WEBVTT 1 00:00:00.000 --> 00:00:09.870 Mark Kushner: I think the microphone is only for Zoom, but I'm going to use it, in any case. It's my distinct honor to introduce today's speaker, Dr. Jesse Woodruff from Los Alamos National Laboratory. 2 00:00:09.870 --> 00:00:21.999 Mark Kushner: Dr. Woodruff earned his Bachelor's in Physics from Augsburg University, and then his PhD from the University of Minnesota, looking at Whistler waves and other waves, and the magnetosphere and ionosphere environment. 3 00:00:22.340 --> 00:00:27.909 Mark Kushner: He continued this work, as well as radiation belt work, as a postdoc at Embry-Riddle. 4 00:00:28.540 --> 00:00:32.470 Mark Kushner: Subsequently joining the, Time Distinguished team. 5 00:00:33.000 --> 00:00:40.270 Mark Kushner: I was there as well, at Los Alamos National Laboratories Space Science and Applications Group. Amongst a lot of work. 6 00:00:40.320 --> 00:00:53.359 Mark Kushner: Dr. Woodruff contributed significantly to the area of space weather, a topic that's near and dear to my heart. I especially appreciate his contributions to the field of geomagnetically induced currents in the high-voltage power transmission grid. 7 00:00:55.380 --> 00:01:01.350 Mark Kushner: After working there for some time as a staff scientist, he joined DARPA, and later 8 00:01:01.370 --> 00:01:22.850 Mark Kushner: became a program manager at NASA headquarters, leading some unique and important programs related to space weather. He has since returned to Los Alamos National Laboratory as a team lead for Space Science and Applications Group. This is a group of over 100 scientists doing a large variety of work, and today he's going to talk to us about 9 00:01:22.920 --> 00:01:30.580 Mark Kushner: space science and an anthropogenic Environment, the kind of title you pick to trip up. Introduce it. 10 00:01:30.660 --> 00:01:34.129 Mark Kushner: Before we continue, I've been asked to share with you 11 00:01:35.770 --> 00:01:52.030 Mark Kushner: the official MIPSI mug. This is version 2, I believe. Please smile. I don't know, you can do it again. 12 00:01:52.200 --> 00:01:55.519 Mark Kushner: So please welcome Dr. Jesse Woodruff. 13 00:02:00.310 --> 00:02:16.820 Mark Kushner: All right, thank you so much. It's an honor to be here. Michigan is such an important center of science, in space sciences, and just broadly in general. And to have the opportunity to address you all is, again, a privilege that I… 14 00:02:16.950 --> 00:02:32.900 Mark Kushner: will remember, at least for the rest of the day, for a long time. In fact, the welcome you all have all laid out for me has been exceptional. Speaking with your professors and speaking lunch with the students of this organization is… 15 00:02:33.050 --> 00:02:51.130 Mark Kushner: really terrific for me. Although my organization does have students, student interns, and please look for our job applications this summer, I don't get the opportunity to really sit down and talk about things with them in the same way I did today. So, my thanks to the students and to the organizers for that opportunity. 16 00:02:51.130 --> 00:03:00.790 Mark Kushner: Today, I wanted to talk to you about what I see as an emerging area, not a discipline within space science, but an emerging area of interest. 17 00:03:00.800 --> 00:03:14.409 Mark Kushner: This is going to be more of stitching together a story, a patchwork quilt, than it is to tell you one coherent narrative, but I hope by the end you will kind of see where it is all going. For those of you who are 18 00:03:14.540 --> 00:03:19.990 Mark Kushner: New to this, if there's one thing you can take away, it is what anthropogenic means, which is human-generated. 19 00:03:20.270 --> 00:03:29.560 Mark Kushner: It says, they said, the kind of worried you bring out to trip up the guy who's giving an introduction, but it's also one of the highly specific words that describes a highly specific situation. 20 00:03:29.920 --> 00:03:36.859 Mark Kushner: When I was asked to give a talk to MIPSE, I thought to myself about 21 00:03:37.020 --> 00:03:43.780 Mark Kushner: Past discussions we had on space and the relationship to plasma science and plasma physics. 22 00:03:43.870 --> 00:04:00.549 Mark Kushner: And when we discussed about how to pitch space in the context of plasma physics, when I was at NASA, we talked about space as a laboratory for plasma physics. You could run experiments in space, natural experiments, that you couldn't really do in the laboratory due to scale or 23 00:04:00.550 --> 00:04:05.079 Mark Kushner: other challenges of fitting in a laboratory instrument. But… 24 00:04:05.760 --> 00:04:09.029 Mark Kushner: There is a twin to that, which is… 25 00:04:09.130 --> 00:04:27.110 Mark Kushner: Is it a natural laboratory? Is it pristine? What about that… what assumptions are you making about that laboratory that may or may not be true? And one thing I have been able to see over the course of my career, past 7 to 8 years, is that there are emerging, 26 00:04:27.300 --> 00:04:39.209 Mark Kushner: hints that we are not dealing with a pristine laboratory in space. We are dealing with a laboratory in which we are constantly changing the parameters of the experiment. 27 00:04:39.440 --> 00:04:40.540 Mark Kushner: So… 28 00:04:41.230 --> 00:04:57.849 Mark Kushner: Does that mean everything we know today is going to be true tomorrow? The physics? Yes. The details? No. And what are the impacts of that? Many of you may be dealing with those questions down the road, and so I want to introduce you to some of the ideas here, in this talk. 29 00:05:03.390 --> 00:05:06.890 Mark Kushner: Okay, so this is a talk in many parts. 30 00:05:07.250 --> 00:05:24.639 Mark Kushner: First off, just want to touch quickly on the idea of plasma experimentation and how this all ties together. Then I want to give you a case study on Starfish Prime. Starfish Prime was a nuclear weapons test, and as coming from Los Alamos National Laboratory, it is near and dear to my heart. 31 00:05:24.690 --> 00:05:37.750 Mark Kushner: Then I wanted to talk about a broader theme, and in fact, some of you may or may not know this, the term anthropogenic space weather really hit the big time in a paper that was, co-led by Thomas Kombosi from University of Michigan. 32 00:05:37.820 --> 00:05:43.099 Mark Kushner: So this is an idea, even, to an extent, that has a genesis at Michigan. 33 00:05:43.460 --> 00:05:46.539 Mark Kushner: I'll talk to you about space debris and dusty plasmas. 34 00:05:47.000 --> 00:05:52.500 Mark Kushner: Electromagnetic waves that we are introducing into the system and not even knowing about it. 35 00:05:53.290 --> 00:06:08.630 Mark Kushner: the impact of just having spacecraft in the system and measuring it. You may be familiar with the concept of the observer problem. Just by observing the system, you, by very nature, affect the outcome of the experiment. Well, you're actually seeing that, too, in space, in a very different context. 36 00:06:08.680 --> 00:06:14.000 Mark Kushner: Then want to synthesize it all together, and just close out with some challenges for you all. 37 00:06:15.570 --> 00:06:16.420 Mark Kushner: Okay. 38 00:06:16.670 --> 00:06:22.760 Mark Kushner: As I said, the long-term view, this one view I was brought up on, is that space is a laboratory 39 00:06:22.810 --> 00:06:31.080 Mark Kushner: for plasma physics. You can explore fundamental scientific process, fundamental physical processes in space that you could not necessarily explore in the lab. 40 00:06:31.080 --> 00:06:46.509 Mark Kushner: Magnetic reconnection, plasma turbulence. These are all fundamental, universal concepts that naturally occur in space. And that's true. Absolutely, 100%. It is tough to do some experiments you would want to do to understand some things in the lab. 41 00:06:46.600 --> 00:06:53.850 Mark Kushner: But you can do them in space. And, of course, controlled experiments in the lab can teach you things you don't learn from space. They're very synergistic. 42 00:06:54.150 --> 00:06:59.329 Mark Kushner: Plasma physics is universal. The appearance of plasma physics in any given case is not. 43 00:06:59.810 --> 00:07:02.350 Mark Kushner: But… 44 00:07:04.200 --> 00:07:17.229 Mark Kushner: We are not leaving space alone. We are exponentially increasing our footprint in space. Where I was in the start of my career in the early 2000s, as to where we are today, we have seen 45 00:07:17.230 --> 00:07:29.719 Mark Kushner: thousands and tens of thousands of more objects in space. Active spacecraft, communication spacecraft, Starlink, for instance, is just an unthinkable presence from where I was when I started my career. 46 00:07:30.000 --> 00:07:34.939 Mark Kushner: Those aren't scientific platforms, but they are present and they are doing things. 47 00:07:35.710 --> 00:07:41.070 Mark Kushner: And as I've noticed, and as a ever-increasing 48 00:07:41.470 --> 00:07:50.080 Mark Kushner: corpus of research publications is showing, our presence in space is changing the environment and is changing what we are measuring. 