From Earth orbit to the Moon and Mars, explore the world of human spaceflight with NASA each week on the official podcast of the Johnson Space Center in Houston, Texas. Listen to in-depth conversations with the astronauts, scientists and engineers who make it possible.
On episode 369, three flight controllers from NASA’s Mission Control Center discuss how their consoles, ADCO, TOPO, and SPARTAN, keep the space station flying from the ground. Listen and find out what each console does! This episode was recorded on December 16, 2024.
Transcript
Host (Dane Turner): Houston, we have a podcast. Welcome to the official podcast of the NASA Johnson Space Center, episode 369 Mission Control Station in motion. I’m Dane Turner, and I’ll be your host today. On this podcast, we bring in the experts, scientists, engineers, and astronauts, all to let you know what’s going on in the world of human space flight and more. The Mission Control Center, or MCC, is the iconic epicenter of space flight operations. It takes a large talented team in order to assure the safety and success of any mission, whether to low earth orbit or beyond. You may have seen the depictions of mission control in the movies or seen video of it during a NASA broadcast. The mission control team is there 24/7 365, monitoring all of the systems and activities aboard our laboratory in orbit. There are a lot of consoles in the International Space Station, MCC and each one has an important job. We’ll be dedicating six episodes to covering the positions in Space Station Mission Control, what they do and how they work together to keep the orbiting lab operating smoothly. In this episode, we’ll be covering the attitude determination and control officer, or ADCO, represented by Krista Farrell, the trajectory operations and Planning Officer, or TOPO, represented by Joe Scalora and the Station Power Articulation and Thermal Control Officer, or SPARTAN, represented by Logan Berck. Together these consoles cover the Space Station’s motion and power controls from the attitude of the station, the speed and direction it flies to the creation and storage of the electricity that powers everything aboard. Let’s find out how they keep the ISS flying. Recorders to flight speed. ADCO,
Krista Farrell: Go.
Host: TOPO.
Joe Scalora: Go.
Host: SPARTAN
Logan Berck: go.
Host: We are go for Houston We Have a Podcast.
Host: Thank you all for coming on. Houston, we have a podcast. We really appreciate you being here today. Uh, to go around the room here, if you can each introduce yourself, I’d really appreciate, uh, let us know who you are, which console you’re on. Gives a a real quick description of the console and, uh, and maybe a little bit of your background too. ADCO, can we start with you?
Krista Farrell: Yes. Um, my name is Krista Ferrell. I’m an ADCO flight controller. Um, I ADCO is the flight controller that monitors the hardware and the software, um, that determines the state vector and the attitude or the orientation of the ISS. We also maintain, the ISS attitude control and we work with our Russian counterparts to do that. My background is in aerospace engineering and I’ve been a flight controller for about eight years.
Host: Great. Uh, TOPO, how about you?
Joe Scalora: My name is Joe Scalora. Um, TOPO is the trajectory operations and Planning Officer. Uh, we’re responsible for the ISS’s trajectory. That’s the position and velocity over the course of time. Um, we do that for ISS. It includes reboots planning with our Russian counterparts. It includes, um, collision avoidance maneuvers. The low Earth orbit is extremely populated these days, so that keeps us busy, uh, 24/7. Um, we also maintain a level of oversight over the visiting vehicles that come to and from station maintaining, awareness of their trajectory as well. I also have an aerospace engineering background. Um, I was hired here around seven and a half years ago. I’ve been certified for about four years now.
Host: Awesome. And, uh, SPARTAN, how about you?
Logan Berck: Hey, my name’s Logan Burke. Um, I work for the SPARTAN Console. Um, we operate the electrical power system, external thermal system, and the rotating joints on ISS, so the solar arrays and the radiators. Um, I have a background in electrical engineering before I came here and I interned here at NASA in a few different groups and then ended up starting in SPARTAN full-time about three years ago.
Host: Really cool. Okay. So, uh, altogether these are the consoles that really are, are about keeping the station in orbit, flying in the correct trajectory and, and where it’s really supposed to be in space. Is that that right?
Krista & Joe: Yep
Host: Okay. Um, so ADCO, can we start with you there? Uh, you, you gave us a a brief description of everything. Uh, how, how does your console, what, what does it do for the ISS a little bit more in depth?
Krista Farrell: Um, yeah, so we are monitoring, um, all the hardware and software, like I said, that, um, tell us the position velocity and time and then also the, um, orientation, which is what we call attitude of the ISS. Um, we also are responsible for maintaining the attitude control. Um, so we have hardware on the US segment and the Russian segment, um, that has to work together to keep the space station, um, in the right orientation that we want. And so we’re the ones who monitor that and then also do all the planning and execution when we’re changing the orientation of the space station.
Host: You say you work with the, uh, the Russian counterparts there. Uh, about how much responsibility is there on either side for this?
