Welcome to text Stuff, a production from my Heart Radio. Hey there, and welcome to tech Stuff. I'm your host, Jonathan Strickland. I'm an executive producer with iHeart Radio and I love all things tech, and today we're going to listen to a classic episode titled tech Stuff Goes on a Voyage. It's about the Voyager program and this episode originally published on April two thousand thirteen. The Voyager program is one of those really fascinating space programs that I absolutely loved learning about, so I hope you guys enjoy this classic episode. The first thing we wanted to talk about was kind of what was the purpose of the Voyager missions, which, by the way, are still going. But we want to talk about kind of the timeline of the missions, and then we'll get into more details about the space craft itself and then follow that up with a discussion about the science that has been discovered by these amazing spacecraft. So going back to May nineteen seventy two, that's when NASA begins to fund a mission that will involve designing, building, and launching spacecraft that are meant to explore the outer planets of our Solar System. And even before this back in the engineer named Gary Flandreau noticed that sometime in the nineteen seventies, the outer planets would be aligned planetary alignment in such a way as to make this very possible. And this was you know, the space program was going and booming, and it was kind of an incredible alignment of the stars that allowed us to write when we had money to do this stuff. Right, So, so, I mean that planetary alignment is really what makes the voyager missions possible because you know, if the if the plants were in such an alignment, so that let's say that alignment, well there's still aligned properly, they're just not viable for us to explore. But let's say let's say like jupiters on one side of the Sun and Saturn's on the other side of the Sun, then it would be really tricky to design a spacecraft sector could explore both. Right, So, and this particular alignment isn't going to occur again for another hundred and seventy six years, so you had to jump on the opportunity. And so in nineteen seventy two, even though it was still years away from when this alignment would occur, NASA gets on the ball and starts to design this, and in nineteen seventy seven they are finished with the design and the spacecraft they had been designing was under the working name the Mariner Jupiter slash Saturn nineteen seventy seven, but they decided to rename it a little bit of a mouthfall, yeaheah. They called it Voyager, and on August twenty, nineteen seventy seven, a Titan Centaur rocket carried one of the two Voyager spacecraft from Cape Canaveral, Florida, into the atmosphere and ultimately into space. Which one was it that will launched first? It was Voyager two that launched first. Which one launched second? Voyager one? Okay, So so this this was basically for pr purposes because the way that they were designed, Voyager one was going to due to its trajectory, it was going to reach Jupiter first and so start sending back images of Jupiter, you know, fingers crossed if all goes well first, and NASA thought that the public would be incredibly confused if if the Voyager one launched first but got to the planets second, whereas some for some reason launching second and getting to the planet first is less confusing. No one was paying attention to the launch. Yeah, goodness knows, no one pays attention to something. Yeah, the one thing you're actually able to watch while you're still on Earth. It still makes me tear up every single time anything gets launched into space. I'm like, just humanity is so beautiful. That's pretty awesome. I mean when you think about what it takes to get something into space, and is phenomenal the amount of engineering and ingenuity that went into that. But yes, absolutely so. The Voyager to launches first. The Voyager one launches about sixteen days later, in fact, not about sixteen days later, at launches nicely on September and it's using the same sort of rocket, the Titans Centaur rocket, which, by the way, I love it anyway. The initial purpose was for these to explore the giant planets in the Outer Solar System. Those giant planets are Jupiter, Saturn, Uranus, and Neptune. Pluto, of course not a giant planet. It does not get the treatment, not for these missions. Forget you Pluto. And there were two separate trajectories that were being used. Voyager one, of course, was designed so that the trajectory was chosen so that it would reach Jupiter first, then move on to Saturn, and then get flung off to head toward interstellar space. Uh. Voyager too would do a visit to all four of the giant planets. So that's why you have the different timelines, because even though Voyager two launched first, for it to be able to hit this trajectory where it was going to to pass by each of the four giants, it had to do that at a different Yeah. So that's the you know. And if you were to just look at a model of the Solar System and just spin the planets around at the different rates, you would see like, oh, yeah, now I understand you would have to be really particular about when you would launch and how you would launch for it to be able to hit all of these points properly. I mean, it's an amazing amount of engineering that's required and and just math that's required to make sure that you've got the right the right timing. Yeah, and it was it was kind of shady, you know, basically until it happened, no one was sure that it was going to happen, right and Uh, And it's interesting because the Voyager spacecraft actually used the planets themselves to help make sure they got to where they needed to go. But we'll get into that. It's pretty awesome though. So moving down the timeline, they they've launched in nineteen seventy seven. Almost two years later, on March five, nineteen seventy nine, Voyager one has its closest approach to Jupiter and it captures a lot of images of Jupiter and Jupiter's moons. Uh. And then July nine, nineteen seventy nine, so same year, that's when Voyager two passes closest to Jupiter. Uh. Then we go to the next year. On November twelve, eighty Voyager one has its closest approach to Saturn, and then it begins its trip out of the Solar System, saying so long, suckers, and starts heading off into the well. It would be the sunset, except it can't be in the opposite of the sunset, right, It's not the sun rise either. That's that would normally be the opposite of a sunset, the sun diminishing into a tin year ball. I guess not nearly as poetic. But August one, that's when Voyager two gets its closest approach to Saturday. But of course Voyager two is not flung off into in our interstellar space right away. Instead, it is then heading toward Uranus, which it passes closest to on January fourth, nineteen eight six. So it took five years for Voyager two to go from Saturn to Uranus. Uh, and it would take um it would take a few more years before it would like five well three more years, I'm sorry, three more years