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24380	29020	Welcome back to another episode of Competition Update, Space Security Challenge style.
29020	30860	I'm your host, Jordan Wines.
31080	35860	Several teams are showing indications that they're making progress on the hardest challenge, number four,
35860	38620	but we don't have any confirmed solutions yet.
38620	43660	Be aware, though, that at some point in the next few hours, the scoreboard might be going off.
43740	49140	Depending on the organizers, anyway, many in-person CTFs have a tradition of blanking the scoreboard toward the end
49140	52600	for a little bit of increased drama, and I'm told we might see that happen here
53300	56320	so teams could slip in a surprise solution when that happens.
56400	62000	With no point decay, you probably have no incentive to hold back on an answer that you might otherwise do in a normal CTF.
62160	68060	If you've been watching this carousel webcams, you might have noticed the occasional astronaut heading into space
68060	71040	around our flatsats. Let's go ahead and take a look now.
71040	73520	Oh, we've got some audio. Let's see if we can mute that.
77300	81040	I'm not sure if it's coming through on that. Yeah, unfortunately, we've got a little bit too much audio on that video,
81040	83780	so we're going to have to probably kill that one.
83780	87920	The video that you're not seeing actually has some of the CubeSats in slow motion.
87920	98680	If you've been watching the webcams, we've actually got different views showing each of the satellites, the flatsats,
98680	101940	as they're spinning around, orienting themselves on top of the sun.
101940	107960	If we can stop this video before we zoom, it's going to be really good, or else you're going to hear some really interesting background noise.
108420	115280	One of our explorers was able to get that video. It showed 1550 trees flatsat as it actually orbited around the room.
115280	118680	We'll make sure to get that up on the YouTube playlist afterwards so you can catch it.
118680	123860	It was able to keep itself oriented on the sun as it went around the room, that, of course, being one of the previous challenges.
124480	128480	All right, for more information on the other things that have been going on behind the scenes,
128480	132300	we're going to see if we can bring Alex Taylor from Crimealance into the feed as well.
132720	134460	Alex, can you hear me, first of all?
134940	136120	Yeah, I can hear you great.
136120	140480	And I hear you, too. This is good. Awesome. All right, well, welcome to the stream. Thanks for coming on.
140480	141020	Yeah, thank you.
141560	145160	Okay, so first, can you tell me a little bit about what's been happening behind the scenes?
145160	150880	I talked to Bright, I talked to the Jasons, and they kind of gave me some updates on some of the design things.
150880	155840	But in terms of what's actually happening today and yesterday, anything interesting been going on?
156380	168220	Sure. So all of the flatsats in the room are connected to the ground stations that the teams are on via radios.
168380	173180	So one of the things that we have to do occasionally is move some of the radios around the room.
173180	180020	Sometimes there is some interference either from other radios or, you know, just from things that get moved around in the room.
180020	182700	Somebody starts to microwave a floor below or something, maybe?
185020	188220	There's some bits of metal and stuff that might be in the way, too.
188220	194300	So one of the things that you might see people come into frame doing is moving some of those radios around
194300	200640	just to make sure that teams are not getting large amounts of packet loss when they're communicating with the satellites.
201520	206420	Yeah, a little bit less deterministic than, I guess, a network challenge where the networks are a little bit more reliable.
206420	211840	When you're working with RF for every connection you make, you've got to deal with a little bit of that. That makes sense.
211840	217300	Yeah, and something we had to communicate to teams earlier as well is that this isn't a network service.
217300	220620	So they have to be very careful with the amount of data that they're sending.
220740	227060	They don't want to trip over themselves and cause their messages to not get completely sent.
227140	230880	I saw that message going on in the team chat, and I like that because you kind of, as an organizer,
230880	233860	you have to strike the balance between how much information you give.
233860	237280	And, you know, you don't want to give a hint on something that may help one team more than others.
237280	240340	But you want to also help everyone make productive progress.
240340	243760	And you want people to be doing things that might hurt themselves.
243880	245560	How else do you kind of have to deal with, like, fairness?
245560	249280	Have any other kind of concerns that have come up throughout the game so far?
249700	259700	Sure, yeah. So actually, early on day one, we realized that we had left a couple of files on certain teams' command and control systems
260120	264120	from some earlier testing that we had done to make sure the challenges were solvable.
264120	272340	Fortunately, the files that were left behind, we don't believe, gave away any information that would have been, you know,
272340	275060	would have given teams an unfair advantage in the competition.
