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25260	111640	Let me tell you a story, when I was young, I had dreams of glory.
112940	119980	All these mistakes, seemed to come like a flood.
120840	126430	Until my days, my days, they were done.
126430	133590	I don't want to feel like I wish for thinking.
133750	138790	Pick myself up and move to the beat of my heart and my soul.
138790	141410	Sing a song for the dreamer.
145010	149650	This is also going to be a one-cut take, like a normal DEF CON presentation would be.
149650	153050	So, there's going to be a lot of flubs, a lot of hems, a lot of haws.
153590	154950	That's about it.
154950	157470	Anyways, without further ado, let's get going.
157470	159630	Can't even transition a slide, all right.
160230	162210	So, a little bit about me and my background.
162430	164950	I started off my professional life as a civil engineer.
164950	169410	I went to college, got my bachelor's degree, master's degree in civil engineering,
169410	172970	became a professional engineer, and realized it really wasn't for me.
173090	175970	I didn't really like it as much as I thought it was going to.
176230	182010	I then got an opportunity to start a security analyst position at Barracuda Networks.
182010	184370	We started coming to DEF CON, DEF CON 22.
184370	187150	So, I've been here for, what, six years now, seven years now.
188090	190350	And I love doing anything wireless.
190350	191630	I love wireless security.
191670	196910	So, I started playing in the wireless CTF, and we won three years in a row, I believe.
197190	200130	And now I'm a village member, so now I get to help make the challenges.
201190	205370	And, yeah, it's one of those things that the reason I started off with this is because I forever feel like a noob.
205850	209830	I forever feel like the imposter syndrome is a real thing.
209830	215070	And this talk is more of a, I'm not an expert in this, but it's something that I find really interesting,
215070	219070	and it definitely encapsulates that hacker mentality.
219330	223410	So, if this is your first DEF CON, you're going virtual, you're watching this talk,
224370	227210	don't hesitate to get your feet wet to reach out to people,
227690	230590	because at the end of the day, I feel like everybody feels like a noob.
230590	233250	And if they don't, then they definitely are a noob.
233570	236170	So, that, I basically just want to give my background.
236170	243230	I didn't have a computer science degree, I didn't have a formal background in computer security,
243230	246670	or really anything at all except for civil engineering.
246670	251530	So, don't hesitate to get yourself out there.
251890	255170	So, this talk, talking to satellites, why?
255170	257110	Personally, I think it's cool.
257530	261050	The International Space Station is specifically what we're going to be going to cover.
261090	264870	But there's a lot of satellites that are floating up above us or orbiting above us
264870	270610	that are capable of ham radio communication or just communication from the ground,
270610	277590	just by normal citizens that don't require any special permission other than ham radio license to transmit to.
278570	282230	What's cool about the International Space Station, I mean, it's orbiting 200 miles above us,
282230	286570	which actually, when I first started doing this, 200 miles didn't seem like a lot to me.
286570	290050	It seemed like that it should be orbiting higher than that.
291050	294610	It's going roughly 17,000 miles an hour.
295210	298930	And that's 10 times faster than a bullet, just kind of put it in like rough perspective.
299390	307050	And it is orbiting so quickly that it can go around the entire planet in about 90 minutes, which I think is incredible.
307310	312550	And it's also the most expensive object ever built, which is kind of neat that just being a normal civilian,
312550	318970	I can talk to the International Space Station and even to astronauts on the International Space Station
319650	323190	with just, you know, general equipment and just a ham radio license.
323810	328250	And even if you don't have a ham radio license, you can still listen to transmissions from the International Space Station,
328250	329750	which is also, I think, pretty cool.
331030	337710	So here's a quick overview. Basically, we have a talk to ISS on the cheap, the hows and the whys of, you know,
337710	342210	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,
342210	345570	the rough skills that you might need to have or, you know, brush up on,
345910	349890	timing when you're going to talk to the International Space Station, because it's orbiting every 90 minutes
349890	356150	and there's only very narrow windows that you can actually, you know, try and communicate with it on.
356210	359010	And then basically just now that you have all this power, how not to be a jerk.
359010	363590	I feel like hacker mentality is the, you know, like, oh, my gosh, we're going to do all these bad, terrible things.
363590	367490	But at the end of the day, you know, should you? This is this is something that's pretty cool.
367830	370610	And you want to give others the opportunity to do it as well.
371770	379030	See, moving on to the housing wise. So there's AR-ISS, which is amateur radio on the International Space Station.
379030	383070	Basically, this is up there for educational purposes. It's community driven.
383070	388970	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?
388970	392970	Why is space important? So I think it's kind of cool that they have a couple, you know,
392970	399830	amateur radio stations on board or not stations, but I guess transceivers on the International Space Station
399830	403370	that are that are meant for amateur radio operators to interact with.
403610	409710	Specifically, what we're going to be talking about is the two meter packet radio that's unattended on the International Space Station.
409850	415370	There are definitely some attempts that you can have where crew members might be staffing the International Space Station
415370	418870	and actually on the ham radio that you can talk to via voice.
418870	427930	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.
427930	431970	Whereas the unattended packet radio basically is going to act as like a repeater for you.
431970	434490	And it's always up and always operational.
435790	439650	And it's just one of those things that it's far easier to get a communication, you know,
439650	442490	repeated from the International Space Station because it's done automatically.