before I would get close to Neptune. But before we get to that point, seven, Voyager two observes the supernova nineteen seven eight Voyager returns the first color images of Neptune. So that Voyager two that is, so it's getting closer to Neptune. It's still not the closest it will be, but that's when we first started getting color images of Neptune back from Voyager, and on August nine, Voyager two as its closest approach to Neptune. And that concludes the primary mission of the of both Voyager spacecraft, that primary mission being the exploration of those outer planets. So the cost of the missions from nineteen seventy two to the time when they finished their mission their primary mission was eight hundred sixty five million dollars. Now, NASA points out that if you break this down by the population of the United States and year over year, that's about eight cents per person per year. So it's it's essentially saying like, look, really in the grand scheme, and it sounds like a lot of money, but in the grand scheme of things, this is just a tiny investment. So look at these pictures of center. Yeah. Uh, keep keep calm and keep exploring, is what they said. I hate that name anyway. So the that that million dollars included everything include the expense of the launch vehicles, the radioactive power source, which we'll get to talk about in a little bit, uh, and and just the maintaining of the missions. By nine, Voyager one was heading toward interstellar space and on vale In Tine's Day in nineteen nine, we get the final images from Voyager, which is a portrait of the Solar System. Happy Valentine's Day, I gave you the Solar System. Sweet Three days later, February I'm sorry three days in eight years later on fantasy, I should read the year before I read the day February sevent have all my notes in front of me, it's just, you know, my typing and viewing skills are Apparently there's something to be desired. February seventeenth, the Voyager one passes the Pioneer ten, which had obviously been launched previously, and so that makes the Voyager one the most distant human made object in space. It is still to this day the most distant human made object in space. It's actually most distant stir and it was because it keeps going. That was good. Well, I figured it might as well measure up to my reading and comprehension skills. Uh. Decenumber fifteen two thousand four. Edge or one crosses the termination shock comination shock. This is this is pretty cool, guys, and do the heally you sheath. Yeah. So here's here's some things that you need to know about our wacky little solar system. Here you might ask, what's the edge of the Solar System? Is it Pluto? No? No, it's not Pluto. Well, I mean again, it all depends on how you're defining the edge of the Solar System. But the way NASA defines it, Nope, not Pluto, especially since it's not it's still on a planet right now, that's not it's a dwarf planet. There's that never mind, there's yeah, it's you know, it's Pluto is right there with happy, sneezy, sleepy Adobe doc bashful. Uh So, termination shock, that's that's the point where the solar wind particles start to slow down. They were traveling essentially at kind of the speed of sound would be, but anyway, they're traveling really fast. They start slowing down because you can think of the solar wind as this uh, this force that pushes out from the Sun. All right, Now, think of the interstellar space kind of having its own pressure. It's sort of like air pressure. It's pushing in on the solar made of magnetic fields instead of air pressure. So there exactly, they're not air particles. It's all we're talking. There are particles on space, but that's that's a different thing anyway. So the solar wind is pressing against these these other pressures. So once you get to the point where the solar wind is slowing down, that's the termination shock. Right, there's kind of a boundary with a with a shock wave fare and also still not the edge of the Solar system. Also, you also have the heliosphere. Now this is where we still have we still have evidence of the solar wind within the heliosphere. Then you have the helio pause, which is the very boundary of where the solar wind is, and that still is not the edge of the Solar System, not according to NASA. According to NASA, really we need to think of the edge of the Solar System as being an area where the Sun's gravitational poll has no greater effect on you than any other particular celestial body out there. So, in other words, you aren't being pulled towards the Solar System at that point anymore than you're being pulled towards some other point, right, Yeah, so that that area is ill defined by the very nature of gravity. But um, that would take us a very long time to get there, and we'll talk about that when we get into the science section. So anyway, termination shock has all these fluctuating magnetic fields due to the change and the speed of the Solar wind, and that's kind of why it's called what it's called. And Voyager one, like I said, crossed it on December two thousand four and begins to encounter the interstellar medium. That doesn't mean that it's in interstellar space yet, but starting to encounter the particles that would be an interstellar space September five, two thousand seven, three years later, that's when Voyager two catches up and crosses the termination shock at a totally different point. By the way, these two spacecraft are in two totally different sections of no nowhere near each other anymore, not at all. And then in July and two thousand twelve, Voyager one enters a new region of space which is still inside the Solar System. It's another region of the helio heliosphere helio she called a magnetic highway YEP. And the directions of the particles that it's encountering are beginning to change, which suggests that the spacecraft is at the very edge of the heliosphere. And UM engineers didn't expect that the data that they got back. They thought that it would have passed beyond this point earlier, which just tells us that our Solar system is actually larger, thought that the Sun is more powerful than we previously expected. Never underestimate the power of the Sun. It can turn me read in a matter of minutes, very susceptible to that sort of thing. So, yeah, that's we've already talked about how they have, they left at different times in their pathways, meant that they are traveling in different directions and different at different speeds. Uh, and they visited different you know, like voice You're two visited two more planets than Voyage or one did. But we talked about how the planets helped move the spacecraft and direct the spacecraft. So if you guys have seen science fiction films like Star Trek four, the Voyage Home where they sling shot around the Sun, they're actually using the Sun's gravity to kind of accelerate a ship to the point where it can travel back in time. I don't understand that. By the way, if you've got warp speed, you technically anyway, that's another episode. We already did. That episode we