WEBVTT 00:25.260 --> 00:26.240 Let 01:40.380 --> 01:51.640 me tell you a story, when I was young, I had dreams of glory. 01:52.940 --> 01:59.980 All these mistakes, seemed to come like a flood. 02:00.840 --> 02:06.430 Until my days, my days, they were done. 02:06.430 --> 02:13.590 I don't want to feel like I wish for thinking. 02:13.750 --> 02:18.790 Pick myself up and move to the beat of my heart and my soul. 02:18.790 --> 02:21.410 Sing a song for the dreamer. 02:25.010 --> 02:29.650 This is also going to be a one-cut take, like a normal DEF CON presentation would be. 02:29.650 --> 02:33.050 So, there's going to be a lot of flubs, a lot of hems, a lot of haws. 02:33.590 --> 02:34.950 That's about it. 02:34.950 --> 02:37.470 Anyways, without further ado, let's get going. 02:37.470 --> 02:39.630 Can't even transition a slide, all right. 02:40.230 --> 02:42.210 So, a little bit about me and my background. 02:42.430 --> 02:44.950 I started off my professional life as a civil engineer. 02:44.950 --> 02:52.970 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. 02:53.090 --> 02:55.970 I didn't really like it as much as I thought it was going to. 02:56.230 --> 03:02.010 I then got an opportunity to start a security analyst position at Barracuda Networks. 03:02.010 --> 03:04.370 We started coming to DEF CON, DEF CON 22. 03:04.370 --> 03:07.150 So, I've been here for, what, six years now, seven years now. 03:08.090 --> 03:10.350 And I love doing anything wireless. 03:10.350 --> 03:11.630 I love wireless security. 03:11.670 --> 03:16.910 So, I started playing in the wireless CTF, and we won three years in a row, I believe. 03:17.190 --> 03:20.130 And now I'm a village member, so now I get to help make the challenges. 03:21.190 --> 03:25.370 And, yeah, it's one of those things that the reason I started off with this is because I forever feel like a noob. 03:25.850 --> 03:29.830 I forever feel like the imposter syndrome is a real thing. 03:29.830 --> 03:39.070 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. 03:39.330 --> 03:50.590 So, if this is your first DEF CON, you're going virtual, you're watching this talk, don't hesitate to get your feet wet to reach out to people, because at the end of the day, I feel like everybody feels like a noob. 03:50.590 --> 03:53.250 And if they don't, then they definitely are a noob. 03:53.570 --> 03:56.170 So, that, I basically just want to give my background. 03:56.170 --> 04:06.670 I didn't have a computer science degree, I didn't have a formal background in computer security, or really anything at all except for civil engineering. 04:06.670 --> 04:11.530 So, don't hesitate to get yourself out there. 04:11.890 --> 04:15.170 So, this talk, talking to satellites, why? 04:15.170 --> 04:17.110 Personally, I think it's cool. 04:17.530 --> 04:21.050 The International Space Station is specifically what we're going to be going to cover. 04:21.090 --> 04:37.590 But there's a lot of satellites that are floating up above us or orbiting above us that are capable of ham radio communication or just communication from the ground, just by normal citizens that don't require any special permission other than ham radio license to transmit to. 04:38.570 --> 04:46.570 What's cool about the International Space Station, I mean, it's orbiting 200 miles above us, which actually, when I first started doing this, 200 miles didn't seem like a lot to me. 04:46.570 --> 04:50.050 It seemed like that it should be orbiting higher than that. 04:51.050 --> 04:54.610 It's going roughly 17,000 miles an hour. 04:55.210 --> 04:58.930 And that's 10 times faster than a bullet, just kind of put it in like rough perspective. 04:59.390 --> 05:07.050 And it is orbiting so quickly that it can go around the entire planet in about 90 minutes, which I think is incredible. 05:07.310 --> 05:23.190 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 and even to astronauts on the International Space Station with just, you know, general equipment and just a ham radio license. 05:23.810 --> 05:29.750 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. 05:31.030 --> 05:32.490 So here's a quick overview. 05:33.550 --> 05:44.410 Basically, we have a 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, 05:44.410 --> 05:56.150 brush up on, timing when you're going to talk to the International Space Station, because it's orbiting every 90 minutes and there's only very narrow windows that you can actually, you know, try and communicate with it on. 05:56.210 --> 05:59.010 And then basically just now that you have all this power, how not to be a jerk. 05:59.010 --> 06:03.590 I feel like hacker mentality is the, you know, like, oh, my gosh, we're going to do all these bad, terrible things. 06:03.590 --> 06:05.790 But at the end of the day, you know, should you? 06:05.790 --> 06:07.490 This is this is something that's pretty cool. 06:07.830 --> 06:10.610 And you want to give others the opportunity to do it as well. 06:11.770 --> 06:14.570 See, moving on to the housing wise. 06:14.570 --> 06:19.030 So there's AR-ISS, which is amateur radio on the International Space Station. 06:19.030 --> 06:21.930 Basically, this is up there for educational purposes. 06:21.930 --> 06:23.070 It's community driven. 06:23.070 --> 06:28.970 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? 06:28.970 --> 06:30.130 Why is space important? 06:30.130 --> 06:43.370 So I think it's kind of cool that they have a couple, you know, amateur radio stations on board or not stations, but I guess transceivers on the International Space Station that are that are meant for amateur radio operators to interact with. 06:43.610 --> 06:49.710 Specifically, what we're going to be talking about is the two meter packet radio that's unattended on the International Space Station. 06:49.850 --> 06:58.870 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. 06:58.870 --> 07:07.930 However, to try and get that to work is is, you know, it's far more limited and you have to plan far more, you know, up in advance. 07:07.930 --> 07:11.970 Whereas the unattended packet radio basically is going to act as like a repeater for you. 07:11.970 --> 07:14.490 And it's always up and always operational. 07:15.790 --> 07:22.490 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. 07:22.910 --> 07:27.090 And there's a bunch of other operating modes that the International Space Station has. 07:27.570 --> 07:30.310 And, you know, you can go online at any point in time and check that. 07:30.310 --> 07:33.630 But really what we're going to be focusing on is the two meter packet radio. 