Krista Farrell: Um, it is, I would say a very equal responsibility. So, um, on the Russian segment they have thrusters and that’s what they use to control the attitude of the ISS. Um, on the US side we have control moment gyroscopes, and these are four large spinning wheels, um, and with spinning wheels that creates angular momentum. And so if you move, um, the spin axes of the CMGs, uh, that changes the angular momentum and that puts a torque on the space station. Um, and so only one system can really be in control of the ISS attitude at a time. Um, so we’re, we’re really monitoring both systems. So we have a lot of insight into what the Russian segment is doing. They have some insight into what we’re doing, um, and we are making sure that the right, uh, segment has attitude control, um, and that everything looks good.
Host: Oh, that’s really neat. When you, when you’re working with, uh, uh, needing to do different attitude maneuvers and stuff, uh, how, how much control do you have over that sort of thing?
Krista Farrell: So our console does a lot of planning that with the Russian segment. Um, depending on how large the maneuver is, uh, we, we may have to use Russian thrusters to do those maneuvers. Um, and so if that’s the case, we do what we call an attitude control handover to the Russian segment, and then they’re gonna be the ones who are actually commanding to move the space station. Um, if it’s a small maneuver, we can do that with the control moment gyroscopes. And so while we tell our Russian counterparts, um, when we’re gonna be maneuvering into what attitude we’ll be maneuvering, uh, we command that as the ADCO flight controller.
Host: Uh, how often do these maneuvers need to be done?
Krista Farrell: So it really depends. Um, I would say most of the time when we are changing the attitude of the ISS, it is for, uh, visiting vehicle, um, docking or undoing. And so that, those maneuvers are really dependent on when we have vehicles either coming to the ISS or departing from the ISS. Um, some maneuvers that we do on our control moment gyroscopes include, uh, like maneuvers to a yaw biased attitude. Um, so that’s when we are just yawing slightly to either the right or the left. Um, and we do these sometimes to, um, shadow the Russian segment to keep it a little bit cooler depending on kinda the configuration of the ISS orbit and where the sun is. Um, and so we do those about four times a year.
Host: So Yawing is, is turning almost like a car with turning the, the nose, uh, one way or the other.
Krista Farrell: Yep, that’s a good way of thinking about it.
Host: So in order to keep the, the Russian segment, uh, a little more shaded, you, you kind of like drift the ISS, is that what
Krista Farrell: Mm-hmm, Yep. <laughs>
Host: Had no idea, could do that. That’s really cool.
Krista Farrell: Yes. Yep. And that’s something we’re coordinating with our Russian counterparts. You know, they request that from us and then we’re able to, uh, to command that.
Host: Fascinating. Uh, TOPO how about, how about you? Uh, can you give us a little bit more depth about, uh, what it is you do?
Joe Scalora: Sure, yeah. Um, one of TOPOs primary responsibilities is maintaining the ground ephemeris. So this is the position of velocity over time, but um, the knowledge is kept on the ground. So it’s separate from the onboard systems where GPS is being downloaded once a second and ISS always knows where it is. Um, often we can keep more accurate products on the ground. This includes, you know, visiting vehicle mass changes. It includes when the solar arrays articulate and our area changes. It includes our planned reboots and such. Um, so this Ephemeris is normally used for planning products, um, like solar, um, solar power for example. You got sunrise and sunset times. Um, it’s also used by public customers. Um, it’s, you know, out there on spot the station, for example. So if you ever look for ISS overhead, that’s all being seated by the TOPOs ground data. Um, these type of things that are in there. The reboost, for example, we do those about once a month. There are like one to two meters per second that’s like two to four miles per hour change. Um, in Delta V those are primarily to set up the Russian launch and landing activities. So a lot of people think that they’re just to maintain altitude. Um, they do maintain our altitude, but their primary purpose is to put ISS over, you know, the launch site or the landing site so that we can easily set up our, our Russian, uh, crew launches and landings. Um, in addition to the reboosts that we plan once a month, like I mentioned earlier, it’s this 24/7, um, debris environment. So our colleagues at the, um, US Space Command, they have ground systems that basically look up at the sky and track debris, satellites, objects, um, anything that’s in space 24/7. Um, we have a direct line to an orbit safety analyst, um, that, you know, provides us with conjunction data. This is a close approach between ISS and a debris, for example, a piece of debris. We are at probably a thousand close approaches a year these days. Um, we’re, our maneuver rate is still around two debris of maneuvers a year. Um, we’ve done about 40 of them in the history of, of space station. Uh, they get to be pretty public when they happen. We just had two in the month of November. So, um, you probably saw those on the, on the space news, but, um, that’s TOPOs biggest job in keeping the crew and the space station safe is maneuvering us outta the way of debris.
Host: You mentioned that, uh, you have to keep track of, uh, visiting vehicle mass changes and the, uh, the inclination of the solar arrays and stuff. How much does that really affect the, the trajectory of the station?