442910	447090	And there's a bunch of other operating modes that the International Space Station has.
447570	450310	And, you know, you can go online at any point in time and check that.
450310	453630	But really what we're going to be focusing on is the two meter packet radio.
454130	460270	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.
462090	467110	Yeah, so we'll just, you know, break down the basics of it to transmit and talk to the International Space Station.
467110	469210	You're going to need a ham license and that's just the transmit.
469210	474670	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.
474670	480390	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.
480390	485470	This is something that, you know, you're going to have transmit power and you want to be judicious with how you use it.
485630	490610	However, that being said, if there's something that's interesting to you, you can listen without a ham license.
490610	494070	No problem at all. You know, you don't need anything just to listen.
494070	496710	It's really just transmitting because that could affect other people.
497090	503570	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.
503570	507830	Normally it's, I think, $20, but everything's going to be virtual, obviously, because it's DEF CON.
507830	511650	And for $5 to, you know, make an attempt at your technician license.
511690	514870	It's one of those things I think you have to renew it every 10 years.
514930	518990	I definitely recommend checking it out. You know, it's definitely a great opportunity.
521050	526070	All right. So there's a lot of things that I never quite understood when I was getting into all this.
526070	536830	And I'm, again, by all, by no means an expert. 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.
537130	545710	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.
546010	554990	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.
555550	564610	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.
565410	576510	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.
576690	584810	But at the end of the day, what happens to C is the speed of light. So if you divide that by your frequency, which is a megahertz, a megahertz is a million hertz.
584810	594810	So a million cycles per second. 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.
595210	601750	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.
601970	609730	That's, you know, kind of how the math works out. 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.
609730	623010	And I think the two meter band is anywhere from 144 to 148 megahertz. But that's what people are talking about. 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.
623610	631590	And that's also considered VHF. So you'll hear VHF, two meter and, you know, 144 megahertz. Those are all kind of in the same ballpark.
631990	642390	You know, and that's just one of those things. I hear those terms thrown around a lot and I had no idea what they meant. 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.
642630	649790	Oh, okay. That means 144 megahertz-ish, you know, and that's also considered VHF, very high frequency.
650310	656050	So the next part of that, what is FM? You know, you probably have heard of AM FM radio in your car.
656450	665670	AM is amplitude modulation. So you can see the little graphic on the bottom right of the screen. That's where the wave is actually modulated up and down. So you can kind of think of this waves in a pond.
667070	673730	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.
674170	680670	Whereas FM is how close those waves are, you know, in a ring, in a circle. Sorry, I'm using my hands a lot. I don't probably look like a magician.
681470	688610	But basically you're stretching like a slinky, you know, FM waves. You're modulating the frequency, how fast it goes.
689030	694290	So, you know, there's AM FM. So we're looking at two meter band FM. So it's frequency modulated.
694450	702570	And this is typically not something that you're gonna have to worry about. 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.
703710	712610	Gosh, 1200 BPS. So it's BOD, not bits. If you mess this up, you know, the internet's going to murder you because you're, you know, technically wrong.
712650	721390	I always thought that BOD and bits were exactly the same. It wasn't until I dug into it that I actually realized, oh gosh, they're, you know, they can be different.
721630	725270	So you can think of a BOD as like a signal interval or like a pulse.
725930	732330	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.
732330	738590	So it would basically just be one BOD and one bit were the same. So 1200 bits and 1200 BOD were the same exact thing.
738590	745390	However, now there's craftiness in there that allows you to transmit at a higher bit rate with the same level of BOD rate.
745390	754010	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.
754290	760750	I don't really know. Again, it's one of these things that that's just what APRS or the packet radio service uses.
760750	766730	The software takes care of it all for you. You don't have to worry about it, but it is helpful to know so that the internet doesn't murder you.
767250	775130	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.
775130	782450	Say that at a party and no one will want to talk to you. So it's one of those things, again, super nerdy stuff, but it kind of helps to know.
782450	787190	For me, you can look at that and at least kind of digest it and understand maybe not why it's that way,
787190	795550	but at least that's what all of these things mean. When somebody says, oh, two meter band FM at 1200 BOD, you kind of know what's going on there.
796210	803890	And then packet radio, you know, I guess to me, this wasn't any news, but it's packetized data, right?
803890	810250	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.
810250	816970	And especially for, you know, for APRS, it uses the AX25, which includes your call sign.
816970	825590	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.
825990	830430	And so this basically satisfies that. But yeah, data comes in in packets.
831070	837350	And what happens is, say you have like a small walkie talkie or not walkie talkie, but a small handheld radio.
837350	844930	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.
844930	851090	And so the goal of the packet radio service, or I think it's packet radio, packet reporting system, I can read my slides,
852010	860530	is basically to repeat that information out farther. So your handheld, you know, radio is going to only make a certain distance,
860530	869250	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.
869470	872990	And the way that APRS works, I think I have this in my next slide, maybe not.
872990	879470	But the way that essentially works is you can select how far out you want that message to be repeated.
879470	887370	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,
887370	893050	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.
893290	896730	That basically says, hey, you know, repeat this out this many hops.
896730	900550	And the whole goal of this is essentially to reach what's called an IGate.
900550	907270	And an IGate will take your packet radio, take your transmission and put it on the public internet.
907270	911850	So that way, you know, anybody in the world then can now look at it or, you know, any other,
911850	917030	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.
