1 00:00:00,000 --> 00:00:04,560 What kind of download speeds can you expect on the International Space Station? 2 00:00:04,560 --> 00:00:08,920 What about on Mars? Well, as you can imagine, it's not great. 3 00:00:08,920 --> 00:00:14,320 NASA communicates with its rovers on Mars and all of its deep space probes using the 4 00:00:14,320 --> 00:00:21,560 NASA Deep Space Network, or DSN, which unfortunately has some pretty serious limitations, due to 5 00:00:21,560 --> 00:00:25,520 being both based on radio waves and established in 1963. 6 00:00:25,520 --> 00:00:28,600 We'll see if you're still spry when you turn 60. 7 00:00:28,600 --> 00:00:33,720 To overcome these challenges, NASA's Jet Propulsion Laboratory is working on a new system 8 00:00:33,720 --> 00:00:40,160 called Deep Space Optical Communications, or DSOC, which is a laser system that might 9 00:00:40,160 --> 00:00:44,040 just be a game changer for interplanetary communication. 10 00:00:44,040 --> 00:00:47,040 And yes, they've already used it to send a cat video. 11 00:00:47,040 --> 00:00:51,240 Before we get into that, though, let's talk about the old system that DSOC needs to be 12 00:00:51,240 --> 00:00:56,880 better than. In many ways, the DSN is a scientific and engineering marvel. 13 00:00:56,880 --> 00:01:02,720 It uses three antenna arrays in California, Spain, and Australia in order to ensure coverage 14 00:01:02,720 --> 00:01:08,640 of the entire sky, and each array is located in a bowl-shaped mountainous area to shield 15 00:01:08,640 --> 00:01:16,280 it from as much radio interference as possible. The DSN uses a small subset of relatively high-frequency radio waves that can easily 16 00:01:16,280 --> 00:01:21,320 escape Earth's atmosphere, rather than bouncing off the ionosphere and coming right back, 17 00:01:21,320 --> 00:01:25,880 which can happen with low-frequency radio waves like those used for AM radio. 18 00:01:25,880 --> 00:01:30,640 Radio waves, being a form of electromagnetic radiation, move at the speed of light, so 19 00:01:30,640 --> 00:01:36,000 using lasers wouldn't really speed up communication in the strictly literal sense. 20 00:01:36,000 --> 00:01:40,160 They would, however, massively increase efficiency and bandwidth. 21 00:01:40,160 --> 00:01:45,840 The longer an electromagnetic wavelength is, the less information it can carry every second. 22 00:01:45,840 --> 00:01:50,680 Unfortunately, radio waves are the longest of the electromagnetic spectrum, and thus 23 00:01:50,680 --> 00:01:57,640 have the lowest carrying capacity. The lasers that desoc will use are in the near-infrared region, making them comparably 24 00:01:57,640 --> 00:02:01,400 tiny, and therefore allowing a much higher bandwidth. 25 00:02:01,400 --> 00:02:05,840 This means that an important communication from a nearby planet like Mars would take 26 00:02:05,840 --> 00:02:11,400 basically the same amount of time to physically reach Earth, between 3 and 22 minutes depending 27 00:02:11,400 --> 00:02:19,000 on where the two planets are in their orbits. But 10 to 100 times more information could be sent every second. 28 00:02:19,000 --> 00:02:23,240 A data package that would otherwise take days or months could instead be downloaded 29 00:02:23,240 --> 00:02:30,600 in a matter of hours. The hardware necessary to communicate via lasers is also lighter and more compact than 30 00:02:30,600 --> 00:02:35,480 comparable radio systems, meaning that it's easier to fit onto a relatively small probe 31 00:02:35,480 --> 00:02:41,040 or rover without excessively increasing the fuel needed to escape Earth's gravity well. 32 00:02:41,040 --> 00:02:45,640 You know, another problem with radio waves is that they tend to spread as they're transmitted. 33 00:02:45,840 --> 00:02:50,480 And that's not a problem when you want them to go everywhere, like with a television broadcast, 34 00:02:50,480 --> 00:02:55,000 but it means that the signal quickly becomes very weak once it travels any significant 35 00:02:55,000 --> 00:03:02,000 distance from its original source. And unfortunately, almost everything in space is very, very far away. 36 00:03:02,000 --> 00:03:06,440 With lasers, you still need to account for signal interference and distortion over long 37 00:03:06,440 --> 00:03:11,400 distances, but a coherent beam of energy is going to maintain its strength for longer. 