 Thank you so much for joining this morning. My name is Josh Walney, and I am a project manager at SecureWorld Foundation, and today I'll be moderating this webinar about small satellites and space weather. Briefly, I'll say that SecureWorld Foundation is a private operating foundation that focuses on the long-term sustainable peaceful uses of outer space. In our work, SecureWorld spans many different parts of the space community, from national security to space applications, exploration, and to where we are today at the juncture of scientific space weather and the Virginia Small Satellite Community. So, this event was originally going to be held in person at the Small Satellite Conference in Utah, so I want to welcome all those small satellite attendees and say that we hope to connect with you here today, but also hope to connect with you in person next year. So, with that, briefly, I'll go over our agenda and introduce our speakers, and then we'll get into it. So, we're going through the intro right now, and then we'll have about 10-minute or 10-minute panelist presentations, and we'll then come to the question and answer period at the end. Like I said, my name is Josh Walney. I'm a project manager at SecureWorld Foundation. Our first speaker will be Tom Berger, who is the executive director of the Space Weather Technology Research and Education Center at the University of Colorado, Boulder. Tom is a solar physicist by training with degrees in mechanical engineering and astrophysics from Stanford University. He previously worked at Lockheed Martin Solar and Astrophysics Laboratory in Palo Alto, California, where he was a co-investigator for the Japanese U.S., U.K., Hinoe Day Mission that launched in 2006. Tom is also a project scientist for the Daniel K. Inouye Solar Telescope at the National Solar Observatory and the director of NOAA's Space Weather Prediction Center from 2014 to 2017, before coming to CU Boulder and leading the Space Weather Trek program. Our second speaker will be Sean Burnsma, who is a geologist by training, and he got his PhD in Aerospace Sciences, both at the Technical University of Delft, Delft in the Netherlands. He was a research engineer at the service there on the main from 1998 to 1999, where he started upper atmospheric modeling, and then since 2000 he has worked at the French Space Agency, CNES, on topics such as precise orbit determination, satellite drag, modeling, and space weather. Our third speaker will be Janet Green. Janet realizes and specializes in understanding the damaging effects of space weather on satellites. She received her PhD in Space Physics from UCLA, where she studied the physics that controls the radiation environment that surrounds her. She spent almost 10 years at NOAA where she led satellite anomaly investigations, monitored the radiation data from NOAA satellites, and developed products and tools for assessing the real-time radiation hazards. She now continues this work on the radiation environment and its hazards as a founding owner of Space Hazards application. And lastly is Matt Angling. Matt is the ionospheric program lead for Spire Global. Previously, he was a kinetic fellow and then the Royal Academy of Engineering and Defense Science and Technology Laboratory Professor in Space, Environment and Radio Engineering at the University of Birmingham. In all of these roles, his focus has been understanding and mitigating the impact of ionospheric space weather on communications, navigation, radar, and other RF systems. So thank you to my panelists for joining me. And I will just go over one more bit of housekeeping, which is how to ask questions in Zoom here. I'm sure we're all experts at this point, but just to go over it, you'll see at the bottom of your screen, if you're an attendee, there's a button that says Q&A. And so if you have a question, your first step is to click that button and it will bring up a separate window for question and answer. And so look and see. You can see other questions that have been asked. You can upvote questions. You can't downvote at this point. We'll see if they put that into the future use. But right now you can upvote questions. And then if you don't see a question that's already been asked, or a question you can answer and keep it short and simple, please, I will be moderating these throughout. And at the end, we'll try to get as many as possible. So with that, thank you all very much for joining. Let me just do an audience check. We're at about 140 people. So greetings to all of you who joined us after I started. And now I'll pass it off to Tom for an intro about what space weather is. And thank you so much, Tom. Thank you, Josh. Audio check. Can you hear me? Sounding good. Great. Thank you very much to everyone for attending today. I'm Dr. Tom Berger, as Josh said, from the University of Colorado. And in the interest of time, I'm going to jump right ahead to our next slide if I can. Did you give me the mouse, Josh? I did. I'll start you there and see if that picks up. OK, and there we go. So just very quickly, for the purposes of this conference, where we're talking mostly about satellites in orbit, we're going to be defining space weather as the variation of photon radiation, charged particle radiation, which is basically electrons, protons, and energetic ions, and magnetic fields, plasma density, and upper atmosphere composition in near-Earth space. And by near-Earth space, we mean, again, all orbits, basically, from Leo to Geo, all the way out to Cis Lunar, where there's going to be increasing activity in the next decade or so, we think. And space weather, this variation in all these physical parameters is really caused by two major interactions. One, the interaction of the Earth's magnetic field and atmosphere with outputs from the sun. And the other from propagating disturbances from the lower atmosphere, which actually can make their way up into near-Earth space. So this talk will be broken down into those two pieces. We'll start by talking about the sun and how it influences the Earth's environment. And then we'll end briefly with a discussion of the lower atmosphere and its propagating disturbances, which we sometimes refer to as space weather from below. So moving right along here, we have the sun is a magnetic star. So this is really the key to why the sun creates space weather in our planetary system. The magnetic field can be seen in general when you look at the sunspot, when you look at the sun in white light, for instance, you see sunspots, these dark regions on the sun. If you then measure the magnetic field of the sun and take what we call a magnetogram or a picture of the magnetic field, you see that sunspots are actually these very intense magnetic fields. Black is negative polarity, in this case, white positive polarity. Opposite polarity is interacting very closely to create these sunspots. And where you see opposite polarity magnetic fields interacting, you can get magnetic reconnection and therefore activity in the form of eruptions and flares and CMEs. And so we'll talk a little bit about those. But first, it's important to know that the sun goes through a magnetic cycle. Every 11 years or so, the number of sunspots peaks and then wanes over this regularity, which has occurred now for 25 numbered cycles with cycle number one in about 1760. We've gone through cycle 24. We are right now, as you can see around 2020, just at the beginning of cycle 25, as we call it. We're starting to see the first sunspots from cycle 25. What you see on the plot there for cycle 25 are predictions, which