Joe Scalora: Yeah, the mass changes, um, it’s about like 2% of the total ISS mass is a visiting vehicle, 1-2%. Um, so in the short term, the effects aren’t that aren’t that significant, but when you’re trying to, um, predict ISS over a 30 day, 60 day time period so that you can plan a launch event, um, all of those factors add up. And especially, um, you know, when we’re talking about the propellant required to keep space station along this trajectory, keep it in orbit, something like, you know, how much the arrays are facing in the wind actually has a really significant impact.
Host: You say wind I, I know we’re, you know, just dipping into the atmosphere with, uh, the, the space station. Uh, how much wind is there up there?
Joe Scalora: Yeah, the, so there’s, um, the atmospheric density is still very sparse, right? You, you’re not gonna feel it on your face, for example. Um, but the term drag still applies in low earth orbit. And we are flying through, you know, atmospheric particles, even though they’re very sparse. When you’re going 17,500 miles per hour, you know, over and over and over again, you keep getting bombarded with the particles and it slows you down. Um, I think the decay rate, you know, maybe is something that is, is present in our trajectory product. So for all the, the students out there, if you pull our data from spot the station or spacetrack.org, you can, you know, calculate the decay rate that ISS sees pretty easily.
Host: Wow. And you also mentioned, uh, the, the close approaches. How close is a close approach?
Joe Scalora: Oof. Well, um, we are being notified of things within a plus or minus two kilometer by 25 by 25 kilometers. So the, the first axis is like up and down, and then the other two axis are along your velocity vector and out of plane. Um, so two kilometers is a lot. The, the average distance that we probably maneuver for is much closer. Um, you’re talking about distances within a kilometer or two. Um, it just kind of depends on the geometry. The way that we do, um, debris avoidance is based off a probability of collision. So it’s not just your missed distance, but it’s also the uncertainty that you have in both the ISS and the debris position. And the analog I like to give is, if I were 100% confident that a piece of debris would fly right through the uprights of space station, I’d have a zero pc, you’d be very confident, 100% confident it goes right through the uprights, wouldn’t have to maneuver. Um, but in reality, the, the way in which we track objects in space, the speeds at which they fly, the sizes of the objects, you have uncertainty and, um, something that is projected to miss within a kilometer be a lot of, a lot of distance. If you just think about where you would stand in relation to that, um, the uncertainty adds up such that the probability collision is high enough that you’d wanna move station.
Host: Interesting. and last but not least SPARTAN, uh, what, what is it that, uh, can we go into a little more depth on what you do?
Logan Berck: Yeah, sure. So in SPARTAN, we control three main systems. So, uh, first off, the electrical power system. So that’s everything from generating power with the solar arrays and then transporting, uh, that power to, uh, the modules where the astronauts, uh, are actually using that power for either their like life support equipment or their food warmer or, uh, even just things like charging their iPads, things you would do here on earth. Um, and then converting that voltage. Um, we have a lot of like circuit breaker like equipment that you would see like in a house or in like in a city power grid, um, to be able to reroute power, power stuff on, power stuff off, et cetera. Um, and then next we have the external thermal control system. So we, uh, collect all the heat from both the internal modules as well as the external powered equipment. And then we transport that heat out to our radiators where we eject the heat out to space. And then lastly, we have the rotating joints. So that’s kind of a mix of the power system and thermal system. ’cause it’s just rotating the solar array and the radiators. So we have some, uh, redundant like complicated mechanisms that control, the articulation of those joints. Um, and we have to do that for a variety of purposes. I think a big one that comes to mind is for anytime we’re like burning thrusters, like in a reboost for example, we have to position the solar arrays such that they don’t actually get hit by the thrust, um, coming out. So, those are kind of like the high level functions of SPARTAN <laugh>.
Host: Really cool. Um, is, is it a lot of math work to, to figure out? I, you know, I haven’t done, uh, electrical math since high school, but I know, you know, we used OHMs law and, and other things like that to, to calculate, um, the, the amperage and, and the amount of current, uh, is there a lot of that kind of calculation in your position?
Logan Berck: I would say most of that calculations are handled by, like, ground-based telemetry processing, so you don’t really have to do it live most of the time. Um, it is good to have that understanding though, especially when like thinking about like anomaly response. Like if you see some current that’s a little bit too high or you see some voltage that’s a little bit low, you need to understand like what the impact is on power to that, or where that, difference might be coming from home.
Host: Uh, you also mentioned that you manage, uh, the hardware and software that really controls that kind of stuff. Can you give some examples of, of what is the electrical system both inside and outside?
Logan Berck: Uh, yeah, sure. So, um, I think the two sort of main power sources are the solar arrays and the batteries. So when we’re in the sun, the solar arrays are generating power and that’s being controlled by, you know, another, um, electrical box called a sequential shunt unit. And then while we’re in the sun, in addition to powering all the loads on station, um, we’re also charging up the batteries so that way when the ISS goes behind the earth and we’re no longer in the sun, uh, we can make it through the night, so to speak. Um, other boxes we have, like I mentioned, a circuit breaker type, just a bunch of switches that we can individually turn on and off equipment. We have voltage converters, stuff that steps down. Uh, we generate voltage at a very high level and then we step that voltage down at a couple of different phases. And then by the time it gets to, uh, the cruise like wall outlet, so to speak, it’s um, about 124 volts.