920630	926110	So APRS was created by somebody, his name is Bob. I don't know how to say his last name.
926170	930050	Bob created it, I believe, in 1973-ish.
930430	938330	And if you look at this image of the world, every continent-ish or every, you know, region of the world has a different,
938330	942930	slightly different frequency that it transmits APRS on, and those are all in megahertz.
942930	947950	So you can see anywhere in the United States, if you're, you know, which is where I am at least,
947950	955130	it's going to be transmitted on 144.390 megahertz is the frequency that everything is going to share.
955370	960830	The kind of bummer part about that is that because we're all using, you know, and say we ham operators,
960830	967970	if we're all transmitting 144.390 megahertz, well, your transmission will interrupt somebody else's transmission.
967970	974050	So there's a lot of room for collision, especially when you figure that every time you transmit a message,
974050	979230	what's going to happen is that's going to be repeated by any number of other larger repeaters.
979230	983570	So there's a lot of, you know, potential congestion in there.
983750	987750	So it's one of those things that you don't always want to transmit your message as far as it will possibly go.
987750	991810	You just want to get it as far as you need to go to kind of be respectful of the space.
991810	997530	And again, I'm breaking all this down because you'll see why it's important when it comes to the ISS later on.
999850	1003930	So automatic packet reporting system, that's what APR stands for.
1004070	1010770	A lot of times what people will do is ham operators will have, you know, little tracking device,
1010770	1017190	beacon devices that have a GPS unit on there, and they will beacon out, you know, a location at a set interval.
1017190	1020990	You know, it could be 10 minutes, could be one minute, whatever their specified interval is.
1020990	1028250	And they will beacon from the small transmitter to, you know, larger repeaters with the intent of getting online.
1028270	1031210	And this is useful if, you know, you're somewhere where there's not cell coverage,
1031210	1034850	or, you know, this was invented before cell phones ever existed.
1034850	1037330	Like, I guess, like, as ubiquitous as they are now.
1037370	1039730	And so it was a great way to track things.
1039850	1044510	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.
1044830	1048410	You know, people have used them for hot air balloons, you know,
1048410	1051470	and just all sorts of things where maybe cell coverage isn't going to fit.
1051470	1054610	This is a great way to track assets, really.
1054870	1058330	So you can see from this little image there, you know, this is kind of like the traditional,
1058330	1061690	what people think of when they hear APRS or, you know, packet radio.
1061730	1064990	They think of a radio that actually transmits the signal.
1065130	1069830	They think of, there's a little device, I think it's called a terminal node controller.
1069830	1076010	Yeah, TNC, which basically takes your GPS data and any message data or any other additional data.
1076010	1079450	And it basically makes that into an audio format.
1079790	1083650	You know, it encodes into an audio format that then is transmitted out by a radio.
1083650	1086250	So that's kind of the traditional way that this looks.
1086510	1089530	However, things have changed now since everybody has cell phones.
1089630	1090890	So you can do a couple of things here.
1090890	1094990	So instead of having, you know, a device that has to have onboard GPS
1094990	1099230	and you already have to have an additional piece of GPS information
1099230	1102790	and an additional computer and additional encoder and all this different stuff.
1102790	1106410	Instead of what you're going to have here is you can have a Raspberry Pi that does it.
1106410	1110450	Or you could just have a phone that, you know, automatically has GPS onboard,
1110450	1112750	automatically has the audio cable onboard.
1112770	1118990	And basically you hook up an audio cable or a sound card if you're using a Raspberry Pi to a radio.
1118990	1124190	I chose Baofeng. People love and hate these types of radios, but I like mine personally.
1124450	1130530	And basically what you do is you use then these devices to encode your message, you know,
1130530	1134410	as an audio file that is then transmitted out your radio.
1135270	1137770	And the whole purpose of that is essentially, you know,
1137770	1141830	you could take what used to be a giant apparatus that would fill, you know, like an entire desk
1141830	1143730	and now it's something that can easily go in your pocket
1143730	1146770	and the batteries last for a pretty decent amount of time.
1147530	1153830	And so that's kind of how this, how like hardware-wise, at least what you need or what that looks like.
1154090	1156910	The next part, at least when I was starting out looking at this,
1156910	1162270	I thought that, man, I must need a ton of power in order to transmit to the International Space Station.
1162270	1164070	Like it must just be crazy amounts of power.
1164070	1167550	I'm probably going to dim the lights in my house trying to get the signal that far away.
1167550	1173610	But really it's incredibly low. I've heard that people have done it on as low as a single watt,
1173610	1181370	but five watts that comes on your standard Baofeng radio is more than enough to transmit to International Space Station.
1181370	1186610	And really when you think about it, that's less power than what your phone charger puts out,
1186610	1193710	which I thought was pretty interesting that you could transmit up to something orbiting up in upper atmosphere,
1193710	1197130	you know, low Earth orbit for just five watts.
1197190	1200950	Just seems kind of crazy that I can't get that far, I guess.
1201590	1206370	So this kind of is a better way to show what I was trying to explain,
1206370	1209370	is that there's a little tracker you can see that I think that I've...
1209370	1212770	I forget what the name of that tracker is, but basically it's super small tracker.
1212770	1215870	I think it's about a hundred dollars that, you know, will beacon out,
1215870	1220530	I believe one watt at a pre-described interval with GPS and everything on board.
