WEBVTT 00:00.900 --> 00:11.380 Yesterday, our teams collectively worked their way through Challenges 0 through 2, leaving with half of the challenges solved by at least one team, and three challenges remaining to be solved today. 00:11.920 --> 00:18.060 PFS grew their lead throughout the day yesterday, but the biggest drama occurred after hours. 00:18.060 --> 00:19.000 When the 4 p.m. 00:19.000 --> 00:25.780 Pacific deadline for the On Orbit Challenge passed, only four teams had submitted solutions deemed acceptable. 00:25.780 --> 00:27.620 What's an acceptable solution? 00:28.860 --> 00:31.760 Let's take a look at solving the On Orbit Challenge. 00:31.940 --> 00:34.380 First, some terms you'll want to know. 00:34.640 --> 00:36.860 Two-line element set, or TLE. 00:37.000 --> 00:42.620 A data format containing information about an object's position and velocity at a specific point in time. 00:42.620 --> 00:48.740 It is used to calculate where a satellite will be at some point in the future, with increasing uncertainty the further out in time. 00:48.740 --> 00:50.400 Window of opportunity. 00:50.560 --> 00:55.260 The period of time during which the satellite can be positioned to complete the desired goal. 00:55.260 --> 00:56.740 Vector. 00:56.740 --> 01:00.000 A line indicating a specific direction in magnitude. 01:00.160 --> 01:07.260 A satellite will have assigned X, Y, and Z vectors associated with the body of the vehicle that can be used in a coordinate system. 01:07.260 --> 01:14.420 Camera boresight, camera mounting position, and camera body vector all describe the satellite camera and where it's pointed. 01:14.520 --> 01:15.460 Quaternion. 01:15.460 --> 01:19.180 A number system that is handy for calculating 3D rotations. 01:19.640 --> 01:20.600 Got it? 01:20.600 --> 01:21.660 Here we go. 01:21.660 --> 01:24.300 The first step in solving the on-orbit challenge. 01:24.320 --> 01:26.040 Identify the key data. 01:26.080 --> 01:34.100 The TLE, camera mounting position, target, and window of opportunity are all supplied in the challenge description or the on-orbit handbook. 01:34.260 --> 01:39.380 The data is used to calculate the orbit of both the satellite and the moon toward the window of opportunity. 01:39.380 --> 01:43.340 And don't forget to grab the camera body vector, which will be needed later. 01:43.580 --> 01:44.740 The second step. 01:44.740 --> 01:49.020 Calculate the time of image by defining the relationship between these key vectors. 01:49.020 --> 01:50.100 1. 01:50.100 --> 01:54.800 Determine the satellite-to-moon vector, which points directly from the satellite towards the moon. 01:54.800 --> 01:55.340 2. 01:55.340 --> 02:00.060 Determine the nadir vector, which points directly from the satellite towards the center of the Earth. 02:00.060 --> 02:00.740 3. 02:00.740 --> 02:02.480 Determine the angle between 1. 02:02.480 --> 02:06.000 the satellite-to-moon vector and the nadir vector and 2. 02:06.000 --> 02:10.200 the angle between the satellite negative Z vector and the camera body vector. 02:10.200 --> 02:20.900 The instance when the difference between the two angles is minimized gives us the time of image, the moment along its orbit when the satellite will be in position to take our all-important moonshot. 02:21.840 --> 02:23.220 The third step. 02:23.220 --> 02:29.440 Calculate the attitude or the position within its orbit that the satellite must take for the camera to capture the image. 02:29.540 --> 02:32.760 This is accomplished by lots of math. 02:33.140 --> 02:38.600 Specifically, something called a direction cosine matrix, DCM, or rotation matrix. 02:38.600 --> 02:41.840 The DCM calculates a satellite attitude that points 1. 02:41.840 --> 02:44.320 the camera boresight to the moon and 2. 02:44.320 --> 02:50.440 the satellite's negative Z vector to Earth's center, which is the attitude needed to accomplish the goal. 02:50.940 --> 03:02.540 The DCM supplies us with a specific quaternion which, when uploaded and applied to the satellite's attitude determination and control system, ADCS, moves the satellite into the desired position. 03:02.540 --> 03:04.500 On to the final step. 03:04.500 --> 03:08.240 Apply all that information and get the image we're after. 03:08.780 --> 03:18.320 We take the time of image and back out the commands around it, giving the satellite enough time to apply the quaternion and be in position when it arrives at the window of opportunity. 03:18.340 --> 03:20.840 The proper order of commands would be as follows. 03:20.840 --> 03:31.460 Turn on the ADCS, slew to the commanded quaternion, turn the camera on, set the exposure time, capture the image, and finally, turn the camera off. 03:31.460 --> 03:32.600 That's it. 03:32.600 --> 03:34.160 Challenge accomplished. 03:34.700 --> 03:39.320 But what does all of this have to do with hacking and keeping our satellites secure? 03:39.400 --> 03:42.740 The on-orbit challenge was completed with full trust. 03:42.740 --> 03:47.480 Our satellites rely on data and sensors from multiple sources in order to complete an objective. 03:47.480 --> 03:51.480 The TLE that was provided relied on data from the satellite and ground stations. 03:51.480 --> 03:55.620 Authenticated communications were required to upload the proper command sequence. 