one thousand, twenty
Speaker 1: four by one pixels, which is not quite a two
Speaker 1: megapixel image. And in an interesting analogy, NASA has compared
Speaker 1: the mission to a human getting a medical check up.
Speaker 1: The Insight Lander is going to check Mars's vitals, which
Speaker 1: includes the planet's pulse, temperature, and reflexes. So what was
Speaker 1: that all about. Well, these are all kind of cute
Speaker 1: ways to talk about the main instruments and scientific projects
Speaker 1: connected to the Insight Lander. So let's start with the pulse,
Speaker 1: the pulse of the planet in this case. In this context,
Speaker 1: it refers to the seismological events on Mars. So things
Speaker 1: that make the earth shake, or I guess I should
Speaker 1: say Mars shake, it's not the earth there so, or
Speaker 1: as my former co host Crispalett would say, stuff what
Speaker 1: makes the ground shake. One of the instruments inside has
Speaker 1: is a special seismometer with a super cool wind and
Speaker 1: thermal shield. The seismometer has a cable tether that connects
Speaker 1: it back to the Insight Lander, and the cable's purpose
Speaker 1: is twofold. It contains both the power line and the
Speaker 1: data line for the seismometer. So this is the way
Speaker 1: that the lander can provide electricity to the seismometer, and
Speaker 1: the seismometer can feed data back to the lander. The
Speaker 1: illustrations I've looked at make it a little like the
Speaker 1: insight lander is kind of walking a weird, lumpy robot dog.
Speaker 1: The lander's robotic arm is responsible for lifting the seismometer
Speaker 1: off the platform and placing it on the surface of
Speaker 1: Mars near the lander itself. Then it has to put
Speaker 1: the uh the thermal and wind shield over the seismometer.
Speaker 1: The purpose of the shield is pretty much what sounds like.
Speaker 1: It's meant to protect the seismometer from gusts of wind,
Speaker 1: primarily that would possibly cause the seizemometer to register false readings.
Speaker 1: If the wind pushes the seismometer around that it's going
Speaker 1: to start registering as if there's an earthquake or Mars quake.
Speaker 1: I guess this way, the shield blocks that wind and
Speaker 1: the seizemometer just keeps on, you know, monitoring the movement
Speaker 1: of the ground beneath it. The wind and thermal shield
Speaker 1: is made out of aluminum. The main shielding part on
Speaker 1: the top anyway, is made out of aluminum. It looks
Speaker 1: like a dome with little lander legs almost like a
Speaker 1: little ufo. It also has a metallic skirt that hangs
Speaker 1: down beneath the dome. It's the thermal skirt. It's actually
Speaker 1: made out of gold. And then this gold skirt has
Speaker 1: a bottom edge made out of and I am not
Speaker 1: making this up, honest to goodness, the edge is made
Speaker 1: out of chain mail, like the stuff that nights used
Speaker 1: to wear back in medieval times. How cool is that?
Speaker 1: So this chain mail actually serves a couple of different purposes.
Speaker 1: For one, it's it's heavier than the skirt is, so
Speaker 1: it helps pull down on the skirt while the little
Speaker 1: arm is lifting the shield up off the deck of
Speaker 1: the lander. The chain mail provides the weight to help
Speaker 1: pull the skirt straight so that it goes down all
Speaker 1: around the sides of the seismometer. Also, the chain mail
Speaker 1: is flexible, so it can drape over any small pebbles
Speaker 1: or rocks to allow a pretty good seal of the
Speaker 1: shield over the seismometer. The shield itself is about fourteen
Speaker 1: inches or thirty five centimeters tall, twenty seven inches or
Speaker 1: sixty nine centimeters in diameter, and has a mass of
Speaker 1: twelve kilograms, which means here on Earth it would weigh
Speaker 1: about twenty six and a half pounds. I'll finish up
Speaker 1: this section by giving a quick overview of how seismometers work,
Speaker 1: and then we'll talk about the other two experiments in
Speaker 1: the next section. So typically we would pair a seismometer
Speaker 1: up with some sort of recording device, which would mean
Speaker 1: that we would have a seismograph. That's when you have
Speaker 1: the two components together. So a simple version of this
Speaker 1: one that you might see here on Earth uh, an
Speaker 1: old school simple mechanical version of a seismometer would be
Speaker 1: a frame that has good contact with the ground. So
Speaker 1: you've got a frame that is set on whatever surface
Speaker 1: you're measuring. Suspended from the top of that frame would
Speaker 1: be a weight on a spring, and the weight would
Speaker 1: hold some sort of writing utensil, like a pen. That
Speaker 1: pen the end of it would rest against a strip
Speaker 1: of paper that could be rolled or pulled in such
Speaker 1: a way that the pen is drawing a line on
Speaker 1: that strip strip of paper as the paper moves past it.