49 00:07:50.430 --> 00:08:04.720 Mark Kushner: And that's interesting, because it provides a significant challenge for future generations of scientists and engineers. But it also provides opportunity, because understanding how that's changing provides new opportunities for looking at things differently. 50 00:08:05.240 --> 00:08:06.170 Mark Kushner: bomb. 51 00:08:08.860 --> 00:08:13.710 Mark Kushner: So, I will start with so many good stories start with a bang. A big bang. 52 00:08:15.420 --> 00:08:28.050 Mark Kushner: As some of you are probably familiar, if no other reason than having seen some recent movies, Oppenheimer, Los Alamos National Laboratory was founded around the development and fielding of a nuclear weapon in World War II. 53 00:08:28.070 --> 00:08:45.259 Mark Kushner: And we continue to be, centered around the nation's mission of security in the nuclear arena. Specifically, my group, ISR, Intelligence and Space Research, is focused on treaty verification. We make sure that people who said they are not going to blow something up don't blow something up. 54 00:08:45.290 --> 00:08:49.560 Mark Kushner: And we call them on it if they do. Thankfully, that doesn't come up very often. 55 00:08:49.640 --> 00:09:02.479 Mark Kushner: It is a good day for us when we get no result, I tell you. But for a long time after the dawn of the nuclear age, you know, we had an active testing program. 56 00:09:02.480 --> 00:09:11.649 Mark Kushner: the United States and the Soviet Union were competing to show how powerful their arsenals were, and they were testing these things in two and different locations. 57 00:09:11.670 --> 00:09:13.280 Mark Kushner: In 1958, 58 00:09:13.530 --> 00:09:21.799 Mark Kushner: We blew up a bomb in the atmosphere. This was called Checkmate, Operation Checkmate. It was at, tens of kilometers altitude. 59 00:09:22.110 --> 00:09:34.060 Mark Kushner: pretty low yield, but we noticed something interesting. Radio frequency communications that we were using to communicate during that test were disrupted. This test in the atmosphere disrupted 60 00:09:35.270 --> 00:09:36.320 Mark Kushner: space. 61 00:09:37.230 --> 00:09:40.900 Mark Kushner: This, of course, led the scientists to say, oh! 62 00:09:41.590 --> 00:09:50.409 Mark Kushner: let's look deeper into that. Let's see more about that. Let's do it bigger. So there was a series of tests culminating in the 63 00:09:50.710 --> 00:09:56.340 Mark Kushner: Starfish Prime test, called Prime because the first one was a dud. So, Starfish Prime went off 64 00:09:56.340 --> 00:10:13.650 Mark Kushner: with a bang. It was a 1.4 megaton nuclear device that was detonated at an altitude of 250 miles above Johnston Island in the Pacific. For reference, the Hiroshima nuclear device, I believe, was 50 kilotons. This thing was massive. And what it did. 65 00:10:13.820 --> 00:10:15.780 Mark Kushner: Is it initially? 66 00:10:16.780 --> 00:10:35.409 Mark Kushner: expanded. Big, expanding cloud, insanely hot gas and X-rays. But it's also in the void of space, so you're not looking at a mushroom cloud situation, you're looking at an expanding cloud. That is not Starfish Prime, by the way. There is no picture of Starfish Prime's initial blast that I'm aware of. That is actually, I think, checkmates. But… 67 00:10:35.420 --> 00:10:37.630 Mark Kushner: Hawaii, 900 miles away. 68 00:10:37.890 --> 00:10:40.299 Mark Kushner: Saw a early sunrise? 69 00:10:40.920 --> 00:10:50.369 Mark Kushner: There was later time, Auroral borealis was observed at a very non-aaural latitude. This was a… 70 00:10:50.550 --> 00:10:57.479 Mark Kushner: massively energetic disruption of the space environment by human influence, and this was, I'd say, the first anthropogenic 71 00:10:57.610 --> 00:11:02.310 Mark Kushner: It's not the first, actually, time we affected the space environment, but it's the first real anthropogenic experiment with the environment. 72 00:11:02.650 --> 00:11:07.129 Mark Kushner: This led to a number of interesting consequences. 73 00:11:10.480 --> 00:11:14.329 Mark Kushner: One of the most striking was the creation of a new artificial radiation duct. 74 00:11:14.820 --> 00:11:27.710 Mark Kushner: So, you know that there… you may know that there is an inner radiation belt and an outer radiation belt. Well, the detonation of Starfish Prime created a third radiation belt that was many times more intense than either of those radiation belts. 75 00:11:27.930 --> 00:11:31.549 Mark Kushner: And it was long-lasting. It lasted multiple years. 76 00:11:31.670 --> 00:11:42.820 Mark Kushner: Starfish Prime was detonated, I said, Johnston Islands as low latitude. If you're familiar with the concept of magnetic L shelves, this was L1 in a fraction. 77 00:11:43.090 --> 00:12:01.140 Mark Kushner: But the debris from starfish and the radiation from starfish spread out broadly across the magnetosphere to Ls of 3, 4, 5, 6. It was observed by satellites throughout… there weren't a ton of satellites at this time. Don't get me wrong. Down to the space age, Sputnik was 57. 78 00:12:01.320 --> 00:12:03.190 Mark Kushner: Starfish Prime. 79 00:12:03.770 --> 00:12:14.480 Mark Kushner: 62. Not a huge amount of time to populate space, but they did have satellites out there. As the table down there at the bottom shows, there are multiple satellites that did get a chance to observe this. 80 00:12:14.800 --> 00:12:24.319 Mark Kushner: But, observations from the aerial satellite at the time, which had a radiation detector on it, saw that the enhancement was huge. 81 00:12:24.600 --> 00:12:26.030 Mark Kushner: And, 82 00:12:26.240 --> 00:12:31.769 Mark Kushner: I'd tell you it was… they could tell you how long it lived, but actually the aerial satellite and many other satellites had their lives 83 00:12:31.880 --> 00:12:35.140 Mark Kushner: Drastically cut short due to this new radiation belt. 84 00:12:35.300 --> 00:12:41.420 Mark Kushner: This, in fact, taught us Probably our biggest lesson about the impact of radiation on satellites. 85 00:12:41.620 --> 00:12:47.190 Mark Kushner: And that you can expose a satellite to far too much radiation far too quickly. 86 00:12:47.300 --> 00:12:59.150 Mark Kushner: it was a lot of useful lessons for future science experiments. We've gone a long way from sending Geiger tubes up with VanElen to where we are today, and part of that was learning about the extremes of space. 87 00:12:59.890 --> 00:13:01.460 Mark Kushner: Through things like this. 88 00:13:01.800 --> 00:13:07.000 Mark Kushner: Los Alamos has become very good at putting radiation-tolerant devices up in space ever since. 89 00:13:07.220 --> 00:13:11.280 Mark Kushner: But you can see here, 90 00:13:11.400 --> 00:13:13.370 Mark Kushner: I've got a pointer, I'll use that. 91 00:13:13.910 --> 00:13:16.740 Mark Kushner: You see here, on this… But… 92 00:13:17.280 --> 00:13:20.529 Mark Kushner: Here is deadlines, here is the ambient. 93 00:13:20.750 --> 00:13:34.830 Mark Kushner: radiation spectrum. Solid lines here are the post-Hayne artificial radiation spectrum. You're talking orders of magnitude more radiation at high energies. This is not an environment anything was built to survive. 94 00:13:35.510 --> 00:13:42.230 Mark Kushner: And so… We learned… That mankind, despite the fact that space is big. 95 00:13:42.650 --> 00:13:45.530 Mark Kushner: Mankind can do big things and affect it. 96 00:13:45.690 --> 00:13:50.019 Mark Kushner: This was our first real anthropogenic experiment. 97 00:13:51.000 --> 00:13:54.919 Mark Kushner: we've… Since learned a lot of… 98 00:13:55.350 --> 00:14:13.269 Mark Kushner: lessons. Most notably, if you want to keep a constellation of satellites alive, don't nuke space, which is why U.S. and Russia eventually did sign a non-proliferation treaty, non-testing, non-atmospheric, and space testing agreement. 99 00:14:13.300 --> 00:14:15.800 Mark Kushner: Because, as you see here. 100 00:14:16.410 --> 00:14:29.139 Mark Kushner: Solar cell damage to track, complete failure of command decoders, commanding command system failure, encoder malfunctions, malfunctions, malfunctions, degradation. 101 00:14:29.300 --> 00:14:33.509 Mark Kushner: Within 6 months, approximately half of all our satellites on orbit were dead. 102 00:14:33.650 --> 00:14:38.249 Mark Kushner: Some satellites had the misfortune of being launched almost simultaneous with that. 103 00:14:39.600 --> 00:14:43.400 Mark Kushner: And… We kind of couldn't see incoming, but… 104 00:14:44.640 --> 00:14:50.609 Mark Kushner: I will tell you that this actually was predicted. Once they saw that result in 1958, they were like, oh! 105 00:14:50.610 --> 00:15:05.870 Mark Kushner: It would explain this. And a scientist named Nicholas Christophilus came up with an explanation for it. It's called the Christophilus Effect. Now I think it's called the Argus Effect, various things here. But this was a very expensive, very showy confirmation of that theory. 