07:34.130 --> 07:40.270 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. 07:42.090 --> 07:47.110 Yeah, so we'll just, you know, break down the basics of it to transmit and talk to the International Space Station. 07:47.110 --> 07:49.210 You're going to need a ham license and that's just the transmit. 07:49.210 --> 07:54.670 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. 07:54.670 --> 08:00.390 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. 08:00.390 --> 08:05.470 This is something that, you know, you're going to have transmit power and you want to be judicious with how you use it. 08:05.630 --> 08:10.610 However, that being said, if there's something that's interesting to you, you can listen without a ham license. 08:10.610 --> 08:11.910 No problem at all. 08:11.910 --> 08:14.070 You know, you don't need anything just to listen. 08:14.070 --> 08:16.710 It's really just transmitting because that could affect other people. 08:17.090 --> 08:23.570 And if you want your ham radio license, the Ham Radio Village is offering, I believe, five dollar exams, which is, I mean, pretty cheap. 08:23.570 --> 08:27.830 Normally it's, I think, $20, but everything's going to be virtual, obviously, because it's DEF CON. 08:27.830 --> 08:31.650 And for $5 to, you know, make an attempt at your technician license. 08:31.690 --> 08:34.870 It's one of those things I think you have to renew it every 10 years. 08:34.930 --> 08:37.030 I definitely recommend checking it out. 08:37.070 --> 08:38.990 You know, it's definitely a great opportunity. 08:41.050 --> 08:41.670 All right. 08:41.670 --> 08:46.070 So there's a lot of things that I never quite understood when I was getting into all this. 08:46.070 --> 08:48.510 And I'm, again, by all, by no means an expert. 08:48.510 --> 08:56.830 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. 08:57.130 --> 09:05.710 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. 09:06.010 --> 09:14.990 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. 09:15.550 --> 09:24.610 Initially, 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. 09:25.410 --> 09:36.510 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. 09:36.690 --> 09:39.190 But at the end of the day, what happens to C is the speed of light. 09:39.190 --> 09:44.810 So if you divide that by your frequency, which is a megahertz, a megahertz is a million hertz. 09:44.810 --> 09:46.470 So a million cycles per second. 09:46.570 --> 09:52.930 So, you know, you can think of Wi-Fi as 2.4 gigahertz, you know, or 5.8 gigahertz. 09:53.030 --> 09:54.810 Just kind of put that in perspective. 09:55.210 --> 10:01.750 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. 10:01.970 --> 10:03.790 That's, you know, kind of how the math works out. 10:03.790 --> 10:05.750 And so when people say like, oh, it's only two meter band. 10:05.750 --> 10:09.730 Well, you know, that's the same thing as saying it's about, you know, 144 megahertz-ish. 10:09.730 --> 10:13.570 And I think the two meter band is anywhere from 144 to 148 megahertz. 10:13.990 --> 10:15.530 But that's what people are talking about. 10:15.530 --> 10:23.010 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, off the top of my head. 10:23.610 --> 10:25.490 And that's also considered VHF. 10:25.490 --> 10:29.610 So you'll hear VHF, two meter and, you know, 144 megahertz. 10:29.610 --> 10:31.590 Those are all kind of in the same ballpark. 10:31.990 --> 10:33.630 You know, and that's just one of those things. 10:33.630 --> 10:36.190 I hear those terms thrown around a lot and I had no idea what they meant. 10:36.190 --> 10:42.390 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. 10:42.630 --> 10:43.350 Oh, okay. 10:43.350 --> 10:49.790 That means 144 megahertz-ish, you know, and that's also considered VHF, very high frequency. 10:50.310 --> 10:52.270 So the next part of that, what is FM? 10:52.270 --> 10:56.050 You know, you probably have heard of AM FM radio in your car. 10:56.450 --> 10:57.930 AM is amplitude modulation. 10:57.930 --> 11:00.790 So you can see the little graphic on the bottom right of the screen. 11:00.930 --> 11:03.790 That's where the wave is actually modulated up and down. 11:03.790 --> 11:05.670 So you can kind of think of this waves in a pond. 11:07.070 --> 11:13.730 You know, if you throw a rock in and there's a big splash, those waves are going to be bigger and that's going to be amplitude, you know, there's a varying amplitude there. 11:14.170 --> 11:18.150 Whereas FM is how close those waves are, you know, in a ring, in a circle. 11:18.150 --> 11:19.070 Sorry, I'm using my hands a lot. 11:19.070 --> 11:20.670 I don't probably look like a magician. 11:21.470 --> 11:25.990 But basically you're stretching like a slinky, you know, FM waves. 11:25.990 --> 11:28.610 You're modulating the frequency, how fast it goes. 11:29.030 --> 11:30.630 So, you know, there's AM FM. 11:30.630 --> 11:32.650 So we're looking at two meter band FM. 11:32.650 --> 11:34.290 So it's frequency modulated. 11:34.450 --> 11:36.850 And this is typically not something that you're gonna have to worry about. 11:36.850 --> 11:42.570 It's lower level stuff that the radio is going to take care of, but it's just good to know because I didn't know it when I started out. 11:43.710 --> 11:45.450 Gosh, 1200 BPS. 11:45.450 --> 11:46.910 So it's BOD, not bits. 11:46.910 --> 11:52.610 If you mess this up, you know, the internet's going to murder you because you're, you know, technically wrong. 11:52.650 --> 11:55.330 I always thought that BOD and bits were exactly the same. 11:55.330 --> 12:01.390 It wasn't until I dug into it that I actually realized, oh gosh, they're, you know, they can be different. 12:01.630 --> 12:05.270 So you can think of a BOD as like a signal interval or like a pulse. 12:05.930 --> 12:12.330 And in the early days, I guess, I don't know, I wasn't around during the early days, but early modems would do one bit per BOD. 12:12.330 --> 12:15.330 So it would basically just be one BOD and one bit were the same. 12:15.330 --> 12:18.590 So 1200 bits and 1200 BOD were the same exact thing. 12:18.590 --> 12:25.390 However, now there's craftiness in there that allows you to transmit at a higher bit rate with the same level of BOD rate. 12:25.390 --> 12:34.010 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. 