show that we don't expect it to be much stronger than cycle 24, which was a fairly weak cycle. But these are just predictions, predicting the solar cycle and the strength of each sunspot cycle has its vagaries. And we're not really sure what we're gonna get for cycle 25. So anyway, it's important to know that every 11 years you get this peak, we're heading towards the peak in about three to four to five years of cycle 25. Right now it's very quiet. Looking ahead, we see that, whoops, let's go back, sorry. So what does the magnetic field of the sun do? The main thing it does is that it heats the outer atmosphere of the sun. The sun's surface is about 6,000 degrees Kelvin. The outer atmosphere of the sun or the corona, as you see on the left there is about a million degrees. So the magnetic field churning through the atmosphere of the sun heats the outer corona to about a million degrees. This in turn causes a solar wind to constantly flow out from the sun. Oops, I'm sorry about that again, trying to start this movie here. Oh well, that movie was the solar wind flowing out from the sun. The other thing that the magnetic field does is it builds up a lot of energy in those sunspot active regions, which eventually can erupt in the form of very large, what we call magnetic eruptions. And those magnetic eruptions are the major things we call, they cause photonic output in the form of flares. Those flares can send out both x-rays, extreme ultraviolet radiation. And we classify flares briefly in these sort of ABC, M and X logarithmic scales that you see on the right. These are measured by the NOAA GOES satellites and reported when they occur by the Space Weather Prediction Center here in Boulder on that scale. So not only does the solar magnetic field heat the outer atmosphere, but it occasionally gets in these sunspot active regions, gets twisted up into very energetic configurations, which then erupt in the form of these magnetic eruptions, causing both x-ray flares. And as you'll see from mass ejections, the x-ray flares, however, are the main cause of radio absorption in the ionosphere. So when those big flares go off, they send out a lot of x-rays and a lot of extreme ultraviolet light. That in turn ionizes the upper atmosphere of the earth, very much more so than it normally is ionized. And you get radio absorption, particularly in the high frequencies from about five to 40 megahertz over the course of a few hours as that sun lit side of the earth is bombarded by the x-rays from the flares. Over the horizon radar was also affected by these events. And they can also put out a lot of radio noise so that you will in fact see a GNSS interference because the sun is actually putting out a lot of radio noise during flares in the GNSS bands. And this is on the left, you see during a particularly bright, radio bright flare back in December of 2006. As the radio output of the sun on the lower plot, there arises during the flare, all those GNSS stations on the sun lit side of the earth lost complete lock of all GNSS satellites. So that wasn't a particularly loud, radio loud solar flare, we call it. Another event happened back in 2013 when the Swedish flight control radars, which were pointing right at the sun during the morning of August 17th, were blinded by a radio flare and they had to shut down the airspace around Sweden. So solar flares are basically photonic in nature and they last for a few hours, but they can't have these effects on communications in GNSS, which can be fairly severe. Moving on to the coronal mass ejections, these are really the major parts of the eruptions that happen when the magnetic field lets loose on the sun. You can see there on the left, a movie of an active region didn't play very well, but it's throwing off huge amounts of plasma as that magnetic field reconnects and that plasma and magnetic field charged particles flow out into space in the form of what we call a coronal mass ejection or a CME. And the movie on the right here shows a very, a view from basically near the Earth, where you can see the plasma coming off. And then you can also see this snow on the camera of the satellite, this is the SOHO satellite at the L1 Lagrangian point. That snow is highly energetic charged particles caused by the shockwave of the CME as it travels through interplanetary space. So coronal mass ejections can go in any direction from the sun, they don't always come right towards the Earth. And really one of the major challenges of space weather prediction and forecasting is to determine which CMEs that come off the sun are coming our way and are gonna drive radiation towards the Earth and or collide with the Earth to cause geomagnetic storming. So really CMEs are the big drivers of radiation storms. The shockwaves in front of the CME are what accelerate the particles. On the right you see a measurement again from the NOAA GO satellite showing an event back in 2014 in which you get a very sudden spike in the charge particle radiation out at the geo orbit here. It begins to decay but then there's another explosion on the sun and other CME comes out and it accelerates those particles even further. So this is one of those one, two punch kind of events where you get a lot of charge particle radiation accelerated by the CME as it comes off the sun and towards the Earth in this case. The other thing that the CMEs do when they collide with the Earth is they perturb the magnetic field of the Earth, they dump a lot of energetic particles into the upper atmosphere and that's what causes the aurora. So the aurora is really the only visible effect of space weather but it's a very good gauge of how big a geomagnetic storm we're experiencing. The farther south you can see the aurora the bigger the geomagnetic storm. So that's sort of our visible indicator of how big the CME impact on the Earth is. You can see at the bottom these points just point out that the radiation storms are really one of the major concerns for both astronauts in space, humans and high altitude flight especially near the poles where a lot of these auroral particles are coming down. But also they drive a lot of the geomagnetic effects in the ionosphere which again can create disturbances in the ionosphere interfering with GNSS and radio communications. They also by heating the atmosphere, driving these currents in the atmosphere, they cause the thermosphere, the upper atmosphere of the Earth to expand and Sean will talk a lot more about the details of that and how it affects the orbits of satellites in low Earth orbit in particular. And finally, geomagnetic storms when they drive the magnetic field of the Earth in this complex way actually create currents in the ground, the crust of the Earth responding to the changing magnetic field. It's Ampere's law basically when you have a changing magnetic field, you can drive electric fields. Electric fields are generated in the Earth which then generate geomagnetically induced currents as we call them. And these GICs in the Earth's crust can be picked up by the power grid and in very extreme geomagnetic storms can actually destabilize the power grid causing blackouts as they did back in 2003 in Sweden again. Sweden seems to get hit by space weather particularly hard. The other thing they do when this geomagnetic storm hits is by perturbing the magnetic field. Whoops, geez, sorry. That's supposed to be a movie, but it's not playing. Anyway, the Van Allen radiation belts which you see here and they're a sort of normal configuration of an outer electron belt and an inner electron and proton belt are