106 00:15:06.530 --> 00:15:24.010 Mark Kushner: The Soviet Union did match this later on. In later 1962, they detonated a series of nuclear bursts over Kazakhstan, called the K-Series of tests. It actually yielded a very different result on the radiation belt. It enhanced the radiation environment, but it didn't do the same thing as the 107 00:15:24.100 --> 00:15:39.750 Mark Kushner: Starfish one. One, there were fewer satellites in orbit, because we'd already killed them, but two, the space physics of it is different, because Kazakhstan is at a higher latitude, and the magnetic field configuration is a little bit different. The trapping and the lifetimes were different. 108 00:15:39.910 --> 00:15:43.300 Mark Kushner: So, this is a natural artificial environment interaction. 109 00:15:43.940 --> 00:16:02.819 Mark Kushner: I mention this because it is, to me, it is a compelling entrance to the narrative that mankind has created a radiation belt, and it has seen the effects of that artificial belt on its own resources, but it also starts to tell the bigger, more subtle picture. 110 00:16:04.580 --> 00:16:09.020 Mark Kushner: Mankind, as it moves into space, is increasingly 111 00:16:09.560 --> 00:16:13.110 Mark Kushner: Changing the environment, interacting with the environment, and affecting the environment. 112 00:16:13.990 --> 00:16:15.030 Mark Kushner: through… 113 00:16:15.950 --> 00:16:34.650 Mark Kushner: Starkish Prime, we demonstrated the ability to create artificial aurora, and to trigger phenomena that were known to just be natural for an artificial means. Later on, what we are finding is, through our unnatural activities, we are going to be modifying the natural environment. 114 00:16:36.000 --> 00:16:44.409 Mark Kushner: In long-term ways. So, I'd like to pivot from that, pivot from the big boom to just a whisper, of dust and debris. 115 00:16:45.180 --> 00:16:49.749 Mark Kushner: First off, you know, even if… 116 00:16:49.970 --> 00:16:58.049 Mark Kushner: We have launched tens of thousands of satellites into orbit, and the Starlinks and whatever else are there. Base is still largely empty. 117 00:16:58.340 --> 00:17:06.010 Mark Kushner: You all know large space isn't a vacuum space is full of plasmas, and it is full of electromagnetic energy. 118 00:17:06.310 --> 00:17:07.319 Mark Kushner: But… 119 00:17:07.690 --> 00:17:18.129 Mark Kushner: it is far from empty, but it is getting less and less physically empty. Recently, actually, NASA estimates that the rate at which mass is entering 120 00:17:18.349 --> 00:17:24.250 Mark Kushner: the orbit around Earth. There's always this natural entry of mass into Earth. We've got 121 00:17:25.140 --> 00:17:31.159 Mark Kushner: comets and asteroids coming in, little dust micro… precipitating in towards the Earth. 122 00:17:31.240 --> 00:17:43.109 Mark Kushner: But the rate at which this mass is entering is now equaled or exceeded by the rate at which we are naturally add… or unnaturally adding it through human contributions, through… 123 00:17:43.110 --> 00:17:52.070 Mark Kushner: putting satellites in space, blowing satellites up in space, and various permutations therein. And that's only going to keep increasing. 124 00:17:52.320 --> 00:17:57.510 Mark Kushner: on large scales, this is a familiar macro problem. 125 00:17:57.510 --> 00:18:16.260 Mark Kushner: Space debris, space junk. You've probably heard about this before. You've probably even heard of the so-called Kessler Syndrome. Maybe you haven't, and of which case I'll happily introduce it to you. Kessler Syndrome is the idea that you can put enough space junk in orbit that you can never put anything else in orbit. Because as soon as you plant something there, it'll get hit by a piece of junk. And then you just make more space junk. 126 00:18:16.260 --> 00:18:23.169 Mark Kushner: And so on and so forth. It's a runaway, catastrophic orbital overflow problem. It was predicted 127 00:18:23.170 --> 00:18:30.810 Mark Kushner: Decades ago, and thankfully, we have not reached that point, and we are projected to have decades plus before we do. 128 00:18:31.110 --> 00:18:33.410 Mark Kushner: And that is… 129 00:18:33.530 --> 00:18:44.839 Mark Kushner: strongly helped by understanding of the environment and proper stewardship of it. But we have not always been proper stewards of the environment. In fact, even the best laid schemes go awry. 130 00:18:45.140 --> 00:18:53.100 Mark Kushner: We are constantly adding more satellites, more rocket bodies into orbit, and not everybody is conscientious about bringing those down. 131 00:18:53.350 --> 00:19:05.819 Mark Kushner: It used to be that every time you put up a rocket, you'd leave some junk behind. You'd leave a rocket booster, you'd leave an O-ring, you'd leave XYZ, and you're adding junk to the… to space. And we track these things. 132 00:19:05.920 --> 00:19:13.689 Mark Kushner: And… Over time, There's been a very clear uptick in the amount of stuff we put in space. 133 00:19:15.880 --> 00:19:29.379 Mark Kushner: These label some key events in the course of space history for orbital debris. And this is not to talk about orbital debris. Orbital debris is an entry into where I want to go, but I think it's important to understand how this stuff is getting there. 134 00:19:29.680 --> 00:19:34.340 Mark Kushner: Initially, We had… Something exploded. 135 00:19:34.480 --> 00:19:37.879 Mark Kushner: An explosion naturally creates more debris, it's just the nature of things. 136 00:19:38.540 --> 00:19:40.800 Mark Kushner: Again, explosion. 137 00:19:41.000 --> 00:19:51.720 Mark Kushner: Anti-satellite test. That's the… the Chinese government blew up a satellite to show us that they could blow up a satellite. They succeeded. Look at the population of debris. Satellite test, boom. 138 00:19:51.830 --> 00:19:57.230 Mark Kushner: 25% increase in the amount of debris. Cosmos, this was a satellite, broke up. 139 00:19:58.420 --> 00:20:07.000 Mark Kushner: The Iridium cosmos, this is two satellites colliding, boom, boom, boom, boom. You're just watching the amount of debris in orbit increase over time. 140 00:20:07.580 --> 00:20:20.060 Mark Kushner: So, what we find is planned human activity is, of course, exponentially increasing the amount of stuff in space. It can roughly break out an exponential curve if you squint and hope really hard, but… 141 00:20:20.400 --> 00:20:30.619 Mark Kushner: Unintentional human activity, or… Non… peaceful human activity is occasionally causing that to go out of step. 142 00:20:31.080 --> 00:20:33.910 Mark Kushner: And increase the population rapidly. 143 00:20:34.270 --> 00:20:36.919 Mark Kushner: Well, what does this mean? And why am I bringing it up? 144 00:20:37.170 --> 00:20:40.509 Mark Kushner: Because measurements of debris suggest 145 00:20:41.060 --> 00:20:48.119 Mark Kushner: So, looking, for example, here are, some photos from the NASA Orbital Debris Program Office that are showing 146 00:20:48.170 --> 00:20:58.019 Mark Kushner: debris holes from a panel that was brought back from a space mission. So this thing lived out in space and got hit by whatever was sitting out in space with it. 147 00:20:58.070 --> 00:21:08.220 Mark Kushner: There were a bunch of centimeter-scale holes due to rapid-moving debris ramming into satellites. And there were zillions of millimeter-scale holes 148 00:21:08.280 --> 00:21:10.910 Mark Kushner: Due to smaller stuff running into the satellites. 149 00:21:13.630 --> 00:21:28.039 Mark Kushner: Let me just digress for a second here and give you an idea of this. When something runs into you in space, that is an event unlike anything you've ever seen on Earth, because orbital speeds are unimageable compared to 150 00:21:28.570 --> 00:21:33.279 Mark Kushner: human inter… human experience speeds. We're talking… 151 00:21:33.620 --> 00:21:39.810 Mark Kushner: a satellite in Leo goes around the Earth in 44… In about an hour? 152 00:21:40.250 --> 00:21:44.019 Mark Kushner: Whereas if you're in an airplane, that takes you more than a day. 153 00:21:44.340 --> 00:22:03.150 Mark Kushner: So, you're thinking a factor of 20 faster than anything that you've ever been on, and an airplane is moving faster than you have any real experience with. You're talking about a car, the airplane's a factor of 10 faster than you're going in a car, the car is a factor of 20 faster than you walk, so your orders and orders of magnitude than any speed you're used to. 154 00:22:03.190 --> 00:22:15.309 Mark Kushner: A piece of dust, or a ball bearing, or something in space running into your satellite is like getting hit by an artillery shell at close range. It is destructive, it is powerful. 155 00:22:15.360 --> 00:22:17.450 Mark Kushner: And it is devastating. 156 00:22:17.710 --> 00:22:25.959 Mark Kushner: And it is becoming more and more present, and yet this is still not a talk about orbital debris. This is a talk about what happens at the tail of the debris distribution. 