12:34.290 --> 12:35.170 I don't really know. 12:35.170 --> 12:40.750 Again, it's one of these things that that's just what APRS or the packet radio service uses. 12:40.750 --> 12:42.450 The software takes care of it all for you. 12:42.450 --> 12:46.730 You don't have to worry about it, but it is helpful to know so that the internet doesn't murder you. 12:47.250 --> 12:55.130 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. 12:55.130 --> 12:57.530 Say that at a party and no one will want to talk to you. 12:57.530 --> 13:02.450 So it's one of those things, again, super nerdy stuff, but it kind of helps to know. 13:02.450 --> 13:10.490 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's what all of these things mean. 13:10.490 --> 13:15.550 When somebody says, oh, two meter band FM at 1200 BOD, you kind of know what's going on there. 13:16.210 --> 13:23.890 And then packet radio, you know, I guess to me, this wasn't any news, but it's packetized data, right? 13:23.890 --> 13:30.250 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. 13:30.250 --> 13:36.970 And especially for, you know, for APRS, it uses the AX25, which includes your call sign. 13:36.970 --> 13:45.590 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. 13:45.990 --> 13:48.550 And so this basically satisfies that. 13:48.730 --> 13:50.430 But yeah, data comes in in packets. 13:51.070 --> 13:57.350 And what happens is, say you have like a small walkie talkie or not walkie talkie, but a small handheld radio. 13:57.350 --> 14:04.930 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, at not a very far distance. 14:04.930 --> 14:16.150 And so the goal of the packet radio service, or I think it's packet radio, packet reporting system, I can read my slides, is basically to repeat that information out farther. 14:16.150 --> 14:29.250 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. 14:29.470 --> 14:32.990 And the way that APRS works, I think I have this in my next slide, maybe not. 14:32.990 --> 14:39.470 But the way that essentially works is you can select how far out you want that message to be repeated. 14:39.470 --> 14:53.050 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. 14:53.290 --> 14:56.730 That basically says, hey, you know, repeat this out this many hops. 14:56.730 --> 15:00.550 And the whole goal of this is essentially to reach what's called an IGate. 15:00.550 --> 15:07.270 And an IGate will take your packet radio, take your transmission and put it on the public internet. 15:07.270 --> 15:17.030 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. 15:20.630 --> 15:24.590 So APRS was created by somebody, his name is Bob. 15:24.650 --> 15:26.110 I don't know how to say his last name. 15:26.170 --> 15:30.050 Bob created it, I believe, in 1973-ish. 15:30.430 --> 15:42.930 And if you look at this image of the world, every continent-ish or every, you know, region of the world has a different, slightly different frequency that it transmits APRS on, and those are all in megahertz. 15:42.930 --> 15:55.130 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 is going to share. 15:55.370 --> 16:07.970 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. 16:07.970 --> 16:19.230 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. 16:19.230 --> 16:23.570 So there's a lot of, you know, potential congestion in there. 16:23.750 --> 16:27.750 So it's one of those things that you don't always want to transmit your message as far as it will possibly go. 16:27.750 --> 16:31.810 You just want to get it as far as you need to go to kind of be respectful of the space. 16:31.810 --> 16:37.530 And again, I'm breaking all this down because you'll see why it's important when it comes to the ISS later on. 16:39.850 --> 16:43.930 So automatic packet reporting system, that's what APR stands for. 16:44.070 --> 16:57.190 A lot of times what people will do is ham operators will have, you know, little tracking device, beacon devices that have a GPS unit on there, and they will beacon out, you know, a location at a set interval. 16:57.190 --> 17:00.990 You know, it could be 10 minutes, could be one minute, whatever their specified interval is. 17:00.990 --> 17:08.250 And they will beacon from the small transmitter to, you know, larger repeaters with the intent of getting online. 17:08.270 --> 17:14.850 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. 17:14.850 --> 17:17.330 Like, I guess, like, as ubiquitous as they are now. 17:17.370 --> 17:19.730 And so it was a great way to track things. 17:19.850 --> 17:24.510 You know, it's a great way to track, you know, you can put them in your car, put them in a boat, put them in a plane. 17:24.830 --> 17:31.470 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. 17:31.470 --> 17:34.610 This is a great way to track assets, really. 17:34.870 --> 17:41.690 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. 17:41.730 --> 17:44.990 They think of a radio that actually transmits the signal. 17:45.130 --> 17:49.830 They think of, there's a little device, I think it's called a terminal node controller. 17:49.830 --> 17:56.010 Yeah , TNC, which basically takes your GPS data and any message data or any other additional data. 17:56.010 --> 17:59.450 And it basically makes that into an audio format. 17:59.790 --> 18:03.650 You know, it encodes into an audio format that then is transmitted out by a radio. 18:03.650 --> 18:06.250 So that's kind of the traditional way that this looks. 18:06.510 --> 18:09.530 However, things have changed now since everybody has cell phones. 18:09.630 --> 18:10.890 So you can do a couple of things here. 18:10.890 --> 18:22.790 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 an additional computer and additional encoder and all this different stuff. 18:22.790 --> 18:26.410 Instead of what you're going to have here is you can have a Raspberry Pi that does it. 18:26.410 --> 18:32.750 Or you could just have a phone that, you know, automatically has GPS onboard, automatically has the audio cable onboard. 18:32.770 --> 18:38.990 And basically you hook up an audio cable or a sound card if you're using a Raspberry Pi to a radio. 18:38.990 --> 18:39.910 I chose Baofeng. 18:39.910 --> 18:44.190 People love and hate these types of radios, but I like mine personally. 18:44.450 --> 18:54.410 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. 18:55.270 --> 19:06.770 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. 19:07.530 --> 19:13.830 And so that's kind of how this, how like hardware-wise, at least what you need or what that looks like. 19:14.090 --> 19:22.270 The next part, at least 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. 