Host: Do you control the electrical system on both the US and the Russian side?
Logan Berck: So just on the US side we do supply power to the Russian segment. Um, quite a bit of power, um, that they would otherwise be able to generate. Uh, they have to partially retract their solar array ’cause of some of our constraints on the US side. And so kind of part of that arrangement is we also give them, um, power to kinda help out with that. ’cause we typically have some access that we can give them.
Host: And you said that this power is used to, uh, like charge iPads and stuff. Uh, the, the amount of power, uh, coming out of the, the wall sockets there, is it comparable to what we have coming outta the wall, you know, here, uh, of a wall socket?
Logan Berck: Yeah, the voltage, the voltage is nearly identical. We use 120 volts at least here in America. And, um, it’s 124 on ISS, so roughly the same. Um, and then in terms of like current they have available to them? Yeah, it’s, it’s generally gonna be comparable. Um, overall ISS is using a lot more power than your house is going to use. Um, so the ISS uses around, um, I would say about 80 kilowatts at any given moment on average. And compare that to like your average house, it’s probably on the order of one or two kilowatts. So we’re talking like 40 to 80 like American homes is about what we’re using on ISS at any given time.
Host: Oh, wow. Uh, now you also mentioned that you are working with the thermal systems and the, uh, the, uh, heat dissipation fins. How hot do those get?
Logan Berck: Um, so they actually are really cold. Um, so they are pointed edge onto the sun typically, or like roughly edge onto the sun. And so they’re actually not getting hit much with the sun. And so space ambiently is very cold and the Raiders have been designed to be very cold. So that way when we flow hot fluids through them, um, it cools off and then we can send that cold fluid back to the rest of the system to collect more heat.
Host: Okay. How hot’s that fluid then?
Logan Berck: Um, so it’s controlled to about like three degrees or four degrees Celsius. And so it typically stays at that temperature unless we have some sort of issue. Like for example, we might be doing a spacewalk where the crew’s gonna be working very close to the radiator, so we need to lock it in place in a position where it’s not going to be in their way. And if that position is bad for heat rejection, AKA if more surface area of that giant radiator is getting hit by the sun, um, then we may start to see those temperatures start to kind of rise up. And so if it ever got to like 15 degrees, that’s kind of our trigger to shut the loop down. And so we obviously try to avoid that. Um, and we have some ways to shift kind of the loading between the two radiators and kind of help each other out. But that is the gist.
Host: Oh, wow. Uh, and then I know the ISS batteries were recently upgraded and that, uh, we’re doing a series of spacewalks, uh, to augment the solar arrays with the rollout solar arrays. Uh, how’s that changed the power systems of the station over time?
Logan Berck: Yeah, sure. So, uh, the batteries were all kind of about done by the time I started and so I didn’t kind of get to see a great before and after. But I mean, as you can imagine, 20 years on lithium ion battery technology. I mean, the old ones weren’t even lithium ion, so, um, they have a lot more efficiency. Uh, they’re newer, bigger capacity, et cetera. Um, for the solar arrays, that has been a huge help. We still have I think, two more to install. Um, so we’re at six of our eight channels now have them. And it has, uh, even though the new solar arrays are smaller, they, they roll out over on top of the old solar array. So it actually shadows some of the legacy array to where those cells aren’t even being used. But even despite it being smaller and covering some of the old one, the technology has just improved so much. And just the fact that they’re new, we’ve more or less restored the original capability of the full set of eight arrays.
Host: Oh, that’s really neat. Uh, so I wanna go back around real quick. And when I was working broadcasts for, uh, things like vehicle dockings and spacewalks and stuff, I’ve seen that, uh, there are some very symbols, uh, or unofficial mascots that, uh, sit near the console’s nameplates. Uh, do any of your consoles have, uh, any mascots or traditions or anything that people might see?
Krista Farrell: Sure. Um, for ADCO, um, you may have seen the baseball bat that sits across the ADCO nameplate. Um, and that is just our attitude control device.
Host: How, how do you control attitude with a bat
Krista Farrell: <laugh>? I don’t know that I’m allowed to say <laugh>. Careful. I’ve never had a threaten a foreign or TOPO with it. <laugh>
Host: TOPO, do you have anything?
Joe Scalora: No, we don’t have an official mascot. Um, although the, the flight directors will hand out what’s called the gremlin, and that’s a furry friend. That means your console has brought doom to the flight control team. So often the TOPO console gets the gremlin, like we’re in control of what debris wants to come close to Space Station <laugh>. Um, but that’s why we’ll, we’ll get the Gremlin every once in a while. We don’t have an official mascot.