157 00:22:26.450 --> 00:22:39.920 Mark Kushner: Routinely, we monitor the content of space. This is a duty of the U.S. Space Command. They've got the space fence radar, they track tens of thousands of objects. 158 00:22:39.930 --> 00:22:47.699 Mark Kushner: to make sure that they're not running into each other. And they're advising people who do run objects to get out of each other's way when it happens. 159 00:22:49.820 --> 00:23:02.420 Mark Kushner: But what I want to point out here is, when you go from the centimeter scale to the millimeter scale, centimeter scale, millimeter scale, you see more than two orders of magnitude increase in the number of recognized objects. 160 00:23:02.540 --> 00:23:14.690 Mark Kushner: And this appears to be a robust scaling down to very small scales, centimeter to millimeter to micron to da-da-da-da-da-da. What you are seeing, essentially, is the growth 161 00:23:15.060 --> 00:23:17.749 Mark Kushner: Of a new population of dust. 162 00:23:19.430 --> 00:23:41.150 Mark Kushner: there is, this being a plasma physics and engineering seminar, on to bring up the idea of a dusty plasma. There was a… in fact, there was a paper in archives a few years back that suggested Earth could be approaching a dusty plasma regime. We are not there, but I appreciate the heck out of the person who was willing to put that up there as a… an idea. It is the kind of challenging idea that we need to think about. 163 00:23:41.190 --> 00:23:42.370 Mark Kushner: Because… 164 00:23:42.650 --> 00:23:55.979 Mark Kushner: The more dust you put out there, eventually the more dust interacts, the more it breaks itself apart, two smaller pieces of dust interact, boom, little dust cloud, and so what you have is this cascade of space objects creating more and more dust. 165 00:23:56.200 --> 00:24:10.919 Mark Kushner: This mass loading we're seeing increasing is going to lead over time to an increased population of dust in the Earth. Are we ever going to be like Saturn's rings or Jupiter's rings? Probably not. But it is not unthinkable that we are going to approach a regime where 166 00:24:10.920 --> 00:24:17.800 Mark Kushner: it is possible to disrupt the fundamental scientific underpinnings of our plasma physics near Earth. 167 00:24:19.250 --> 00:24:36.100 Mark Kushner: So, the fact that there is essentially a robust power law distribution for dust and debris suggests, you know, scale-free process. The same kind of interactions are happening at all scales until the physics changes. You can't break dust down beyond atoms. You get these small. 168 00:24:36.130 --> 00:24:40.289 Mark Kushner: Dust grains, and eventually the physics changes, and you don't get that anymore. 169 00:24:40.930 --> 00:24:42.050 Mark Kushner: But… 170 00:24:42.610 --> 00:24:51.959 Mark Kushner: This cascade of cushion products could lead us to a new regime of plasma physics and a new everything you learned is slightly wrong sort of situation. 171 00:24:52.170 --> 00:24:55.989 Mark Kushner: Because what is dust relative to a plasma? 172 00:24:56.110 --> 00:25:04.410 Mark Kushner: As you probably know, plasmas are, at the most fundamental level, a conglomeration of positive and neutral charged particles, usually protons and electrons. 173 00:25:04.670 --> 00:25:07.189 Mark Kushner: Protons Light, 1836. 174 00:25:07.460 --> 00:25:11.059 Mark Kushner: Electrons… really liked half a… 175 00:25:11.310 --> 00:25:24.859 Mark Kushner: at an MAV, but dust is macroscopic. It doesn't just carry a charge, it usually carries a bunch of charge. Stuff gloms onto it. Even if it's nanometer size, it is still big compared to an atom. 176 00:25:25.120 --> 00:25:35.680 Mark Kushner: So dust grains agglomerate charge, they add mass, they change the dynamics of a plasma. A wave that used to think, I'm oscillating through protons and electrons, always says. 177 00:25:35.680 --> 00:25:46.289 Mark Kushner: I'm really weighed down, and, doesn't behave the same, or it introduces new wave modes. This is what you see in the study of dusty plasmas within the solar system. 178 00:25:48.290 --> 00:25:56.360 Mark Kushner: there is a potential. We are not there. I really want to emphasize that. There's no evidence we are there yet, but there's evidence we could go there over time. 179 00:25:56.620 --> 00:26:01.130 Mark Kushner: Of having a dust-influenced environment. This is, you know. 180 00:26:01.820 --> 00:26:16.519 Mark Kushner: parameterized by the so-called heaviness parameter, which basically tells you the number of dust particles in one day-by-length sphere, a modulo, a few factors. When you have this parameter small, that is, when you only have a few dust grains within a day-by-length. 181 00:26:16.520 --> 00:26:25.799 Mark Kushner: It's just a dust in a plasma. It's there, it's a tourist, it doesn't change anything. But when it gets big, on the order 1 or above 1, then your dynamics start changing. 182 00:26:25.920 --> 00:26:37.129 Mark Kushner: And, you know, I think we're in the 10 to the 5 to 10 to the 7 low area right now, but it's not where it was, would have been 10 years ago, and it's not where it would be 10 years from now. 183 00:26:37.490 --> 00:26:43.120 Mark Kushner: This is an outstanding question, and I, in fact, am coming to you with just as many questions as I have answers, probably more. 184 00:26:43.300 --> 00:26:52.710 Mark Kushner: you all being future scientists, future engineers who are going to be operating in this environment, thinking about these problems, I lay these out as challenges to you for the future. 185 00:26:56.210 --> 00:27:04.179 Mark Kushner: But mass isn't the only thing that's important. In fact, dynamically, it has yet to manifest itself in a huge way. 186 00:27:04.520 --> 00:27:09.100 Mark Kushner: Electromagnetic noise, however, is another interesting problem that we are already seeing. 187 00:27:10.160 --> 00:27:16.790 Mark Kushner: So… Anybody know how you communicate with a submarine? 188 00:27:18.780 --> 00:27:19.850 Mark Kushner: Sonar. 189 00:27:20.350 --> 00:27:29.949 Mark Kushner: That's, yeah, you have to send a signal through the water, and the big challenge is you want to communicate with the submarine without telling your enemies where the submarine is. 190 00:27:30.410 --> 00:27:38.649 Mark Kushner: Water is a challenge, because it's saltwater, especially because it's a conductor. It attenuates signals, so you need to send them information 191 00:27:38.910 --> 00:27:44.609 Mark Kushner: That is both non-specific in location, yet able to get where you want to go. 192 00:27:44.990 --> 00:27:52.789 Mark Kushner: The U.S. Navy uses very low frequency waves to do that. Some of you may know what very low frequency, or VLF waves are. 193 00:27:52.790 --> 00:28:10.609 Mark Kushner: But these are waves in frequency range of 3 to 30 kilohertz, where you lay out a massive antenna along the ground, and you modulate it in order to send a signal actually up at space, bounce it off the ionosphere, and send it to long distances. Then, because of its long wavelength, it can 194 00:28:10.900 --> 00:28:19.709 Mark Kushner: propagate through the water to submarine depths, and get the message across at about 60 characters a minute. Low bandwidth, but it gets the job done. 195 00:28:20.210 --> 00:28:38.950 Mark Kushner: The U.S. Navy started doing this in 1959, proved it out, worked, and they started broadly deploying this stuff in the mid-60s. Why do you care, and why does this matter? Well, BLF is actually a classification we use for space plasma waves as well. BLF in the space plasma regime is Whistler. 196 00:28:39.170 --> 00:28:46.729 Mark Kushner: Waves. Whistler waves are incredibly important, for dynamics in the space environment because they interact with charged particles. 197 00:28:46.900 --> 00:28:56.689 Mark Kushner: It turns out that these ground-based VLF transmitters that we've set up starting in the late 50s and early 60s, energy leaks through the ionosphere and makes it into space. 198 00:28:56.930 --> 00:29:02.530 Mark Kushner: It's… it's not a perfect reflector by any means, and… 199 00:29:02.900 --> 00:29:07.959 Mark Kushner: So we have a long history of pumping electromagnetic energy into space. 200 00:29:08.530 --> 00:29:23.260 Mark Kushner: And it was observed as early as the 1970s, possibly even earlier, that there would be correlated bursts of, electromagnet… or of electrical charge particles precipitating in the atmosphere at the same time as VLF transmitters were operating. 201 00:29:23.720 --> 00:29:25.030 Mark Kushner: The theorists? 202 00:29:25.420 --> 00:29:45.079 Mark Kushner: Hacked this problem, and came up with the solution that, well, these VLF waves from the transmitters are going into space, interacting with the charged particles, causing them to scatter. Instead of bouncing along magnetic field lines in a… as a trapped radiation environment, which is what the natural radiation belts would be. It causes them to actually become more field-aligned and plow into the atmosphere. 