generally very perturbed by geomagnetic storms and they can grow and shrink. Let's see if it plays if I click on it. There we go. You can see them growing and shrinking in response to geomagnetic storming. So that the radiation belts are actually variable in their intensity and their size and their extent. You can see here I've overlaid the different orbital regimes roughly, it's not exact. But in general, Leo sits below the second radiation belt and Janet will talk more about how Leo radiation is affected by the changes in the radiation belt and incoming solar particles. But you can see that in general Leo sits below that gap in the second radiation belt. The horns, as we call them, that come down closer to the earth can be problematic for higher inclination orbits. Mio sits right in the middle of the radiation belt so satellites and Mio have to be very radiation resistant. Geo is in general outside the second radiation belt but as you can see during extreme events, actually this isn't an extreme event, this was just a strong event back in 2015. It can also have the second belt extend out to that regime. So finally, in terms of the magnetosphere and its effect in space weather, we can actually create man-made space weather. This is an illustration of the Starfish Prime thermal nuclear explosion at 400 kilometers in space back in 1962 on the left is a picture of the actual shot and you can see it actually caused its own red aurora. On the right is a measurement of the electrons, the energetic electrons in orbit. You can see that it created its own artificial Van Allen radiation belt of energetic electrons. On the bottom half of that plot is a plot of the St. Patrick's Day geomagnetic storm that I showed earlier. You can see it affected the radiation belts to some degree. The Starfish Prime created this very artificial, very intense radiation belt, very low down. And at the time in 1962, there weren't very many satellites in Leo, but two thirds of the satellites that were in Leo were either destroyed or damaged by this man-made space weather, this artificial radiation belt, if you will. So now let's quickly finish up with a little discussion of space weather from below. This is really propagation of waves and vortices from the troposphere stratosphere system, making their way upwards into the mesosphere, which is the layer of atmosphere between the stratosphere and the thermosphere, and all the way up into the thermosphere. So you can see here what we call orographic waves breaking over the mountains, propagating up and causing secondary gravity waves, which can actually cause traveling ionospheric disturbances, we call them, in the ionosphere, again, interfering with radio transmission. You can see if you try to bounce a radio wave off of that ionospheric layer, hoping to reflect it down somewhere else on the earth, it's gonna be disturbed by that structure in the TID, as we call them. Similarly, thunderstorms, particularly in the equatorial latitudes, can generate their own very strong gravity waves, which propagate up and can cause instabilities in the ionosphere, leading to large-scale bubbles or something called a Rayleigh-Taylor instability, which then creates very big voids in the ionosphere. And when you try to get GPS signals through these plasma bubbles, it's often impossible. They get scintillated, as we call them, the phase gets shifted, and you really can't receive your GPS signals well at all, trying to travel through these plasma bubbles. So this shows that not only do we have to worry about the solar input from above, but there's a lot of activity in the lower atmosphere, which can propagate up in the form of waves to cause space, particularly in the ionosphere, and interfere with communications, geolocation, GNSS reception through these instabilities. So that's really about it. This final slide is just an eye chart, which shows on the top the yellow, the solar magnetic cycle, and its effect on the sun, and on the bottom in the blue is the Earth's atmospheric cycle, and its major phenomenon, which impact various effects in the natural system in green, causing these impacts in the orange and red to technological systems on the left and right. So that's really just a reference for you, but you can see one of the ways to use this is to see that solar magnetic eruptions can cause solar flares, which can generate X-rays, which can generate atmospheric expansion, which can then have impacts on low Earth orbit satellite orbital trajectories, which can then lead to unexpected collisions when you have displacements that are unexpected in your satellite. So that's one way to use this chart, and I believe that's it. For more information, you can look at these websites here, and I guess now we'll hand off to Sean for more information, specifically on that atmospheric expansion and drag. Wonderful, all right, thank you so much, Tom, for that primer. I am just gonna pass it over to Sean. Okay, thank you, Josh. I'm gonna stop my video to save Ben. I'm not alone at home, so sorry. Okay. So I will give a short overview of the upper atmospheric variability, which is proportional to satellite drag. It should go, I'll get you on the first one. Okay, so any object in low Earth orbit loses altitude due to interaction with the neutral air particles, so the thermosphere that Tom mentioned, which is the altitude range between about 100 and 500 to 600 kilometers altitude. So satellite drag is modeled using the equation yellow box. So we have the aerodynamic coefficient CD, which represents the interaction between the atmosphere and the satellite surfaces. Then we have the area to mass ratio, so A over M. So the RAM surface of the satellite and the mass, so that is something that sometimes you know, and sometimes, for example, in case of debris, you do not. We have the satellite speed squared with respect to a co-rotating atmosphere. And finally, the parameter that is very variable in this equation, the thermosphere density. And this comes from a model in our case, of course, when we do the computations. Something happening. So any object, of course, in Leo, ultimately will re-enter the lower atmosphere. And so what you see in this plot on the right, you see the altitude decay of two satellites. In red is CHAMP. And one way to counteract, for example, this decaying altitude is orbit raising maneuvers. And so in case of CHAMP, this was done four times, increasing a lifetime to a total of about 10 years. For GRACE, which was much higher, you see in the blue line, you see the altitude is decaying much slower. And there were no altitude maneuvers executed over this period of time. Now, if you're doing mission lifetime estimates or remaining lifetime estimates, you need to know the solar activity. So some spots or actually the solar EUV emissions. And you need to have this as a forecast for the next couple of months, years, and sometimes even solar cycles. Here's an example for CHAMP, the decay prediction that was made about one year before it actually re-entered using two scenarios of solar activity. You see that the blue and the red line, there's only about five, six weeks difference in re-entry time, but this was an easy one. The satellite was already very low and we were in the solar minimum of the solar cycle phase. At the same time, the GRACE one scenario was also computed. And here you see the very large uncertainty due to the solar activity forecast. So all these colored lines are different solar activity forecasts. And this large uncertainty then translates to almost 12 years of spread. So GRACE actually