Host: Is, is there like a, a little gremlin that you actually get, mm-hmm <affirmative>. Yeah. Yeah. Oh Wow
Joe Scalora: Yeah, they just walk over to your console and say, good job. But you also get this <laugh>,
Host: Oh no, <laugh>, SPARTAN. Do you have anything?
Logan Berck: So we have two. So the first one is a little SPARTAN Warrior helmet, um, and then the other one is a like Halo master Chief. ’cause like in Halo, they’re like the Spartans as well, so.
Host: Oh, that’s really, really clever there. Um, so going on to the mission of the ISS here, uh, can we talk about how your consoles all work together to, to help support the ISS?
Krista Farrell: Sure, yeah. Um, ADCO actually sits right between TOPO and SPARTAN and um, we do a lot of work with both of them. So for SPARTAN we really like Spartans ’cause they give us all the power to our equipment. So the CMGs, um, one of the great things about them is that they only require power to operate. So instead of using propellant, which is a consumable that we’d have to send more up, um, we generate enough power on the ISS to keep the CMGs going, uh, which is great. Um, we also work with Spartans a lot because, uh, what we’re doing for ISS attitude control, um, drives a lot of constraints for what they can do with the solar arrays and sometimes even the radiators. And so if we’re gonna go to Russian thresher control, like Logan mentioned, um, the solar arrays need to be at safe angles. Um, and so our consoles do a lot of coordination both, um, in real time planning and making sure that our plans line up. And then also if there’s contingency cases, we work a lot with Spartans on that too.
Joe Scalora: I’ve got a pretty easy role, at least we’re trying to move the space station and I need the two of them to do that. So, um, yeah, for TOPO at least I’m gonna rely on ADCO and SPARTAN to configure station so that we can actually do a reboost or a debris avoidance maneuver. That’s definitely the, the, um, chief responsibility of the two of them. Um, for, you know, there’s some tangential things like the onboard GNC for example, has some parameters that we have to keep up to date and TOPO will provide, um, those inputs to ADCO so they can up, they can command them on, you know, a monthly basis for example. And that’s just so that the ISS knows exactly where it is and knows exactly where the TDRS are so that it can maintain pointing. Um, so those things happen routinely.
Logan Berck: Yeah, I just wanna echo what they say, um, work with both of them on the things that they mentioned. Um, we, I think in those aspects are kind of a combination of just a service provider, like AKA, just giving power, making a power down plan so we can get through the event, making a solar array plan so we can get to the event. Um, and then just actually, uh, executing the plan and doing all the commanding to make it happen. And then, uh, like Krista mentioned, um, everyone needs power. So, um, <laugh> we get to work with everybody a little bit and get to have some at least surface level understanding of what they do and what the impacts are if they lost their equipment.
Host: Are there any consoles that aren’t here that you guys work with, uh, regularly?
Joe Scalora: Probably say VVO is the, the Visiting Vehicle Officer. Um, so you mentioned the broadcast of, you know, vehicles that dock and undock from station. Um, the visiting vehicle officer on the day of docking or undocking is in all of our ears in the same way that I would want ADCO and SPARTAN to make sure that we’re go for a reboost, they need the systems to also be go for docking or docking. Um, and there’s an interesting, you know, handover between TOPO and VVO and during the flight, of a visiting vehicle where we transition to what’s called farfield, it’s more traditional rendezvous design to proximity operations where the actual spacecrafts relative navigation systems take over. And so that’s when the VVO is front and center in the flight control room.
Logan Berck: SPARTAN works with, um, OSO quite a bit, so they’re kind of like the on orbit maintenance, uh, officer console and they work with procedures to guide crew through doing upgrades like removing failed equipment, putting in new equipment, et cetera. And SPARTAN can be very involved in reviewing those plans and working with them on the day of, because a lot of the equipment is electrical in nature and if the crew’s going to be mating and demating cables, we need to put in electrical saving AKA, having sufficient levels of unpowered, um, upstream switches so that the crew is not at risk of, um, either shocking themselves or creating molten metal that could then become like dangerous debris in Space Station. Um, and then we also work a lot with ethos for, um, the thermal control interface. So Ethos controls the internal cooling system, we control the external cooling system and their system rejects heat out to our system. And so there’s a lot of like collaboration and coordination that needs to happen with that on occasion.
Host: Oh, that makes a lot of sense. Uh, do you also work with PLUTO a lot?
Logan Berck: Um, we do have some coordination with PLUTO. So they, one of the main ways that we interface with them, they control what’s called the plugin plan. So imagine keeping track of every single thing plugged into every single outlet in your house at all times. Like even if, you know, let’s say you have a kid and they move their iPad charger to the other room, like they need to know about that and track it. Um, and so we have to be able to understand, ’cause Pluto doesn’t work 24/7, and so as Spartans, we have to be able to understand how to, uh, at least read that plan and understand it. Um, and then, um, the equipment that the crew plugs stuff into the wall outlets are actually called UOPs or Utility Outlet Panels and SPARTAN owns the hardware part of that and so kind of they control what’s plugged into it. We control the hardware, um, and so there’s some collaboration and coordination there as well.
