1 00:00:05,780 --> 00:00:10,640 Hey everyone, my name is Eric Escobar and today my presentation is going to be on talking to satellites. 2 00:00:10,640 --> 00:00:12,340 And this is really a 101. 3 00:00:13,000 --> 00:00:15,740 You've never tried it before and you don't even know where to begin. 4 00:00:15,940 --> 00:00:20,200 This is also going to be a one cut take like a normal DEF CON presentation would be. 5 00:00:20,200 --> 00:00:23,500 So there's going to be a lot of flubs, a lot of hems, a lot of haws. 6 00:00:24,120 --> 00:00:25,360 That's about it. 7 00:00:25,360 --> 00:00:27,560 Anyways, without further ado, let's get going. 8 00:00:27,900 --> 00:00:29,900 I can't even transition a slide alright. 9 00:00:30,680 --> 00:00:32,600 So a little bit about me and my background. 10 00:00:32,880 --> 00:00:35,320 I started off my professional life as a civil engineer. 11 00:00:35,320 --> 00:00:43,340 I went to college, got my bachelor's degree, master's degree in civil engineering, became a professional engineer and realized it really wasn't for me. 12 00:00:43,340 --> 00:00:46,480 I didn't really like it as much as I thought it was going to. 13 00:00:46,680 --> 00:00:52,460 I then got an opportunity to start a security analyst position at Barracuda Networks. 14 00:00:52,460 --> 00:00:54,820 We started coming to DEF CON, DEF CON 22. 15 00:00:54,820 --> 00:00:57,660 So I've been here for what, six years now, seven years now. 16 00:00:58,360 --> 00:01:00,780 And I love doing anything wireless. 17 00:01:00,780 --> 00:01:02,060 I love wireless security. 18 00:01:02,160 --> 00:01:07,400 So I started playing in the wireless CTF and we won three years in a row, I believe. 19 00:01:07,600 --> 00:01:08,780 And now I'm a village member. 20 00:01:08,780 --> 00:01:10,580 So now I get to help make the challenges. 21 00:01:11,400 --> 00:01:15,780 And yeah, it's one of those things that the reason I started off with this is because I forever feel like a noob. 22 00:01:16,160 --> 00:01:20,260 I forever feel like the imposter syndrome is a real thing. 23 00:01:20,600 --> 00:01:29,540 And this talk is more of a, I'm not an expert in this, but it's something that I find really interesting and it definitely encapsulates that hacker mentality. 24 00:01:29,900 --> 00:01:37,720 So if this is your first DEF CON, you're going virtual, you're watching this talk, don't, don't hesitate to get your feet wet to reach out to people. 25 00:01:38,080 --> 00:01:41,060 Because at the end of the day, I feel like everybody feels like a noob. 26 00:01:41,060 --> 00:01:43,720 And if they don't, then they definitely are a noob. 27 00:01:43,840 --> 00:01:49,300 So that, that I basically just want to give my background that I didn't have a, you know, computer science degree. 28 00:01:49,300 --> 00:01:57,080 I didn't have a formal background in computer security or really anything at all except for civil engineering. 29 00:01:57,080 --> 00:02:02,000 So don't, don't hesitate to get your, get yourself out there. 30 00:02:02,120 --> 00:02:05,620 So this talk, talking to satellites, why? 31 00:02:05,620 --> 00:02:07,480 Personally, I think it's cool. 32 00:02:07,580 --> 00:02:11,500 The International Space Station is specifically what we're going to be going to cover. 33 00:02:11,540 --> 00:02:27,960 But there's a lot of satellites that are floating up above us or orbiting above us that, that are capable of, you know, ham radio communication, or just communication from the ground, just by, by normal citizens that don't require, you know, any special permission other than ham radio license to transmit to. 34 00:02:29,080 --> 00:02:40,480 What's cool about the International Space Station, I mean, it's orbiting 200 miles above us, which actually, when I, when I first started doing this, 200 miles didn't seem like a lot to me, it seemed like that, that should be orbiting higher than that. 35 00:02:40,480 --> 00:02:44,980 But 200 miles up, it's going roughly 17,000 miles an hour. 36 00:02:45,280 --> 00:02:49,260 And that's 10 times faster than a bullet, just kind of put it in like rough perspective. 37 00:02:49,620 --> 00:02:57,420 And it, it, it is going, it's orbiting so quickly that it can go around the entire planet in about 90 minutes, which I think is incredible. 38 00:02:57,760 --> 00:03:13,700 And it's also the most expensive object ever built, which is kind of neat that just being a normal civilian, I can talk to the International Space Station, even to astronauts on the International Space Station, with just, you know, general equipment and just a ham radio license. 39 00:03:14,020 --> 00:03:20,220 And even if you don't have a ham radio license, you can still listen to transmissions from the International Space Station, which is also I think, pretty cool. 40 00:03:21,500 --> 00:03:22,960 So here's a quick overview. 41 00:03:23,760 --> 00:03:34,840 But basically, we're how to talk to ISS on the cheap, the hows and the whys of, you know, why you'd want to do it and how you do it, the gear that you're going to need, the software that you'll need, the rough skills that you might need to have or, you know, 42 00:03:34,840 --> 00:03:40,520 brush up on timing when you're going to talk to the International Space Station, because it's orbiting every 90 minutes. 43 00:03:40,520 --> 00:03:46,580 And there's only very narrow windows that you can actually, you know, try and communicate with it on. 44 00:03:46,680 --> 00:03:53,980 And then basically, just now that you have all this power, how not to be a jerk, I feel like hacker mentality is the, you know, like, Oh, my gosh, we're gonna do all these bad, terrible things. 45 00:03:53,980 --> 00:03:58,000 But at the end of the day, you know, should you, this is this is something that's pretty cool. 46 00:03:58,240 --> 00:04:01,060 And you want to give others the opportunity to do it as well. 47 00:04:02,280 --> 00:04:03,480 See, moving on. 48 00:04:03,600 --> 00:04:04,800 So the hows and whys. 49 00:04:04,820 --> 00:04:09,420 So there's AR-ISS, which is amateur radio on the International Space Station. 50 00:04:09,420 --> 00:04:12,640 Basically, this is up there for educational purposes. 51 00:04:12,640 --> 00:04:13,520 It's community driven. 52 00:04:13,520 --> 00:04:19,380 It's one of these things that kind of inspire the, you know, the heart of people of, hey, what are we going to do with space? 53 00:04:19,380 --> 00:04:20,580 Why is space important? 54 00:04:20,580 --> 00:04:33,720 So I think it's kind of cool that they have a couple, you know, amateur radio stations on board in or not stations, but I guess transceivers on the International Space Station that are that are meant for amateur radio operators to interact with. 55 00:04:34,140 --> 00:04:40,140 Specifically, what we're going to be talking about is the two meter packet radio that's unattended on the International Space Station. 56 00:04:40,320 --> 00:04:49,300 There are definitely some attempts that you can have where crew members might be staffing the International Space Station and actually on the ham radio that you can talk to via voice. 57 00:04:49,300 --> 00:05:02,380 However, to try and get that to work is is, you know, it's a far more limited and you have to plan far more, you know, up in advance, whereas the unattended packet radio basically is going to act as like a repeater for you. 58 00:05:02,380 --> 00:05:05,000 And it's always up and always operational. 59 00:05:06,220 --> 00:05:12,940 And it's just one of those things that it's far easier to get a communication, you know, repeated from the International Space Station because it's done automatically. 60 00:05:13,160 --> 00:05:17,540 And there's a bunch of other operating modes that the International Space Station has. 61 00:05:18,000 --> 00:05:20,720 And, you know, you can go online at any point in time and check that. 62 00:05:20,720 --> 00:05:24,040 But really what we're going to be focusing on is the two meter packet radio. 63 00:05:24,520 --> 00:05:30,680 And it's also I also had no idea that, you know, a lot of ISS crew members are also ham radio operators, which I thought was kind of cool. 64 00:05:32,060 --> 00:05:38,560 Um, yeah, so we'll just, you know, break down the basics of it to transmit and talk to the International Space Station, you're going to need a ham license. 65 00:05:38,560 --> 00:05:39,640 And that's just a transmit. 66 00:05:39,640 --> 00:05:45,100 And that's really because you're going to be operating on frequencies and with hardware that could, you know, cause issues for other people. 