275060	283500	But what we did is we decided to put all those files together into a single archive and give those out to all of the teams
283500	288100	so that if we were wrong and those files contained something that was useful,
288100	293080	at least every team had access to the same information before those challenges got released.
293080	296140	Yeah, no, that makes sense. And I think that's, you know, you always have to, as an organizer,
296140	300720	like, balance what decisions you make and trying to be fair is certainly important.
300940	304360	One thing I'm asking everyone, what is your favorite challenge?
304360	307560	And if it's not one we've seen yet, no spoilers, but if it's one we've already seen about,
307560	311340	you can, of course, talk in detail, or even just which one you worked on that you thought was most interesting.
311520	317880	Sure. Well, that's an interesting question. So you might expect me to say Challenge Zero, since that was the one that I worked on.
317880	318840	I know you did that one. Yeah, yeah.
318840	323820	Right. I would also say that Challenge Five, which is coming up, is pretty cool,
323820	327620	because it's the culmination of everything that the teams have been doing.
327760	332560	My personal favorite, though, is probably Challenge Three, just because it's the kind of challenge
332560	335480	I would be interested in solving if I were playing this event.
335480	339300	My background is very heavy on reverse engineering and exploitation.
339580	342740	And that's exactly what you have to do to solve those challenges.
342740	347520	Have a heavy amount of reverse engineering, you wind up with an exploit. It's good stuff.
347520	350180	Yeah, I agree. That's why I highlighted that one as well.
350180	353720	So, Alex, thank you very much for taking some time out from helping keep the game going.
353720	357620	I'll let you get back to that, and we'll continue wrapping up this update.
358040	359000	Thanks for having me.
360760	364820	Finally, here's our last Space Talk episode of the event from Just Coffee,
364820	367520	with a summary of how communications in space work,
367520	371180	something our teams have surely demonstrated competence with over these past few days.
371180	377080	Why do we use satellites like these for long-distance communication?
387240	392020	Communicating with a satellite ranges from several buildings' worth of highly specialized equipment
392020	395940	to a couple hundred dollars' worth of handheld amateur radio hardware.
396000	401420	LEOSATs, only about 400 to 2,000 kilometers up, are even close by terrestrial standards.
401420	404680	That means simple ham radios are often used to communicate with them.
404680	408580	There's even one aboard the International Space Station that you can use to talk to the astronauts
408580	411480	if you catch them at the right time and they're not too busy.
411480	415680	The complexity with communicating with LEO satellites is actually their orbital speed.
415740	421980	LEOSATs are moving so quickly that we have to use antennas that track them as they move rapidly across the sky.
421980	425820	This tracking can be really difficult due to the uncertainty of the satellite location
425820	429000	and how fast they move in and out of view.
429040	433420	A satellite coming in and out of view from horizon to horizon is called a pass.
433420	436960	Passes are the only times that we can actually communicate with satellites.
436960	444260	Management of LEO satellites especially revolves entirely around these concept of passes and maximizing their effectiveness.
444260	448700	For instance, it doesn't help having an imaging satellite over the target location
448700	453640	if you didn't have a pass before it got to that location to tell it to take that photo.
453640	459300	Similarly, you have to wait until the next pass to be able to actually bring that data back down to ground.
459300	463640	Passes are roughly about 5 to 10 minutes for LEO satellites.
463640	467580	This duration changes drastically based on where the ground station is located.
467580	474020	Near the equator, the Earth's rotation actually causes the ground station and the satellite to lose contact with each other faster.
474020	480780	But near the poles, Earth's rotation is negligible and the satellite is actually in view for almost twice as long, if not more.
480780	486300	Essentially, the higher the latitude of your ground station, the more useful your passes actually end up being.
486300	492240	This is the reason most ground stations are located in the higher latitudes, even in the very hard to reach locations.
492240	498460	One of the best examples of that is Svalbard, a Norwegian archipelago that's extremely close to the North Pole.
498460	505060	It has over 100 commercial ground station antennas, making it the largest commercial ground station in the world.
514430	522390	As always, thanks Jess for the content and thanks to the team at the different studios for that awesome editing and animations that go into those Space Talk episodes.
522570	528010	That's our last hourly update of the competition. I look forward to seeing everyone at 4pm Pacific,
528010	537230	7pm Eastern, as we will have our final daily recap where we will reveal which team's solution is being run on our satellite.