Speaker 1: If there's a trimmer, the frame is going to move
Speaker 1: along with the ground, but the suspended weight will tend
Speaker 1: to remain motionless as it is largely isolated from the
Speaker 1: ground and the frame and an object at rest tends
Speaker 1: to stay at rest. So you can think of it
Speaker 1: as the frame and the earth and everything else is
Speaker 1: moving up and down. The weight is kind of just
Speaker 1: staying where it was, and that means that the paper
Speaker 1: is going to be moving up and down against the pen.
Speaker 1: Not the pen against the paper. The paper itself is
Speaker 1: moving up and down because the ground is moving up
Speaker 1: and down. And that means that the pen is gonna
Speaker 1: start drawing squiggles on this paper. And so you could
Speaker 1: look over the paper and wherever you saw squiggles, you'd say,
Speaker 1: all right, well that was where there was an earthquake
Speaker 1: or an aftershock, or maybe a large truck drove by
Speaker 1: or whatever. The seismometer on the insite works on a
Speaker 1: similar principle, except instead of holding a pen, instead of
Speaker 1: it being mechanical, the relative motion between the weight and
Speaker 1: the frame would create an electrical voltage, and changes in
Speaker 1: that voltage are recorded by a computer system on the
Speaker 1: insite and transmitted back to Earth, and those are interpreted
Speaker 1: as the various quakes. I have a lot more to
Speaker 1: say about the experiments aboard the Insight, but first let's
Speaker 1: take another quick break to thank our sponsor. So the
Speaker 1: second vital sign Insight is going to monitor is temperature.
Speaker 1: The deck of the lander has a temperature censor of
Speaker 1: its own to give surface readings. But what I think
Speaker 1: is super interesting is what is called the HP three instrument.
Speaker 1: HP three stands for heat flow and Physical Properties probe.
Speaker 1: It's another tethered instrument that connects back to the lander,
Speaker 1: and like the seismometer, the robotic arm has to lift
Speaker 1: up the HP three and then place it on the
Speaker 1: surface of Mars in the work space in front of
Speaker 1: the lander. Inside this instrument is a probe. It looks
Speaker 1: like almost like a spike, and it's called the mole
Speaker 1: and it's tied. It's a type of pine traumater. I
Speaker 1: didn't even know that was a word until I did
Speaker 1: this research, but that essentially is a tool designed to
Speaker 1: pay to trate a surface. That's the name pentatrometer. In
Speaker 1: this case, we're talking about the Martian soil. So inside
Speaker 1: this spike, which again is is got a cable out
Speaker 1: the back of it that goes back up into the instrument.
Speaker 1: The cable is held in a way where it can
Speaker 1: be fed out gradually, so that as the spike is
Speaker 1: digging down it can continue to have enough slack to
Speaker 1: do this. But inside the spike, inside the penta traumeter
Speaker 1: is a weight on a spring. Essentially, that's a hammer.
Speaker 1: It's inside the spike. So imagine you've got a nail
Speaker 1: or a railroad spike or something like that. But the
Speaker 1: hammer for this nail or spike is actually inside the
Speaker 1: spike or the nail itself, so it's a self hammering nail.