67 00:05:45,100 --> 00:05:50,800 So it's not just like a cell phone where, you know, your phone is going to take responsibility for talking back and forth to a cell tower. 68 00:05:50,800 --> 00:05:55,820 This is something that, you know, you're going to have transmit power, and you want to be judicious with how you use it. 69 00:05:56,100 --> 00:06:02,360 However, that being said, if there's something that's interesting to you, you can listen without a ham license, no problem at all. 70 00:06:02,440 --> 00:06:04,500 You know, you don't need anything just to listen. 71 00:06:04,500 --> 00:06:07,180 It's really just transmitting because that could affect other people. 72 00:06:07,400 --> 00:06:15,340 And if you want your ham radio license, the ham radio village is offering a bleep $5 exams, which is, I mean, pretty cheap, normally, I think $20. 73 00:06:15,620 --> 00:06:22,240 But everything's gonna be virtual, obviously, because it's DEF CON and for $5 to, you know, make an attempt at your technician license. 74 00:06:22,240 --> 00:06:25,300 It's one of those things, I think you have to renew it every 10 years. 75 00:06:25,300 --> 00:06:27,520 I definitely recommend checking it out. 76 00:06:27,560 --> 00:06:29,480 You know, it's definitely a great opportunity. 77 00:06:31,480 --> 00:06:36,500 All right, so there's a lot of things that I never quite understood when I was getting into all this. 78 00:06:36,500 --> 00:06:38,760 And I'm, again, by all by no means an expert. 79 00:06:38,760 --> 00:06:47,580 So there's probably a ton of, you know, things in these slides that a seasoned, you know, extra ham operator is going to know that I'm going to completely flub up on. 80 00:06:47,700 --> 00:06:56,160 But I basically just this is something that, you know, I whenever I looked at this, I would always kind of say, Oh, my gosh, I don't even know what all of this garbage means. 81 00:06:56,420 --> 00:07:06,500 So when people always said two meter band, I had no idea what the heck is a two meter band, you know, FM 1200 BPS packet radio, all that stuff just sounded like gibberish to me, initially. 82 00:07:06,600 --> 00:07:15,080 And I really wish that somebody would have explained it to me in layman's terms, you know, just so I could at least get the basics and then kind of dig down from there at least, at least kind of get my feet wet. 83 00:07:15,800 --> 00:07:26,960 So if you look at that small little equation on the right hand side of your screen, you're going to see it's C equals I think that's lambda and then whatever the new I don't even know the Greek symbols, right. 84 00:07:27,140 --> 00:07:29,640 But at the end of the day, what happens to C is the speed of light. 85 00:07:29,640 --> 00:07:36,760 So if you divide that by your frequency, which is a megahertz, a megahertz is a million hertz, so million cycles per second. 86 00:07:36,760 --> 00:07:45,240 So, you know, you can think of Wi Fi as 2.4 gigahertz, you know, or 5.8 gigahertz, just kind of put that in perspective. 87 00:07:45,580 --> 00:07:52,160 So if you divide the speed of light by the megahertz of the frequency you're transmitting on, you divide those two and you get two meters. 88 00:07:52,440 --> 00:07:54,240 That's, you know, kind of how the math works out. 89 00:07:54,280 --> 00:08:00,220 And so when people say like, oh, it's only two meter band, well, you know, that's the same thing as saying it's about, you know, 144 megahertz ish. 90 00:08:00,220 --> 00:08:04,000 And I think the two meter bands anywhere from 144 to 148 megahertz. 91 00:08:04,680 --> 00:08:05,980 But but that's what people are talking about. 92 00:08:05,980 --> 00:08:13,500 So 70 centimeters, you can do the same, you know, the same math and figure out that it's, you know, about 460 megahertz, I think of off the top of my head. 93 00:08:14,020 --> 00:08:15,900 And that's also considered VHF. 94 00:08:15,900 --> 00:08:20,060 So you'll hear VHF, two meter and 144 megahertz. 95 00:08:20,060 --> 00:08:22,060 Those are all kind of in the same ballpark. 96 00:08:22,820 --> 00:08:25,520 You know, and that's just one of those things to hear those terms thrown around a lot. 97 00:08:25,520 --> 00:08:26,560 And I had no idea what they meant. 98 00:08:26,560 --> 00:08:32,820 So I figured it would be helpful to kind of throw out a slide and explain that briefly when somebody says I'm operating on the two meter band. 99 00:08:33,260 --> 00:08:36,400 Oh, okay, that means 144 megahertz ish. 100 00:08:36,820 --> 00:08:40,200 You know, and that's also considered VHF, very high frequency. 101 00:08:40,680 --> 00:08:42,740 So the next part of that, what is FM? 102 00:08:42,740 --> 00:08:46,460 You probably have heard of AM FM radio on in your car. 103 00:08:46,820 --> 00:08:48,400 AM is amplitude modulation. 104 00:08:48,400 --> 00:08:51,080 So you can see the little graphic on the bottom right of the screen. 105 00:08:51,320 --> 00:08:54,220 That's where the wave is actually modulated up and down. 106 00:08:54,220 --> 00:08:56,140 So you can kind of think of this waves in a pond. 107 00:08:57,600 --> 00:09:00,440 You know, if you throw a rock in and there's big splash, those waves are going to be bigger. 108 00:09:00,440 --> 00:09:04,220 And that's going to be amplitude , you know, there's a varying amplitude there. 109 00:09:04,480 --> 00:09:08,540 Whereas FM is how close those waves are, you know, in a ring and a circle. 110 00:09:08,540 --> 00:09:09,500 So I'm using my hands a lot. 111 00:09:09,500 --> 00:09:14,940 I don't probably look like a you're stretching like a slinky. 112 00:09:15,200 --> 00:09:19,040 You know, FM waves, you're modulating the frequency how fast it goes. 113 00:09:19,460 --> 00:09:21,140 So you know, there's AM FM. 114 00:09:21,140 --> 00:09:23,080 So we're looking at two meter band FM. 115 00:09:23,080 --> 00:09:24,700 So it's frequency modulated. 116 00:09:24,940 --> 00:09:27,240 And this is typically not something that you're gonna have to worry about. 117 00:09:27,240 --> 00:09:29,580 It's lower level stuff that the radio is going to take care of. 118 00:09:29,580 --> 00:09:33,120 But it's just good to know because I didn't know it when I started out. 119 00:09:33,700 --> 00:09:35,880 Um, gosh, 1200 BPS. 120 00:09:35,880 --> 00:09:37,380 So it's BOD not BITS. 121 00:09:37,380 --> 00:09:42,960 If you mess this up, you know, internet's gonna murder you because you're, you know, technically wrong. 122 00:09:43,060 --> 00:09:45,760 I always thought that BOD and BITS were exactly the same. 123 00:09:45,760 --> 00:09:51,820 It wasn't until I dug into it that I actually realized, oh, gosh, they're, you know, they can be different. 124 00:09:52,040 --> 00:09:55,700 So you can think of a BOD as like a signal interval or like a pulse. 125 00:09:56,220 --> 00:10:00,180 And in the early days, I guess, I don't know, I wasn't around during the early days. 126 00:10:00,200 --> 00:10:02,780 But early modems would do one BIT per BOD. 127 00:10:02,780 --> 00:10:05,780 So basically just be one BOD and one BIT were the same. 128 00:10:05,780 --> 00:10:09,040 So 1200 BITS and 1200 BOD were the same exact thing. 129 00:10:09,040 --> 00:10:15,820 However, now there's craftiness in there that allows you to transmit at a higher BIT rate with the same level of BOD rate. 130 00:10:15,820 --> 00:10:24,380 So if you can transmit eight BITS in a single BOD pulse, that should come out to 9600 BITS per second, even though your BOD rate is only 1200. 131 00:10:24,720 --> 00:10:25,580 I don't really know. 132 00:10:25,580 --> 00:10:31,120 Again, it's one of these things that that's just what APRS or the packet radio service uses. 133 00:10:31,260 --> 00:10:32,840 The software takes care of it all for you. 134 00:10:32,840 --> 00:10:37,160 You don't have to worry about it, but it is helpful to know so that the internet doesn't murder you. 135 00:10:37,660 --> 00:10:45,520 And then the technique that is used for like, you know, packing things, you're packing eight BITS per single BOD is called quadrature amplitude modulation. 136 00:10:45,520 --> 00:10:47,940 Say that at a party and no one will want to talk to you. 137 00:10:47,940 --> 00:10:52,900 So it's one of those things, again, super nerdy stuff, but it kind of helps to know. 138 00:10:52,900 --> 00:11:00,900 For me, you can look at that and at least kind of digest it and understand maybe not why it's that way, but at least that that's what all of these things mean. 139 00:11:00,900 --> 00:11:05,940 Somebody says, oh, two meter band FM at 1200 BOD, you kind of know what's going on there. 140 00:11:06,580 --> 00:11:14,340 And then packet radio, you know, I guess to me this wasn't any news, but it's packetized data, right? 