1220590	1224570	And the whole goal of it is that that little transmitter may not be able to get very far.
1224570	1228030	But the whole point of it is that you're trying to reach a single digipeter,
1228030	1230590	and these digipeters are set up by their ham radio operators.
1230610	1233970	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,
1233970	1237790	just to spread the net of APRS far and wide.
1237790	1241550	But essentially the whole goal is for that little tracking device,
1241550	1246510	or, you know, any other end node that you maybe have in your pocket or whatever,
1246510	1252690	to transmit to a higher power digipeter, you know, repeater that digitally repeats it,
1252690	1257030	with the express purpose of really trying to get it to a larger gateway.
1257030	1259910	And the gateway, you know, in this case is an iGate.
1259910	1262770	And an iGate can then connect it to the internet.
1262770	1267970	Nice part about that is once it's connected to the internet, there are websites like aprs.fi,
1267970	1270610	which will aggregate all of this data globally.
1270610	1275230	So you can look around and see all the devices that are transmitting out and about in the world.
1275230	1279410	And, you know, you can look at the other side of the world and just see all the devices that are out there.
1279410	1284350	And there's weather stations, there's, you know, hot air balloons, a lot of cars, boats, planes, you name it.
1284350	1287030	There's a lot of devices that are tracked, you know, on APRS.
1287030	1290570	And it's kind of neat to be able to see where all these devices are out on the internet.
1291210	1294470	So that was a full big explanation of APRS.
1294470	1299710	And why it matters is that the ISS has one of these DigiPeters on board,
1299710	1304710	which at the end of the day is kind of neat because you figure normally you would try and, you know,
1304710	1307810	reach a DigiPeter that is going to be, say, on a mountaintop nearby.
1307970	1313090	But really, if you can transmit to the International Space Station and have it repeat your signal,
1313090	1318890	so DigiPete your message, well, now you can be received on a huge far and wide area down below
1318890	1322910	because the International Space Station has a great vantage point on the rest of the planet.
1323130	1329370	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.
1329610	1335030	And likewise, normally to, you know, transmit a message that far to, you know, 1,000 miles,
1335030	1337910	you would need a decent amount of power, a great vantage point, and, you know,
1337910	1345790	everything would need to be kind of go right to transmit on, you know, especially VHF or the two meter band that far.
1345790	1350130	Whereas now with the International Space Station, because of its vantage point in space and clear line of sight,
1350130	1354470	you know, down to the earth, you can transmit your message really far, which I, again,
1354470	1359290	I just think is really cool that, you know, the most expensive object that any, you know,
1359290	1362250	it's ever been built that we have the capability as, you know,
1362250	1367250	as amateurs to be able to transmit and relay a message off of it. I just think it's kind of neat.
1369330	1374270	Yeah, so this is a website. If you go to ariss.net, you know,
1374270	1379170	it looks like what a website would look like if I made it. You know, the graphics aren't crazy,
1379170	1384150	but at the end of the day, it's really cool in that it aggregates all of the stations that heard the ISS
1384150	1389150	and have transmitted the International Space Station. So again, you don't need any hardware at all.
1389150	1393390	If you have a phone, you can pull up ariss.net and basically just see, oh,
1393390	1396370	what stations around me have heard the International Space Station?
1396370	1401150	Where is the International Space Station? What messages are coming off the International Space Station?
1401250	1407370	Again, because the whole point of it, or maybe not the whole point of APRS, but, you know, at least, at least a,
1407970	1413550	I don't know, a takeaway of APRS is that if that information all gets aggregated online,
1413550	1417910	you know, you can see it from anywhere in the world, which I think is kind of neat.
1418750	1420250	So let's talk about the hardware.
1420250	1426290	I have made the horrific mistake in the past of trying to post links to hardware on, you know,
1426290	1430530	my slides and then, you know, I find a better price somewhere or I find, oh, it's not there anymore.
1430750	1434190	So what I'm going to try and do this time is if you want to look at the hardware,
1434190	1438610	I'm going to try and keep an up-to-date list at github.com. Again, you can see the link right there.
1438610	1442790	And the whole purpose of that is so that I can update this list and find better prices or whatever,
1442790	1447790	because things change and, you know, there are better spots, you know, to potentially get some stuff at.
1447790	1453510	So again, this is kind of my like go-to hardware, which again, if you look at it, it's pretty darn cheap.
1453510	1457470	You're looking at $35, $20, $10, $8.
1457470	1464990	You're looking at under $100 to be able to transmit a signal to the International Space Station,
1464990	1471150	which again, for that price and the skill requirement and just being an amateur and a civilian, I think it's pretty cool.
1471770	1475810	Baofeng Radio, this is a cheap Chinese radio. I personally really like them.
1475810	1480410	I know a lot of people on the Internet have hate for them, but it works well for me.
1480410	1484950	And I find that it, you know, for $35, it's a great way to just, you know, not break the bank,
1484950	1488690	but really figure out a Pam Radio just in general is going to be a good hobby for you.
1488690	1494250	It has a lot of other capabilities. You can listen to normal FM radio, you know, can be a police scanner.
1494550	1498970	There's just a lot of other stuff that it can do. And so I really like it for $35 on Amazon.
1498970	1502210	You can't really beat it. So let's see.
1502210	1506630	So it comes with what's, you know, a little stick antenna, like what you'd see on a walkie talkie.
