[00:24.380 --> 00:29.020]  Welcome back to another episode of Competition Update, Space Security Challenge style.
[00:29.020 --> 00:30.860]  I'm your host, Jordan Wines.
[00:31.080 --> 00:35.860]  Several teams are showing indications that they're making progress on the hardest challenge, number four,
[00:35.860 --> 00:38.620]  but we don't have any confirmed solutions yet.
[00:38.620 --> 00:43.660]  Be aware, though, that at some point in the next few hours, the scoreboard might be going off.
[00:43.740 --> 00:49.140]  Depending on the organizers, anyway, many in-person CTFs have a tradition of blanking the scoreboard toward the end
[00:49.140 --> 00:52.600]  for a little bit of increased drama, and I'm told we might see that happen here
[00:53.300 --> 00:56.320]  so teams could slip in a surprise solution when that happens.
[00:56.400 --> 01:02.000]  With no point decay, you probably have no incentive to hold back on an answer that you might otherwise do in a normal CTF.
[01:02.160 --> 01:08.060]  If you've been watching this carousel webcams, you might have noticed the occasional astronaut heading into space
[01:08.060 --> 01:11.040]  around our flatsats. Let's go ahead and take a look now.
[01:11.040 --> 01:13.520]  Oh, we've got some audio. Let's see if we can mute that.
[01:17.300 --> 01:21.040]  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,
[01:21.040 --> 01:23.780]  so we're going to have to probably kill that one.
[01:23.780 --> 01:27.920]  The video that you're not seeing actually has some of the CubeSats in slow motion.
[01:27.920 --> 01:38.680]  If you've been watching the webcams, we've actually got different views showing each of the satellites, the flatsats,
[01:38.680 --> 01:41.940]  as they're spinning around, orienting themselves on top of the sun.
[01:41.940 --> 01:47.960]  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.
[01:48.420 --> 01:55.280]  One of our explorers was able to get that video. It showed 1550 trees flatsat as it actually orbited around the room.
[01:55.280 --> 01:58.680]  We'll make sure to get that up on the YouTube playlist afterwards so you can catch it.
[01:58.680 --> 02:03.860]  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.
[02:04.480 --> 02:08.480]  All right, for more information on the other things that have been going on behind the scenes,
[02:08.480 --> 02:12.300]  we're going to see if we can bring Alex Taylor from Crimealance into the feed as well.
[02:12.720 --> 02:14.460]  Alex, can you hear me, first of all?
[02:14.940 --> 02:16.120]  Yeah, I can hear you great.
[02:16.120 --> 02:20.480]  And I hear you, too. This is good. Awesome. All right, well, welcome to the stream. Thanks for coming on.
[02:20.480 --> 02:21.020]  Yeah, thank you.
[02:21.560 --> 02:25.160]  Okay, so first, can you tell me a little bit about what's been happening behind the scenes?
[02:25.160 --> 02:30.880]  I talked to Bright, I talked to the Jasons, and they kind of gave me some updates on some of the design things.
[02:30.880 --> 02:35.840]  But in terms of what's actually happening today and yesterday, anything interesting been going on?
[02:36.380 --> 02:48.220]  Sure. So all of the flatsats in the room are connected to the ground stations that the teams are on via radios.
[02:48.380 --> 02:53.180]  So one of the things that we have to do occasionally is move some of the radios around the room.
[02:53.180 --> 03:00.020]  Sometimes there is some interference either from other radios or, you know, just from things that get moved around in the room.
[03:00.020 --> 03:02.700]  Somebody starts to microwave a floor below or something, maybe?
[03:05.020 --> 03:08.220]  There's some bits of metal and stuff that might be in the way, too.
[03:08.220 --> 03:14.300]  So one of the things that you might see people come into frame doing is moving some of those radios around
[03:14.300 --> 03:20.640]  just to make sure that teams are not getting large amounts of packet loss when they're communicating with the satellites.
[03:21.520 --> 03:26.420]  Yeah, a little bit less deterministic than, I guess, a network challenge where the networks are a little bit more reliable.
[03:26.420 --> 03:31.840]  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.
[03:31.840 --> 03:37.300]  Yeah, and something we had to communicate to teams earlier as well is that this isn't a network service.
[03:37.300 --> 03:40.620]  So they have to be very careful with the amount of data that they're sending.
[03:40.740 --> 03:47.060]  They don't want to trip over themselves and cause their messages to not get completely sent.
[03:47.140 --> 03:50.880]  I saw that message going on in the team chat, and I like that because you kind of, as an organizer,
[03:50.880 --> 03:53.860]  you have to strike the balance between how much information you give.
[03:53.860 --> 03:57.280]  And, you know, you don't want to give a hint on something that may help one team more than others.
[03:57.280 --> 04:00.340]  But you want to also help everyone make productive progress.
[04:00.340 --> 04:03.760]  And you want people to be doing things that might hurt themselves.
[04:03.880 --> 04:05.560]  How else do you kind of have to deal with, like, fairness?
[04:05.560 --> 04:09.280]  Have any other kind of concerns that have come up throughout the game so far?
[04:09.700 --> 04:19.700]  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
[04:20.120 --> 04:24.120]  from some earlier testing that we had done to make sure the challenges were solvable.
[04:24.120 --> 04:32.340]  Fortunately, the files that were left behind, we don't believe, gave away any information that would have been, you know,
[04:32.340 --> 04:35.060]  would have given teams an unfair advantage in the competition.