03:55.620 --> 04:01.040 Trusted execution was required to process sensor and actuator data to close control loops. 04:01.040 --> 04:05.360 Secure onboard communications were required to carry out operations in orbit. 04:05.560 --> 04:21.000 We need security-focused people to help with these problems because just as much as it takes a team of people to strap explosives to a computer to get a satellite into orbit, it takes a team of people from both space and security communities to ensure that space remains a viable, 04:21.000 --> 04:22.500 usable resource. 04:24.640 --> 04:31.520 The four teams with successful on-orbit solutions during the time period were Poland Cannon to Space. 04:31.520 --> 04:34.620 In fact, theirs came well over an hour before anyone else's. 04:34.700 --> 04:46.280 ADD Vulcan, Flux Rocket Repeat, and Samurai all came in within about 10 minutes of each other within the last 15 minutes of that window. 04:46.600 --> 04:52.480 Remember, the on-orbit portion involves a team computing a mission plan for an actual satellite to take a picture of a moon. 04:52.480 --> 04:58.500 All acceptable solutions were evaluated and the most accurate solution submitted before the 4 p.m. 04:58.500 --> 05:02.460 deadline will be chosen to be sent into space into our orbiting satellite. 05:02.520 --> 05:06.730 We'll learn whose solution that was amongst those four later on today. 05:07.060 --> 05:10.920 As we entered into our overtime period after the 4 p.m. 05:10.920 --> 05:14.980 deadline yesterday, the alternate acceptance criteria kicked into play. 05:14.980 --> 05:17.640 While the four teams submitting before 4 p.m. 05:17.640 --> 05:25.100 were automatically eligible for their solution to be sent and automatically into prize eligibility, we had to get more teams available. 05:25.100 --> 05:26.800 The limit was six. 05:26.800 --> 05:32.620 This meant that two teams of the remaining four would be out of contention for the final prize pool. 05:32.880 --> 05:41.280 The four teams fighting for those two spots included PFS, 1553, 1064 Seabred, and Solarwine. 05:41.280 --> 05:48.480 1553 managed to submit a solution that was valid only three minutes after the deadline, quickly grabbing that fifth spot. 05:48.560 --> 05:54.680 That left PFS, 1064 Seabred, and Solarwine on the ropes for that last spot. 05:54.760 --> 06:04.540 PFS and 1064 Seabred were number one and number four on the scoreboard at that point, so no matter what happened, someone in contention for the podium would not be eligible. 06:04.540 --> 06:10.080 All of the contest organizers were on a shared video chat, waiting to see the results as they came in. 06:10.080 --> 06:18.400 1064 Seabred had what looked to be an extremely close solution that was just outside the acceptance criteria, and PFS didn't seem to be close. 06:18.400 --> 06:20.700 Then, at 7.48 p.m. 06:20.700 --> 06:22.980 Eastern, or 4.48 p.m. 06:22.980 --> 06:31.020 Pacific, PFS came in with a valid solution, just edging out 1064 Seabred and Solarwine on the list of on-orbit acceptance. 06:33.400 --> 06:39.280 Unfortunately, that means that 1064 Seabred and Solarwine are both ineligible for a spot on the podium. 06:39.280 --> 06:42.380 That said, they can still have an impact on the game. 06:42.440 --> 06:49.760 Either team scoring first blood will potentially change the number of available points left on the board for their competitors and impact the final result. 06:49.800 --> 06:58.720 It's sad to see two great teams out of contention for the prize pool, but they can still end up on the leaderboard from a points perspective and attain the associated bragging rights. 06:58.720 --> 07:03.400 In fact, let's go ahead and take a look at the scoreboard now in our live octagon feed. 07:04.340 --> 07:06.300 And they definitely haven't slowed down. 07:06.300 --> 07:10.600 You'll notice that Solarwine actually scored first blood on Challenge 3. 07:10.620 --> 07:13.560 Congratulations to them for the great work overnight. 07:13.700 --> 07:20.620 The pressure is now on the remaining teams to show that they made good use of the downtime as well to land Challenge 3. 07:20.620 --> 07:27.480 You can also see Flux Repeat Rocket scoring just before this broadcast with only a 5% reduction in total points. 07:27.480 --> 07:29.440 So that's a good amount of points for them. 07:29.760 --> 07:34.580 That means Solarwine and Flux Repeat Rocket are both moving on to Challenge 4. 08:00.330 --> 08:05.010 This is the first time we've seen Flux Repeat Rocket make a big move on the scoreboard. 08:05.010 --> 08:06.570 Let's check out their team bio. 08:36.200 --> 08:43.560 Like many of the combined CTF teams that we've seen here today, I have good memories of playing Hack Lou CTF. 08:43.560 --> 08:48.660 In fact, it's often the case that the competition participants are also organizers in other times. 08:48.660 --> 08:57.960 So one of those teams that makes up the composition of Flux Repeat Rocket, Flux Fingers, runs Hack Lou, which is another great CTF competition you should check out. 08:58.060 --> 08:59.720 What an exciting first day. 08:59.720 --> 09:04.420 I'm looking forward to seeing what happens today as our teams battle through these last few challenges. 09:04.420 --> 09:10.600 Come back and join us at our 10.50am Pacific, 1.50pm Eastern for our next competition update.