19:22.270 --> 19:24.070 Like it must just be crazy amounts of power. 19:24.070 --> 19:27.550 I'm probably going to dim the lights in my house trying to get the signal that far away. 19:27.550 --> 19:29.870 But really it's incredibly low. 19:29.870 --> 19:41.370 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. 19:41.370 --> 19:57.130 And really when you think about it, that's less power than what your phone charger puts out, which I thought was pretty interesting that you could transmit up to something orbiting up in upper atmosphere, you know, low Earth orbit for just five watts. 19:57.190 --> 20:00.950 Just seems kind of crazy that I can't get that far, I guess. 20:01.590 --> 20:09.370 So this kind of is a better way to show what I was trying to explain, is that there's a little tracker you can see that I think that I've... 20:09.370 --> 20:12.770 I forget what the name of that tracker is, but basically it's super small tracker. 20:12.770 --> 20:20.530 I think it's about a hundred dollars that, you know, will beacon out, I believe one watt at a pre-described interval with GPS and everything on board. 20:20.590 --> 20:24.570 And the whole goal of it is that that little transmitter may not be able to get very far. 20:24.570 --> 20:30.590 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. 20:30.610 --> 20:37.790 And if there's not one in your area, you know, it's one of those things would be kind of cool to set one up, just to spread the net of APRS far and wide. 20:37.790 --> 20:57.030 But essentially the whole goal is for that little tracking device, or, you know, 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. 20:57.030 --> 20:59.910 And the gateway, you know, in this case is an iGate. 20:59.910 --> 21:02.770 And an iGate can then connect it to the internet. 21:02.770 --> 21:10.610 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. 21:10.610 --> 21:15.230 So you can look around and see all the devices that are transmitting out and about in the world. 21:15.230 --> 21:19.410 And, you know, you can look at the other side of the world and just see all the devices that are out there. 21:19.410 --> 21:24.350 And there's weather stations, there's, you know, hot air balloons, a lot of cars, boats, planes, you name it. 21:24.350 --> 21:27.030 There's a lot of devices that are tracked, you know, on APRS. 21:27.030 --> 21:30.570 And it's kind of neat to be able to see where all these devices are out on the internet. 21:31.210 --> 21:34.470 So that was a full big explanation of APRS. 21:34.470 --> 21:47.810 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. 21:47.970 --> 22:02.910 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. 22:03.130 --> 22:09.370 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. 22:09.610 --> 22:25.790 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. 22:25.790 --> 22:39.050 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, 22:39.050 --> 22:45.810 you know, it'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. 22:45.810 --> 22:47.250 I just think it's kind of neat. 22:49.330 --> 22:50.990 Yeah, so this is a website. 22:50.990 --> 22:57.170 If you go to ariss.net, you know, it looks like what a website would look like if I made it. 22:57.170 --> 23:06.770 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 the International Space Station. 23:06.770 --> 23:09.150 So again, you don't need any hardware at all. 23:09.150 --> 23:16.370 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? 23:16.370 --> 23:18.090 Where is the International Space Station? 23:18.090 --> 23:21.150 What messages are coming off the International Space Station? 23:21.250 --> 23:36.170 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, 23:36.170 --> 23:37.910 which I think is kind of neat. 23:38.750 --> 23:40.250 So let's talk about the hardware. 23:40.250 --> 23:50.530 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. 23:50.750 --> 23:57.030 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. 23:57.090 --> 23:58.610 Again, you can see the link right there. 23:58.610 --> 24:07.790 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. 24:07.790 --> 24:13.510 So again, this is kind of my like go-to hardware, which again, if you look at it, it's pretty darn cheap. 24:13.510 --> 24:17.470 You're looking at $35, $20, $10, $8. 24:17.470 --> 24:31.150 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 it's pretty cool. 24:31.770 --> 24:34.370 Baofeng Radio, this is a cheap Chinese radio. 24:34.370 --> 24:35.810 I personally really like them. 24:35.810 --> 24:40.410 I know a lot of people on the Internet have hate for them, but it works well for me. 24:40.410 --> 24:48.690 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 a Pam Radio just in general is going to be a good hobby for you. 24:48.690 --> 24:50.110 It has a lot of other capabilities. 24:50.110 --> 24:54.250 You can listen to normal FM radio, you know, can be a police scanner. 24:54.550 --> 24:56.170 There's just a lot of other stuff that it can do. 24:56.170 --> 24:58.970 And so I really like it for $35 on Amazon. 24:58.970 --> 25:00.710 You can't really beat it. 25:01.490 --> 25:02.210 So let's see. 25:02.210 --> 25:06.630 So it comes with what's, you know, a little stick antenna, like what you'd see on a walkie talkie. 25:06.630 --> 25:09.950 That's what if you were buying this Baofeng Radio, it would come with. 25:09.950 --> 25:13.750 But you can build a directional antenna, which is what you're going to want. 25:13.870 --> 25:24.910 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. 25:24.910 --> 25:30.410 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. 25:30.410 --> 25:33.750 And I should probably have a slide in there that has, you know, these radiation patterns. 25:34.110 --> 25:43.870 But really what we want is a directional antenna that kind of focuses that being more like a flashlight, you know, into the general spot in the sky where you're trying to focus all of your energy. 25:44.230 --> 25:48.690 And so for $10, $20, you can really build your own antenna, which I think is even cooler. 25:49.090 --> 25:57.790 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. 25:57.790 --> 25:59.890 Typically, most people have cell phones. 26:00.330 --> 26:06.150 And so just an audio cord for that, you know, under $100, you can no problem transmit the International Space Station. 26:06.390 --> 26:08.410 And again, I'm going to try and keep this updated. 26:08.510 --> 26:20.690 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. 