Speaker 1: The mechanism draws power from the lander to pull back
Speaker 1: the weight that compresses a spring, and then you latch
Speaker 1: it into place. When it's completely compressed, you can unleash
Speaker 1: this weight. The spring will expand rapidly, pushing the weight
Speaker 1: down so that it collides with a little section at
Speaker 1: the very tip of this probe, and it's like a
Speaker 1: hammer knocking a nail, and it starts to hammer the
Speaker 1: spike down. This is actually a pretty slow process. It
Speaker 1: does not happen super fast. It's not like one, uh
Speaker 1: one bash and suddenly the spike is several feet in
Speaker 1: the soil. That's not the way it works. It's very gradual.
Speaker 1: So by keeping a careful tension on the cable so
Speaker 1: that the spike is properly positioned, and by doing this
Speaker 1: several times, you start to drive the spike down into
Speaker 1: the soil. It's gonna take months, but ultimately this mole
Speaker 1: is going to dig down to a depth of about
Speaker 1: five meters or sixteen feet, which is deeper than anyone
Speaker 1: has dug on Mars up to this point as far
Speaker 1: as we know anyway. But obviously this instrument is doing
Speaker 1: more than just digging a hole on Mars. I mean,
Speaker 1: that's super cool the way they're doing it, but that's
Speaker 1: not the only thing it's doing. The probe and the
Speaker 1: tether that's trailing behind it contains temperature sensors, and those
Speaker 1: sensors will monitor the heat flowing from the interior of Mars,
Speaker 1: which will help tell scientists what the inside of Mars
Speaker 1: is like. It could inform scientists about how active Mars
Speaker 1: is and whether it's made out of similar stuff as Earth.
Speaker 1: The probe isn't just listening either. As the probe digs
Speaker 1: down at certain stages, it will occasionally stop and it
Speaker 1: will put out a pulse of heat of its own.
Speaker 1: Then it will monitor how that heat flows through the
Speaker 1: material around the probe. So if that material happens to
Speaker 1: be a good conductor like metal, like coppers. A great
Speaker 1: conductor of heat, the heat will decay very quickly, it'll
Speaker 1: move outwards through this conductive material. But if it's a
Speaker 1: poor conductor, more like glass, the heat's going to stick
Speaker 1: around a lot longer. The HP three probe weighs in
Speaker 1: at about six point five pounds at least it would
Speaker 1: here on Earth. That means it has a mass of
Speaker 1: about three kims and it only consumes to watts max
Speaker 1: as the probe starts to dig down into the Martian soil.
Speaker 1: The last of the three big experiments would be a
Speaker 1: pair of RISE antennas on the deck of the lander.
Speaker 1: These would not be removed from the deck and placed
Speaker 1: on the Martian soil. They will stay on the lander.
Speaker 1: RISE stands for Rotation and Interior Structure Experiment. These antennae
Speaker 1: will track Mars's motions as it rotates, so essentially, it's
Speaker 1: all about detecting that wobble. So how much does Mars
Speaker 1: wobble around? Knowing how much it wobbles around will tell
Speaker 1: scientists valuable information about Mars's core. How big is Mars's core,
Speaker 1: Is it a solid core, is it a liquid core?
Speaker 1: What elements besides iron might be in the core. Well,
Speaker 1: the way Rise works is actually pretty darn simple. It
Speaker 1: listens for an incoming signal from Earth, and then it
Speaker 1: sends the signal back to Earth. This will reveal the
Speaker 1: precise location of the lander, well precise location from a
Speaker 1: few minutes in the past. Because again the signals can
Speaker 1: only travel as fast as light, it may take a
Speaker 1: few minutes for that to happen, depending upon where Earth
Speaker 1: and Mars are in their respective orbits. But back on Earth,
Speaker 1: computers will take this this return signal and analyze it
Speaker 1: for changes and looking for evidence of Doppler shift. I've
Speaker 1: talked about Doppler shift many times on this show, but
Speaker 1: just so you remember, if you've got something moving in
Speaker 1: a wave, whether it's a radio wave or a physical wave,
Speaker 1: whatever it may be, h it has a certain frequency.