141 00:11:14,340 --> 00:11:20,680 And so that's one of those things where instead of it just being a continuous flood of data, all the data comes in packets. 142 00:11:20,860 --> 00:11:27,320 And especially for, you know, for APRS, it uses the AX25, which includes your call sign. 143 00:11:27,320 --> 00:11:35,980 And I believe for FCC requirements, you need to transmit your call sign anytime that you're going to transmit, you know, power out into the atmosphere. 144 00:11:36,280 --> 00:11:38,940 And so this basically satisfies that. 145 00:11:39,140 --> 00:11:40,820 But yeah, data comes in in packets. 146 00:11:41,240 --> 00:11:47,740 And what happens is say you have like a small walkie talkie, or not walkie talkie, but a small handheld radio. 147 00:11:47,940 --> 00:11:55,420 If you were to transmit on that small radio, what's going to happen there is it is going to get sent out, you know, and not a very far distance. 148 00:11:55,420 --> 00:12:06,580 And so the goal of the packet radio service, packet reporting system, I can read my slides, is basically to repeat that information out farther. 149 00:12:06,580 --> 00:12:19,760 So your handheld, you know, radio is going to only make a certain distance, hopefully gets far enough away that, you know, that it can reach a larger repeater that's then going to take your message and repeat it. 150 00:12:19,780 --> 00:12:29,960 And the way that APRS works, I think I have this in my next slide, but the way that essentially works is you can select how far out you want that message to be repeated. 151 00:12:29,960 --> 00:12:43,620 So if you're say, you know, out in the sticks, and there's not a whole lot of, you know, there's not a whole lot of repeaters out there, you might want to set a wider setting, or, you know, like a time to live, if you're familiar with, you know, internet lingo, 152 00:12:43,620 --> 00:12:47,080 that basically says, hey, you know, repeat this out this many hops. 153 00:12:47,080 --> 00:12:50,980 And the whole goal of this is essentially to reach what's called an IGate. 154 00:12:50,980 --> 00:12:57,600 And an IGate will take your packet radio, your take, take your transmission, and put it on the public internet. 155 00:12:57,600 --> 00:13:08,160 So that way, you know, anybody in the world then can now look at it or, you know, any other, if you have a program written or something like that, you can digest that information and see where it's coming from, from anywhere in the world. 156 00:13:09,660 --> 00:13:16,500 So APRS was created by somebody, his name is Bob Brun... I don't know his last name. 157 00:13:16,500 --> 00:13:20,440 Bob created it, I believe, in 1973-ish. 158 00:13:20,920 --> 00:13:31,560 And if you look at this, this image of the world, every, every continent-ish or every, you know, region of the world has a different, slightly different frequency that it transmits APRS on. 159 00:13:31,560 --> 00:13:33,080 And those are all in megahertz. 160 00:13:33,740 --> 00:13:45,380 So you can see anywhere in the United States, if you're, you know, which is where I am, at least, it's going to be transmitted on 144.390 megahertz is the frequency that everything's going to share. 161 00:13:45,600 --> 00:13:58,420 The kind of bummer part about that is that because we're all using, you know, and say we ham operators, if we're all transmitting 144.390 megahertz, well, your transmission will interrupt somebody else's transmission. 162 00:13:58,420 --> 00:14:09,480 So there's a lot of room for collision, especially when you figure that every time you transmit a message, what's going to happen is that's going to be repeated by any number of other larger repeaters. 163 00:14:09,480 --> 00:14:13,960 So there's a lot of, you know, potential congestion in there. 164 00:14:14,340 --> 00:14:18,200 So it's one of those things that you don't always want to transmit your message as far as it will possibly go. 165 00:14:18,200 --> 00:14:22,220 You just want to get it as far as you need to go to kind of be respectful of the space. 166 00:14:22,620 --> 00:14:27,840 And again, I'm breaking all this down because you'll see why it's important when it comes to the ISS later on. 167 00:14:30,040 --> 00:14:34,320 So automatic packet reporting system, that's what APRS stands for. 168 00:14:34,400 --> 00:14:49,060 A lot of times what people will do is ham operators will have, you know, little tracking beacon devices that have a GPS unit on there and they will beacon out, you know, a location at a set interval, you know, it could be 10 minutes, could be one minute, 169 00:14:49,060 --> 00:14:51,120 whatever their specified interval is. 170 00:14:51,600 --> 00:14:58,700 And they will beacon from the small transmitter to, you know, larger repeaters with the intent of getting online. 171 00:14:58,700 --> 00:15:07,680 And this is useful if, you know, you're somewhere where there's not cell coverage or, you know, this was invented before cell phones ever existed, like, I guess, like as ubiquitous as they are now. 172 00:15:07,680 --> 00:15:21,880 And so it was a great way to track things, you know, you can put them in your car, put them in a boat, put them in a plane, you know, people have used them for hot air balloons, you know, and just all sorts of things where maybe cell coverage isn't going to fit. 173 00:15:21,880 --> 00:15:24,960 This is a great way to track assets really. 174 00:15:25,320 --> 00:15:32,020 So you can see from this little image there, you know, this is kind of like the traditional what people think of when they hear APRS or, you know, packet radio. 175 00:15:32,080 --> 00:15:35,340 They think of a radio that actually transmits the signal. 176 00:15:35,520 --> 00:15:40,240 They think of, there's a little device, I think it's called a terminal node controller. 177 00:15:40,240 --> 00:15:46,440 Yeah, TNC, which basically takes your GPS data and any message data or any other additional data. 178 00:15:46,880 --> 00:15:50,020 And it basically makes that into an audio format. 179 00:15:50,260 --> 00:15:54,080 You know, it encodes into an audio format that then is transmitted out by your radio. 180 00:15:54,080 --> 00:15:56,700 So that's kind of the traditional way that this looks. 181 00:15:56,980 --> 00:15:59,980 However, things have changed now since everybody has cell phones. 182 00:16:00,060 --> 00:16:01,300 So you can do a couple things here. 183 00:16:01,300 --> 00:16:13,240 So instead of having, you know, a device that has to have onboard GPS, and you already have to have an additional piece of GPS information and additional computer and additional encoder and all this different stuff. 184 00:16:13,440 --> 00:16:16,820 Instead of what you're going to have here is you can have a Raspberry Pi that does it. 185 00:16:16,820 --> 00:16:23,180 Or you could just have a phone that, you know, automatically has GPS on board , automatically has the audio cable on board. 186 00:16:23,180 --> 00:16:29,420 And basically you hook up an audio cable or sound card if you're using a Raspberry Pi to a radio. 187 00:16:29,420 --> 00:16:30,320 I chose Baofeng. 188 00:16:30,320 --> 00:16:34,640 People love and hate these types of radios, but I like mine personally. 189 00:16:35,080 --> 00:16:44,840 And basically what you do is you use then these devices to encode your message, you know, as an audio file that is then transmitted out your radio. 190 00:16:45,480 --> 00:16:57,220 And the whole purpose of that is essentially, you know, you could take what used to be a giant apparatus that would fill, you know, like an entire desk, and now it's something that can easily go in your pocket and the batteries last for a pretty decent amount of time. 191 00:16:57,780 --> 00:17:04,280 And so that's kind of how this, how like the hardware-wise, at least what you need or what that looks like. 192 00:17:04,560 --> 00:17:12,660 The next part, at least what I, when I was starting out looking at this, I thought that, man, I must need a ton of power in order to transmit to the International Space Station. 193 00:17:12,660 --> 00:17:14,480 Like it must just be crazy amounts of power. 194 00:17:14,480 --> 00:17:18,000 I'm probably going to dim the lights in my house trying to get the signal that far away. 195 00:17:18,000 --> 00:17:20,180 But really it's incredibly low. 196 00:17:20,320 --> 00:17:31,740 I've heard that people have done it on as low as a single watt, but five watts that comes on your standard Baofeng radio is more than enough to transmit to International Space Station. 