re-entered GRACE one in December, 2018 and GRACE two in March, no, in December, 2017. GRACE two in March, 2018. So it's the green line that came closest. So thermosphere density, the variability is a function, what is going on, is a function of location and mainly a function of altitude. So the top plot shows you the exponential decay as a function of altitude. Just note that in this case, we have almost six orders of magnitude in density between 200 to 1,000 kilometers altitude just to give you an idea of what is the biggest variation. And then secondly, we have latitude and longitude for a more natural coordinate is local solar time. And the bottom plot shows you a typical structure of density in this case at 250 kilometers. So what you see is the density maximum sitting in the late afternoon and minimum densities on the night sides. Then the variability is also a function of date, in particular due to the modulation due to the solar and geomagnetic activity. So the solar activity that Tom showed you in the solar cycles. What I show you here is the solar activity as measured in the 10.7 centimeter radio flux. So that is the proxy we use for the solar EUV emissions, which we cannot measure on the surface. So that is why we use this radio flux. And at the bottom on the right, you see the geomagnetic activity, which is our proxy index for solar wind interactions with the magnetosphere. So you see this variability. This is semi lock scale, this is index. So the 31st of October, that is a geomagnetic storm. So that is one of the CMEs that hit the earth. Then finally, we have variability due to season. So that is simply the fact that earth rotation pull is tilted with respect to the ecliptic. And so we have a summer hemisphere that receives more solar energy than the winter hemisphere. And that translates to these two images in the middle. So the top shows you the model prediction of NRL-MSIS of a temperature, typically for summer, more than the hemisphere summer and the bottom southern hemisphere summer. So we have all these variations on different timescales. So we have the slowest and the fastest variations are actually the most important, let's say in size. Blue shows you again in the plot on the right, the solar cycle, so of approximately 11 years plus or minus one year or something. And you see already that the size of these solar cycles is not identical. And then in red, we have the fastest variations, which are due to these solar geomagnetic storms. The duration of these events is of the order of hours to days and these are depicted by the red dots. So what you see is the red dots are severe geomagnetic storms. When the dots are above Kp8, so above approximately the middle to the top. And so what you see is that these are actually rare events. Fortunately, the geomagnetic storms are rare events and the most intense ones, the Kp9, so at the top of the plot, there are only 11 measured since 1970. All in all, if we take all these severe storms, we only have about a month or so of severe storm over this entire 50-year period of time. But the effects are quite large and we'll show it a little bit later, again, how big this can be. Here is the effect measured by Champagne-Grace. So at 400 and 490 kilometers altitude, for one of the more severe storms, you see an increase, what's going on? You see an increase of five to six times the storm before the density within 12 hours. Now to put this into perspective, so what is the impact of solar cycle effect versus geomagnetic storm effect? Here are, again, NRL-MSIS predictions for densities from 120 to 1200 kilometers altitude in the light blue line that is during solar minimum for geomagnetic quiet times. And the dark blue line is then the effect of a severe geomagnetic storms. And so the model predicts that density increases between four and six. And so NRL-MSIS is mostly underestimated in a little bit. Then to put this into perspective, here is the effect of the solar cycle itself. So this is a big solar cycle with respect to a solar minimum. Here the effects are 15 times bigger at 400 kilometers to up to 90 times bigger at 70 kilometers. And then finally, if you compute, again, a solar storm at this solar maximum, you get densities that are more than, that can be up to 200 or more times bigger than during solar minimum. So I did a quick simulation using the storm that is depicted in the bottom right. So that's the Halloween storm of 2003. So this is a KP9 event. So you see the three peaks at 400, that is the highest level of geomagnetic activity that we can measure. And so when I do this simulation for a spherical satellite in a polar and circular orbit at three different altitudes over a seven day period, you can more or less predict the impact of due to the storm only. And so at 250 kilometers altitude, the effect is pretty important. Four kilometers, decay of the semi-major axis due to the storm alone. With respect to 14 kilometers of the total decay effect, keep that in mind. Then we go up to 500 kilometers and the effect of the storm is still only 66 meters. And at 750 kilometers, the decay is only five meters. Then if we take a slightly lighter object, so with a service to mass ratio of 0.01, both, that would be the order of a cube set of one kilogram and the other one, a cube set of 10 kilogram to have some numbers. In the first case at 250 kilometers, this object would re-enter due to the storm. And then at 500 kilometers, the effect is like 670 meters and 750 kilometers, about 50 meters decay. So above 500 kilometers, the effects are relatively small. So as take-home message, I would say, if it comes up. So we have order of magnitude changes in density over a solar cycle for altitudes higher than 300 kilometers. So if we're below 300 kilometers, these changes get a little bit smaller. But anyway, most satellites will not stay in orbit long, below 300 kilometers unless they have propulsion systems. So the solar cycle phase, the time of launch in the total solar cycle phase has a large impact on satellite lifetime. The density increases several hundreds of percent during geomagnetic storms within hours, what I've just shown, as a measured case. Sorry for this delay here. So the orbit decay can be significant due to a solar storm of the order of kilometers for very, very low orbits, but it is not dimensioning for lifetime simply because these events only take a few days with respect to lifetime usually of the order of years. And finally, and that is very important, geomagnetic storms cannot reliably be predicted at the present times. There are many studies going on and this has been a subject of study for a long time. We are still not able to predict storms more than a few hours out. And finally, this is a very interesting report to read if you're interested in extreme events in space weather, not just drag, but everything that is discussed today. That is, in this report, we have the benchmarks of one in 100 year events. Thank you. Thank you so much, Sean. And thank you for working through the clicking there. I know we were having a couple of issues. So I'll pass it off to Janet and Janet, I think you're just gonna have to tell me to advance the slides, which thankfully... It's not working. Seems to be pretty easy. Yeah, it was having a little bit of issues there. So the floor is yours and if you can just say next slide, I will happily advance for you. Okay, today I'm gonna be talking about space radiation and how it impacts satellite operation. So let's jump to the next slide. So put release succinctly. Space radiation can damage or degrade components