1506630	1509950	That's what if you were buying this Baofeng Radio, it would come with.
1509950	1513750	But you can build a directional antenna, which is what you're going to want.
1513870	1516710	If you're going to talk to satellites or the International Space Station,
1516710	1524910	because a traditional stick antenna is going to radiate its signal out kind of like a donut.
1524910	1528810	So if you're to hold it like thumbs up, you know, so the radios, so the antenna sticking up,
1528810	1530410	it's going to radiate out like a donut.
1530410	1533750	And I should probably have a slide in there that has, you know, these radiation patterns.
1534110	1538970	But really what we want is a directional antenna that kind of focuses that being more like a flashlight,
1539350	1543870	you know, into the general spot in the sky where you're trying to focus all of your energy.
1544230	1548690	And so for $10, $20, you can really build your own antenna, which I think is even cooler.
1549090	1553030	And then you need an audio cable, an audio card if you're going to use the Raspberry Pi,
1553630	1557790	or if you're if you don't use Raspberry Pi at all and you're just going to use your cell phone.
1557790	1562790	Typically, most people have cell phones. And so just an audio cord for that, you know, under $100,
1562790	1566150	you can no problem transmit the International Space Station.
1566390	1574170	And again, I'm going to try and keep this updated. If there's something, you know, missing from it,
1574170	1580690	I'll shoot me a message and I can update it or see if there's really anything else out there.
1580690	1585370	And again, it's one of those things, you know, for the amount of money, what you get out of it,
1585370	1588650	especially because I'm sure a lot of you have kids that are home from school,
1588650	1592270	or maybe you're a kid that, you know, is learning remotely now.
1592610	1598110	What an awesome project for under $100 to learn about physics, space, orbits, math,
1598110	1602170	you know, all these things that are super nerdy because I'm a super nerd.
1602170	1607390	But really, there's a lot of other applicable lessons to other stuff out there.
1608270	1610730	The other thing that you're going to want to do is turn on Vox.
1610730	1614230	Again, this is one of those things that I'm probably getting internet hate mail for.
1614230	1619390	Vox is voice-operated switch. So basically, you can think of it as when you start talking,
1619390	1624450	the radio is going to detect that you're talking already, and it will then start transmitting right away.
1624450	1629710	That's nice because that means if you plug an audio cable in from your phone or from a Raspberry Pi,
1629710	1634370	the second that it starts playing audio over that jack, it's going to start transmitting.
1634470	1639670	Why this isn't ideal is because there's always a little bit of space of, you know,
1639750	1645130	a little bit of transmit time after you're done talking where the radio is still on,
1645130	1650530	and that can mess up some communications. So it's not ideal. You really want push-to-talk.
1650530	1656130	But if you're just getting started, it doesn't hurt just to use Vox, just to get your feet wet.
1656130	1660110	That's my personal opinion. Again, I'm going to get hate mail, I'm sure, but whatever.
1660810	1665930	So I own an aero-directional antenna. It's very similar to the one that's in that image right there.
1665930	1669930	It's like $150, which is more than the entire cost of the project.
1670030	1673090	And if hand radio is potentially something you're not going to get into, you know,
1673090	1676490	are you going to want to buy some giant antenna? I don't really know.
1676590	1679370	Personally, I have one because it's something that I really enjoy.
1680090	1685050	However, it's $150, and it's pretty steep. Or you could build your own.
1685070	1689670	And this is one of those things that I was just, you know, checking stuff out online,
1689670	1697730	and I saw that somebody had built their own directional Yagi antenna for like $10 in like PVC parts and like a measuring tape,
1697730	1701270	which is like perfect because I build everything with Raspberry Pis in PVC anyway.
1701270	1704230	So I had a lot of that basically just lying around.
1704690	1710310	And a measuring tape, which funnily enough, I didn't think about it, but I guess it's, you know, measuring tapes are steel.
1710310	1719690	And so as long as you, you know, basically sand off the tips of your antenna to solder your cables to,
1719690	1721830	it's one of those things that, oh, wow, that's kind of neat.
1721830	1728070	Like you can make an antenna out of a steel measuring tape, and it folds up nicely too, which is the added benefit.
1728070	1730590	I'll have a link to this on that GitHub page that I mentioned.
1730590	1735690	But if you just want to Google it right now while you're watching this, if you just do Legios,
1735690	1738630	I don't know how you say it, that's how you say it, but that's how I say it.
1739570	1743190	And then Yagi, all the instructions, the build list, everything.
1743190	1749370	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.
1749370	1756370	Just go online, look at it. Plenty of other people have done a lot of work to make that pretty nice.
1757790	1763930	So it's one of those things too that, like, I personally think this is a nerd merit badge to build your own antenna.
1764030	1766890	That's one of those things, if you're a student, if this is interesting to you,
1767710	1772370	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,
1772370	1774070	and now I can talk to International Space Station.
1774070	1778270	There's a little bit of that hacker spirit, hacker mentality, just to like,
1778270	1783770	you know, I built this antenna out of raw parts, you know, and kind of cobbled it together to get it to work.
1783770	1787990	And to me personally, I think that's kind of neat just to, you know, kind of have this project of like,
1787990	1789350	yeah, this is something I built with my hands.
1789450	1795550	And, you know, I'm talking to the most expensive, expensive object, you know, that humanity's ever built, you know, arguably.