197 00:17:32,000 --> 00:17:44,080 And really, when you think about it, that's less power than what your, what your, you know, your phone charger puts out, which I thought was pretty, pretty interesting that you could transmit up to something orbiting up, up in, you know, upper atmosphere, 198 00:17:44,080 --> 00:17:47,360 you know, low Earth orbit for just five watts. 199 00:17:47,460 --> 00:17:51,360 It just seems kind of crazy that, that there, you know, that it can get that far, I guess. 200 00:17:52,020 --> 00:17:58,000 So this kind of is a better way to, to show what I was trying to explain is that there's a little tracker. 201 00:17:58,000 --> 00:17:58,560 You can see that. 202 00:17:58,560 --> 00:18:03,180 I think that I've, I forget what the name of that tracker is, but basically it's super small tracker. 203 00:18:03,180 --> 00:18:10,720 I think it's about a hundred dollars that, you know, we'll, we'll beacon out, I believe one watt at a pre-described interval with GPS and everything on board. 204 00:18:11,020 --> 00:18:20,960 And the whole goal of it is that that little transmitter may not be able to get very far, but the whole point of it is that you're trying to reach a single digipeter and these digipeters are set up by their ham radio operators. 205 00:18:21,040 --> 00:18:28,380 And if there's not one in your area, you know, it's one of those things that'd be kind of cool to set one up just to spread the net of APRS far and wide. 206 00:18:28,560 --> 00:18:47,460 But essentially the whole goal is for that little tracking device or, you know, any other, any other end node that you maybe have in your pocket or whatever to transmit to a higher power digipeter, you know, repeater that digitally repeats it with the express purpose of really trying to get it to a larger gateway. 207 00:18:47,460 --> 00:18:53,200 And the gateway, you know, in this case is an iGate and an iGate can then connect it to the internet. 208 00:18:53,320 --> 00:19:01,100 A nice part about that is once it's connected to the internet, there are websites like APRS.fi, which will aggregate all of this data globally. 209 00:19:01,180 --> 00:19:05,640 So you can look around and see all the devices that are transmitting out and about in the world. 210 00:19:05,640 --> 00:19:09,840 And, you know, you can look at the other side of the world and just see all the devices that are out there. 211 00:19:09,840 --> 00:19:14,780 And there's weather stations, there's, you know, hot air balloons, a lot of cars, boats, planes, you name it. 212 00:19:14,780 --> 00:19:17,460 There's a lot of devices that are tracked, you know, on APRS. 213 00:19:17,460 --> 00:19:20,940 And it's kind of neat to be able to see where all these devices are out on the internet. 214 00:19:21,820 --> 00:19:24,900 So that was a full big explanation of APRS. 215 00:19:24,900 --> 00:19:38,240 And why it matters is that the ISS has one of these DigiPeters on board, which at the end of the day is kind of neat because you figure normally you would try and, you know, reach a DigiPeter that is going to be, say, on a mountaintop nearby. 216 00:19:38,360 --> 00:19:53,340 But really, if you can transmit to the International Space Station and have it repeat your signal, so DigiPete your message, well now you can be received on a huge far and wide area down below because the International Space Station has a great vantage point on the rest of the planet. 217 00:19:53,600 --> 00:19:59,800 So what's kind of neat is I think I've gotten up to 800 or 1,000 miles from how far I've heard somebody else transmit from. 218 00:20:00,080 --> 00:20:16,160 And likewise, normally to, you know, transmit a message that far to, you know, 1,000 miles, you would need a decent amount of power, a great vantage point, and, you know, everything would need to be kind of go right to transmit on, you know, especially VHF or the two meter band that far. 219 00:20:16,160 --> 00:20:29,580 Whereas now with the International Space Station, because of its vantage point in space and clear line of sight, you know, down to the earth, you can transmit your message really far, which I, again, I just think is really cool that, you know, the most expensive object that any, 220 00:20:29,580 --> 00:20:36,240 you know, that's ever been built that we have the capability as, you know, as amateurs to be able to transmit and relay a message off of it. 221 00:20:36,240 --> 00:20:37,760 I just think it's kind of neat. 222 00:20:39,800 --> 00:20:41,400 Yeah, so this is a website. 223 00:20:41,400 --> 00:20:47,580 If you go to ariss.net, you know, it looks like what a website would look like if I made it. 224 00:20:47,580 --> 00:20:57,200 You know, the graphics aren't crazy, but at the end of the day, it's really cool in that it aggregates all of the stations that heard the ISS and have transmitted to the International Space Station. 225 00:20:57,200 --> 00:20:59,580 So again, you don't need any hardware at all. 226 00:20:59,580 --> 00:21:06,800 If you have a phone, you can pull up ariss.net and basically just see, oh, what stations around me have heard the International Space Station? 227 00:21:06,800 --> 00:21:08,600 Where is the International Space Station? 228 00:21:08,600 --> 00:21:11,500 What messages are coming off the International Space Station? 229 00:21:11,500 --> 00:21:26,600 Again, because the whole point of it, or maybe not the whole point of APRS, but, you know, at least, at least a, I don't know, a takeaway of APRS is that if that information all gets aggregated online, you know, you can see it from anywhere in the world, 230 00:21:26,600 --> 00:21:28,200 which I think, again, is kind of neat. 231 00:21:29,200 --> 00:21:30,660 So let's talk about the hardware. 232 00:21:30,720 --> 00:21:41,000 I have made the horrific mistake in the past of trying to post links to hardware on, you know, my slides and then, you know, I find a better price somewhere or I find, oh, it's not there anymore. 233 00:21:41,180 --> 00:21:47,520 So what I'm going to try and do this time is, if you want to look at the hardware, I'm going to try and keep an up-to-date list at github.com. 234 00:21:47,580 --> 00:21:49,140 Again, you can see the link right there. 235 00:21:49,140 --> 00:21:58,260 And the whole purpose of that is so that I can update this list and find better prices or whatever, because things change and, you know, there are better spots, you know, to potentially get some stuff at. 236 00:21:58,620 --> 00:22:03,880 So again, this is kind of my like go-to hardware, which again, if you look at it, it's pretty darn cheap. 237 00:22:03,880 --> 00:22:07,820 You're looking at $35, $20, $10, $8. 238 00:22:07,880 --> 00:22:21,560 You're looking at under $100 to be able to transmit a signal to the international space station, which again, for that price and the skill requirement and just being an amateur and a civilian, I think is pretty cool. 239 00:22:22,100 --> 00:22:24,820 Baofeng Radio, this is a cheap Chinese radio. 240 00:22:24,820 --> 00:22:26,260 I personally really like them. 241 00:22:26,260 --> 00:22:30,820 I know a lot of people on the internet have hate for them, but it works well for me. 242 00:22:30,820 --> 00:22:39,140 And I find that it, you know, for $35, it's a great way to just, you know, not break the bank, but really figure out if ham radio just in general is going to be a good hobby for you. 243 00:22:39,140 --> 00:22:40,720 It has a lot of other capabilities. 244 00:22:40,720 --> 00:22:44,720 You can listen to normal FM radio, you know, can be a police scanner. 245 00:22:44,980 --> 00:22:46,640 There's just a lot of other stuff that it can do. 246 00:22:46,640 --> 00:22:49,420 And so I really like it for $35 on Amazon. 247 00:22:49,480 --> 00:22:50,840 You can't really beat it. 248 00:22:51,860 --> 00:22:52,620 So let's see. 249 00:22:52,620 --> 00:22:57,020 So it comes with what's, you know, a little stick antenna, like what you'd see on a walkie talkie. 250 00:22:57,020 --> 00:23:15,320 That's what if you were to buy this Baofeng Radio, it would come with, but you can build a directional antenna, which is what you're going to want if you're going to talk to satellites or the International Space Station, because a traditional stick antenna is going to radiate its signal out kind of like a donut. 251 00:23:15,320 --> 00:23:20,840 So if you're to hold it like thumbs up, you know, so the radios, so the antenna sticking up, it's going to radiate out like a donut. 252 00:23:20,840 --> 00:23:24,140 And I should probably have a slide in there that has, you know, these radiation patterns. 253 00:23:24,540 --> 00:23:34,320 But really what we want is a directional antenna that kind of focuses that beam more like a flashlight, you know, into the general spot in the sky where you're trying to focus all of your energy. 