causing a complete or partial system or mission loss. And typically we talk about four different types of issues. The first is surface charging. So this is when electrons and protons from the environment collect on a satellite surface, charging it up to high differential voltages, which eventually can lead to a damaging arc or electrostatic discharge, which can then create an electromagnetic pulse that couples into your satellite electronics, putting it into some unusual state. The second issue is internal charging. So this is caused by higher energy electrons that instead of accumulating on the surface can pass right into the satellite and build up on dielectric materials like circuit boards or on ungrounded metals. Eventually the charge can build to the point of a breakdown and cause a discharge that can damage sensitive electronics or again make a pulse that couples into your satellite and puts it into some unusual state. The third is caused single event upsets. These are caused by very energetic ions that can pass right through your satellite. If they happen to go through an electronic device it can flip a bit that then requires some kind of ground intervention to fix or can cause a latch up and a complete device failure. The last is total dose. So this just refers to this low degradation of components from the constant radiation dose throughout the mission or from a stepwise increase in that radiation dose which ultimately reduces the lifetime of your satellite. Next slide. So the best solution to the problem is to design satellites that are impervious to the radiation and there are a number of tools available that will allow you to estimate your satellite susceptibility. Most groups I know tend to focus on the last one there, total dose using one of those tools listed and may or may not consider the other three issues. Next slide. Even if you do consider all the issues there's still a possibility that your satellite can have a problem once on orbit either because the radiation environment has exceeded the threshold you designed your satellite for could be an extreme hundred year event or it could just be that there was some unexpected design feature. And unfortunately we don't have a process for tracking satellite anomalies. So we don't know exactly what this new generation of VO satellites, what type of anomalies they're experiencing but we do have some estimate of what to expect based on past missions. So in Leo orbit single event upsets and surface charging are the most common concern. The other two are less of an issue simply because they take a longer accumulation period and satellites in Leo orbit spend less time in the very intense radiation. Next slide. So once your satellite's on orbit there's not much you can do to prevent anomalies from occurring. However, it is useful to try and understand if you do have an issue whether or not it's related to space weather. And unfortunately it's a complicated process and there is no single space weather indicator that can explain all of these issues. Each one of these are caused by different particle populations. They're enhanced at different times and in different locations. Next slide. So what can you do to try and understand whether space weather may have caused an issue for your satellite? We'll talk about single event upsets first because that's the most common in Leo and there's a number of different particle populations that can cause this. First there's a stably trapped proton belt which in the figure over the right if you could actually see it would look like a donut wrapped around the earth. What sometimes confuses people is that in Leo orbit the bottom plot there is showing a latitude and longitude plot. So at a fixed altitude and in Leo orbit this donut actually looks like a red bull's eye and that's just because where the magnetic field is reduced it allows those protons to come down to lower altitudes. The peak fluxes from this stably trapped belt vary only by about a factor of two over the solar cycle but it's always there. So every time you go through that region there is some probability of an anomaly occurring and it's an instantaneous effect. So if you wanted to do some forensics and understand if an issue you're having is related to this stably trapped belt you could use a tool like AP-9 to define the location of that belt relative to your satellite along its orbit. Next slide. Maybe a more concerning issue for single event upsets are solar energetic particle events. So Tom mentioned this in the beginning these are extremely energetic ions that stream from the sun. So they fill the polar cap regions. In this case the Earth's magnetic field actually acts as a shield and that deflects those ions from reaching lower latitudes. So in that middle plot you can again see the stably trapped proton belt that looks like a giant bull's eye and then up at the higher latitudes you can see the effect of the solar energetic particles. These events can last days to weeks. Occasionally they can be trapped and form a temporary new belt and you may think that you have no issues with these SCPs with your satellites but I just wanna point out that we have had no SCP events since September 2017. So if you launched after that your satellite is really untested. There's a number of tools for doing forensics to know if your satellite is being affected by these solar energetic particles. So first you can refer to the space weather prediction plots of GOES protons or the alerts that are sent out that will tell you whether or not there is an SCP in progress. It won't tell you if you're in the high flux or the low flux region and we don't have great tools for doing that at the moment. One thing you can refer to is a report by the Aerospace Corporation called the Human in the Loop Decision Tool and what it is is just a set of steps that you can work through to at least estimate whether or not you are experiencing an anomaly due to solar energetic particles. And then in the future my group is working on a tool that will allow you to track these different populations in real time and better understand anomalies. Next slide. On the last population that can cause single event upsets are galactic cosmic rays. So these are high energy ions that stream from outside our solar system from things like supernova. They are always present at higher latitudes at low levels. The fluxes don't change dramatically but they are anti-correlated with the solar cycle. And unfortunately we don't have good real time tools for understanding if an anomaly is related to these. The best you can do is to define statistical access regions from tools such as Supreme 96 which is what I had done a few years ago with my colleagues at EU Metsat and an issue with the Meta-E satellite. Next slide. And then lastly surface charging. This is caused by energetic electrons accelerated in the high latitude or rural regions. So this plot over on the right is a plot showing as if you are looking down on the northern polar cap of the earth and it's showing you the regions where the Sandpac satellite experienced high charging. And unfortunately we have a bit of a gap here. There are not good tools for estimating surface charging effects. There is a tool that was developed by Aerospace but it's not publicly available yet. So the best option here again would be to refer to this human and the loop decision tool to at least get an estimate if your satellite is experiencing this issue. Next slide. And then just a quick slide here on extreme events. The US is working on a space weather action plan to define