did. But anyway, they use it to sling shot around the Sun, which magically lets them travel back in time. There's some truth to that in the sense that we have used that same kind of principle with designing the voyage or spacecraft. Right. What we what we kind of realized is that if you okay, you're you're you're moving towards the planet, you're a probe okay, okay, and uh, as you move towards the planet. You're going to start accelerating as the planet's gravitational pull starts pulling you in. Right, if you only kind of graze by it, then hypothetically you'll deseller right on the way out because you're losing energy to that gravitational pull. Right. And by the way, because of the conservation of energy, technically, the planet's orbit actually slows sure infanticimally, Yeah, it's uh say, I've got wait, wait, wait, I have it written down. I know I've got it written down. It's something like, uh, one foot in a trillion years. Well, but hey, that is an impact you are. You are making a difference. But Jupiter is going to be a little late to its to its appointment in one trillion years. Right. However, because planets are moving in their orbits, if you are going on the same trajectory as a planet's orbit, you can pick up that orbital speed as you slingshot around the planet. Ye, And so that that has allowed the Voyager spacecraft to get propulsion from one plant to the next without having to have massive thrusters on board. In fact, when we get to the actual description of the spacecraft, you'll find out that their thrusters are not incredibly powerful at all, but they were able to use the power of gravity to direct and propel themselves something as large as as Jupiter. You know, it's moving through space at something like thirty thousand miles per hour forty tho kilometers and uh yeah, so so and and that's yeah, it's a completely free energy boost of about that much speed. According to NASA, because of the use of planetary gravity, Voyager too ended up having a fuel economy of about thirteen thousand kilometers per leader or thirty thousand miles per gallon. That's efficient. That beats That beats my car. That's highway miles, city miles. They did not give me, so I don't I don't know how it would do in the city. Uh. There, the Voyager two's flight path got a look, like we said, at all four of the giant plants um and uh and it's a couple of billion miles further inside the Solar System than the Voyager one. So the Voyager one got a kind of a head start into interstellar space um and is more than eleven billion or seventeen point seven eleven billion miles or seventeen point seven billion kilometers away from the Sun at this point more more more than eighteen as of as of today, there's there's a there's a tracker on on NASA nice where you can check all this out. So uh and and uh. At that distance, it takes hours for a for data to go from the spacecraft to be picked up here on Earth. About seventeen hours. Wow. Yeah, so that's a long time. So the way that let me let me find my note on it that it's really interesting the way that they receive those radio signals because they're they're pretty far away, they're getting increasingly difficult to check all the times. They have a whole series of two and thirty ft radio dishes right basically to pull Voyager data. These are the deep space antenna that they have to pick up this information, um and uh. And they actually upgraded those over the course of the life of the Voyager program. When they first started, they were significantly smaller, and they didn't have to be as big because the Voyager spacecraft were relatively closer to the Earth. Uh. And now now we've got to a point where we keep upgrading the antenna so that we can continue to pick up these increasingly weak signals, so it's pretty amazing. According to NASA, the emissions from Earth to Neptune required the equivalent of eleven thousand work years of human work. Eleven thousand work years, which they said, there's only a third of what it took to build the Great Pyramid. So well, hey, so you know we're slack, and yes, you know, really they're just saying, look how much more efficient we are. They were piling up rocks, we were sending spacecraft into space. Um and uh, and again we've learned that the Solar System is actually larger than what we have previously anticipated and um. So by the time the Voyager two flew by Neptune, the two spacecraft together had transmitted about five trillion bits of scientific data back at Earth and it was someone's job to look at all that. But yeah, the deep space tracking antennas are the ones we were talking about earlier that have been upgrades several times, and that that kind of that's the brief overview of the mission, and next we're going to take a look at the spacecraft itself and also some kind of cool records that are above the two spacecraft. But before we do that, let's take a quick pause to thank our sponsored. Okay, let's talk about the actual spacecraft for a minute. We know what they were supposed to do and what they have done. Um so uh And one thing I did not mention, I guess is that the whole inner interstellar travel stuff that's totally planned as well, in fact, has been added on as a secondary mission. The primary mission was the outer planets. Secondary is what's up with this interstellar stuff we don't know anything about. Well, they realize that their power sources would work until about and so figured well, hey, let's just kind of roll with it. Yeah. Yeah, so that's five. That's about when we expect the power resources to be to the point where they can no longer power the transmitter to send us back data. And we'll talk about that. That's one of the things that that's interesting about this spacecraft. There are a lot of interesting things. So both of them, uh, because because they're identical, Yes, they are identical. So each one of them weighs just under a ton. And now when they were on top of the the launch vehicle, they weighed a lot more than that, but the spacecraft themselves are just under a ton each unearthed obviously, because weight is all relative to where you are. Yes, uh, And they are each made up of about sixty five fouls and individual parts. But these parts are often made up of tinier components. So they have a term they use which is equivalent parts. And equivalent parts means like if you were to look at, for example, if I were to say my computer is part uh, is one part of the equipment that I use, someone else could point out, well, that computer has multiple chips in it, and those chips have transistors, and so really that one part is a representation of lots and lots and lots of parts. So NASA was like, well, if you want to know how many equivalent parts there are, there about five million of them. Compare that to your old standard definition color television. There will be about two thousand, five D equivalent parts. So lots more than a color TV, which is kind of what you want when you're when you're expo space. Yeah, you need a little bit more than it than your average standard