203 00:29:45.200 --> 00:29:48.230 Mark Kushner: Creating, a patch of precipitation. 204 00:29:48.360 --> 00:29:50.429 Mark Kushner: And that's what the scientists were seeing. 205 00:29:52.290 --> 00:30:09.949 Mark Kushner: We have then since been able to look much more detail at, actually, the electromagnetics in space. A French satellite, Demeter, carried a radio receiver, and they observed VLF enhancements that were directly traceable back to VLF transmitters, and subsequent studies have also shown 206 00:30:09.950 --> 00:30:19.620 Mark Kushner: that there is a direct correlation between the presence of active transmitters and VLF activity and particle precipitation. 207 00:30:20.210 --> 00:30:27.900 Mark Kushner: There is, in fact, you know, this is… we're stepping out a little bit more into the hypothetical territory here, but there is… 208 00:30:28.700 --> 00:30:41.999 Mark Kushner: The truth of the matter is the timing is a little unfortunate for us. They started doing VLF transmitter activity in the late 50s, early 60s. We started putting radiation monitoring satellites in space late 50s, early 60s. 209 00:30:42.480 --> 00:30:50.420 Mark Kushner: We know these transmitters are affecting the natural environment, because we see this… we see them turn on, we see the radiation depleted. 210 00:30:51.400 --> 00:31:01.209 Mark Kushner: We may have never seen a pristine natural radiation environment. By the time we had satellites up in space to look at it, we were already affecting it through our BLF transmitters. 211 00:31:01.850 --> 00:31:11.400 Mark Kushner: So… our best bet on seeing a pristine radiation environment may not even be looking at Earth. It's going to another planet where we have yet to do that. 212 00:31:11.580 --> 00:31:22.279 Mark Kushner: Of course, the other planets, you know, we do… you do a lot of planets here at Michigan. The other planets have their own challenges. Insanely strong magnetic fields, or… 213 00:31:22.570 --> 00:31:27.580 Mark Kushner: other challenging radiation environments, but… Is? 214 00:31:27.700 --> 00:31:34.080 Mark Kushner: the physics of Earth's radiation belts, the space environment here. Is that universal, or is that… 215 00:31:34.520 --> 00:31:42.700 Mark Kushner: Unique to us because of how we shaped it through our activities. I can't answer that question, but there is a question mark there. 216 00:31:43.290 --> 00:31:52.680 Mark Kushner: There is, in fact, question whether or not the slot region, this is the region between the inner and outer radiation belts, is partially 217 00:31:52.880 --> 00:32:02.699 Mark Kushner: due to VLF enhancement from these transmitters. Did we, in fact, accidentally, unintentionally, create a feature of our own magnetosphere? 218 00:32:03.510 --> 00:32:15.189 Mark Kushner: And there are some evidence that slot regions do occur naturally, radiation observations from outer planets, but the degree to which ours is present and enhanced is suggestive. 219 00:32:18.970 --> 00:32:35.489 Mark Kushner: But there has been some excellent work in the last decade showing that VLF power being generated in the atmosphere on the ground propagates into space, bounces around, and populates a good region of space just in this area. Particularly on the night side. 220 00:32:35.680 --> 00:32:48.880 Mark Kushner: Not so much on the day side, having to do with changes in the ionosphere conditions, but it's a very interesting interaction between human technology, communications, and space environments that we didn't really plan on. 221 00:32:52.640 --> 00:32:54.660 Mark Kushner: Getting to a smaller scale. 222 00:32:54.920 --> 00:33:01.769 Mark Kushner: But it's still a very important thing to me, is, what happens when you have a spacecraft in space? 223 00:33:01.890 --> 00:33:16.500 Mark Kushner: We put a spacecraft in space because we're interested in examining something. We want to measure a magnetic field, we want to measure a charged particle, we want to take a picture of something. We put it out there for a reason, but we get unintended side effects as well. 224 00:33:16.890 --> 00:33:27.640 Mark Kushner: It turns out, and recent observations are bearing this out more and more, that the interaction between the natural environment and the satellite itself is creating a new source of noise. 225 00:33:27.940 --> 00:33:32.219 Mark Kushner: It was long been known that satellites charge up in space. 226 00:33:32.220 --> 00:33:49.290 Mark Kushner: You put something going from light to dark, it charges up due to photo emission. You get something sending in the way of an injection of charged particles during a magnetospheric substorm or something like that. It charges up due to that. We observe extreme charging above 1,000 volts 227 00:33:49.290 --> 00:33:52.949 Mark Kushner: at jail on some satellites that Los Alamos runs, for example. 228 00:33:53.130 --> 00:34:06.870 Mark Kushner: Well, when you put a big voltage on something, as you may know, eventually it can discharge, especially when you have an awkwardly shaped geometry. Satellites often are not designed to be friendly to electrical charging, they're designed to get the job done. 229 00:34:07.160 --> 00:34:17.290 Mark Kushner: So, when you have… certain geometries can lead to electromagnetic discharge arcing, between two points that are strongly differential… differentially charged. 230 00:34:17.530 --> 00:34:29.210 Mark Kushner: That's, you know, where the charge goes from one place to another to nullify the difference. When that happens, a rapid transfer of charge from one place to another is basically the lightning bolt. 231 00:34:29.370 --> 00:34:33.899 Mark Kushner: And a lightning bolt emits radiation across a fairly broad range. 232 00:34:34.350 --> 00:34:44.219 Mark Kushner: Just recently, something that caught my eye was a clickbait, headline, but it… a dead NASA satellite that sent a strange radio signal to Earth. 233 00:34:44.800 --> 00:34:46.020 Mark Kushner: Did it? No. 234 00:34:46.520 --> 00:34:50.459 Mark Kushner: What happened was a defunct satellite from the 60s 235 00:34:50.870 --> 00:34:59.579 Mark Kushner: Built up a lot of electric charge, and discharged an unprecedentedly large electromagnetic pulse from an… or electrostatic discharge. 236 00:34:59.740 --> 00:35:05.249 Mark Kushner: And it was… Faster rise time and more intense than anything we'd ever seen. 237 00:35:05.770 --> 00:35:12.429 Mark Kushner: Hey, things… nature occurs along spectrums. There are a lot of small things, and a few large things. 238 00:35:12.600 --> 00:35:20.049 Mark Kushner: Well, the more satellites we add to orbit, the more we are going to see the larger end of the spectrum. We are exposing ourselves to more and more of the tail. 239 00:35:20.760 --> 00:35:26.649 Mark Kushner: A recent study by some of my colleagues at Los Alamos revealed that on the… 240 00:35:26.920 --> 00:35:33.890 Mark Kushner: STPSAT 6, Space Test Platform Satellite 6, there was a radio receiver. 241 00:35:34.250 --> 00:35:40.750 Mark Kushner: And, radio receiving is one of the phenomenologies we're very interested in at Los Alamos. 242 00:35:41.040 --> 00:35:44.349 Mark Kushner: And they kept seeing noise. 243 00:35:45.000 --> 00:35:53.439 Mark Kushner: When they'd see electron fluxes come in at the satellite, because there was a charged particle sensor on it, they would correlate, see big bursts of electro-noise. 244 00:35:53.860 --> 00:35:58.890 Mark Kushner: This is different… differentiatable from the natural things we're interested in. Here's lightning. 245 00:35:59.550 --> 00:36:12.909 Mark Kushner: This is what lightning looks like in a radio receiver. This is an impulsive discharge from satellite. We see these things all the time. And so we have a radio receiver out there trying to do science that is constantly getting shocked when the natural environment enhances itself. 246 00:36:13.970 --> 00:36:16.729 Mark Kushner: It turns out, you know, this… 247 00:36:17.120 --> 00:36:35.320 Mark Kushner: That NASA satellites radio signal? That was observed on the ground by the Murchison Widefield Array in Australia. That's a radio astronomy experiment. So these are not just, I've got a sensor here and a sensor here, and I'm seeing the signal. This is over hundreds of kilometers distance. 248 00:36:35.890 --> 00:36:54.509 Mark Kushner: So what you see is that these discharges are ever increasing… going to increase in frequency because there are just more satellites out there. It is already observed to create some extreme and confusing signals. This thing did not look like any ESD we'd ever seen before, and it's just going to continue to increase, so… 249 00:36:54.620 --> 00:36:56.849 Mark Kushner: That offers a possible 250 00:36:57.110 --> 00:37:06.510 Mark Kushner: Increase in the natural radio background, which will affect ground-based radio astronomy and ground-based, or space-based studies of things like lightning. 