radiation benchmarks for extreme events. They've already gone through phase one and there's a report listing some extreme event flux values for SEPs as well as GCRs. And work is underway now to refine those benchmarks and deliver a phase two report. Next slide. So that's all I have for today. Just to summarize there's four different issues to be concerned about regarding space radiation, surface charging, internal charging, single event upsets and total dose. The two major concerns at Leo are single event upsets and surface charging. Single event upsets have three different populations that can contribute to that type of anomaly and surface charging is most likely in the high latitude or rural regions. And I'll leave it at that. Wonderful, Janet. Thank you so much. And we'll come once again now to Matt. Matt, I'll advance the slides again. And thank you so much for walking through. Good morning and good afternoon to everyone, depending on where you are in the world. I'm going to present a slightly different look at space weather from my perspective, working in a company that runs small satellites. So I'm going to try to touch on some of the challenges, but also touch on where the opportunities are and where Spire thinks it can make a contribution into this field. Okay, let's go on to the next slide. Okay, so for those who don't know Spire, we are a small satellite company and we build and launch a large constellation of 3U CubeSats. And the philosophy of the company is really in the pin by a couple of points. One is that what we're trying to do is target, target situations where having many more observations is important rather than having very large, expensive science grade sensors. So we like to have small sensors, but lots of them. And then also to try to make everything very reprogrammable on orbit so that we can, once the satellites are in space, then we also have opportunities to upgrade, replace software, change how the satellites are working. It's pretty much a Spire product all the way through. So we design and build satellites in Glasgow in the UK. And it's almost all entirely Spire produced now. And that's really good for us because it allows us to make changes, allows us to innovate and modify things very quickly. Next slide, please. As I said, we operate 3U CubeSats and that's traditionally historically, I say historically the company was founded in 2012. So it's still quite a young company. We're beginning to look at some 6U CubeSats as well, but at the moment everything we fly is 3U CubeSat. We've launched over 100 and there are over 80 still in orbit. We designed them for a pretty short design lifespan and that's important, we'll come back to that. So two to three years realistically. We've had many launch campaigns with lots of different launch providers. One of the advantages of CubeSats, as I'm sure most people know, is being able to work with lots of different launch providers fairly easily. And as well as the space segment, we've got over 30 ground stations distributed around the world in order to try to get data down quickly. So the system gives us pretty good global coverage. There's a mix of orbits, some launched from the ISS, some synchronous orbits, some mid inclination, but they're all operating between 400 and 600 kilometers. So it's low Leo orbit. Okay, go on please. And the focus is really on things that we can do with signals of opportunity. It's much easier to put receivers on small satellites than to try to run transmitters with large power requirements. So at the moment the primary payloads are threefold. One is a GNSS receiver, which we can use for radioactation to feed into weather forecasting systems. We can also use that to sense the atmosphere, both above the satellite, but also in an arrow sense, looking down through the atmosphere as well. And we can use the GNSS for slightly more normal things, such as looking at surface reflectometry where we can sense soil moisture or ground roughness looking at the reflected GNSS signals. The other two missions are again, both software radio defined. So there's an AIS receiver, which does ship tracking and ADS-B receiver, which does aircraft tracking. And then one area that's really emerging over the last year or so is to open up the platform into looking at hosted payloads and orbital services where we can fly things for other people if that's what they wish. Next slide, please. Okay, so I'm not going to go through this very famous Bell Labs picture because the other speakers have done a good job of describing all the problems, the many problems that space where they can present to people. But I, so, but I just briefly, I'm going to split up the effects into three different areas where we have to worry about these things. One is anospheric effects and that's primarily from a radio propagation point of view. One is thermospheric drag, Sean spoke about, and radiation effects that Janet spoke about. Okay, next slide, please. So let's take a look at each of those in turn. So, anospheric effects, which is really my background. So I apologize if I get the other domains entirely wrong. We have to worry about all radio systems that are operating through the atmosphere, which operate below about two gigahertz of the potential to be affected by the atmosphere. So from a satellite operator's point of view, the main issue there is potential impact on the BHF and UHF communications between the ground stations and the satellites. Sintlations likely to be constrained to equatorial regions or possibly in the auroral regions. I have to say, this is not an impact that we've really observed much if at all. And I'm part of that is because we're at the bottom of the sunspot cycle we don't necessarily expect to. The other place that that's going to get mitigated is as on our roadmap is transitioning our comms to higher frequencies to get higher bandwidths, higher data rates. And as we go up in frequency, the ionospheric effects are going to become less and less. Okay, go on please. Okay, now, as I said, each satellite carries a dual frequency gene assessed receiver. And that gives us opportunities here to actually measure the ionosphere and try to produce products for other people. So first off, we can do direct measurements of the ionospheric synthlation. So that's the issues that may cause us problem, but we can also sense it ourselves. So on the right here, there's a picture showing some data from a radioactation geometry and we can see there are periods in the bottom panel, there are periods where the signal is fairly stable at the start from zero to a hundred seconds. And then it moves into a simulating environment where we see rapid variations in the signal amplitude, in this case, but there'll be associated also associated with rapid variations in the signal phase. So we can use the gene assessed receiver to actually sense these and use that to provide situational awareness for other users where this becomes important. Next slide please. We can also use the radioactation data to do high resolution sensing in lower answer. So there are techniques that have been developed, which are in the literature, which take essentially the data that's being used for the MET community. So it's high rate 50 Hertz data and we can construct high resolution. And by high resolution, I mean vertical resolutions of about 100 meters in the lower atmosphere. So this is quite high resolution. And the example that you can see here is two different measurements, one for two different measurements collected from different receivers and from different transmitters. So