Host: Okay, that makes a lot of sense. We’ve mentioned a lot about how ADCO and TOPO have to keep track of visiting vehicles and uh, uh, the things that are around the outside of the station when there’s an EVA, do the astronauts on the EVA count as a, a vehicle of some sort that you guys have to keep track of?
Krista Farrell: Well, ADCO keeps track of them, but not so much, um, thinking of them as a vehicle. Again, it goes back to, um, the thrusters that we have and, uh, we obviously don’t want crew members to be near those, but we also, um, there are certain things on the outside of the Space Station where we don’t want a crew member, you know, pushing on that at the same time that we’re firing thrusters. So ADCO is really following crew member location very closely in an EVA to know when we could, um, use the Russian thrusters if we needed them. Um, but that’s, that’s why we pay attention.
Joe Scalora: Yeah, for TOPO it’s, well, for every, every flight control member you have to pay attention to the crew. When they’re outside the door, they get that full level of respect and attention. Um, for us in particular, it’s the overboard items. So a crew accidentally drop something or even if it’s, it doesn’t come intentionally from a crew member, it could come from an airlock as it’s, you know, depressing. For example, as soon as you open up the shoot, something comes flying out. Um, so it’s one of TOPO’s responsibilities to inform the flight control team whether there’s any risk of that object coming back to, to Space Station, um, and to inform our colleagues at space command so they can begin tracking that object. And it becomes part of the 20 plus thousand objects in space. And um, usually, you know, you drop a hand towel or something that there are some items that you cannot bring back into Space Station because they have, you know, fluid on there that’s hazardous. So you do have to chuck some things on purpose. And hand towel, for example, decay very quickly. Um, they’ll be in the atmosphere in a matter of days, but you know, if you lose a tool bag for example, that’ll be in orbit for quite a while.
Host: That sounds like a lot of responsibility watching for tools floating away during the EVA
Joe Scalora: <laugh>. I can’t say that it’s a team effort. So yes, when TOPO is sitting in the seat, you get pinged nonstop. TOPO did you see that <laugh>? I thought it saw a fleck <laugh>. So we’re, we’re just receiving it from other people. We don’t catch everything <laugh>.
Host: So you guys are the ones that are in mission control in the seats doing the, you know, front room work. Uh, what kind of support do you guys have from back rooms?
Logan Berck: So in SPARTAN we actually have two backroom positions. So we have one, um, that we call Spock as like a nickname. It does have an acronym, but um, they are trained in the same technical information that a SPARTAN front room is trained in. And so the difference is kind of the focus of the work that they’re doing. So while SPARTAN in the front room is integrating with the rest of the team, speaking to the flight director, kind of speaking for the console and doing all the integration work, um, the back room is really focused on kind of being the expert in our system, really focused on the commanding and the execution and the procedures and the timeline. And so, uh, that frees up a lot of our bandwidth so that we can keep SA and what the crew’s doing or what the rest of the team is doing. And then we have an additional background position called PRO or Power Resource Officer, and they do, uh, the sort of short to medium term power planning for ISS. And so whether it’s taking a look at, hey, how much power do we think like we’re gonna get out this new, uh, rollout solar array, or hey, where, how much power are we gonna have during this EVA where the solar arrays have to be parked in six months? Um, and then they also do more in depth, uh, very detailed analysis for the weak outlook at power. So they’re modeling, they’re getting inputs from all the payload community, all the other flight controllers that have hardware to say like, this is the configuration. We think we’re gonna be on string two of this carbon scrubber, et cetera. And so, um, they are taking all of those inputs and then using a analysis tool to model all the power on station. And then they, uh, observe and assess that power throughout the week and say, okay, well we need to shift some power to this channel on Tuesday because of this spacewalk that we’re doing, or we need to perform this power down for this stocking that we’re doing on this day.
Host: ADCO, what kind of backrooms do you have?
Krista Farrell: We have two backroom as well. Uh, the first is Hawkeye. You can think of Hawkeye, is to ADCO what Spock is SPARTAN. So they have all the technical training that ADCOs get, um, that their focus is on looking at all the telemetry, the data that we’re receiving and then sending any commands. Um, we also have another backroom, Pointing, and they do the long term communications predictions for the ISS and they’re also involved in line of sight analysis, um, which really what that means. If you’ve seen any of the cool photos astronauts have taken of like hurricanes or other rocket launches Pointing was probably involved in like determining what they could see and how they could photograph it. Um, so they do a very different type of work than the ADCO team does. Um, but we really appreciate all the cool stuff they do for the ISS.
Host: That’s really cool.
Joe Scalora: So TOPO historically has been a single flight control room position. Um, up until about five years ago, uh, we saw a need really as driven by training objectives. Um, back rooms in addition to supporting mission, provide great opportunity to get trainees in SIMS so that they can achieve their front room certification faster. Um, so we have an ORCA that’s an Orbital Reboost in Conjunction Analyst. We all make up backroom names, you know, so ORCA is what we went with. Um, got an ORCA pod people that are certified to be Orca. Uh, they support Reboost and to be avoidance maneuvers. Um, they support, you know, sims so they can get, you know, that time in the seat and then it, it’ll help them achieve the TOPO cert faster.