1795550	1801630	Right. And it's just kind of cool to me that you can talk to International Space Station with PVC and a measuring tape
1801630	1805370	and like a radio that you bought off Amazon. And it takes about an hour to build.
1805370	1812190	If you have kids and you want to all get them interested in space and engineering and STEM stuff, you know,
1812190	1815310	or just to get their hands dirty, I think this is personally a really cool project
1815310	1817530	and it's not going to break the bank to try it.
1819130	1821590	And let's see, I don't know why I can't change sides.
1821590	1824570	So there it goes. So this is my antenna up on top of my patio.
1824570	1827530	It's on top of my patio, obviously, so I can get a better line of sight.
1827690	1831330	And I keep everything in a nice little ammo box and I use a tripod.
1831330	1836630	But again, you can just hold your hand out there with an extra piece of PVC and it works just as well.
1837670	1841250	It's one of those things that it looks, it looks homemade and that's what it is.
1841250	1844610	But you're talking to a satellite with a homemade antenna. I think that's pretty cool.
1846770	1850190	So obviously, if you build your own antenna, you're going to have to tune it a little bit.
1850190	1857270	Luckily, if you follow the instructions online of the antenna that at least I made when I went to tune it
1857270	1862250	and from what I've heard from others when they go to tune it, everything is pretty spot on if you measure things carefully.
1862550	1867890	But the way that you tune your antenna is by looking at the standing wave ratio or SWR.
1868030	1869990	And this really just measures the performance.
1870030	1876390	I like to think of it as, say you have a tube of gift wrap, right?
1876390	1884030	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.
1884030	1888490	And that's kind of how you can think of SWR working with your antenna of,
1888490	1895410	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
1895410	1902130	or how much of it's going to be wasted, you know, kind of just banging around the, you know, just kind of radiating off of it.
1902130	1910210	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.
1910590	1914850	You can buy a cheap one online for $20. I don't have one of those. I don't know how well it works.
1915150	1922870	I personally have a Nano VNA. It was like 50 or something dollars online and does a bunch more stuff other than just looking at SWR.
1922870	1925450	But it's really small, has a battery. I personally really like it.
1925450	1930130	But again, if you're trying to not break the bank, you know, maybe a $20 one online is worth it.
1930130	1934770	Or you find a ham radio operator that you just say, hey, can I plug this in real quick and test it?
1934770	1940130	You know, there are plenty of older ham radio operators that would love nothing more than to talk radio and talk shop.
1940130	1946450	And it's a great way to build a community, build a hobby, because ham radio operating is an aging hobby.
1946730	1954730	You know, just go to any ham radio operator meeting, you know, in your city, in your state, in your wherever you're from.
1954910	1959530	And it's definitely an older person's hobby, but I don't think it has to be that way at all.
1959990	1967010	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.
1967410	1974170	And again, I think mine when I did it was 1.3 to 1, which I think perfect SWR is 1 to 1.
1974170	1977270	To me, this is just magic. I don't really understand how it works.
1977270	1980690	I just know that you want your numbers to be as close to 1 to 1 as possible.
1980690	1984730	Again, if I'm wrong, shoot me a message and let me know and I'll update the slides.
1985950	1988250	So the next piece of this is the software.
1989430	1992610	Again, I have lots of Raspberry Pis lying around from a bunch of other projects.
1992610	1996910	I personally like to use Raspberry Pi. I use the software called Direwolf.
1996910	2003070	It's just an apt-get install. Again, if you check out the GitHub page, you'll have the instructions on how to set it up perfectly.
2003950	2011350	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.
2011930	2021810	And then when you install Direwolf, it'll also install KissUtil, which is what I use to be able to transmit messages into Direwolf.
2022130	2024870	And then the next thing is there's a tool called Zaster.
2024870	2027690	I don't know how you actually say that because it has an X and a str in it.
2027690	2029650	So I don't know. I assume that's how you say it.
2029650	2034810	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,
2034810	2041310	you know, it'll automatically plot where radio transmissions are coming from as they come in through APRS.
2041310	2047310	So if you were to be receiving information and you had Zaster up and running and you're receiving it with Direwolf,
2047310	2054850	you could potentially see all of the beaconing devices or all the other APRS transmitters that are out and about,
2054850	2058390	which is kind of cool when the ISS goes over and all of a sudden you have to zoom far out to see.
2058390	2063130	Wow, look, there's all these people, you know, transmitting from all over the world.
2063130	2071370	The last time that I did this, I got a contact from Canada, which, you know, I'm in central California, right?
2071370	2076470	So it's, you know, crossing over at least two states just to get there and a good part of California as well.
2076470	2078070	So I thought that was kind of neat.
2078170	2081910	And those are all applications that you want to look at if this is something you're interested in.
2082110	2085090	There's also a lot of APRS applications for phones.
2085270	2089210	I personally, like I said, I use the, you know, I use the Raspberry Pi.
2089210	2094510	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.
2094510	2098030	So it's one of those things that I would just recommend checking out an app.
2098030	2101270	You can get trials, I'm sure, of all of these applications and just try it out.
2101270	2107070	Hook up an audio jack to your phone and, you know, just plug it in your Baofeng and you're off to the races.
2107070	2109890	And it's one of those things that your phone is kind of the perfect device.