definition color television. I agree, I would hope. So yeah, also larger than your standard yes, well, unless you're a crazy rich person. The main body is a is a ten sided box that's about six ft or one point eight meters across, and that's where the fuel tank, the and and some of the electronic instruments. Yeah, and we'll talk about those instruments. They are all lot of them. Yeah, they're they were. They both have areas that are hardened against radiation and shielded. And the reason for that is obviously that when you go into space, you are going to encounter things that you would not encounter here on the surface of the planet. And the reason for that is that the Earth atmosphere and magnetos sphere mag magnetosphere sphere still makes me think that we're watching x men. I would say, I would say magnetosphere. I know you would, but shere it is the sphere in which magneto travels, and it's also a magnetic field that surrounds the Earth, penetrates and binds us together like the force. Now, what it does is actually repels certain types of waves and particles, which allows us to remain. Yeah, we do. We're not being bombarded by cosmic radiation or gamma raise or things like that, because that would be a much were sunburned than that other sa burned than we were talking. The combination of the of our atmosphere and the magnetosphere or magnetosphere protectas, and so the thing is that when you're out in space, you don't have the benefit of that protection. So that's why both of them have these these shielding areas and casings that are hardened against radiation to protect them if they were to encounter any of these waves or particles. Clearly very important, interesting little side fact. So Earth has a magneto sphere, Mars doesn't, So if we were to make a colony on Mars we would not have that protection that we would we need to compensate for it in some wame, right, So you wouldn't want to go on any long strolls on the Martian soil without some serious protection. So that's all of those All of those fashionable space bikinis that were that were really popular back in the nineties would not probably be good. The interesting thing I heard was I was I was listening and I'll go ahead. It was a skeptic skuide to the universe. A great podcast has no affiliation with us, but they are fantastic, very fun, interesting educational podcast. They had a recent episode where um they had an astronomer on talking about things like Mars and they were even talking about, all right, let's let's look into a science fiction future where we can terraform Mars, so we're able to transform Mars so that the actual surfaces habitable. And even then, because of the lack of the magnetosphere, you would still be prone to things like cosmic radiation, gamma radiation. You would you would still be vulnerable with that, so you would not be able to terraform it for any extended length of time. Eventually that stuff would kill the life on that planet. Right, because things like gamma radiation, for example, aren't as cool is for example, teenage meeting nincha turtles make it sound or almost mostly you just die. Yeah, yeah, it's not. It's not attractive. In fact, uh NASA said that because of the distance from the the the Voyager spacecraft passed close enough to Jupiter that it received more than a thousand times the radiation that would be a lethal bull of radiation for human Yeah, for a human person, yes, um, So, moving on to more things that are on board this these spacecraft. It has a it has a twelve foot or a three point seven meter high gain antenna which looks like a satellite dish. Yeah, this is what allows it to transmit and receive data to and from Earth, and no matter where it goes, the the antenna is programmed to always point towards Earth. Yes, that's it's actually got a gyroscopic UH system so that no matter how it's oriented, it can it can readjust its attitude so that the UH the antenna is pointing towards US, so we can have the best chants possible to pick up those radio transmissions. UM. It has a lot of different instruments aboard, including besides the high gain antenna, it's got a low energy charged particle instrument and ultra violet spectrometer which currently only the voyager one is using to collect data. Has both narrow and wide angle imaging instruments also known as cameras. It's got a fancy, fancy eight hundred by eight hundred cameras because this was launched in the nineteen seventies seemed pretty cool at the time. UH as a cosmic ray instruments so it can detect and measure cosmic rays, a photopolarimeter, which I have no idea what it does. I was. I ran into it and I thought that's really cool, and I never actually looked more into it because I was lucky that I could say it. There's an infrared interferometer spectrometer UH, an optical calibration targeting system, a planetary radio astronomy and plasma wave antenna. Each spacecraft have two of those UM and also known as the Planetary radio Astronomy Instrument or p r A has the plasma instrument. Voyager ones plasma instrument is non functional, but all other instruments are in working order, and Voyager two is still collecting data through its plasma instruments. It's got UH. It also gets its power from three D O isotope thermoelectric generators and currently it gets about three D and fifteen watts of power. And now the spacecraft are designed so that all of their systems can operate at about four hundreds of power, so it's able to UH. It's still getting power, but it's not enough power to operate everything. And in fact, they designed the Voyager spacecraft with this in mind, the idea being that as the power as the power supply begins to decrease, it begins to shut down unnecessary instruments. So originally there were eleven different UM projects that were involved in gathering data from the Voyager systems and processing that data here on Earth. There were eleven of them. Currently only five of them are still in operation because the other systems have been progressively shut down to make sure that the Voyager spacecraft can still send us information. And like you said, by five or so, that's when we aspect the power to have run down enough where we're not going to be able to get any more information from them, because it's just not gonna have the power necessary to broadcast right right Well, because the way that this this engine of sorts works is that pellets of plutonium dioxide release heat through their own natural decay process, and so once they have finished decaying, that's it. Yeah, that's true. And then I forgot. There also some magnet magnetometer boom, which is designed toss to measure magnetic fields. So that was one of those things we didn't really know a lot about the magnetic fields of the Elder planets before we sent these these spacecraft up. That's one of the really huge sources of information that it is it has sent us. Yeah, and uh so then it has a flight data subsystem which handles all the information, and it has an eight track digital tape recorder. So you've got an eight track