251 00:37:06.990 --> 00:37:09.509 Mark Kushner: And other, important phenomena. 252 00:37:10.630 --> 00:37:13.729 Mark Kushner: And… we're just starting to get a handle on it. 253 00:37:14.320 --> 00:37:17.289 Mark Kushner: Because I will tell you one thing, 254 00:37:18.070 --> 00:37:33.639 Mark Kushner: This is a little tong-in-cheek, but if you ask a satellite operator if there are any problems with the satellite, the answer is no. They do not charge, there have never been any issues with charging, and it's working just fine, thank you. So, I would say the first key to solving a problem is admitting you have a problem. 255 00:37:37.240 --> 00:37:41.800 Mark Kushner: But that still is not the full story of it. 256 00:37:42.160 --> 00:37:54.970 Mark Kushner: In fact, some even more recent papers, 2425, have revealed observations that are showing there is a significant uptick in the presence of so-called unintended electromagnetic radiation in space. 257 00:37:55.390 --> 00:38:01.260 Mark Kushner: This directly correlates with the second generation of… first and second generation of Starlink satellites. 258 00:38:03.740 --> 00:38:19.739 Mark Kushner: And again, we're back… we're in the VHS range now, instead of VLF. So you see we've got this radio frequency stuff all over the place. But what has happened is the Starlink satellites, all 10,000 of them, are designed for communicating and transmitting information. 259 00:38:19.910 --> 00:38:36.849 Mark Kushner: And they are hardened to prevent noise in their operating modes. But there is… there are unintended effects to everything. It turns out that these things generate noise in a frequency band that they didn't expect. And this is okay, because the… this is okay by law. Because… 260 00:38:36.880 --> 00:38:53.689 Mark Kushner: The regulation just says you have to mitigate what you know about. If it is an unintended electromagnetic effect, well, that sucks, but, just keep on doing what you're doing. So, the recent studies have shown that there is a significant increase in 261 00:38:53.850 --> 00:38:55.060 Mark Kushner: background. 262 00:38:55.340 --> 00:38:58.069 Mark Kushner: from the Starlink satellites in the 263 00:38:58.310 --> 00:39:08.980 Mark Kushner: 30 to approximately 200 kilohertz range. And this has been… Increasing, increasing, increasing over… 264 00:39:09.190 --> 00:39:17.340 Mark Kushner: past couple of years, and in fact, with the ever-increasing number of Starlink satellites in space, it is increasing 265 00:39:17.470 --> 00:39:21.660 Mark Kushner: Pretty much… Proportional to the number of satellites in space. 266 00:39:22.190 --> 00:39:29.739 Mark Kushner: Which is an interesting problem. It's… it's actually… the noise floor is increasing as, you know, 10 log number of satellites, so… 267 00:39:29.880 --> 00:39:34.250 Mark Kushner: if the Starlink satellites get to where we are expecting them to be after 268 00:39:34.520 --> 00:39:40.549 Mark Kushner: full constellation deployment, it's gonna be… the noise floor is going to be another 5 to 7 decibels up above where it is right now. 269 00:39:41.050 --> 00:39:50.779 Mark Kushner: But this really means that… Additional lightning and radio science investigations may be challenged by 270 00:39:50.990 --> 00:39:56.769 Mark Kushner: Just the natural… natural quote-unquote background due to human activity, the anthropogenic background. 271 00:39:57.010 --> 00:40:01.270 Mark Kushner: We are modifying the entire system we are attempting to investigate. 272 00:40:01.790 --> 00:40:06.250 Mark Kushner: Thus making it more difficult to do what we wanted to do in the first place. 273 00:40:06.710 --> 00:40:19.970 Mark Kushner: And this is in addition to a well-known impact of Starlink satellites at optical frequencies. You put up a bunch of satellites in space, they're gonna get in the way of your telescope. That's just something we know. Starlink flashes are thankfully not as big of a thing anymore, they started painting them black. 274 00:40:20.150 --> 00:40:33.369 Mark Kushner: But there is a broad spectrum unintended impact on electromagnetics due to our population of space with observing platforms, communication platforms, and other resources. 275 00:40:35.820 --> 00:40:40.540 Mark Kushner: I just wanna… Quick shout out to one final! 276 00:40:41.130 --> 00:40:43.250 Mark Kushner: Implication here. Give me a second. 277 00:40:49.500 --> 00:40:56.159 Mark Kushner: If you're ever standing by the side of a road, or something, and you feel traffic go by, you feel the wind breeze by your cheek. 278 00:40:56.440 --> 00:41:03.690 Mark Kushner: Or if you're playing baseball or something, and somebody throws it, it just goes right by you. Something fast, you feel it. 279 00:41:03.760 --> 00:41:19.099 Mark Kushner: Okay, well, it turns out in space, if you feel… if satellite goes by you really fast, you feel it. You just don't feel it in the same way, right? In space, no one can hear you scream, and no one can feel you move, but there is actually an electromagnetic signature about this. 280 00:41:19.130 --> 00:41:37.690 Mark Kushner: I was actually in a lab earlier, and I saw the word CINTRA written on a shelf there. Maybe Michigan has some actual involvement in this program, which would just be another tie-in. But the Intelligence Advanced Research Project Agency, a couple years back, launched a new program called CINTRA, where the purpose of CINTRA was to look for signatures of objects moving in space plasmas. 281 00:41:37.690 --> 00:41:42.509 Mark Kushner: They were interested in finding the things in space that didn't want to be seen. 282 00:41:42.650 --> 00:41:51.330 Mark Kushner: Because even if you have a stealthy something, if you create a ripple, the ripple is gonna ripple, and you're gonna see it. 283 00:41:51.540 --> 00:41:55.870 Mark Kushner: And so, this is a classic, challenge, actually. 284 00:41:56.050 --> 00:41:58.969 Mark Kushner: in stealth, too. You can make a… 285 00:41:59.360 --> 00:42:15.419 Mark Kushner: An airplane looked really small, but it is still the size of an airplane. So as long as you can see the effects it's having on its environment, it doesn't matter how bad your radar is at it. So Cintra started supporting research into looking at the signatures of satellites moving through space plasmas. 286 00:42:15.610 --> 00:42:17.600 Mark Kushner: Theirs was actually… 287 00:42:18.020 --> 00:42:36.950 Mark Kushner: focused on a very novel theory of solitons. For those of you who are not familiar, solitons are a combination of many different plasma physics processes in a nonlinear state, where a disturbance that would… you'd think of it as being a wave actually kind of crests up and just moves along on its own. 288 00:42:37.010 --> 00:42:51.419 Mark Kushner: It's a nonlinear disturbance where steepening balances out dispation, and it all just goes. And so it's a really cool, really clever, really difficult theory to get a handle on. But they said, we think it's possible, so we want to investigate this. 289 00:42:51.490 --> 00:43:01.349 Mark Kushner: So they started supporting researchers to look at this. And a team at the University of Alaska Fairbanks, on the left there, did a, used 290 00:43:02.210 --> 00:43:18.480 Mark Kushner: the swarm satellites, that's a European Space Agency, I think, used radio receivers upon the swarm satellite and correlated swarm close approach with different space objects. I told you earlier, we're tracking space objects, there are lots of them. 291 00:43:18.480 --> 00:43:22.630 Mark Kushner: Well, we know where they are, and we know where the storm satellites are, so we can see when they come in close. 292 00:43:22.780 --> 00:43:31.450 Mark Kushner: And here, they saw a Starlink satellite come by, so… Starlink satellite comes by, big radio pulse. Uradium satellite, radio pulse. 293 00:43:31.780 --> 00:43:43.509 Mark Kushner: Another Starlink satellite, radio pulse, this… they claim that's right. Okay, I'll give it to them. But the argument here being that all of these space objects, satellite, satellite, satellite, piece of junk. 294 00:43:45.190 --> 00:43:57.330 Mark Kushner: that was a former… it's a defunct Russian communication satellite, all disrupted the electromagnetic spectrum as they pass by. This is not because they are transmitting, this is just by the very fact that they're moving. 295 00:43:57.640 --> 00:44:01.330 Mark Kushner: You may know that a conductor in a plasma 296 00:44:01.650 --> 00:44:20.400 Mark Kushner: disrupts the plasma around it. On a very basic electromagnetics level, you know, if you put a dielectric in an electric field, it bends the electric field lines. Put diamagnetic, it bends the magnetic field lines. Well, a satellite is both. So you put it in there, and it's going to change the environment really close by. But then you start it moving, and you start it moving at orbital speeds. 