38 00:03:11,400 --> 00:03:15,600 Think of it like the difference between a shotgun blast and a shot from a sniper rifle. 39 00:03:15,720 --> 00:03:22,880 The energy is more focused and it goes much farther. But infrared lasers do have physical limitations that radio waves don't. 40 00:03:22,880 --> 00:03:28,000 They require far more precise aim, and much like visible light, they can't travel through 41 00:03:28,000 --> 00:03:33,240 opaque objects. That's not a major problem, though, seeing as space is mostly empty. 42 00:03:33,240 --> 00:03:36,440 So when exactly will we be sending those cat videos? 43 00:03:36,440 --> 00:03:39,840 And what kinds of speeds can we expect within our own solar system? 44 00:03:39,840 --> 00:03:44,920 We might be able to send and receive laser transmissions, feline or otherwise, from as 45 00:03:44,920 --> 00:03:50,080 far as our solar system's inner asteroid belt as soon as 2029. 46 00:03:50,080 --> 00:03:55,040 That's because we've actually been developing the technology needed to catch Mars' telecommunications 47 00:03:55,040 --> 00:03:58,680 up to the 21st century for several decades. 48 00:03:58,680 --> 00:04:02,400 Scientists made their first major breakthrough with extraterrestrial laser communications 49 00:04:02,400 --> 00:04:08,840 in 1968, when they proved that the Surveyor 7 moon lander could detect lasers originating 50 00:04:08,840 --> 00:04:15,080 on Earth. In 1995, the Japanese Space Agency was able to establish two-way laser communication with 51 00:04:15,080 --> 00:04:20,000 its ETS-6 satellite at an astounding 1 megabit per second. 52 00:04:20,000 --> 00:04:25,520 By 2001, we had achieved laser communication between satellites, and by 2013, NASA used 53 00:04:25,520 --> 00:04:30,160 lasers to send an image of the Mona Lisa to a satellite orbiting the moon. 54 00:04:30,160 --> 00:04:33,960 The technology has progressed to the point where we can easily transmit data between 55 00:04:33,960 --> 00:04:39,680 Earth and low Earth orbit at not just megabits, but even many gigabits per second. 56 00:04:39,680 --> 00:04:45,180 On October 13th, 2023, NASA launched the Psyche Mission, a spacecraft bound for the 57 00:04:45,180 --> 00:04:50,480 asteroid 16 Psyche, which sits in the asteroid belt between Mars and Jupiter. 58 00:04:50,480 --> 00:04:55,000 That mission will also be an important test for the technology behind DSOC, as the Psyche 59 00:04:55,000 --> 00:04:59,940 spacecraft will encode its data and send it back to Earth using infrared lasers. 60 00:04:59,940 --> 00:05:04,840 The Psyche mission won't arrive at its destination until 2029, but it's already made one successful 61 00:05:04,840 --> 00:05:14,080 test of the new communication system. On December 11th, 2023, from over 19 million miles away, the spacecraft sent back an ultra-high-definition 62 00:05:14,080 --> 00:05:19,880 video of an orange cat, reportedly named Tater, playing with the dot of a laser pointer. 63 00:05:19,880 --> 00:05:25,120 The hope is that Psyche's DSOC will be able to send data back at 2 megabits per second 64 00:05:25,120 --> 00:05:30,200 even after it reaches its destination, far beyond Mars, demonstrating the viability of 65 00:05:30,200 --> 00:05:33,960 laser communication even in the farthest reaches of the solar system. 66 00:05:34,080 --> 00:05:38,080 Wealthy. Inner solar system for now. But we're coming for you, Neptune. 67 00:05:38,080 --> 00:05:44,160 Hey, that was a Techquickie! Thanks for watching! Like, follow, and subscribe if you feel like it, and check out our other videos. 68 00:05:44,160 --> 00:05:47,880 Like this one, on the world's longest wireless internet range. 69 00:05:47,880 --> 00:05:50,380 There may be lasers involved. I haven't seen it. I don't know.