26:20.690 --> 26:32.270 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. 26:32.610 --> 26:42.170 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 a super nerd. 26:42.170 --> 26:47.390 But really, there's a lot of other applicable lessons to other stuff out there. 26:48.270 --> 26:50.730 The other thing that you're going to want to do is turn on Vox. 26:50.730 --> 26:54.230 Again, this is one of those things that I'm probably getting internet hate mail for. 26:54.230 --> 26:56.310 Vox is voice-operated switch. 26:56.310 --> 27:04.450 So basically, you can think of it as when you start talking, the radio is going to detect that you're talking already, and it will then start transmitting right away. 27:04.450 --> 27:14.370 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. 27:14.470 --> 27:27.510 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 communications. 27:28.050 --> 27:28.870 So it's not ideal. 27:28.870 --> 27:30.530 You really want push-to-talk. 27:30.530 --> 27:36.130 But if you're just getting started, it doesn't hurt just to use Vox, just to get your feet wet. 27:36.130 --> 27:37.110 That's my personal opinion. 27:37.110 --> 27:40.110 Again, I'm going to get hate mail, I'm sure, but whatever. 27:40.810 --> 27:43.450 So I own an aero-directional antenna. 27:43.670 --> 27:45.930 It's very similar to the one that's in that image right there. 27:45.930 --> 27:49.930 It's like $150, which is more than the entire cost of the project. 27:50.030 --> 27:55.030 And if hand radio is potentially something you're not going to get into, you know, are you going to want to buy some giant antenna? 27:55.290 --> 27:56.490 I don't really know. 27:56.590 --> 27:59.370 Personally, I have one because it's something that I really enjoy. 28:00.090 --> 28:02.610 However, it's $150, and it's pretty steep. 28:03.190 --> 28:05.050 Or you could build your own. 28:05.070 --> 28:21.270 And this is one of those things that I was just, you know, checking stuff out online, and I saw that somebody had built 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. 28:21.270 --> 28:24.230 So I had a lot of that basically just lying around. 28:24.690 --> 28:30.310 And a measuring tape, which funnily enough, I didn't think about it, but I guess it's, you know, measuring tapes are steel. 28:30.310 --> 28:41.830 And so 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. 28:41.830 --> 28:48.070 Like you can make an antenna out of a steel measuring tape, and it folds up nicely too, which is the added benefit. 28:48.070 --> 28:50.590 I'll have a link to this on that GitHub page that I mentioned. 28:50.590 --> 28:58.630 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. 28:59.570 --> 29:03.190 And then Yagi, all the instructions, the build list, everything. 29:03.190 --> 29:09.370 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. 29:09.370 --> 29:11.110 Just go online, look at it. 29:11.110 --> 29:16.370 Plenty of other people have done a lot of work to make that pretty nice. 29:17.790 --> 29:23.930 So it's one of those things too that, like, I personally think this is a nerd merit badge to build your own antenna. 29:24.030 --> 29:34.070 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 like, oh, I bought all this stuff off the Internet, put it together, and now I can talk to International Space Station. 29:34.070 --> 29:43.770 There's a little bit of that 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. 29:43.770 --> 29:49.350 And 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. 29:49.450 --> 29:55.550 And, you know, I'm talking to the most expensive, expensive object, you know, that humanity's ever built, you know, arguably. 29:55.550 --> 29:56.090 Right. 29:56.850 --> 30:03.530 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. 30:03.730 --> 30:05.370 And it takes about an hour to build. 30:05.370 --> 30:17.530 If you have kids and you want to all get them interested in space and engineering and STEM stuff, you know, or just to get their hands dirty, I think this is personally a really cool project and it's not going to break the bank to try it. 30:19.130 --> 30:21.590 And let's see, I don't know why I can't change sides. 30:21.590 --> 30:22.330 So there it goes. 30:22.450 --> 30:24.570 So this is my antenna up on top of my patio. 30:24.570 --> 30:27.530 It's on top of my patio, obviously, so I can get a better line of sight. 30:27.690 --> 30:31.330 And I keep everything in a nice little ammo box and I use a tripod. 30:31.330 --> 30:36.630 But again, you can just hold your hand out there with an extra piece of PVC and it works just as well. 30:37.670 --> 30:41.250 It's one of those things that it looks, it looks homemade and that's what it is. 30:41.250 --> 30:43.570 But you're talking to a satellite with a homemade antenna. 30:43.570 --> 30:44.610 I think that's pretty cool. 30:46.770 --> 30:50.190 So obviously, if you build your own antenna, you're going to have to tune it a little bit. 30:50.190 --> 31:02.250 Luckily, if you follow the instructions online 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 if you measure things carefully. 31:02.550 --> 31:07.890 But the way that you tune your antenna is by looking at the standing wave ratio or SWR. 31:08.030 --> 31:09.990 And this really just measures the performance. 31:10.030 --> 31:16.390 I like to think of it as, say you have a tube of gift wrap, right? 31:16.390 --> 31:24.030 And you shout down that tube, how much of your sound that's leaving your mouth going through the tube is actually making its way out the tube. 31:24.030 --> 31:37.970 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, 31:37.970 --> 31:42.130 kind of just banging around the, you know, just kind of radiating off of it. 31:42.130 --> 31:50.210 So just one of those things that, you know, if you know a ham radio operator, I'm sure they have, you know, an SWR meter. 31:50.590 --> 31:52.630 You can buy a cheap one online for $20. 31:52.630 --> 31:53.410 I don't have one of those. 31:53.410 --> 31:54.850 I don't know how well it works. 31:55.150 --> 31:57.150 I personally have a Nano VNA. 31:57.250 --> 32:02.870 It was like 50 or something dollars online and does a bunch more stuff other than just looking at SWR. 32:02.870 --> 32:04.250 But it's really small, has a battery. 