254 00:23:34,880 --> 00:23:39,100 And so for $10, $20, you can really build your own antenna, which I think is even cooler. 255 00:23:39,520 --> 00:23:50,320 And then you need an audio cable, an audio card, if you're going to use the Raspberry Pi, or if you're, if you don't use Raspberry Pi at all, and you're just going to use your cell phone, you know, typically most people have cell phones. 256 00:23:50,480 --> 00:23:56,580 And so just an audio cord for that, you know, under $100, you can no problem transmit the International Space Station. 257 00:23:56,580 --> 00:23:58,820 And again, I'm going to try and keep this updated. 258 00:23:59,240 --> 00:24:11,200 If there's something, you know, missing from it, I'll shoot me a message and I can update it or see if there's really anything else out there. 259 00:24:11,260 --> 00:24:22,600 And again, it's one of those things, you know, for the amount of money, what you get out of it, especially because I'm sure a lot of you have kids that are home from school, or maybe you're a kid that, you know, is learning remotely now. 260 00:24:23,020 --> 00:24:37,800 What an awesome project for under $100 to learn about physics, space, orbits, math, you know, all these things that are super nerdy, because I'm super nerd, but really, there's a lot of other applicable lessons to other stuff out there. 261 00:24:38,700 --> 00:24:41,180 The other thing that you're going to want to do is turn on Vox. 262 00:24:41,180 --> 00:24:44,640 Again, this is one of those things that I'm probably getting internet hate mail for. 263 00:24:44,900 --> 00:24:46,740 Vox is voice operated switch. 264 00:24:46,740 --> 00:24:55,060 So basically, you can think of it as when you start talking, radio is going to detect that you're that you're talking already, and it will then start transmitting right away. 265 00:24:55,060 --> 00:25:04,840 That's nice, because that means if you plug an audio cable in from your phone or from a Raspberry Pi, the second that it starts playing audio over that jack, it's going to start transmitting. 266 00:25:04,860 --> 00:25:18,000 Why this isn't ideal is because there's always a little bit of space of, you know, a little bit of transmit time after you're done talking where the radio is still on and that can mess up some some communications. 267 00:25:18,360 --> 00:25:20,820 So it's not ideal, you really want push to talk. 268 00:25:20,820 --> 00:25:26,520 But if you're just getting started, it doesn't hurt just to use Vox just to just to get your feet wet. 269 00:25:26,520 --> 00:25:27,420 That's my personal opinion. 270 00:25:27,420 --> 00:25:29,440 Again, going to get hate mail, I'm sure. 271 00:25:29,600 --> 00:25:30,560 But whatever. 272 00:25:31,240 --> 00:25:36,300 So I own an aero directional antenna from it's very similar to the one that's in that image right there. 273 00:25:36,300 --> 00:25:39,920 It's like $150, which is more than the entire cost of the project. 274 00:25:40,140 --> 00:25:45,540 And if hand radio is potentially something you're not going to get into, you know, you're going to want to buy some giant antenna. 275 00:25:45,640 --> 00:25:47,000 I don't really know. 276 00:25:47,020 --> 00:25:49,880 Personally, I have one because it's something that I really enjoy. 277 00:25:50,480 --> 00:25:53,140 However, it's $150 and it's pretty steep. 278 00:25:53,540 --> 00:25:55,500 Or you could build your own. 279 00:25:55,500 --> 00:26:11,700 And this is one of those things that I was just, you know, checking stuff out online and I saw that somebody had built a their own directional Yagi antenna for like $10 in like PVC parts and like a measuring tape, which is like perfect because I build everything with Raspberry Pis in PVC anyway. 280 00:26:11,700 --> 00:26:14,560 So I had a lot of that basically just lying around. 281 00:26:14,940 --> 00:26:20,700 And a measuring tape, which funnily enough, I didn't even think about it, but I guess it's, you know, measuring tapes are steel. 282 00:26:20,820 --> 00:26:32,220 And so if you, as long as you, you know, basically sand off the tips of your antenna to solder your cables to, it's one of those things that, oh, wow, that's kind of neat. 283 00:26:32,220 --> 00:26:38,520 Like you can make an antenna out of a steel measuring tape and it folds up nicely too, which is the added benefit. 284 00:26:38,520 --> 00:26:49,220 I'll have a link to this on that GitHub page that I mentioned, but if you just want to Google it right now while you're watching this, if you just do Legios, I don't know how you say it, that's how you say it, but that's how I say it. 285 00:26:50,260 --> 00:26:53,620 And then Yagi, all the instructions, the build list, everything. 286 00:26:53,620 --> 00:26:59,800 I'm not going to go over all the super details or my time-lapse of me building mine, because it's not really necessary at all. 287 00:26:59,800 --> 00:27:01,560 Just go online, look at it. 288 00:27:01,560 --> 00:27:06,720 Plenty of other people have done a lot of work to make that pretty nice. 289 00:27:08,280 --> 00:27:14,180 So it's one of those things too that like, I personally think this is a nerd merit badge to build your own antenna. 290 00:27:14,500 --> 00:27:24,480 That's one of those things, if you're a student, if this is interesting to you, it kind of gives you a little bit more stake in it, not just to like, oh, I bought all this stuff off the internet, put it together, and I can talk to International Space Station. 291 00:27:24,480 --> 00:27:34,200 There's a little bit of that like hacker spirit, hacker mentality, just to like, you know, I built this antenna out of raw parts, you know, and kind of cobbled it together to get it to work. 292 00:27:34,200 --> 00:27:45,500 To me personally, I think that's kind of neat, just to, you know, kind of have this project of like, yeah, this is something I built with my hands, and you know, I'm talking to the most expensive object, you know, that humanity's ever built, you know, 293 00:27:45,500 --> 00:27:46,480 arguably, right? 294 00:27:47,820 --> 00:27:53,900 And it's just kind of cool to me that you can talk to International Space Station with PVC and a measuring tape and like a radio that you bought off Amazon. 295 00:27:54,160 --> 00:27:55,780 And it takes about an hour to build. 296 00:27:55,780 --> 00:28:04,060 If you have kids and you want to at all get them interested in space and engineering and STEM stuff, you know, or just to get their hands dirty. 297 00:28:04,140 --> 00:28:07,900 I think this is personally a really cool project, and it's not going to break the bank to try it. 298 00:28:09,600 --> 00:28:12,020 And let's see, I don't know why I can't change sides. 299 00:28:12,020 --> 00:28:12,740 Oh, there it goes. 300 00:28:12,820 --> 00:28:14,980 So this is my antenna up on top of my patio. 301 00:28:14,980 --> 00:28:17,940 It's on top of my patio, obviously, so I can get a better line of sight. 302 00:28:18,080 --> 00:28:20,280 And I keep everything in my little ammo box. 303 00:28:20,360 --> 00:28:21,740 And I use a tripod. 304 00:28:21,740 --> 00:28:27,100 But again, you can just hold your hand out there with an extra piece of PVC and it works just as well. 305 00:28:27,860 --> 00:28:31,040 It's one of those things that it looks, it looks homemade. 306 00:28:31,040 --> 00:28:31,680 And that's what it is. 307 00:28:31,680 --> 00:28:33,940 But you're talking to a satellite with a homemade antenna. 308 00:28:33,940 --> 00:28:35,060 I think that's pretty cool. 309 00:28:36,760 --> 00:28:40,760 Um, so obviously, if you build your own antenna, you're gonna have to tune it a little bit. 310 00:28:41,000 --> 00:28:52,640 Luckily, if you follow the instructions online of the, you know, of the antenna that at least I made, when I went to tune it, and from what I've heard from others, when they go to tune it , everything is pretty spot on it if you measure things carefully. 311 00:28:52,960 --> 00:28:58,160 But the way that you tune your antenna is by looking at the standing wave ratio or SWR. 312 00:28:58,240 --> 00:29:00,420 And this really just measures the performance. 313 00:29:00,420 --> 00:29:06,840 I like to think of it as say you have a, a like a tube of like, you know, gift wrap, right? 