up there. It's uh. So the FDS configures controls, collects data from the various instruments, and the tape recorder handles the data from the plasma wave subsystem because that's the one that gets the highest density of data and the shortest amount of time. So the data tape recorder was the cutting edge technology to handle that that information. And according to NASA, the tape in the digital recorder won't wear out until the tape has moved back and forth through a distance that is equivalent to the width of the United States. Uh. That is not terribly precise, because the United States is not a perfect rectangle, but in general, I would say that's probably about three thousand miles, which is around four thousand, eight hundred kilometers. I assume what they mean is that it's it's doing fine. Yeah, So what they're saying is that that tape is capable of traveling that collective amount of distance without breaking. So you've got to remember the tape itself is not that long. It's just saying that they would you know, by the time you would go through all this tape and is worn out you could have gone all the way across the United States using that same distance of tape being played through. Just kind of that's kind of impressive. There has a command computer subsystem which p it's sequencing and control functions, which includes fault detection, corrective routines, antenna pointing data, and spacecraft sequencing data. The fault detection involves seven top level fault protection routines and each one is able to detect and correct for several possible failures. Basically, it just means that there's the computer has multiple modules and they compare data back and forth between each other and and it will decide if if one module is differing from the others, that that one's faulty and to cut it out of the system. Yes, And it also means that both of the spacecraft are capable of shutting down systems if it needs to automatically autonomously. Because which is so important, because we can't broadcast to these things. They broadcast to us, but they don't have receivers. Their antenna could receive information. Yeah, but it means that it would take seventeen hours for the information to get to us. In seventeen hours for the information to get back and by then whatever the problem was is probably not the biggest issue at that point, right, So, yeah, that it was important to have something to connect autonomously if if you know, if the communication is a barrier. The same sort of thing with the Curiosity Rover when it was landing on the surface of Mars. You know, a lot of that landing. In fact, all of the landing was autonomous because there was no time for us to send any adjustments to the system. It's like you're on your own. By the time we would be able to send an adjustment, it would have already either crash or landed safely. So you had to design a spacecraft that could do this or else it just wouldn't work. Pretty impressive in the nineteen seventies for for the amount of computing power that was going. Oh yeah, definitely. And it also had an attitude in art or still has. I don't know why I'm using the past tense. It's still out there. The Attitude and Articulation Control Subsystem, which is also known the A A c S. It's in charge of maintaining the spacecraft orientation and positions the scan platform. So this is what we're talking about. The system that's that's in charge of making sure that dad antenna has pointed back at Earth. And also that the scan platform, which is really you know, the instrumentation panel this point in the right direction to get the data that the needs. And uh it's yeah, it's got a three access stabilization system and use the celestial or gyro referenced attitude control to make the high gain antenna point back to Earth. Now, we talked about the fact that there is an interesting gold plated copper disc on board each of the two Voyager spacecraft, right the golden records there refer So this is, uh, this was a really cool idea. You know who, of course was the chairman for this, Carl Sagan. Yes, he he had billions and billions of suggestions, but not all of them can make it onto the disc obviously, right. And these are these are these these gold plated copper discs engraved like vinyl records. Yeah yeah, and kids ask your parents, no, no, dear, no no, no. Kids are hipsters these days. They know they know things about vinyl. It's cool. Kids tell your older siblings because they missed down the whole hipster generation. Um, all right, so so yeah, you're talking about a disk that has physical grooves that are in it that can be read using a stylist and cartridge, which which were included. They included the cartridge and stylists. They did not include a turntable, so aliens they have to build it. But they did leave instructions written in a symbolic language to say here's how you would construct something that would be able to play these things. They were their twelve inches in diameter, and they are designed to be played back at sixteen and two thirds revolutions per minute, so actually fairly slowly. I mean, you know, we think about the the forty five or thirty three revolutions per minute for for your average albums, and this is a sixteen and two thirds. So on these Golden records are lots and lots of stuff. Actually, um, it's including things like greetings from in fifty five different languages, including some that aren't being used anymore. They are not being used in a very long time, like which is a Sumerian language which was last used around four thousand BC. UH, a selection of nature sounds yep, yep, So if you ever wanted to hear what frogs burping sounded like and you were from from some distant planet. Here's an opportunity to a lot of So you're for Ford Prefect and you're on your way to Earth. This is a good way to do some homework before you get there. All right, a lot of traditional music, some some Native American chance and Scottish bagpipes. I've got to talk about some of the music that's on here for African ritual music. There's a bunch of classical music, all right. So yeah, I wrote down some of my favorites. This is this is Obviously, there are lots and lots of musical tracks that are on the records. These are just the ones that I personally wrote down because I I they resonate with me. It's not to say that the other ones are not as good, right, I may not be familiar with some of them. But there's the brandon Burg Concerto number two in F. Actually it's just the first movement. That's by a guy named Batch. Johann Batch wrote that, Um, if you've heard he's just some dude. Really yeah, yeah, obviously box Edinburg can chair to a number two. N f uh. Then there's a Melancholy Blues which was performed by Louis Armstrong. Stravinsky's The Right of Spring was included back actually was pretty well represented on this record. He also had the well tempered Clavia on there. There was the first movement of Beethoven's Fifth Symphony, you know, the dah There was a navajo tribes chant, and then of course the most important i think