32:04.250 --> 32:05.450 I personally really like it. 32:05.450 --> 32:10.130 But again, if you're trying to not break the bank, you know, maybe a $20 one online is worth it. 32:10.130 --> 32:14.770 Or you find a ham radio operator that you just say, hey, can I plug this in real quick and test it? 32:14.770 --> 32:20.130 You know, there are plenty of older ham radio operators that would love nothing more than to talk radio and talk shop. 32:20.130 --> 32:26.450 And it's a great way to build a community, build a hobby, because ham radio operating is an aging hobby. 32:26.730 --> 32:34.730 You know, just go to any ham radio operator meeting, you know, in your city, in your state, in your wherever you're from. 32:34.910 --> 32:39.530 And it's definitely an older person's hobby, but I don't think it has to be that way at all. 32:39.990 --> 32:47.010 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. 32:47.410 --> 32:54.170 And again, I think mine when I did it was 1.3 to 1, which I think perfect SWR is 1 to 1. 32:54.170 --> 32:55.390 To me, this is just magic. 32:55.390 --> 32:57.270 I don't really understand how it works. 32:57.270 --> 33:00.690 I just know that you want your numbers to be as close to 1 to 1 as possible. 33:00.690 --> 33:04.730 Again, if I'm wrong, shoot me a message and let me know and I'll update the slides. 33:05.950 --> 33:08.250 So the next piece of this is the software. 33:09.430 --> 33:12.610 Again, I have lots of Raspberry Pis lying around from a bunch of other projects. 33:12.610 --> 33:14.330 I personally like to use Raspberry Pi. 33:14.790 --> 33:16.910 I use the software called Direwolf. 33:16.910 --> 33:18.790 It's just an apt-get install. 33:18.890 --> 33:23.070 Again, if you check out the GitHub page, you'll have the instructions on how to set it up perfectly. 33:23.950 --> 33:31.350 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. 33:31.930 --> 33:41.810 And then when you install Direwolf, it'll also install KissUtil, which is what I use to be able to transmit messages into Direwolf. 33:42.130 --> 33:44.870 And then the next thing is there's a tool called Zaster. 33:44.870 --> 33:47.690 I don't know how you actually say that because it has an X and a str in it. 33:47.690 --> 33:48.470 So I don't know. 33:48.470 --> 33:49.650 I assume that's how you say it. 33:49.650 --> 34:01.310 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. 34:01.310 --> 34:18.390 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 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. 34:18.390 --> 34:23.130 Wow, look, there's all these people, you know, transmitting from all over the world. 34:23.130 --> 34:31.370 The last time that I did this, I got a contact from Canada, which, you know, I'm in central California, right? 34:31.370 --> 34:36.470 So it's, you know, crossing over at least two states just to get there and a good part of California as well. 34:36.470 --> 34:38.070 So I thought that was kind of neat. 34:38.170 --> 34:41.910 And those are all applications that you want to look at if this is something you're interested in. 34:42.110 --> 34:45.090 There's also a lot of APRS applications for phones. 34:45.270 --> 34:49.210 I personally, like I said, I use the, you know, I use the Raspberry Pi. 34:49.210 --> 34:54.510 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. 34:54.510 --> 34:58.030 So it's one of those things that I would just recommend checking out an app. 34:58.030 --> 35:01.270 You can get trials, I'm sure, of all of these applications and just try it out. 35:01.270 --> 35:07.070 Hook up an audio jack to your phone and, you know, just plug it in your Baofeng and you're off to the races. 35:07.070 --> 35:09.890 And it's one of those things that your phone is kind of the perfect device. 35:09.890 --> 35:15.070 It has a battery, has a GPS, has a nice touchscreen, and it can encode audio like nobody's business. 35:15.070 --> 35:20.490 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. 35:20.490 --> 35:22.510 And that's all that's really required. 35:22.510 --> 35:24.670 As long as you have the audio cable in between. 35:26.370 --> 35:27.350 Let's see. 35:27.710 --> 35:31.650 So the next part of this is planning your passive, like when the ISS is going to be over. 35:31.650 --> 35:35.510 This is a screenshot from my app when I was doing the slides. 35:35.510 --> 35:38.410 I use this this application called Gosat Watch. 35:38.410 --> 35:39.430 It's for iOS. 35:39.430 --> 35:43.050 It gives you a little bit of augmented reality, which I really like. 35:43.050 --> 35:51.370 So what you can see, at least from this screen, is you can see that this is currently where the International Space Station is and you can see what its orbit is. 35:51.590 --> 35:52.130 It's kind of cool. 35:52.130 --> 35:55.750 It gives you statistics of how high it is. 35:55.750 --> 35:58.750 So you can see it's like 264 miles orbiting. 35:58.750 --> 36:01.010 That's its altitude elevation. 36:01.010 --> 36:03.550 I don't know what the technical satellite term is for that. 36:03.810 --> 36:05.750 It's also going 17,000 miles an hour. 36:05.790 --> 36:08.990 And then you can kind of see how far it is relative to where you are. 36:08.990 --> 36:22.450 And what's nice is that if you are trying to make 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. 36:22.470 --> 36:33.810 And since it has the compass and everything in there, it'll kind of like orient as to where you want to point your antenna up in the sky to be able to get your best transmission or your best point of contact. 36:33.810 --> 36:35.730 And it gives you live stats. 36:35.730 --> 36:37.490 It'll notify you on good passes. 36:37.490 --> 36:44.830 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. 36:44.830 --> 36:46.550 And it also does a ton of other satellites. 36:46.750 --> 36:57.210 And that's another thing that I probably neglected to mention is that this talk is just going over talking to the ISS, but there are tons of other satellites out there that also perform basically the same operations. 37:03.020 --> 37:04.200 All right, let's see. 37:04.200 --> 37:05.300 Sorry, I had to resume it. 37:05.580 --> 37:07.560 But yeah, so this application is great. 37:07.560 --> 37:13.620 I think it was like $7 in the App Store, but there are plenty of other applications that probably do similar things to just check out. 37:13.620 --> 37:15.000 It's worthwhile, at least. 37:15.900 --> 37:24.320 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. 37:24.320 --> 37:27.280 And that matters for a couple of reasons, which I'll go over here in a second. 37:27.780 --> 37:31.700 So when you're planning your pass, you also have to take into effect the Doppler effect. 