[04:35.060 --> 04:43.500]  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
[04:43.500 --> 04:48.100]  so that if we were wrong and those files contained something that was useful,
[04:48.100 --> 04:53.080]  at least every team had access to the same information before those challenges got released.
[04:53.080 --> 04:56.140]  Yeah, no, that makes sense. And I think that's, you know, you always have to, as an organizer,
[04:56.140 --> 05:00.720]  like, balance what decisions you make and trying to be fair is certainly important.
[05:00.940 --> 05:04.360]  One thing I'm asking everyone, what is your favorite challenge?
[05:04.360 --> 05:07.560]  And if it's not one we've seen yet, no spoilers, but if it's one we've already seen about,
[05:07.560 --> 05:11.340]  you can, of course, talk in detail, or even just which one you worked on that you thought was most interesting.
[05:11.520 --> 05:17.880]  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.
[05:17.880 --> 05:18.840]  I know you did that one. Yeah, yeah.
[05:18.840 --> 05:23.820]  Right. I would also say that Challenge Five, which is coming up, is pretty cool,
[05:23.820 --> 05:27.620]  because it's the culmination of everything that the teams have been doing.
[05:27.760 --> 05:32.560]  My personal favorite, though, is probably Challenge Three, just because it's the kind of challenge
[05:32.560 --> 05:35.480]  I would be interested in solving if I were playing this event.
[05:35.480 --> 05:39.300]  My background is very heavy on reverse engineering and exploitation.
[05:39.580 --> 05:42.740]  And that's exactly what you have to do to solve those challenges.
[05:42.740 --> 05:47.520]  Have a heavy amount of reverse engineering, you wind up with an exploit. It's good stuff.
[05:47.520 --> 05:50.180]  Yeah, I agree. That's why I highlighted that one as well.
[05:50.180 --> 05:53.720]  So, Alex, thank you very much for taking some time out from helping keep the game going.
[05:53.720 --> 05:57.620]  I'll let you get back to that, and we'll continue wrapping up this update.
[05:58.040 --> 05:59.000]  Thanks for having me.
[06:00.760 --> 06:04.820]  Finally, here's our last Space Talk episode of the event from Just Coffee,
[06:04.820 --> 06:07.520]  with a summary of how communications in space work,
[06:07.520 --> 06:11.180]  something our teams have surely demonstrated competence with over these past few days.
[06:11.180 --> 06:17.080]  Why do we use satellites like these for long-distance communication?
[06:27.240 --> 06:32.020]  Communicating with a satellite ranges from several buildings' worth of highly specialized equipment
[06:32.020 --> 06:35.940]  to a couple hundred dollars' worth of handheld amateur radio hardware.
[06:36.000 --> 06:41.420]  LEOSATs, only about 400 to 2,000 kilometers up, are even close by terrestrial standards.
[06:41.420 --> 06:44.680]  That means simple ham radios are often used to communicate with them.
[06:44.680 --> 06:48.580]  There's even one aboard the International Space Station that you can use to talk to the astronauts
[06:48.580 --> 06:51.480]  if you catch them at the right time and they're not too busy.
[06:51.480 --> 06:55.680]  The complexity with communicating with LEO satellites is actually their orbital speed.
[06:55.740 --> 07:01.980]  LEOSATs are moving so quickly that we have to use antennas that track them as they move rapidly across the sky.
[07:01.980 --> 07:05.820]  This tracking can be really difficult due to the uncertainty of the satellite location
[07:05.820 --> 07:09.000]  and how fast they move in and out of view.
[07:09.040 --> 07:13.420]  A satellite coming in and out of view from horizon to horizon is called a pass.
[07:13.420 --> 07:16.960]  Passes are the only times that we can actually communicate with satellites.
[07:16.960 --> 07:24.260]  Management of LEO satellites especially revolves entirely around these concept of passes and maximizing their effectiveness.
[07:24.260 --> 07:28.700]  For instance, it doesn't help having an imaging satellite over the target location
[07:28.700 --> 07:33.640]  if you didn't have a pass before it got to that location to tell it to take that photo.
[07:33.640 --> 07:39.300]  Similarly, you have to wait until the next pass to be able to actually bring that data back down to ground.
[07:39.300 --> 07:43.640]  Passes are roughly about 5 to 10 minutes for LEO satellites.
[07:43.640 --> 07:47.580]  This duration changes drastically based on where the ground station is located.
[07:47.580 --> 07:54.020]  Near the equator, the Earth's rotation actually causes the ground station and the satellite to lose contact with each other faster.
[07:54.020 --> 08:00.780]  But near the poles, Earth's rotation is negligible and the satellite is actually in view for almost twice as long, if not more.
[08:00.780 --> 08:06.300]  Essentially, the higher the latitude of your ground station, the more useful your passes actually end up being.
[08:06.300 --> 08:12.240]  This is the reason most ground stations are located in the higher latitudes, even in the very hard to reach locations.
[08:12.240 --> 08:18.460]  One of the best examples of that is Svalbard, a Norwegian archipelago that's extremely close to the North Pole.
[08:18.460 --> 08:25.060]  It has over 100 commercial ground station antennas, making it the largest commercial ground station in the world.
[08:34.430 --> 08:42.390]  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.
[08:42.570 --> 08:48.010]  That's our last hourly update of the competition. I look forward to seeing everyone at 4pm Pacific,
[08:48.010 --> 08:57.230]  7pm Eastern, as we will have our final daily recap where we will reveal which team's solution is being run on our satellite.