they're fully independent measurements quite closely located. And we can see that barring the trends that we haven't quite taken out. We can see the same sort of perturbation of about 105 kilometers in both of those. And actually having the access to the constellation is important. I've seen lots of these sorts of plots where you see little glitches and nasty things occurring in the arrow and you think, well, is that really real? Is it a problem in the receiver? But it really is real. We can demonstrate it with different receivers using different transmitters co-located and see that these things are really, we really are sensing the environment. Okay, next slide please. And then we can also sense the wide area on a sphere. So using these measurements, we can measure, we get integrated measurements from the GNSS transmitters to the receivers. So we can actually use those within the data assimilation system combined with other data as well, other space data and other ground data in order to produce global maps of what the arm's sphere is doing. And again, use those to derive products for other users in a very similar way to the Met community will provide or try to provide the best possible representation of the neutron atmosphere and then products can be derived from that for different users. Next slide please. Thermospheric drag is clearly potentially a challenge. We are in a low orbit and as Sean shown, those low orbits were affected by thermospheric density and we're relatively low mass. And we know that if we start looking at orbit propagators, then actually drag is those attitudes primarily the largest dominant factor in orbit propagator error. However, this is also an opportunity in the sense that we need that drag in order to meet the UN deorbitating requirements. We don't have active deorbitating and that's one of the reasons why we fly so low is that we want to be good players in NIO and get the satellites out of orbit within the UN mandated time periods. So for us, the thermospheric drag on the long term is really important to get those satellites back out of orbit. Next slide please. It's also an opportunity in that we can sense thermospheric drag because we run GNSS receivers and we need precise orbits in order to do the radio computation. We can actually use those precise orbits to characterize the thermosphere in near real time. Now there's, again, there's work in literature that looks at taking pulse information, precise orbit determination data and turning that into direct measurements of the integrated density over fairly short periods of time. And you can see an example on the right here don't read too much into the fact that it's thinking about so much and it's so different from MCIS. This is a very naive implementation at the moment of some work in the literature. We're not taking into account really the ballistic coefficient or changes of attitude in the spacecraft but we can see that we can make estimates of density that are significantly different from the MCIS. And then we can take data from across the constellation and use various different estimation techniques to try to use the whole constellation in order to come up with a best fit thermosphere across the globe. Okay, next slide please. Okay, radiation, Janet's just done a good job of sending us the problems with radiation. I would contend, well, I'm gonna say in Leo where we are at say four to 500 kilometers it's a relatively benign environment. It would be significantly more difficult if we were at two and a half thousand kilometers or 3000 kilometers. But it's relatively benign which means the satellites can be designed in a way that does not necessarily require huge amounts of hardening on each satellite. And the philosophy here is really about putting in a little bit of redundancy on each satellite. So certain systems might be redundant but in a three year cubes that you haven't got much scope for doing lots of redundancy on each spacecraft. So there we try to take the view that the redundancy is mainly across the constellation. So rather than building lots of redundancy into a small number of platforms we build redundancy across the constellation. And if you're a customer of SPI or if you're buying data from SPI you're not buying data from a particular satellite you're buying data from across the whole system. So from a customer point of view we try not to be dependent on individual satellites making measurements at any real particular time. Okay, next slide. I think we're reaching the end. Okay, so we have challenges. We have opportunities from a range of different space weather effects. I'd like to think we've got more opportunity than challenge and I think some of that comes down to the design philosophy of the constellation, where it is, how it's been designed, short lifetimes and so on. And actually harrying the constellation then gives us big potential for really doing wide area characterization of the atmosphere and thermosphere. And that can obviously be used to support different operational systems. And also to increase forecasting capability because we can sense, we can provide input into digital simulation models where we just don't have the data from ground sensors. Okay, I think that's me. Wonderful, thank you so much, Matt. Appreciate it from Spire's perspective. And so with that, let me just gather this screen share here and we can bring all of our lovely speakers back up for a bit of question and answer as we've got about 10 minutes to go in our allotted time. But I just absolutely wanna thank you all for your presentations one more time. They were enlightening for the space weather nerd that I am. And I just wanna kick off with answering one of the most asked questions thus far most upvoted has been, will the slides be made available? Yes, right at this point there is an extremely large file because of all of the different little video features. And so we have to do a bit of trimming there, but I will venture to get that up on the Secure Worlds website in the next week. Along with the recording as well, that was another very asked question. So thank you very much all for... You guys figured out how to use the upvote feature and you used it par excellence. But I'll just take the chair's prerogative for a moment and ask one of the questions that I had that kind of sparked from hearing Tom and from Sean and from Janet was that, there's a very strong image of space as a void space as empty. And that's even one of the reasons why satellites are talked about as better than air platforms for different types of research and remote sensing and things like that. But the environment that you all described is very much more dynamic than that image would display. So if you were a satellite operator dealing with your specific issue maybe Sean about drag and Janet about radiation, what are the things that you need to be very acutely aware of not just for extreme events, but also for the day to day? I think you did a good job explaining it generally, but tell them just maybe in one or two sentences what you think that the most specific thing is. No, me first then. I would say if we're not talking about extreme events, it would be like choosing the altitude for your specific mission. Like if you need a mission lifetime of a certain number of years, you need to find a compromise between satellite altitude and also, for example, your launch date. Like if you're launching in the rising phase of the solar cycle or close to the solar minimum, it is not at all the same phasing. You will not have the same lifetime. So that