314 00:29:07,140 --> 00:29:14,580 And you shout down that tube, how much of your sound that's from leaving your mouth going through the tube is actually making its way out the tube. 315 00:29:14,580 --> 00:29:28,400 And that's kind of how you can think of SWR working with your antenna of, hey, if I'm going to put five watts of power into my antenna, how much of that power is actually going to be coming out my antenna, or how much of it's going to be wasted, you know, 316 00:29:28,400 --> 00:29:32,480 kind of just banging around the, you know, just kind of radiating off of it. 317 00:29:32,620 --> 00:29:43,060 So there's one of those things that that, you know, if you know, a ham radio operator, I'm sure they have, you know, a SWR meter, you can buy a cheap one online for $20. 318 00:29:43,060 --> 00:29:43,840 I don't have one of those. 319 00:29:43,840 --> 00:29:45,300 I don't know how well it works. 320 00:29:45,560 --> 00:29:47,580 I personally have a nano VNA. 321 00:29:47,680 --> 00:29:54,740 It was like 50 or something dollars online and does a bunch more stuff other than just looking at SWR, but it's really small, has a battery. 322 00:29:54,740 --> 00:29:55,880 I personally really like it. 323 00:29:55,880 --> 00:30:00,540 But again, if you're trying to not break the bank, you know, maybe a $20 one online is worth it. 324 00:30:00,540 --> 00:30:05,100 Or you find a ham radio operator that you just say, hey, can I plug this in real quick and test it? 325 00:30:05,100 --> 00:30:10,540 You know, there are plenty of older ham radio operators that would love nothing more than the talk radio and talk shop. 326 00:30:10,540 --> 00:30:16,880 And it's a great way to, you know, build a community, build a hobby, because ham radio operating is an aging hobby. 327 00:30:17,100 --> 00:30:25,140 You know, just go to any ham radio operator meeting, you know, in your city, in your state, in your wherever you're from. 328 00:30:25,340 --> 00:30:27,960 And it's definitely an older person's hobby. 329 00:30:27,960 --> 00:30:30,200 But I don't think it has to be that way at all. 330 00:30:30,440 --> 00:30:37,500 The next thing is, it's really just one of those things that if you follow the instructions, you can probably have a pretty good SWR. 331 00:30:37,800 --> 00:30:44,600 And again, I think mine when I did it was 1.3 to 1, which I think perfect SWR is 1 to 1. 332 00:30:44,600 --> 00:30:45,860 To me, this is just magic. 333 00:30:45,860 --> 00:30:47,680 I don't really understand how it works. 334 00:30:47,700 --> 00:30:51,120 I just know that you want your numbers to be as close to 1 to 1 as possible. 335 00:30:51,120 --> 00:30:55,100 Again, if I'm wrong, shoot me a message and let me know and I'll update the slides. 336 00:30:56,420 --> 00:30:58,540 So the next piece of this is the software. 337 00:30:59,920 --> 00:31:03,000 Again, I have lots of Raspberry Pis lying around from a bunch of other projects. 338 00:31:03,000 --> 00:31:04,720 I personally like to use Raspberry Pi. 339 00:31:05,260 --> 00:31:07,360 I use the software called Direwolf. 340 00:31:07,360 --> 00:31:09,220 It's just an apt-get install. 341 00:31:09,400 --> 00:31:21,980 Again, if you check out the GitHub page, I'll have the instructions on how to set it up perfectly, as well as my configuration files to kind of mess with so you can look at them and not have to recreate it from scratch. 342 00:31:22,640 --> 00:31:32,220 And then when you install Direwolf, it'll also install Kissutil, which is what I use to be able to transmit messages into Direwolf. 343 00:31:32,460 --> 00:31:35,280 And then the next thing is there's a tool called Zaster. 344 00:31:35,280 --> 00:31:38,180 I don't know how you actually say that because it has an X and a str in it. 345 00:31:38,180 --> 00:31:38,920 So I don't know. 346 00:31:38,920 --> 00:31:40,100 I assume that's how you say it. 347 00:31:40,100 --> 00:31:51,720 And this is more of a GUI tool that you can have on the Raspberry Pi, which is kind of neat because you can see, you know, it'll automatically plot where radio transmissions are coming from as they come in through APRS. 348 00:31:51,840 --> 00:32:08,840 So if you were to be receiving information and you had Zaster up and running and you're receiving it with Direwolf, you could potentially see all of the beaconing devices or all the other APRS, you know, transmitters that are out and about, which is kind of cool when the ISS goes over and all of a sudden you have to zoom far out to see, 349 00:32:08,840 --> 00:32:13,560 wow, look, there's all these people, you know, transmitting from all over the world. 350 00:32:13,600 --> 00:32:21,780 The last time that I did this, I got a contact from Canada, which, you know, I'm in central California, right? 351 00:32:21,780 --> 00:32:26,920 So it's, you know, crossing over at least two states just to get there and a good part of California as well. 352 00:32:26,920 --> 00:32:28,440 So I thought that was kind of neat. 353 00:32:28,620 --> 00:32:32,280 And those are all applications that you want to look at if this is something you're interested in. 354 00:32:32,580 --> 00:32:35,460 There's also a lot of APRS applications for phones. 355 00:32:35,800 --> 00:32:39,620 I personally, like I said, I use the, you know, I use the Raspberry Pi. 356 00:32:39,620 --> 00:32:44,960 So that's not something that I'm, you know, I've checked out a couple of them for iOS, but I haven't played with any of the Android applications. 357 00:32:44,960 --> 00:32:48,440 So it's one of those things that I would just recommend checking out an app. 358 00:32:48,440 --> 00:32:51,700 You can get trials, I'm sure, of all of these applications and just try it out. 359 00:32:51,700 --> 00:32:57,480 Hook up an audio jack to your phone and, you know, just plug it in your Baofeng and you're off to the races. 360 00:32:57,480 --> 00:33:00,340 And it's one of those things that your phone is kind of the perfect device. 361 00:33:00,340 --> 00:33:05,540 It has a battery, has a GPS, has a nice touchscreen, and it can encode audio like nobody's business. 362 00:33:05,540 --> 00:33:10,920 So it's one of those things that before, like I said, you'd have a desk full of equipment, and now it's a phone and a radio. 363 00:33:10,920 --> 00:33:15,060 And that's all that's really required, as long as you have the audio cable in between. 364 00:33:16,840 --> 00:33:17,720 Let's see. 365 00:33:18,180 --> 00:33:22,040 So the next part of this is planning your path of like when the ISS is going to be over. 366 00:33:22,040 --> 00:33:25,960 This is a screenshot from my app when I was doing the slides. 367 00:33:25,960 --> 00:33:28,740 I use this application called GoSatWatch. 368 00:33:28,740 --> 00:33:29,760 It's for iOS. 369 00:33:29,920 --> 00:33:33,600 It gives you a little bit of augmented reality, which I really like. 370 00:33:33,880 --> 00:33:41,780 So what you can see, at least from this screen, is you can see that this is like currently where the International Space Station is and you can see like, you know, what its orbit is. 371 00:33:41,960 --> 00:33:42,540 It's kind of cool. 372 00:33:42,540 --> 00:33:46,180 It gives you statistics of, you know, how high, you know, how high it is. 373 00:33:46,180 --> 00:33:51,500 So you can see it's like 264 miles, you know, orbiting like that's its altitude elevation. 374 00:33:51,500 --> 00:33:54,020 I don't know the technical satellite terms for that. 375 00:33:54,280 --> 00:33:56,320 It's also going 17,000 miles an hour. 376 00:33:56,380 --> 00:33:59,420 And then you can kind of see how far it is relative to where you are. 377 00:33:59,420 --> 00:34:12,620 And what's nice is that if you are trying to make, you know, some communication, if you're trying to digipede off of the ISS, what this app allows you to do is if you hit the sky button down below, you can actually hold up your phone. 378 00:34:12,620 --> 00:34:24,340 And since it has the compass and everything in there, it'll kind of like orient as to like where do you want to point your antenna up in the sky to be able to get your, you know, best transmission or, you know, your best, you know, point of contact. 379 00:34:24,600 --> 00:34:26,180 And it gives you live stats. 380 00:34:26,180 --> 00:34:27,860 It'll notify you on good passes. 381 00:34:27,860 --> 00:34:35,260 And then you can, you know, based upon where you are, you can see all the different times of day or night when the ISS is going to come. 382 00:34:35,260 --> 00:34:37,100 And it also does a ton of other satellites. 383 00:34:37,180 --> 00:34:43,080 And that's another thing that I probably neglected to mention is that this is just talking to, or this talk is just going over talking to the ISS. 384 00:34:43,280 --> 00:34:47,700 But there are tons of other satellites out there that also perform basically the same operations. 385 00:34:48,900 --> 00:34:49,300 All 386 00:34:52,780 --> 00:34:54,660 right, let's see. 387 00:34:54,660 --> 00:34:55,760 Sorry, I had to resume it. 388 00:34:56,060 --> 00:34:58,000 But yeah, so this application is great. 