37:32.100 --> 37:35.020 I really like the... I'm not sure if anybody's seen Big Bang Theory. 37:35.020 --> 37:36.680 I'm sure plenty of you have. 37:36.920 --> 37:38.420 Sheldon's costume of the Doppler effect. 37:38.420 --> 37:39.700 I just had to throw it in there. 37:39.760 --> 37:41.980 But you've all heard the Doppler effect before. 37:41.980 --> 37:46.180 It's, you know, an ambulance or police car is going by, as you can see the little graphic down below. 37:46.180 --> 37:51.760 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. 37:51.760 --> 38:01.740 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. 38:02.080 --> 38:07.740 And because the International Space Station is traveling at 17,000 miles an hour relative to where you are on the planet. 38:08.280 --> 38:13.900 It's actually having the frequency, you know, it's frequency that's on board is Doppler shifting. 38:13.900 --> 38:24.340 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. 38:24.340 --> 38:29.480 And then as it's leaving, you know, so as it's going away from you, it's going to be a longer wavelength. 38:29.900 --> 38:31.320 I hope I did that right. 38:31.320 --> 38:33.460 If not, again, whatever you understand. 38:34.800 --> 38:45.480 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. 38:45.480 --> 38:57.660 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. 38:57.660 --> 39:01.800 And again, a single pass is about five minutes. 39:01.800 --> 39:06.540 So you don't have a lot of time to really fiddle with your radio and trying to readjust or do anything like that. 39:07.080 --> 39:13.900 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. 39:13.900 --> 39:15.260 And you can go Google this online. 39:15.260 --> 39:16.560 You don't even need an app for it. 39:16.560 --> 39:29.820 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. 39:29.820 --> 39:36.300 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. 39:36.300 --> 39:47.320 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. 39:47.420 --> 39:54.560 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. 39:54.560 --> 40:02.520 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. 40:02.760 --> 40:06.740 And then if that were to fly over the United States, you know, it covers a good portion. 40:06.740 --> 40:13.560 And when it flies over California, you can hit Idaho, Colorado, you know, again, depending on whatever its orbit is. 40:15.100 --> 40:19.740 Okay, so this was the hardest part for me is finding out how to actually send a message. 40:19.740 --> 40:22.840 I didn't think it would be as difficult as it was. 40:22.840 --> 40:26.560 But again, I was using Raspberry Pi and I was trying to do everything on command line. 40:26.560 --> 40:30.380 And maybe I was making it more difficult for myself than I really needed to. 40:30.380 --> 40:32.820 But again, I could use my phone, have it been easier. 40:33.860 --> 40:38.560 But again, with some of the plans that I have going forward, I'd rather do this kind of more in an automated fashion. 40:39.460 --> 40:46.880 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. 40:46.880 --> 40:50.960 But essentially, I had three separate screens for my Raspberry Pi. 40:50.960 --> 40:53.780 I had Direwolf that ran my Direwolf configuration. 40:53.780 --> 40:59.640 That's what "-c", "-t", is to not do any color on the output of when Direwolf runs. 40:59.820 --> 41:02.920 I have the KissUtil, which is installed when you install Direwolf. 41:02.920 --> 41:12.560 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. 41:12.980 --> 41:15.660 And so that's kind of nice because I can just drop text files in there. 41:15.820 --> 41:23.160 And then the KissUtil and Direwolf will take care of converting that to audio and then transmitting it out, which is awesome. 41:23.160 --> 41:25.800 Because then at that point, you can script up whatever you want. 41:25.800 --> 41:28.900 You can do things in an automated manner or manually. 41:29.560 --> 41:35.440 But again, you only have five minutes or so that you're trying to, you know, communicate with the International Space Station. 41:35.440 --> 41:39.940 And then even more of a narrow window when it's directly above you or when it's kind of prime time. 41:39.940 --> 41:51.680 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. 41:51.680 --> 41:57.100 And if you remember, the International Space Station is operating on a single frequency. 41:57.100 --> 42:04.220 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... 42:04.760 --> 42:05.560 You Google it, right? 42:05.560 --> 42:06.920 Like it's out there. 42:06.920 --> 42:10.200 But only one person can talk to International Space Station at a time. 42:10.200 --> 42:15.860 So you don't want to be constantly transmitting because then you'll prevent other people from also communicating with it. 42:16.040 --> 42:27.240 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. 42:27.620 --> 42:36.740 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. 42:36.740 --> 42:37.520 Personally, I like that. 42:37.520 --> 42:46.340 But if this is just you're just trying to make a contact or, you know, you're trying to, you know, if you want to be digitated off the International Space Station, that's your only goal. 42:46.520 --> 42:49.280 You know, just with your phone, you can just send the message out that way manually. 42:49.280 --> 42:52.160 You don't have to go through all this dire wolf craziness. 42:52.160 --> 42:55.720 Most phone applications should be able to do it pretty darn easily. 42:58.370 --> 43:04.250 All right, so this is a sample message and I'm going to decipher it here real quick. 43:04.250 --> 43:13.050 So if you see the KJ60HH, that's my call sign, followed by APRS and then ARISS. 43:13.050 --> 43:17.390 That indicates basically that I want to be digitated by the International Space Station. 43:17.390 --> 43:21.510 Then you'll see my call sign again, followed by a dash seven. 43:21.510 --> 43:25.450 That's because this is coming from my mobile unit, which is just my Baofeng radio. 43:25.770 --> 43:27.990 After that, you'll see my GPS coordinates. 43:27.990 --> 43:33.650 They're kind of in a funny format, not a format that I'm used to seeing, but it's not hard to kind of decipher what those mean. 43:33.810 --> 43:40.270 And then followed by a dash and then after that dash is just whatever message you'd like to send to the International Space Station. 43:40.270 --> 43:48.070 So it's not super difficult to decipher, but if it's your first time looking at APRS messages, it might be a little bit more difficult than you would have anticipated. 