musical work that was included out of all the pieces that were on there. As as we all know from the documentary Back to the Future, It's saved Marty McFly, It'll save the human race. We're talking about Chuck Berry's Johnny be Good. Yeah. Um, there's actually a book all about the process that they used to select which sounds went on the Golden Record, right, Yeah. It finally came out with a CD companion at some point. I'm sure it's on digital. The book itself is out of print, but you can sometimes find copies. It is called Murmurs from Earth, So if you want to learn more about how they came about choosing which sounds go in there. Um, that's it's it's a really well done piece. It's it's something that I've I've heard nothing but good things about it. I personally have not had a chance to read it. By the time I learned about it was running on a print, so it's kind of fine. But there's also a bunch of images on the desks, including a star map clearly showing the location of Earth. Here's what humans taste like, maps of Earth images. I'm just I'm just ignoring that entirely. There are people who have said what a huge mistake it was to essentially include directions directly to us. I think, well, I think it's pretty ridiculous because the odds of anyone and the odds of anyone finding the voyagers as big as it turns out, really big, no, no, no, bigger than that. Not. You might think it's a long walk to the chemist style on the corner, but that's just nuts compared to space. But it's going to be tens of thousands of years before either the voyager craft encounter anything near another star. Yeah, exactly. So really, by the time, I'm betting we will have either kill ourselves off or hit the Singularity. And and plus on top of that, you know, it would all depend on from one direction the other creatures were approaching Earth, Because I mean, there's there are a lot of different vectors you could take and only a couple of them would intersect with the pathway of either voyagers. Way more vectors than most science fiction movies are willing to acknowledge. There's more than just ship spaceship battles, than just the single plane. Yeah. Uh So there was also an hour long recording of the brain waves of a woman named Anne Druian, who would become Carl Sagan's wife. Yep, she's an author. She concentrates mainly on cosmology and science, and she she signed up for this. She volunteered to have her brain waves reported. Yea. She and Carl Sagan had talked about it, and she thought it was a really interesting idea, and so she went in for the process where her brainless waves and her heartbeat were read and then transferred into data analog data, we have to say, because it's an analog disc and um. She says that what she did was she she thought about big historical moments that were very important in the development of human history, and then she spent some time thinking about the current situation on Earth, how what that's like things and and not sugarcoating at things like violence between people and the Yeah. So she really spent some time thinking about things that she felt needed to be addressed. And then she said that she took the liberty towards the end of the session to take a little bit of time and think about what it's like to fall in love, which I think is amazing, just the most wonderful suite. Ye. Yeah, so now we those aliens can't tell us they don't know how to love because she thought about it for for a while, darn it. Um. So, yeah, those radio signals do take a long time to get to us. So. But and and the record that's on there, if you want to hear some of the stuff, Uh, there are there are a lot of different sites out there that that keep all the things that aren't on there. It tells you what's there, and most of that's pretty easy to get access to and listen to. I'll try that. We'll try to find one and link it up on social. Yeah, we'll see if we can find something. And you know, maybe I'll see if I can make it a Spotify playlist or something and get a uku lele and play Johnny be Good on the ukulele. That's uh, that would probably be Johnny please stop. That would be the name of that song. All right, So, um, anyway, that's that's kind of the the wrap up of the spacecraft and the stuff that was aborted. But we still haven't talked about the actual science that's returned. So we're going to do that in just a moment, but before we do, let's take a quick moment to thank our other sponsor. Okay, so we've talked about what the mission was, we talked about the spacecraft. Let's talk about what the spacecraft found. So out of the all in investigation teams that were originally involved in the Voyager mission, like I said earlier, only five of them are still supported. And those five are magnetic field investigation, low energy charged particle investigation, cosmic ray investigation, plasma investigation, which is only active on the Voyager too because the Voyager ones doesn't work anywhere, and plasma wave investigation. So plasma investigation plasma wave investigation two different things, right, and these are clearly the more important ones because there's not all that much too. For example, take pictures of Yeah, once you're done taking the photo of the Solar system from way the heck out there, there's really no purpose to keep going to that. So yeah, that's been shut down. Um, and uh, the five instruments that support these five missions are the Magnetic Field Instrument or MG, the low energy Charged Particle Instrument, the l e CP Cosmic ray instrument that's the CRS, the plasma instrument that's p l S, and the Plasma Wave Instrument that's p WS. And really at this point, uh, now that we've finished taking photos and measurements of all the planets, which that was the main science before was really getting good images and getting some good scientific data about the actual plants and their moons. It was the origin of the program. Yeah, before they kind of realized, oh hey, we can do more stuff out there. Yeah, so now now we're we've switched it over to interstellar. But some of the stuff they found because of these and then later on have have expounded upon by sending out other orbiters like Cassini for example. But some of the stuff they discovered were like they took a closer look at Europa, which is one of Jupiter's moons, and saw that it had a water ice surface, and originally they thought that maybe Europa could have an ocean underneath that ice, but some scientists now say they think that it's probably more like a slush or maybe even solid solid ice, but that was a stability um. They the Voyager spacecraft also observed Pale, which is the largest of the volcanoes on Io, which is the another moon of U, and they observed that Paley was erupting sulfur and sulfur dioxide, and these eruptions were going up to heights that are equivalent to about thirty times the elevation of Mount Everest, the tallest mountain on Earth. Multiply that by well, tallest mountain on the surface, like not underwater, because you could look at underwater and there's but the above