297 00:44:20.580 --> 00:44:38.119 Mark Kushner: 7 plus kilometers a second. That is A a disruption, and it's B is a strongly Doppler-shifted disruption. That orbital velocity pushes that into the kilohertz range, which is what we are seeing here. So what you have is, just by the very nature of satellites moving through space. 298 00:44:38.550 --> 00:44:46.500 Mark Kushner: creating a bunch of kilohertz noise because they are just present. So you're basically… your satellite is hearing other satellites whistling by it at high speeds. 299 00:44:46.990 --> 00:45:01.710 Mark Kushner: It's great if you're trying to identify the satellites going by, but it's terrible if you're trying to have a pristine, quiet radio background. And it's interesting if your problem in space is VLF waves, because now you've got a lot of new VLF noise. 300 00:45:02.880 --> 00:45:07.069 Mark Kushner: Another study done by a group at, 301 00:45:07.650 --> 00:45:10.710 Mark Kushner: Oh, they're not called that. Orion Space Systems. 302 00:45:11.030 --> 00:45:24.289 Mark Kushner: I'll just call them Astra, but they found a strong correlation between periods when the Arasi satellite, which is a Japanese research satellite, was near objects and 303 00:45:24.840 --> 00:45:34.430 Mark Kushner: versus when it wasn't near objects, they found a statistically highly significant correlation, increased VLF activity from the presence of satellites as to the non-presence of satellites. 304 00:45:34.470 --> 00:45:47.379 Mark Kushner: So that was a statistical confirmation that these results from the Alaska study, which is just a few cherry-picked results, that this is indeed the case. Satellites are seeing more noise due to the presence of other satellites. 305 00:45:48.810 --> 00:45:54.030 Mark Kushner: And, you know, IARPA's program actually shows that's an opportunity to solve another problem. 306 00:45:54.300 --> 00:45:56.599 Mark Kushner: And in fact, when I was working with NASA, 307 00:45:56.650 --> 00:46:10.530 Mark Kushner: We viewed space dust and space debris as an opportunity, because it is another signature of the space environment. If that space dust, space debris couples to the space environment, you can study that to get understanding of the space environment. 308 00:46:10.530 --> 00:46:24.209 Mark Kushner: If I don't know what the electromagnetic fields are, but I know what this chunk of junk is doing, I can use that chunk of junk to watch what everything else is doing. It's a tracer. So there are opportunities for clever people to take these changes to the environment that we're making. 309 00:46:24.210 --> 00:46:27.650 Mark Kushner: Whether intentionally or unintentionally, and to do something with it. 310 00:46:27.700 --> 00:46:39.420 Mark Kushner: But scientists in the space environment moving forward need to be aware that we are affecting it, and some of the things we've learned, like, some of the things that we think are true, may not be as true today. 311 00:46:41.340 --> 00:46:43.870 Mark Kushner: So… Outlook here. 312 00:46:44.310 --> 00:46:49.870 Mark Kushner: I think this is an incredibly interesting and challenging time for space science, and not just because of the funding issues. 313 00:46:50.030 --> 00:46:58.879 Mark Kushner: Not only do we have proliferative measurements and interest from diverse stakeholders, everything is in space these days. Communications, internet. 314 00:46:59.330 --> 00:47:05.309 Mark Kushner: Imagery, national security, commercial, science, it's all up in space. 315 00:47:05.740 --> 00:47:12.029 Mark Kushner: But it's getting more and more complex due to the interaction and feedback between us and the environment we're observing. 316 00:47:13.490 --> 00:47:23.689 Mark Kushner: So space, I argue, cannot be considered a pristine natural laboratory. It may have never been a pristine natural laboratory for us. It just may have been good for some applications. 317 00:47:24.220 --> 00:47:27.820 Mark Kushner: But unless priorities and geopolitics change abruptly. 318 00:47:27.970 --> 00:47:37.860 Mark Kushner: We are going to have to come to terms with this complexity. We are going to keep adding satellites to orbit, we are going to keep operating these constellations, we are going to keep having unintended consequences. 319 00:47:38.470 --> 00:47:42.240 Mark Kushner: Historical results, based on our understanding of the environment. 320 00:47:42.340 --> 00:47:47.890 Mark Kushner: In 1960 may no longer hold, and in 2030, or even sooner. 321 00:47:48.120 --> 00:48:06.930 Mark Kushner: And so, what we understand and what we think we know about the environment may need to be revisited as we come to grips with the changes that we are causing. That is a great opportunity for people, but it is also a challenge, because we base our future science on the science we've done in the past. If we can't always stand on that. 322 00:48:07.540 --> 00:48:09.510 Mark Kushner: That leaves us on shaky ground. 323 00:48:10.950 --> 00:48:12.030 Mark Kushner: So, thank you. 324 00:48:18.380 --> 00:48:29.780 Mark Kushner: We certainly have some time for some questions. Mark, I think we do need to pass around the mic, right, to make sure people assume here. So I'll walk around with this, and any questions for our speaker? 325 00:48:37.040 --> 00:48:47.500 Mark Kushner: Thanks for your talk. I just wanted to ask about the dusty plasma discussion. I can imagine how that would impact, on a sort of fundamental physics textbook level, like. 326 00:48:47.800 --> 00:49:04.949 Mark Kushner: physics of the space environment near Earth, but are there particular technologies or other sort of implementation concerns that would change? Like, are there things we rely on working some way that would not work that way if it was a dusty plasma? So, I can't tell you, for example, if it would impact 327 00:49:04.950 --> 00:49:13.949 Mark Kushner: Well, it would impact, for example, antenna coupling and transmission, so it would impact how we communicate through Smith. I don't know if it would have a significant impact. 328 00:49:14.040 --> 00:49:33.890 Mark Kushner: on that. It would change the environment you're trying to measure. I don't know. There are scientists here who are probably more qualified than me to address some of the downstream impacts of that, but if you're trying to measure a plasma… making assumption for a Langer probe, for example, maybe some of your fundamental assumptions about the plasma behavior are no longer valid. 329 00:49:34.020 --> 00:49:49.059 Mark Kushner: It's a beautiful instrument, but you would have to re-examine how a plasma sheath is formed and what the characteristics of that sheath are before you analyze plasma characteristics out there. So it definitely would have impacts on science. I don't know what the impacts would be on particular infrastructure. 330 00:49:51.250 --> 00:49:54.680 Mark Kushner: Other questions over here on maintaining… 331 00:49:58.460 --> 00:50:08.740 Mark Kushner: Jesse, thank you for this talk. So, if you could propose an enforceable regulation, what would it be? Would it be the number of satellites? 332 00:50:08.740 --> 00:50:27.310 Mark Kushner: you know, some formula of number times size of satellites? What would it be? That's a really interesting question, because as the talk highlighted, there are a variety of ways in which this growth of space activity is creating problems. I don't… I'm not gonna say I think that that is… 333 00:50:27.310 --> 00:50:32.269 Mark Kushner: we should stop face activity at all. I'm not arguing for that at all, I'm just saying to be aware of it. 334 00:50:32.470 --> 00:50:44.010 Mark Kushner: for the area of space debris, I think, for example, that is a matter of being responsible, when we're moving into that way. We have deorbit regulations. You have to… if you put something up, you need to be able to bring it down. 335 00:50:44.240 --> 00:50:59.690 Mark Kushner: But we also need to be committed to not blowing things up, which is strangely a problem. But, because, as you saw, the Chinese ASAT test increased the amount of, debris. A Russian ASAT test also decreased the 336 00:51:00.070 --> 00:51:19.809 Mark Kushner: Let's be honest, a USAST test also decreased… increased the amount of debris. But, we did it first, and then we knew that we shouldn't do it again. Other people did not trust us on that. But that's the challenging thing between science and geopolitics. Just because you know something shouldn't be done, sometimes you have to do it to prove a point. 337 00:51:20.050 --> 00:51:22.719 Mark Kushner: At least that's the political perspective. 338 00:51:23.140 --> 00:51:27.030 Mark Kushner: What I would propose is… we should… 339 00:51:27.580 --> 00:51:29.129 Mark Kushner: Learn from what we were doing. 340 00:51:29.350 --> 00:51:31.850 Mark Kushner: We are doing what we're doing right now, great. 