43:49.690 --> 43:51.110 This is the folder structure. 43:51.110 --> 43:55.090 So when I run direwolf, I run it from my home directory, direwolf config is right there. 43:55.090 --> 44:04.210 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. 44:05.690 --> 44:06.690 Let's see. 44:10.050 --> 44:14.910 All right, so some of the things going forward, I think that are important to cover. 44:15.410 --> 44:17.670 So my goal with this is I want to automate it. 44:17.670 --> 44:29.150 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, you know, up and down. 44:29.150 --> 44:32.050 So like if you're looking like a tripod is a great example, right? 44:32.050 --> 44:38.350 I could, you know, change the orientation 360 degrees like a compass and then the elevation up and down. 44:38.370 --> 44:47.090 Because it'd be really cool if on the Raspberry Pi you had some software that basically track where the International Space Station was and anytime it was up overhead to transmit a message automatically. 44:47.090 --> 44:50.390 So that's kind of my idea of what I think would be kind of neat. 44:50.690 --> 44:52.130 So we'll see how that goes. 44:52.150 --> 45:00.930 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 digitated by the International Space Station? 45:01.030 --> 45:05.530 And if you kind of think about it, you know, out onto the horizon. 45:05.530 --> 45:10.410 So if you were out, you know, basically to the horizon, that would be zero degrees. 45:10.410 --> 45:13.470 But obviously there are trees, there are houses, there are all those things in the way. 45:13.970 --> 45:21.290 And so there's a point at which, you know, you can hit the International Space Station, you know, with a signal. 45:21.290 --> 45:22.470 Maybe is that 20 degrees? 45:22.470 --> 45:23.250 Is it 30 degrees? 45:23.250 --> 45:24.050 Is it 40 degrees? 45:24.050 --> 45:30.770 The higher the elevation is relative to where you are on the ground, the easier it will be to communicate with it. 45:30.770 --> 45:33.290 So it's one of those things that automating it, I think would be kind of neat. 45:34.370 --> 45:38.450 And I also like to, you know, investigate looking at other satellites. 45:38.970 --> 45:41.570 Yeah, and basically just seeing what else is out there. 45:42.050 --> 45:51.230 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. 45:51.390 --> 45:57.170 And same thing with AMSAT, there's tons of great information there on how other people have, you know, had successful communications. 45:57.510 --> 46:00.390 And really, at the end of the day, I think this is just something that's kind of cool. 46:00.510 --> 46:08.430 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 internet. 46:08.430 --> 46:09.970 International Space Station. 46:10.550 --> 46:14.810 Not to mention, too, that this is how you can transmit to a lot of other satellites. 46:14.810 --> 46:21.230 And it's really kind of covers the basics in terms of what's required to talk to a satellite, right? 46:21.230 --> 46:29.010 There's a whole bunch of different satellite orbits, a whole bunch of different satellite communication protocols, frequencies, modulations. 46:29.070 --> 46:33.870 And this is just dipping your toe in the water of what's available and what's out there. 46:33.870 --> 46:37.010 And it's for, honestly, a pretty small budget, right? 46:37.010 --> 46:44.830 For $100, $200, you could get a really solid setup to, you know, to communicate with International Space Station, with other satellites. 46:45.250 --> 46:48.330 With just a HAM license, you know, just being an amateur radio operator. 46:48.330 --> 46:54.070 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. 46:54.070 --> 47:00.630 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. 47:00.630 --> 47:07.690 You know, if you just want to listen, you can have an omnidirectional antenna, which is basically just, you know, a longer version of the normal stick antenna that would come with the Baofeng. 47:07.750 --> 47:10.470 Again, I'll post links to everything on that GitHub page. 47:10.510 --> 47:16.170 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. 47:16.170 --> 47:22.550 And then from there, who knows how much farther you can level up and, you know, what other satellite communications you can do. 47:22.550 --> 47:30.870 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. 47:30.870 --> 47:39.350 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. 47:39.350 --> 47:48.130 And especially, again, I know that I've said it a bunch of times, but if you have kids at home, if, you know, if you're a kid at home, this is a great project to really get your feet wet. 47:48.130 --> 47:57.190 When you learn a ton of different principles from physics to, you know, radio to computers to, you know, protocols to just... 47:57.190 --> 48:07.630 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. 48:07.630 --> 48:12.490 If ham radio operating is for you, to find out if chasing satellites across the sky is for you. 48:12.490 --> 48:14.670 So again, I encourage you to take a look at it. 48:14.690 --> 48:17.290 Feel free to check out the GitHub page. 48:17.290 --> 48:23.510 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. 48:23.870 --> 48:25.870 And yeah, hope you enjoy the talk. 48:26.290 --> 48:27.930 See how to pause this thing. 48:34.450 --> 48:35.330 All right. 48:35.490 --> 48:37.170 Thank you for that great talk. 48:37.170 --> 48:39.750 We have Eric here to take some Q&A. 48:40.050 --> 48:45.670 I think one of the ones that came up in the Twitch chat first was the person actually hit by that police car. 48:45.670 --> 48:47.170 They're a little worried about that. 49:02.670 --> 49:03.750 Can you hear me, Eric? 49:33.950 --> 49:35.470 I don't know if Eric can hear us here. 49:35.550 --> 49:36.850 We can't hear you. 49:36.850 --> 49:37.850 Are you talking, Eric? 49:59.640 --> 50:00.680 Hello, Eric. 50:02.080 --> 50:03.420 Yeah, I can hear you fine. 50:03.420 --> 50:06.200 I think our speaker is having some technical difficulties. 50:06.200 --> 50:11.180 So what we'll do is he'll just hang around and chat in the village on the channels there. 50:11.180 --> 50:16.160 And if you have any questions, he'll follow up certainly in text and maybe on one of the voice channels in there. 50:16.640 --> 50:17.660 All righty. 50:18.040 --> 50:21.280 Thanks, everybody, for attending and hope you all enjoy the talk. 50:21.280 --> 50:23.580 I thought it was pretty awesome and we'll go from there.