Host: So how do you guys deal when something’s going wrong? Like what, what if the station moves unexpectedly or gets off course? Is that even possible?
Krista Farrell: Well, the station’s definitely moved unexpectedly. Um, we call that a loss of ISS attitude control, and this can be caused by hardware issues, um, software issues, or sometimes we have unexpected forces pushing the ISS, um, away from where we command it to be. Um, and we call these Loss Of ISIS Attitude Controls or LOAC. Um, when that happens, ADCO um, kinda has a funny role because we are in charge of working with the flight director and the flight control team, to lead the, the response to a LOAC. Um, but we don’t actually do any of the commanding, so we’re just coordinating, um, making sure that everyone is doing what they’re supposed to at the right time. And that is because, uh, when we LOAC, the goal is to first safe all of the hardware on the ISS. Um, so really the big ones are the solar arrays and the thermal radiators. Um, but there’s also payloads that may need to be safe, uh, depending on the operations that we’re doing that day, like robotics, we might need to get those in a safe configuration. And once all of the hardware is safed, then we can hand over attitude control to the Russian segment. Um, or really they take attitude control at that point and they will maneuver us back to our commanded attitude on Russian thrusters. Uh, so ADCO yeah, is following along, um, you know, saying like, this is what needs to happen, here’s who needs to do that, but we also train the crew on how to respond to a loss of ISS attitude control, and so they can actually do the whole response without any help from the ground, um, in the event that they lost communication with us.
Host: Wow. Do you all have any examples of, uh, maybe an event or, or something that’s happened where you’ve all had to work together?
Krista Farrell: Recently, I supported a PDAM, a debris avoidance maneuver, um, just a few weeks ago, so I was not on console, but the ADCO who was on console needed help. So I came in as a Hawkeye, um, to help command all the stuff for the PDAM and TOPO was there, um, you know, telling us like when we needed to burn, um, to change the altitude to avoid like, uh, debris. And then of course we also worked with the SPARTAN and Spock, um, to make sure the solar arrays were safe before we did any of that.
Joe Scalora: Yeah, it’s really unfortunate that we have so much debris space, it’s gonna be, is gonna be a theme maybe. Um, but I’d say one of the most common like contingency plans that make its way to the front room is planning debris avoidance maneuvers, and ultimately we don’t execute a whole lot of them because we can, we can really take it down to the wire, but I’m sure we’ve all been on console numerous times where, um, we’re pulling all the systems to be go or no go for the maneuver. And then, you know, some final tracking updates on the conjunction will, will reduce the probability collision enough that you don’t have to do the maneuver and then it doesn’t make the news or something. But this, these events happen monthly really. So that’s, um, something we sim something we train, but that’s one that’s one that reaches the flight control room pretty often. <affirmative>
Host: You mentioned forces that can kind of change the, the attitude of the ISS unexpectedly. Uh, are, are we talking something like solar flares or is there something else?
Krista Farrell: Oh, it’d have to be something bigger than that. Um, so something we sim a lot is maybe some tanks on the ISS, um, maybe get hit even by some, uh, micrometeoroid, like orbital debris, um, something like that. Um, we’ve also had, uh, problems in the past where, um, thrusters fired when they weren’t supposed to. And, uh, thrusters are much stronger than the control moment gyroscopes. So sometimes when that happens, um, by mistake, we, we have LOAC’ed in the past because of that and had to recover attitude control
Host: With SPARTAN. Uh, do you guys have problems with, uh, power surges ever or did something cause that,
Logan Berck: Um, yeah, actually last year even we had like a Voltage Brown Out on a channel, so the voltage like dipped sufficiently low just due to some just transient on the electrical bus that it caused the whole power channel to fail. And as a result of that we, um, Spartan’s role, so this is what we call Critical Bus Loss. So Spartan’s role in Critical Bus Loss is kind of like ADCO’s role in a LOAC. So SPARTAN is kind of in charge in leading the response to the Critical Bus Loss. So that’s identifying what failure happened, what level in the power chain the failure is at, and what corresponding procedure that, um, the ground and the crew need to run together to get through the event to repower, reconfigure, um, important loads on redundant strings and then figure out from there like what we can repower based on the failure. If it was just a transient, maybe we can just turn everything back on over the course of several hours and maybe that’s fine. Um, but in other situations it might be a more permanent failure where, hey, we’re not gonna get this back until we go do a space walk. And so how can we use, um, jumpers or kind of like an extension cord to get power to this location in the short term, or can we be down, um, one string of this flight computer for the next two weeks? Is that okay? Right. So things like that.
Host: Do you guys have any other anecdotes that might be interesting to share?