341 00:51:32.210 --> 00:51:40.279 Mark Kushner: Let's learn from what we're doing, and build it into the future. You're emitting extra noise? Let's try to engineer around that. You're… 342 00:51:40.730 --> 00:51:53.270 Mark Kushner: you're defunct all… your satellites are going defunct all the time? What's the problem there? And specifically, actually, there's a class of Russian satellites that have tendency to blow up. And so, can we engineer that away? I hope so. I mean, our satellites aren't routinely blowing up. 343 00:51:53.390 --> 00:52:01.020 Mark Kushner: And so, by learning from it, we aren't going to change what has happened, and we are in fact not going to convince 344 00:52:01.460 --> 00:52:12.100 Mark Kushner: Commercial industries to start lining all of their satellites with conductive coating to equalize out all of the charging and eliminate discharge, and 345 00:52:12.100 --> 00:52:27.240 Mark Kushner: And that wouldn't work, because you want to put an antenna out. That's going to… antenna and a hard body, that's going to give you a 90-degree kink, or something, and that's going to be a cost that's going to get discharged sometime, maybe. Or if you have two different materials. That is unlikely to happen, but what you can learn about it is… 346 00:52:27.290 --> 00:52:48.679 Mark Kushner: You can learn from the experiences thus far, you can build it into the mitigation, and if you do it from the start, you can decrease the cost of doing it. Because ultimately, what we need to do is, we as scientists and engineers need to present solutions to industry that solve the problems and don't introduce a ridiculous amount of costs, because that's the only way that we are going to get adopted. 347 00:52:48.680 --> 00:52:49.820 Mark Kushner: People… they don't… 348 00:52:50.200 --> 00:53:05.089 Mark Kushner: They don't want to cause problems, and they do not like to be held up and said, oh, look at this, you're destroying optical astronomy. That's an example of, we heard you, it's… we are going to keep putting up our satellites, but we're going to try to mitigate your problems. 349 00:53:05.140 --> 00:53:10.300 Mark Kushner: They are… they will listen if we learn about what the problems are and present them with possible solutions. 350 00:53:13.740 --> 00:53:33.160 Mark Kushner: Thank you for a wonderful talk. So a lot of these problems are framed as sort of an accidental manipulation of the space environment that we want to avoid, but are there any potential use cases for very deliberate in-situ manipulation of the space environment, either commercially or for research purposes? That's an interesting… 351 00:53:33.620 --> 00:53:48.330 Mark Kushner: So for research purposes, the answer is definitely yes. One of the best examples, I'd say, is you might be familiar with the HARP experiment. It's a high-altitude rural radio, project, where they, auroral research project. 352 00:53:48.330 --> 00:53:55.460 Mark Kushner: Which was a giant antenna that dumped radio waves into the atmosphere and heated up, heated it up. 353 00:53:55.460 --> 00:54:06.070 Mark Kushner: And, for example, what they found was you could create auroral electrojets, that is, aurora-like electrical currents flowing in the ionosphere just by modulating that, and then you could 354 00:54:06.070 --> 00:54:20.539 Mark Kushner: Theoretically, you could send signals around the world for communications, you could actually… the idea was that you could maybe modulate at just the right frequency to launch Whistler waves into space that would cause radiation belts to empty themselves out. 355 00:54:20.800 --> 00:54:39.800 Mark Kushner: This is a problem, I won't get into too many details, but it's a problem of interest to Los Alamos National Laboratory. What happens if you had a starfish-like event where there is an artificial radiation belt? I told you, within 6 months, most satellites in orbit were dead. We don't want most satellites in orbit to die, so can we save them? 356 00:54:40.150 --> 00:54:52.049 Mark Kushner: Well, one way to do that would be to remediate the radiation belt, remove all of those nasty energetic electrons. But how do you do that? You need some way to introduce, say, VLF waves into them. 357 00:54:52.280 --> 00:54:56.970 Mark Kushner: HARP and manipulation of the ionosphere using HARP was one method of doing that. 358 00:54:57.110 --> 00:55:09.039 Mark Kushner: I mean, this comes in the… you have already have a problem due to human interactions, can I fix it? But that is a case where you could use it for good, as opposed to ill. 359 00:55:09.230 --> 00:55:11.900 Mark Kushner: Finding more commercial 360 00:55:12.220 --> 00:55:18.739 Mark Kushner: It's an interesting and growing area. I think we're in the nascent science stage of it right now, where we need to develop out the applications. 361 00:55:21.240 --> 00:55:37.979 Mark Kushner: Very nice talk. Wanted to ask, how, is there a way to predict the movement of this incoming dusty plasma, over, like, satellite orbital bands, or… 362 00:55:38.170 --> 00:55:51.549 Mark Kushner: So, yeah, that's an interesting question. One thing we do know is, since the majority of satellites are concentrated in a specific region, LEO orbits below, like, 800 kilometers, that's where the majority of this stuff is concentrated. 363 00:55:51.740 --> 00:55:57.159 Mark Kushner: The Orbital Pre-Program Office at NASA, these are the people who is tasked with understanding 364 00:55:57.320 --> 00:56:07.330 Mark Kushner: debris, all debris. Really amazing group of people, radically understaffed and radically underfunded, but… They, 365 00:56:07.470 --> 00:56:25.059 Mark Kushner: you know, they know where all of the debris is in altitude, and it peaks in the 500-ish range. So we know, generally speaking, if there's this cascade of debris from large scales to small scales through interactions, that's probably going to be… where the big stuff is, is probably where the small stuff is, and then it kind of just trickles down over time. 366 00:56:25.270 --> 00:56:36.019 Mark Kushner: So you think it's probably… majority of it is in this… where the majority of the satellites are. We can't… we can't directly sense it with traditional measurements. There are dust sensors. 367 00:56:36.020 --> 00:56:51.660 Mark Kushner: the IMAP mission to the Lagrange Point that just launched last week, I think, has a dust detector on it, for example, and there are other missions with dust detectors, like Park Solar Probe. So dust is something we measure and detect, it's just not something we frequently look for by Earth. 368 00:56:52.050 --> 00:57:06.410 Mark Kushner: And I think right now, again, I think it's still too early for us to be looking at it for there, but when and if, that comes to pass, that we start seeing effects, then that could be routinely monitored and used, using existing technologies. 369 00:57:08.590 --> 00:57:18.920 Mark Kushner: If you have time for maybe one more quick question. Aaron raises his hand, you know it's not going to be quick, but we'll get it. I'll do it, I'll do a quick one. I'll do it. 370 00:57:19.080 --> 00:57:21.480 Mark Kushner: One question, at least. One, one question. 371 00:57:21.660 --> 00:57:25.639 Mark Kushner: Let me debate about which one I would like to hear. Sure. So the… 372 00:57:25.870 --> 00:57:43.850 Mark Kushner: The last thing… one of the last things that you talked about was the ability of satellites to basically detect when another satellite goes by, and that the plots that you showed are sort of like… what I inferred was, you knew that the satellite was close, so you went and looked at the data. Yes. 373 00:57:43.930 --> 00:58:02.460 Mark Kushner: And you do the opposite, and then look at the data and say, aha, was there a satellite closed? And then go back and check. That is actually, I believe, the end… the desired end state of that research is to, oh, I see something anomalous in my radio data. That was probably a satellite. Let's look and see. 374 00:58:02.460 --> 00:58:05.779 Mark Kushner: You want to see, is something coming close? There's… 375 00:58:06.400 --> 00:58:12.529 Mark Kushner: You might hear on the news every once in a while, oh, a satellite moved closer to another satellite, and people are very interested in that. 376 00:58:12.580 --> 00:58:27.899 Mark Kushner: And so the desired end state there, yes, is to say, I see the sign of a disruption nearby, let's look. Right now, they had to prove out the idea that there is a disruption nearby, and then the statistical work proved that, yes, in general, you see more… 377 00:58:27.970 --> 00:58:33.890 Mark Kushner: And now I think we need to… and they are working on that problem of inverting it. I think it's going to be a big data AI problem. 378 00:58:34.240 --> 00:58:38.050 Mark Kushner: But it… it's definitely one that's addressable. 379 00:58:39.790 --> 00:58:45.179 Mark Kushner: I think we're out of time here, so let's give our speaker one last big round of applaud. 380 00:58:54.510 --> 00:59:08.920 Mark Kushner: Then you can, like, not.