those are things you can think about if you have that luxury. Sometimes you just have to launch and there's no way out and you just have to launch higher or lower if you wanna stay within a 25 year reentry limit, for example, I think that's the main not extreme event thing to think about. Thanks. Janet? I would say that day to day that the space radiation is probably manageable, but it concerns me a little to hear Matt say that the environment at Leo is benign because it is until it isn't. And a lot of these events are very sporadic and my concern as an operator would be to have a very large SEP event that overwhelms the limited redundancy that you have so that you suddenly lose contact with a large percentage of your satellites. And if that happens at the same time, which is likely that there's drag issues going on, now you've lost contact and you don't know where your satellite is. So there's two compounding issues to consider. Sure, okay. Kyle, did you wanna jump in with anything there? No, that was a good summary. I think it is important though, as Janet said, to keep in mind that these are compounded events. So at the same time, you're getting a very high radiation dose from an event. You could be experiencing drag. You could be experiencing GPS and GNSS communications and locations issues due to ionospheric effects. So space weather comes all at once in a variety of ways, not just in these little discreet pieces. Sure. So, and I think I'll direct, there is a question from the audience, similar to a question that I had for you, Matt, is basically, the question from the audience says, what does Spire do to protect its satellites from radiation? Which we don't not ask you to get in anything proprietary, but I think that leads into my question, which was basically, Spire seems like to be a pretty established small satellite company. I know you said since 2012. It seems like a short period of time, but I think operating that many satellites with the experience you have, it makes you stand out, especially in comparison to university CubeSats or first time CubeSat operators. So my question along with that is, in order for a small satellite operator to be conscious of space weather and to be working on making it an opportunity and addressing the challenge of it, do they need to be more established or is this something that you think that Spire and others could be doing from the get-go? I think you have to do it from the get-go, but you have to do it in a way that works within the business model that you're trying to establish. And I think that's gonna be different from a commercial operator to a university operator to a government operator. But what we can't do is, in case the CubeSats are not some dead, and we have to make choices about where we fly and how we operate the satellites and how we select components and which bits are hardened and redundant and which are not. And I think you have to look at it as a whole. You can't build a small satellite you couldn't enable Spire's business model if you're building large, fully hardened satellites. I think that's fair to say. And I've been involved in projects in previous jobs where you've got customers, funders who might have the opportunity to fly one satellite and the questions all become very different again because at that point, they really want that one satellite to work and work for a long time. And again, it changes all the equations about how you balance the risk across what you're trying to do and how you're trying to collect and deliver the data because fundamentally we're trying to be a data company providing useful data. That's what it's about. It's when the space component is something we have to do to do that. Okay, all right. I'm seeing a question at the top that is similar to some others that have been asked is basically this has been a good resource but if you're a small satellite operator where do you go to look for more information about space operations? Tom, do they enroll at CU Boulder? Is that the answer? Is that simple? Janet, did they pay for space hazards to do things? We do have, we are developing, we do not yet have but we are developing a professional certificate in space weather at CU, so that's coming. So look for that. I put some resources at the end of my presentations and websites that can get you started. There are some textbooks out there. They tend to be more phenomenologically focused. So they talk a lot about the issues I talked about at the beginning of my talk about the sun and its effect on the magnetic field and the atmosphere of the earth and less focused on the technological impacts and the operational impacts that Sean and Janet touched on. So I think there is a gap here that does need to be filled. As I say, we intend to try and fill some of that with our professional certificate. However, in terms of textbooks, I think it's right now in the situation is you have to go and collect a lot of different materials to put together something like you've seen here today which spans everything from phenomenology to impacts. Mm-hmm. Janet? I'd agree with Tom. I think there's a gap and a big need for a textbook that just would collect all this information together and an easy way to understand and implement. There are, there's NASA Handbook 4002A which gives a lot of guidance on how to design satellites to deal with space weather. Another option is there's a CSAU meeting which was supposed to be in October, but was canceled. So next year, and it is a collection of scientists and engineers specifically talking about space weather impacts and what to do about them. All right, and I'll also think of directing people, Tom, to your former place of employment, the Space Weather Prediction Center, their website. They've tried to put out a lot of products and dashboards for if you're a different type of operator, maybe you're an aviation company, maybe you're a satellite operator, you're a grid operator and what kind, you'll get to see a dashboard of what kind of effects you would be interested in knowing about. So if you're drag issues and radiation issues and things like that, so that's a good resource as well. And I've seen we have about just about a minute left. So I just wanna go around to the panelists and if there's any last word, if there's any other way that people could reach out to you and or final message. So I'll go in order, Tom. Anything else to say? Not much, just thank you very much, Josh. This has been a real pleasure and I learned a lot too. Fantastic, Sean? No, not much to add either. So thank you all for listening and maybe next time. Okay, great, Janet? No, thank you for having this. I think someone asked about emails and I'm happy to answer any other questions. There's a way to get emails out. Okay, I can stay tuned to the event page on Secure World's website. We'll make some connections there and share out people's info so that people can connect more. And Matt, the most pressing word, go ahead. Yeah, thanks for organizing and thanks for having us. I will one day get to small site in person. I've never actually been. Indeed, we'll all see each other next year. So thank you all very much. Thank you to our 104, 103 participants that are still out there. Thanks for sticking through with us. Looks like we had a total of about 160 people earlier and so I appreciate your engagement. Thank you for asking all the great questions and we'll stay in touch and continue to watch the Secure World page for a recording and for the slides and contact and stuff. So thank you all and have a fantastic rest of your Tuesday.