2109890	2115070	It has a battery, has a GPS, has a nice touchscreen, and it can encode audio like nobody's business.
2115070	2120490	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.
2120490	2122510	And that's all that's really required.
2122510	2124670	As long as you have the audio cable in between.
2126370	2131650	Let's see. So the next part of this is planning your passive, like when the ISS is going to be over.
2131650	2135510	This is a screenshot from my app when I was doing the slides.
2135510	2139430	I use this this application called Gosat Watch. It's for iOS.
2139430	2143050	It gives you a little bit of augmented reality, which I really like.
2143050	2151370	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.
2151590	2155750	It's kind of cool. It gives you statistics of how high it is.
2155750	2161010	So you can see it's like 264 miles orbiting. That's its altitude elevation.
2161010	2163550	I don't know what the technical satellite term is for that.
2163810	2168990	It's also going 17,000 miles an hour. And then you can kind of see how far it is relative to where you are.
2168990	2182450	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.
2182470	2193810	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.
2193810	2204830	And it gives you live stats. It'll notify you on good passes. 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.
2204830	2217210	And it also does a ton of other satellites. 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.
2223020	2235000	All right, let's see. Sorry, I had to resume it. But yeah, so this application is great. 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. It's worthwhile, at least.
2235900	2247280	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. And that matters for a couple of reasons, which I'll go over here in a second.
2247780	2256680	So when you're planning your pass, you also have to take into effect the Doppler effect. I really like the... I'm not sure if anybody's seen Big Bang Theory. I'm sure plenty of you have.
2256920	2266180	Sheldon's costume of the Doppler effect. I just had to throw it in there. But you've all heard the Doppler effect before. It's, you know, an ambulance or police car is going by, as you can see the little graphic down below.
2266180	2281740	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. 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.
2282080	2287740	And because the International Space Station is traveling at 17,000 miles an hour relative to where you are on the planet.
2288280	2304340	It's actually having the frequency, you know, it's frequency that's on board is Doppler shifting. 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.
2304340	2309480	And then as it's leaving, you know, so as it's going away from you, it's going to be a longer wavelength.
2309900	2313460	I hope I did that right. If not, again, whatever you understand.
2314800	2325480	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.
2325480	2337660	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.
2337660	2346540	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 trying to readjust or do anything like that.
2347080	2353900	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.
2353900	2356560	And you can go Google this online. You don't even need an app for it.
2356560	2369820	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.
2369820	2376300	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.
2376300	2387320	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.
2387420	2394560	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.
2394560	2402520	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.
2402760	2413560	And then if that were to fly over the United States, you know, it covers a good portion. And when it flies over California, you can hit Idaho, Colorado, you know, again, depending on whatever its orbit is.
2415100	2419740	Okay, so this was the hardest part for me is finding out how to actually send a message.
2419740	2426560	I didn't think it would be as difficult as it was. But again, I was using Raspberry Pi and I was trying to do everything on command line.
2426560	2432820	And maybe I was making it more difficult for myself than I really needed to. But again, I could use my phone, have it been easier.
2433860	2438560	But again, with some of the plans that I have going forward, I'd rather do this kind of more in an automated fashion.
2439460	2446880	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.
2446880	2453780	But essentially, I had three separate screens for my Raspberry Pi. I had Direwolf that ran my Direwolf configuration.
2453780	2459640	That's what "-c", "-t", is to not do any color on the output of when Direwolf runs.
2459820	2462920	I have the KissUtil, which is installed when you install Direwolf.
2462920	2472560	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.
2472980	2475660	And so that's kind of nice because I can just drop text files in there.
2475820	2483160	And then the KissUtil and Direwolf will take care of converting that to audio and then transmitting it out, which is awesome.
2483160	2488900	Because then at that point, you can script up whatever you want. You can do things in an automated manner or manually.
2489560	2495440	But again, you only have five minutes or so that you're trying to, you know, communicate with the International Space Station.
2495440	2499940	And then even more of a narrow window when it's directly above you or when it's kind of prime time.
2499940	2507040	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,
2507040	2511680	you know, or maybe just a handful of messages per pass because there are other people also trying to communicate with it.
2511680	2517100	And if you remember, the International Space Station is operating on a single frequency.
2517100	2524220	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...
2524760	2530200	You Google it, right? Like it's out there. But only one person can talk to International Space Station at a time.
2530200	2535860	So you don't want to be constantly transmitting because then you'll prevent other people from also communicating with it.
2536040	2540140	So basically what I had is on a, I believe, every minute interval, I would have it, you know,
2540140	2545320	copy my message.txt into the transmit folder and they would shoot that message off or, you know,
2545320	2551080	transmit that message off, I guess I should say. And so what's kind of neat about this is that you can script it up in such a way that,
2551080	2556740	you know, if you have a program that you want to have automatically begin something out, you can or anything like that.
2556740	2562360	Personally, I like that. But if this is just you're just trying to make a contact or, you know, you're trying to, you know,
2563160	2566340	if you want to be digitated off the International Space Station, that's your only goal.
2566520	2569280	You know, just with your phone, you can just send the message out that way manually.
2569280	2572160	You don't have to go through all this dire wolf craziness.
2572160	2575720	Most phone applications should be able to do it pretty darn easily.
2578370	2584250	All right, so this is a sample message and I'm going to decipher it here real quick.