389 00:34:58,000 --> 00:34:59,860 I think it was like $7 in the App Store. 390 00:34:59,860 --> 00:35:04,040 But there are plenty of other applications that probably do similar things to just check out. 391 00:35:04,040 --> 00:35:05,460 It's worthwhile, at least. 392 00:35:06,280 --> 00:35:14,780 And the other thing too, that again, I really like about this is that it'll notify you and you can point this app up and you can see like where in the sky it is. 393 00:35:14,780 --> 00:35:17,740 And that matters for a couple of reasons, which we'll go over here in a second. 394 00:35:18,200 --> 00:35:22,140 So when you're planning your pass, you also have to take into effect the Doppler effect. 395 00:35:22,380 --> 00:35:25,480 I really like the, I'm not sure if anybody's seen Big Bang Theory. 396 00:35:25,480 --> 00:35:28,860 I'm sure plenty of you have Sheldon's costume of the Doppler effect. 397 00:35:28,860 --> 00:35:30,120 I just had to throw it in there. 398 00:35:30,200 --> 00:35:32,420 But you've all heard the Doppler effect before. 399 00:35:32,420 --> 00:35:42,140 It's, you know, if an ambulance or police car is going by, as you can see the little graphic down below, you know, if it's going away from you, the sound will appear, you know, slower because it's a lower, you know, longer wavelength. 400 00:35:42,140 --> 00:35:52,200 And as the car's approaching you, it'll be higher pitch because it's a smaller wavelength relative to, you know, the object that's traveling. 401 00:35:52,460 --> 00:36:04,320 And because the International Space Station is traveling at 17,000 miles an hour relative to where you are on the planet, it's actually having the frequency, you know, its frequency that that's on board is Doppler shifting. 402 00:36:04,320 --> 00:36:14,820 So when it's coming by you, it's going to be at a higher frequency, you know, so it's going to be 145.825 megahertz plus 3.5 kilohertz. 403 00:36:14,820 --> 00:36:19,900 And then as it's leaving, you know, so as it's going away from you, it's going to be a longer wavelength. 404 00:36:20,220 --> 00:36:21,740 I hope I did that right. 405 00:36:21,740 --> 00:36:35,940 If not, again, whatever you understand, that depending on where you are situated on the planet and where the International Space Station is either approaching or leaving you, it's going to change slightly the frequency that you're going to tune your radio to. 406 00:36:35,940 --> 00:36:48,120 Personally, what I do for this is I try and find a pass when the International Space Station is as far overhead as possible, or as close to overhead as possible, because then there will be no Doppler shift that I really have to take into account. 407 00:36:48,120 --> 00:36:57,000 And again, a single pass is about five minutes, so you don't have a lot of time to really fiddle with your radio and try and readjust or do anything like that. 408 00:36:57,480 --> 00:37:04,320 So this is one of those things to take into account to try and find a pass where the International Space Station is coming as close to overhead as possible. 409 00:37:04,320 --> 00:37:07,080 And you can go Google this online, you don't even need an app for it. 410 00:37:07,080 --> 00:37:20,220 But I personally found that having the app makes it easier to make more longer distance communications, because if the International Space Station is directly above you, and you're sending a signal to it, well, it's going to radiate that, or it's going to digitally beat that signal right below you. 411 00:37:20,220 --> 00:37:26,720 So you're not going to get a contact that's going to be far away necessarily, or at least as far as you can possibly get it. 412 00:37:26,880 --> 00:37:37,760 The optimal kind of thing, if you're looking to try and transmit your signal as far as possible, would be to kind of hit the edge of the International Space Station and then have it transmit at a farther area away from you. 413 00:37:37,840 --> 00:37:44,980 Again, it's one of those things, you know, you can see, I'll go back a couple slides, you can see the size of the area that International Space Station covers. 414 00:37:44,980 --> 00:37:52,900 So at any given point, you can hit, you know, that's a large portion, you know, of whatever that land mass is, Asia and Europe. 415 00:37:53,140 --> 00:37:57,180 And then if that were to fly over the United States, you know, it covers a good portion. 416 00:37:57,180 --> 00:38:03,940 And when it flies over California, you can hit Idaho, Colorado, you know, again, depending on whatever its orbit is. 417 00:38:05,520 --> 00:38:10,120 Okay, so this was the hardest part for me, is finding out how to actually send a message. 418 00:38:10,120 --> 00:38:13,340 I didn't think it would be as difficult as it was. 419 00:38:13,340 --> 00:38:17,020 But again, I was using Raspberry Pi, and I was trying to do everything on command line. 420 00:38:17,020 --> 00:38:20,820 And maybe I was making it more difficult for myself than I really needed to. 421 00:38:20,820 --> 00:38:23,220 But again, I could use my phone had it been easier. 422 00:38:24,300 --> 00:38:29,080 But again, with some of the plans that I have going forward, I'd rather do this kind of more in an automated fashion. 423 00:38:29,980 --> 00:38:37,300 So I use screen, you can use tmux, you can use multiple putty sessions, or you know, whatever you want to connect to your Raspberry Pi. 424 00:38:37,300 --> 00:38:41,320 But essentially, I had three separate screens for my Raspberry Pi. 425 00:38:41,320 --> 00:38:44,200 I had direwolf that ran my direwolf configuration. 426 00:38:44,200 --> 00:38:50,100 That's what dash c is, dash t is to not do any color on the output of when direwolf runs. 427 00:38:50,240 --> 00:38:53,360 I have the kissutil, which is installed when you install direwolf. 428 00:38:53,360 --> 00:39:03,000 And basically, I have the folder rx and the folder tx that you know, if anything I receive will go into the rx folder, anything that I transmit will go into the tx folder. 429 00:39:03,340 --> 00:39:06,020 And so that's kind of nice, because I can just drop text files in there. 430 00:39:06,240 --> 00:39:19,320 And then the kissutil and direwolf will take care of converting that to audio and then transmitting it out, which is which is awesome, because then at that point, you can script up whatever you want, you can do things on in an automated manner or manually. 431 00:39:20,180 --> 00:39:25,780 But again, you only have five minutes or so that you're trying to, you know, communicate with International Space Station. 432 00:39:25,780 --> 00:39:30,500 And then even more of a narrow window when it's directly above your when it's kind of primetime. 433 00:39:30,600 --> 00:39:42,160 And you don't want to necessarily, you know, you want to have everything set up in such a way to where you can send out a single message per pass, you know, or maybe just a handful of messages per pass, because there are other people also trying to communicate with it. 434 00:39:42,160 --> 00:39:56,000 And if you remember, the International Space Station is operating on a single frequency, you know, it's operating on 145.825 megahertz, which again, I don't know if I put that in notes, but again, it'll be, you Google it, right? 435 00:39:56,000 --> 00:39:57,500 Like it's out there. 436 00:39:57,620 --> 00:40:00,620 But, but only one person can talk to International Space Station at a time. 437 00:40:00,620 --> 00:40:06,300 So you don't want to be constantly transmitting, because then you'll prevent other people from also communicating with it. 438 00:40:06,480 --> 00:40:17,700 So basically, what I had is on a I believe every minute interval, I would have it, you know, copy my message.txt into the transmit folder, and they would shoot that message off, or you know, transmit that message off, I guess I should say. 439 00:40:17,940 --> 00:40:27,160 And so what's kind of neat about this is that you can script it up in such a way that you know, if you have a program that you want to have automatically begin something out, you can, or anything like that. 440 00:40:27,160 --> 00:40:27,960 Personally, I like that. 441 00:40:27,960 --> 00:40:37,560 But if this is just you're just trying to make a contact, or you know, you're trying to, you know, begin some or did you be digipeded off of the International Space Station? 442 00:40:37,560 --> 00:40:38,880 Oh my gosh, I can't talk. 443 00:40:38,920 --> 00:40:42,160 If you want to be digipeded off the International Space Station, that's your only goal. 444 00:40:42,280 --> 00:40:48,000 You know, just with your phone, you can just send the message out that way manually, you don't have to go through all this direwolf craziness. 