water. It's the tallest mountain on Earth. Multiply that by thirty times. That's how high up these eruptions were going. Not necessarily a good vacation spot. Now. The scientists also point out that Io's gravity is about six times weaker than that of Earth's, so it's closer to what our moon has. But the fallout zone for the the the sulfur dioxide that was being thrust into the atmosphere of Io was about the size of France. Yeah, so uh that was when I read that, I was like, wow, that is a huge, huge volcano. Um. Now the see what. We also had some information about Saturn's largest moon, which is called Titan. Uh. It discovered the oceans of ethane and methane aboard aboard on Titan, not a board Titan. It is technically a space that's not nothing satellite satellite, but it's a natural satellite, not a man made one. And it has also discovered that has the Titan, the the largest moon of Saturn, has a dense atmosphere and lots of hydrocarbons and maybe it could possibly at some point in the past have supported life. The methane is a possible indication that living things once lived there. Now that does not necessarily the hydrocarbons as well, but that does not necessarily mean that life ever was on Titan, but it's a possibility. Voyager also took images of Uranus's rings, which are very difficult to they're very faint right um, And but they did that. They also observed Saturn's rings and saw that they were made of about ten thousand strands of ice particles and car sized icebergs, and that if you look at them proportionally, their thickness is much much, much, much much smaller than the width of the ring. So if you think of it as like a one of those things called they're not the Frisbees, but you know the rings, they're they're hollow in the middle, right, there's there, so it's just a it's a disc that doesn't have a center to it. Um the width of the band is much wider than the thickness of the band, is what they discovered. So that was kind of interesting. Uh, now we're talking more about the interstellar work, so they're still inside the heliosphere, right, And I did want to mention at some point here on March, and we mentioned this in another podcast that we were recording. Right around March twenty UM, there were there were false reports that that it had left the helo sphere and entered interstellar space, and those were those were false reports. Yeah, NASA came out and said, no, we've not seen the changes in the magnetic radiation that we are expecting to see. That. They did say that they had seen some changes in particle movement, which at first would have indicated that the spacecraft had moved out of the heliosphere, but then they found from the magnetic movement that's not the case. So it's it's one of those things where again we keep finding out the Solar System is larger as we learn more about how it's behaving. So now the next step in this you could think of the interstellar exploration and being in three phases. The first was crossing the termination shock, which both of the spacecraft have already done. The next is the exploration of the Helio sheath, which is happening right now, and then the third is interstellar exploration, which is when the spacecraft have passed beyond the Helio Pause boundary. Now Helio Pause boundary, you can think of this as kind of like a bubble around the Sun that completely encompasses the the entire Solar System. It's not a perfectly round bubble, so don't think like that, but it's it's this whibbli wabbli area. Uh, And beyond this boundary there's no solar wind or magnetic field from the Sun. However, there's still the gravitational influence of the Sun at that point, but particles and waves in this area of space are unaffected by our Sun, and we don't really know a whole lot about them because we haven't been able to observe them directly through any kind of spacecraft. Right. Yeah, and and this is this is a hypothetical heliopause. Yeah, we have not encountered it yet, so but it's still not technically the edge of the Solar System if you if you ask NASA, the edge of the Solar System would be that area where there's no longer that gravitational factor from the Sun, which would require us to travel about two light years away from the Sun. So that will take us about forty thousand years for those spacecraft to get there, which is a you know, set your alarms because it's gonna take a while. So in other words, it'sman tells you that the voyager has passed outside the Solar System, your response should be wow, which alien warped it away from there? Because there's no way that it's done that, at least not by the definition that NASA makes. Now, if they're talking about the helio pause, that's a different story. Different that's a different story. And I think they are anticipating that within our lifetimes. Yeah, they said they said they expected it to happen within ten to twenty years of passing the termination shock. So now it's just probably probably hopefully fingers crossed before before that plutoni and dioxide runs out right before around that area. So, uh, Lauren, you had an interesting idea. One that an experimental idea that we thought we would try, which is that you sent out a tweet saying, hey, guys, if you have any anything interesting that you want to ask or goofy that you want to ask us about our podcast about the Voyage spacecraft, now's the time to do it. And people did. A couple of people did anyway, So hopefully we'll be able to do this in the future and get even more discussion. But this was a fun first attempt. So here's some of the questions we received. Ian on Twitter asked a whole bunch of questions that I'm going to tackle one at a time. The first was how fast are the Voyager spacecraft traveling? Good question, Ian, So Voyager one's traveling at about three point six astronomical units per year and Voyager two is poking along at three point three astronomical units per year. Now, that might not tell you very much unless you know how long an astronomical unit is. It's a measurement of distance that's based upon the mean distance between Earth and the Sun, and that's equivalent to about a hundred and forty nine million, five thousand, eight hundred swenty one kilometers or two million, nine hundred fifty five thousand, eight hundred seven miles. And because Jonathan loves you, he did the math yep. So let's talk about how this sucker breaks down. So remember, Voyager one's going at three point six astronomical units per year. That means it's traveling about five hundred thirty nine million kilometers per year or three hundred thirty five million in miles per year, and that breaks down to four kilometers per hour or thirty eight thousand, one seventy six miles per hour. Either way, it's going wicked fast. Voyager two is three point three astronomical units per year. That breaks down to four four million kilometers per year or fifty six thousand, eighteen kilometers per hour, and in miles, it's three hundred seven million miles per year or thirty five thousand miles per hour. Slightly less wicked fast, but