Speaker 1: And if the wave is coming from a stationary object
Speaker 1: and then it hits a different state stionary object, any
Speaker 1: reflective waves. Reflective waves that come back to the source
Speaker 1: are going to be unchanged except for their direction. Right
Speaker 1: that you're gonna get back the same frequency of wave
Speaker 1: if both objects are stationary, But if the objects are
Speaker 1: moving closer to each other, the returning wave is going
Speaker 1: to be compressed, so it's going to be at a
Speaker 1: higher frequency. If the two objects are moving away from
Speaker 1: each other, the wave is going to be elongated to
Speaker 1: a lower frequency. And by measuring these changes, scientists will
Speaker 1: be able to figure out how much Mars is wobbling
Speaker 1: around as it orbits the Sun. Now, Earth wobbles every
Speaker 1: eighteen years thanks to the Moon's pull on us, and
Speaker 1: we already know that Mars does in fact wobble, In fact,
Speaker 1: it wobbles over the course of a single Martian year,
Speaker 1: but we don't know to what degree how much does
Speaker 1: it wobble. We know it does, we just don't know
Speaker 1: how uh intense that wobble is. So the Rye his
Speaker 1: instruments will provide more information to fill in this knowledge gap.
Speaker 1: And the amount of wobble planet has depends partly on
Speaker 1: what is in the delicious neugute center of that planet. So,
Speaker 1: as NASA points out in a really helpful web page,
Speaker 1: a hard boiled egg is going to spend faster than
Speaker 1: a raw egg. Also, planets that have liquid cores will
Speaker 1: wobble more when they spend. Planets with a solid core
Speaker 1: will wobble less, and this in turn can help us
Speaker 1: make other hypotheses about why Mars has a very weak
Speaker 1: magnetic field in comparison to Earth's magnetic field. So it's
Speaker 1: all about learning more about why is Mars the way
Speaker 1: it is and more about how Mars actually is. There
Speaker 1: are other instruments on the lander that aren't getting quite
Speaker 1: the same level of coverage. The lander has an atmospheric
Speaker 1: pressure sensor, for example. It also has a uh F
Speaker 1: antenna to allow the lander to communicate to satellites that
Speaker 1: are in Martian orbit, which includes the Mars Reconnaissance Orbiter
Speaker 1: and the Mars Odyssey Orbiter, both of which pass over
Speaker 1: in Sight two times every Martian day. And there are
Speaker 1: other satellites that can chat with as well, like the
Speaker 1: European Space Agencies Trace Gas Orbiter or NASA's Mars Atmosphere
Speaker 1: and Volatile Evolution Orbiter also known as MAVEN. It can
Speaker 1: talk to those in a pinch if it needs to.
Speaker 1: So Insight will stand on Mars doing its thing for
Speaker 1: at least a Martian year plus some change, maybe longer
Speaker 1: things continue to work out properly. Sometimes these missions can
Speaker 1: go well beyond their initial projected phase, and if NASA
Speaker 1: can figure out other things to do with the material
Speaker 1: that's already there, then that is incredibly helpful. There's some
Speaker 1: other elements on it as well. There's a reflective surface,
Speaker 1: for example. They could be used to locate the precise
Speaker 1: position of the lander. You just direct a laser at
Speaker 1: it and look for the reflection. I'm sure we'll learn
Speaker 1: tons of interesting things about Mars using this device, and
Speaker 1: probably a lot about Earth as well, which pretty exciting stuff. Now,
Speaker 1: in our next episode, I'm gonna stick with Mars for
Speaker 1: a little bit. I'm gonna talk about the various proposals
Speaker 1: to send people to Mars and what that would entail,
Speaker 1: and we'll talk about why it would be super hard
Speaker 1: to do and why some people like Bill and the
Speaker 1: Science Guy are skeptical that we're ever going to actually
Speaker 1: go there for a prolonged stay. And maybe we'll also
Speaker 1: talk about why Elon Musk thinks there's a decent chance
Speaker 1: he's gonna end up there. So tune in tomorrow to
Speaker 1: hear that episode. If you guys have any suggestions for
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Speaker 1: me know. Send me an email. The addresses tech stuff
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