445 00:40:48,300 --> 00:40:51,100 Most most phone applications should be able to do it pretty darn easily. 446 00:40:51,880 --> 00:40:53,200 This is a simple message. 447 00:40:53,200 --> 00:41:00,940 So if you have a, you know, a client on here, this is this is one of those things that like this is what I use. 448 00:41:01,500 --> 00:41:04,540 Basically, I transmit this text in that message dot txt. 449 00:41:04,540 --> 00:41:06,240 Again, that's my call sign. 450 00:41:06,440 --> 00:41:15,160 When you see my call sign, or so then you see AR ISS, essentially, all that means is that you want to be digipeded by the International Space Station, that's its call sign. 451 00:41:15,360 --> 00:41:21,340 And when you do that, you basically are just saying, Hey, I want you to digipede this message to the International Space Station. 452 00:41:21,500 --> 00:41:26,520 And then what you have is you have my call sign again, followed by dash seven, that's because it's my mobile unit. 453 00:41:27,120 --> 00:41:33,400 Again, not getting too deep into APRS, having that designation there, that dash seven is just showing that you're mobile. 454 00:41:33,400 --> 00:41:42,660 And then the next, you know, digits and numbers right there, it's kind of a weirdly encoded way that I had to like Google how to do of what your current GPS coordinates are. 455 00:41:42,660 --> 00:41:45,680 And then after that, you can see, you know, your message. 456 00:41:45,680 --> 00:41:57,680 So digipeding, you know, DEFCON 28, Aerospace Village out to the International Space Station, which then gets relayed, you know, down to ground stations that receive that message and then off to the greater internet. 457 00:41:58,560 --> 00:42:00,000 This is the folder structure. 458 00:42:00,000 --> 00:42:03,980 So when I run direwolf, I run it from my home directory, direwolf config is right there. 459 00:42:03,980 --> 00:42:13,160 And then I have a tx and an rx folder for the messages that I'm going to send go into the tx folder and messages that I'm going to receive come from or, you know, get placed in the rx folder. 460 00:42:13,620 --> 00:42:16,700 Um, let's see, let's see if I can get this. 461 00:42:19,340 --> 00:42:36,820 All right, so some of the things going forward, I think that are important to cover, you know, so my goal of this is I want to automate it, I want to make some rotors and rotors, if you're not familiar, are basically what it would allow, you know, rotors would allow me to change the elevation, 462 00:42:36,820 --> 00:42:37,920 you know, up and down. 463 00:42:37,920 --> 00:42:40,940 So like, if you're looking like a tripod is a great example, right? 464 00:42:40,980 --> 00:42:47,120 I could, you know, change the orientation 360 degrees, like a compass, and then the elevation up and down. 465 00:42:47,420 --> 00:42:56,220 Because it'd be really cool if on the Raspberry Pi you had some software that basically tracked where the International Space Station was, and anytime it was up overhead to transmit a message automatically. 466 00:42:56,220 --> 00:42:59,280 So that's kind of my idea of what I think would be kind of neat. 467 00:42:59,780 --> 00:43:01,040 So we'll see how that goes. 468 00:43:01,160 --> 00:43:09,820 And then I would also like to see, you know, how far away can I hear from, you know, or how far could I be digipeded by the International Space Station? 469 00:43:10,040 --> 00:43:14,440 And if you kind of think about it, you know, out onto the horizon. 470 00:43:14,440 --> 00:43:19,380 So if you were, if you were out, you know, basically to the horizon, that would be zero degrees. 471 00:43:19,380 --> 00:43:22,400 But obviously there are trees, there are houses, there are all those things in the way. 472 00:43:22,700 --> 00:43:31,380 And so there's a point at which, you know, you can hit the International Space Station, you know, with a signal, maybe is that 20 degrees? 473 00:43:31,380 --> 00:43:32,120 Is it 30 degrees? 474 00:43:32,120 --> 00:43:32,940 Is it 40 degrees? 475 00:43:32,940 --> 00:43:39,660 The higher the elevation is, relative to where you are on the ground, the easier it will be to communicate with it. 476 00:43:39,660 --> 00:43:42,240 So it's one of those things that automating it, I think would be kind of neat. 477 00:43:43,260 --> 00:43:47,360 And then I also like to, you know, investigate looking at other satellites. 478 00:43:48,020 --> 00:43:50,500 Yeah, and basically just just seeing what else is out there. 479 00:43:50,700 --> 00:44:00,080 A huge thank you to AMSAT and ARISS.net just because checking out that website inspired me to, you know, try and get on the board. 480 00:44:00,080 --> 00:44:01,200 It's in the AMSAT. 481 00:44:01,200 --> 00:44:06,120 There's tons of great information there on how other people have, you know, had successful communications. 482 00:44:06,500 --> 00:44:09,220 And really at the end of the day, I think this is just something that's kind of cool. 483 00:44:09,300 --> 00:44:18,780 You know, the hacker mindset here of just kind of scraping and cobbling together all these things to really do something that's kind of neat to be able to transmit to the International Space Station. 484 00:44:19,520 --> 00:44:23,640 Not to mention too, that this is how you can transmit to a lot of other satellites. 485 00:44:23,640 --> 00:44:30,160 And it's really kind of covers the basics in terms of what's required to talk to a satellite, right? 486 00:44:30,160 --> 00:44:42,760 There's a whole bunch of different satellite orbits, a whole bunch of different satellite communication protocols, frequencies, modulations, and this is just dipping your toe in the water of what's available and what's out there. 487 00:44:42,980 --> 00:44:45,900 And it's for honestly a pretty small budget, right? 488 00:44:45,900 --> 00:44:57,320 For $100, $200 you could get a really solid setup to, you know, to communicate with the International Space Station with other satellites with just a HAM license, you know, just be an amateur radio operator. 489 00:44:57,320 --> 00:45:03,260 And if you just want to hear, if you just want to listen to what gets transmitted, you know, you can do that without a license. 490 00:45:03,260 --> 00:45:09,560 And really, you can just get a Baofeng radio, your phone, and, you know, it doesn't even have to be a directional antenna at that point. 491 00:45:09,560 --> 00:45:16,620 You know, if you just want to listen, you can have an omni-directional antenna , which is basically just, you know, a longer version of the normal stick antenna that would come with the Baofeng. 492 00:45:16,620 --> 00:45:19,320 Again, I'll post links to everything on that GitHub page. 493 00:45:19,340 --> 00:45:25,000 But yeah, at the end of the day, this is a great way just to get started if it's something that you're interested in. 494 00:45:25,000 --> 00:45:31,280 And then from there, who knows how much farther you can level up and, you know, what other satellite communications you can do. 495 00:45:31,280 --> 00:45:39,800 You can spend thousands and thousands of dollars and, you know, sink a full-time work week into all of this stuff, especially as an amateur. 496 00:45:39,800 --> 00:45:48,240 So it definitely helps to have a good starting point and to have a good point in time of, like, this is something that I can measurably check off a list and do. 497 00:45:48,240 --> 00:46:01,520 And especially, again, I know that I've said it a bunch of times, but if you have kids at home, if, you know, you're a kid at home, this is a great project to really get your feet wet and you learn a ton of different principles from physics to , you know, 498 00:46:01,520 --> 00:46:21,400 radio to computers to, you know, protocols to just... there's so many small lessons intertwined that I just think it's kind of one of those perfect projects to, you know, to basically figure out if it's for you, if ham radio operating is for you, to find out if chasing satellites across the sky is for you. 499 00:46:21,560 --> 00:46:23,420 So again, I encourage you to take a look at it. 500 00:46:23,680 --> 00:46:26,180 Feel free to check out the GitHub page. 501 00:46:26,180 --> 00:46:32,460 I'll post some of my contact information on there along with the links to all the hardware and all the apps and all the things that I've mentioned. 502 00:46:32,920 --> 00:46:34,680 And yeah, hope you enjoyed the talk. 503 00:46:35,380 --> 00:46:36,680 Let's see, how do I pause this thing?