still wicked fast, but still faster than than me. For example, his next question. Ian's next question was are they accelerating? No, next question was how long will you remain in contact. Well, like we said, we're not really sure. It's all going to depend upon the power supply. Uh. And also whether or not our antenna here on Earth can continue to pick up that week signal, but we expect around five will be the last we hear of them. Uh. And then Ian and also a listener named Jonathan. Also they both asked that we somehow reference a film, Star Trek the motion Picture. Okay, what does Voyager have to do with Star Trek the Motion Picture? Well, in a way, Voyager is the bad guy in Star Trek the motion Picture. In another way, the whole film is the bad guy because the thing is slow as heck. I watched it. I watched it not for anticipation of this podcast. I watched it justly, and I had not seen it since I was a kid. And I don't think I ever sat through it all the way through when I was a kid. I don't think I sat through it all the way there was an adult, I can't. I can't say that i've seen it since I was about a laundry and now Star Trek two amazing movie. Star Trek the motion Picture not so much. But in that story and this is gonna sound really familiar to anyone who watched Star Trek four because it's a very similar story. A probe that has this weird energy field around it enters our Solar system. Actually first it's just moving through space, but everything it encounters it's starting to deactivate, and everyone's kind of upset because because that's as head of right to Earth. So what do we do? How do we stop this? And of course the only person who can stop it as Kirk, who commandeers this starship, Starship Enterprise. He is no longer the captain of the Enterprise at that point. He's teaching at star Fleet, but the Enterprise is is docked in a space station around Earth, and so he, after a very long tour of the ship, of the outside of the ship that Scotty takes him on, eventually gets on board. And this movie moves slowly, is what I'm saying. And just they go and investigate this, uh, this probe that's called VJER and UH and VJR is this artificially intelligent vehicle and actually the vehicle contains a smaller probe like vehicle inside of it. Ultimately they discovered that what Vijure really is is Voyager six, which doesn't exist yet. No, there's only Voyager one and two. But in this in the movie, it was Voyager six that was supposedly launched towards the end of the twentieth century, which I don't know if you notice, we're not in the any or um, so you know, same thing like I think the Eugenics Wars and Star Trek two that are that ever mentioned that con was part of that was supposed to take place in nine, So we had a lot of catching up to do. Uh, Not that I want those to happen anytime soon. But the the VJRE was called vitre because it could no longer uh see the letters that were missing, So all the missing letters were gone, so all that was left was the v g e R. So it's Vidre uh and uh. And in the story, what you find out is that aliens had encountered the Voyager six probe and had enhanced it so that it could learn everything that is learnable and then returned the information to Earth. So it was trying to do a uh. Originally it was supposed to be a benevolent thing, but because vjer had gained sentience, it no longer completely understood the parameters of its mission, and so it started to go a little bonkers um and then of course the some remembers aboard the Enterprise end up essentially reasoning with the artificially intelligent probe. So Veder, like I said, it's kind of the bad Guy and Star Trek the motion picture. If you feel like I spoiled that movie, I didn't. It's really I mean, I mean, and I say this as someone who loves Star Trek. Okay, don't, don't get me wrong, I just I feel like that movie was a lot of the movie is played for grandeur, and the problem is that we've all gotten used to seeing these amazing sort of visuals that are even more amazing than what was available back then. So to kind of have this big reveal moment and you look at the picture and you're like, yeah, okay, it happens on TV every week. Yeah, So that's that's a problem alright. So uh then we also had a listener who has to handle REDNA maybe that's his name, who asked, what about future missions with better equipment? Well, we had the Cassini orbiter, but we also NASA had proposed a couple of joint mission with the European Union. Um, but they haven't really worked out. One of them was the Jupiter Europa orbiter, but that was essentially scrapped because of budget problems. And the other was the Titan Saturn system mission, which was shelved in order for NASA to concentrate on the Jupiter Europa or better. Yeah so, but but originally those were supposed to launch in twenty Now because of the budget cutbacks and everything, and you know the fact that there just hasn't been the time to develop it, that that launch window is kind of closed at this point. So um, as far as I know right now, there are no definitive deep space or outer planet missions planned. I think right now people are really concentrating on Mars, Mars and the Moon and Earth orbit. Those are those are I mean the things that are I hesitate to stay easier but maybe more achievable. Yeah, I have I have heard that that that future Moon landings have been scrapped in favor of future Mars land Yeah. I mean, it's you know, and and this changes from one administration to another because because a lot of these considerations are not just technological or scientific, they're also political. I mean, the whole space race was political, the fact that if there had not been that rivalry between the United States, but you know, we we can send we can send this rocket not only to your face, but all the way to the moon. Yeah, So I mean that was that was you know, without that kind of pressure than it makes it harder for scientists to get the money they need to be able to do the science they do. That's a sad fact of the world is that, you know, money in a way does make the world go round. And that wraps up another classic episode of tech stuff. Hope you guys enjoyed it. This was a lot of fun for us to do. I really had a great time with it. I want to do more episodes that are space related about specific projects. I've done everything from like the Gimin E program or Gimini program to uh, you know, like the Apollo O missions, the Space Shuttle missions. But I want to look at more of the satellite type stuff too. I think that those are really fascinating and I've only done a few of them. So if there are any specific topics, whether they are space related or otherwise, let me know, you know, ones that you want to hear anyway, let me know about it. Reach out on Twitter or on Facebook. The handle for both is text Stuff h SW and I'll talk to you again really soon. Text Stuff is an I Heart Radio production. For more podcasts from I Heart Radio, visit the I Heart Radio app, Apple Podcasts, or wherever you listen to your favorite shows.