2584250	2593050	So if you see the KJ60HH, that's my call sign, followed by APRS and then ARISS.
2593050	2597390	That indicates basically that I want to be digitated by the International Space Station.
2597390	2601510	Then you'll see my call sign again, followed by a dash seven.
2601510	2605450	That's because this is coming from my mobile unit, which is just my Baofeng radio.
2605770	2610730	After that, you'll see my GPS coordinates. They're kind of in a funny format, not a format that I'm used to seeing,
2610730	2613650	but it's not hard to kind of decipher what those mean.
2613810	2620270	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.
2620270	2624690	So it's not super difficult to decipher, but if it's your first time looking at APRS messages,
2624690	2628070	it might be a little bit more difficult than you would have anticipated.
2629690	2635090	This is the folder structure. So when I run direwolf, I run it from my home directory, direwolf config is right there.
2635090	2638990	And then I have a TX and an RX folder for the messages that I'm going to send,
2638990	2644210	go into the TX folder and messages that I'm going to receive come from or, you know, get placed in the RX folder.
2645690	2646690	Let's see.
2650050	2654910	All right, so some of the things going forward, I think that are important to cover.
2655410	2657670	So my goal with this is I want to automate it.
2657670	2663950	I want to make some rotors and rotors, if you're not familiar, are basically what it would allow, you know,
2664550	2669150	rotors would allow me to change the elevation, you know, up and down.
2669150	2672050	So like if you're looking like a tripod is a great example, right?
2672050	2678350	I could, you know, change the orientation 360 degrees like a compass and then the elevation up and down.
2678370	2683290	Because it'd be really cool if on the Raspberry Pi you had some software that basically track where the International Space Station was
2683290	2687090	and anytime it was up overhead to transmit a message automatically.
2687090	2690390	So that's kind of my idea of what I think would be kind of neat.
2690690	2697090	So we'll see how that goes. And then I would also like to see, you know, how far away can I hear from, you know,
2697090	2700930	or how far could I be digitated by the International Space Station?
2701030	2705530	And if you kind of think about it, you know, out onto the horizon.
2705530	2710410	So if you were out, you know, basically to the horizon, that would be zero degrees.
2710410	2713470	But obviously there are trees, there are houses, there are all those things in the way.
2713970	2721290	And so there's a point at which, you know, you can hit the International Space Station, you know, with a signal.
2721290	2724050	Maybe is that 20 degrees? Is it 30 degrees? Is it 40 degrees?
2724050	2730770	The higher the elevation is relative to where you are on the ground, the easier it will be to communicate with it.
2730770	2733290	So it's one of those things that automating it, I think would be kind of neat.
2734370	2738450	And I also like to, you know, investigate looking at other satellites.
2738970	2741570	Yeah, and basically just seeing what else is out there.
2742050	2751230	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.
2751390	2757170	And same thing with AMSAT, there's tons of great information there on how other people have, you know, had successful communications.
2757510	2760390	And really, at the end of the day, I think this is just something that's kind of cool.
2760510	2768430	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.
2768430	2769970	International Space Station.
2770550	2774810	Not to mention, too, that this is how you can transmit to a lot of other satellites.
2774810	2781230	And it's really kind of covers the basics in terms of what's required to talk to a satellite, right?
2781230	2789010	There's a whole bunch of different satellite orbits, a whole bunch of different satellite communication protocols, frequencies, modulations.
2789070	2793870	And this is just dipping your toe in the water of what's available and what's out there.
2793870	2797010	And it's for, honestly, a pretty small budget, right?
2797010	2804830	For $100, $200, you could get a really solid setup to, you know, to communicate with International Space Station, with other satellites.
2805250	2808330	With just a HAM license, you know, just being an amateur radio operator.
2808330	2814070	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.
2814070	2820630	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.
2820630	2827690	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.
2827750	2830470	Again, I'll post links to everything on that GitHub page.
2830510	2836170	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.
2836170	2842550	And then from there, who knows how much farther you can level up and, you know, what other satellite communications you can do.
2842550	2850870	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.
2850870	2859350	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.
2859350	2868130	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.
2868130	2877190	When you learn a ton of different principles from physics to, you know, radio to computers to, you know, protocols to just...
2877190	2887630	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.
2887630	2892490	If ham radio operating is for you, to find out if chasing satellites across the sky is for you.
2892490	2897290	So again, I encourage you to take a look at it. Feel free to check out the GitHub page.
2897290	2903510	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.
2903870	2907930	And yeah, hope you enjoy the talk. See how to pause this thing.
2914450	2919750	All right. Thank you for that great talk. We have Eric here to take some Q&A.
2920050	2927170	I think one of the ones that came up in the Twitch chat first was the person actually hit by that police car. They're a little worried about that.
2942670	2943750	Can you hear me, Eric?
2973950	2977850	I don't know if Eric can hear us here. We can't hear you. Are you talking, Eric?
2999640	3000680	Hello, Eric.
3002080	3006200	Yeah, I can hear you fine. I think our speaker is having some technical difficulties.
3006200	3011180	So what we'll do is he'll just hang around and chat in the village on the channels there.
3011180	3016160	And if you have any questions, he'll follow up certainly in text and maybe on one of the voice channels in there.
3016640	3021280	All righty. Thanks, everybody, for attending and hope you all enjoy the talk.
3021280	3023580	I thought it was pretty awesome and we'll go from there.