Joe Scalora: We have a lot of fun building sims. That’s something that Krista and I have done many times. So yeah, we focus a lot on, on what happens in real life, but there’s an exhaustive amount of effort spent, um, basically brainstorming just like this to come up with cases that confound the trainees that are, you know, actually going to get certified to be in our position. Um, so the exact questions that you’re asking, we ask ourselves what can we, what can we make up that’s within reason and what can we play as a, as a malfunction? And then let’s watch them respond.
Krista Farrell: Yeah, we, we train, um, kinda the worst case scenarios that we could think of. And the reason that we do that is because there’s definitely as good as our simulator is, um, you still know that it, you kinda know it’s fake, right? Um, but when you get into mission control, there’s this huge weight of like, this is the real vehicle. There are real people on there that we care about. Um, and so we spent a lot of time yeah. Training for the worst case so that when the brownouts happen and you have one failure, um, you know how to like take a breath and work through the problem. Um, because I think the anxiety and like the nerves definitely go up when you know that you’re working with the real space station and the real crew on board.
Logan Berck: Yeah, I totally agree. Shortly after my final, which I probably had five major failures with other people that had failures that they needed my support for, looking back on my sim, I remember being very calm, very in control. First failure, real time, I just had one little RPC trip to a load that was a little bit important, but not that important. And I just remember feeling like it was the biggest deal ever. And in Sims it would’ve been a complete, like, not stressful event at all, but just knowing that it’s real, you know,
Host: It gives that extra weight because there, there are lives on the line, on the space station, you know, it’s a, what what you guys do is extremely important and you know that any little thing can, can be become a big thing easily. Um, I really just have one more question for you all and uh, you know, a lot of our listeners, uh, are really curious about how can they get involved in, in NASA in space flight and how might they get to where you are today? Uh, so what kind of special areas of study, uh, are, are most beneficial to people in your kind of roles? ADCO, can we start with you?
Krista Farrell: Sure. Uh, most of us, um, ADCOs have aerospace engineering degrees, but we do have some mechanical engineers. We’ve also in the past had some physics majors, but, um, you know, learning about orbital mechanics is important. Dynamics and control. Having a little bit of knowledge of navigation systems, um, we use GPS, having some background knowledge on that is really important, but probably the biggest thing I would tell people to do is like, put themselves in situations, um, where you’re learning how to think through problems and work with other people to solve those problems. Um, because I use a lot of the technical aerospace things I learned in school, maybe a lot less than, um, how I, when I learned how to learn and learned how to work with other people to solve problems.
Host: TOPO how about you?
Joe Scalora: Yeah, no, I couldn’t agree with Krista more. Um, you’ll find there’s a lot of different backgrounds here in in flight operations. Um, so many of us have engineering degrees, but the range of of backgrounds is really, really significant. Um, finding opportunities to lead in whatever you do, you know, resonates really strongly with NASA. Um, so if you’re considering USA Jobs to, to find a job here, um, it’s less about the, you know, degree that you had, it’s more about, you know, how you succeeded in that, you know, learning how to learn, learning how to solve critical problems and being a leader in that. Um, you’ll never, you never really know. When I interviewed here, um, I had a, a, you know, senior design project where we were developing a replacement for the International Space station and I pitched that to the ISS flight controllers and they didn’t hate it <laugh> unfortunately, but they didn’t hate it. Um, but that wasn’t even really what stood out in the interview. I got the most questions about my experience as a soccer referee when I was in high school because as a, you know, 16-year-old officiating, you know, 12 year olds on a field and dealing with the parents that was like, okay, you’re in charge of, of this specific thing. Tell us how you manage that situation and how you kept doing it. And we talked for like, I dunno, 30, 45 minutes about that. Um, and then in the feedback of the interview, it was like, we loved the referee experience. It’s like, I I just threw that on the resume because that’s how I made money when I was in high school <laugh>
Host: That’s so interesting
Joe Scalora: Yeah, you never know.
Logan Berck: Totally really, I was a lifeguard in high school and I felt like it’s similar. I mean, you got, you have all these lifeguard stands, it’s kinda like little consoles and you’re, you’re trained in, you know, rescue skills and you’re evaluated and, um, it’s a lot of the same just fundamentals. So getting to do something operationsee in like at such a young age and then growing those leadership and operational skills over time is huge. Um, similarly we’ve had people maybe that have like a biology degree, but they were a high school teacher that now they’re a SPARTAN because, um, maybe they really liked in the interview that instructional experience that they had. ’cause a big part of what we do is training flight controllers in the crew.
Host: That’s really cool. There’s such a diverse background in mission control despite the, the similarities of, of what’s going on in there.
Joe Scalora: Yeah. One other thing to note is they, they train us. So if you like, it’s very funny to have a four year college degree get to your place of work and then they say, forget all that you’re gonna learn this for two years. And luckily there’s some overlap with most of us, but, um, they’re dedicated to training us. So, you know, your background is really just showing that you can learn and then you’ll learn what you need to learn for this job. Yeah.
Logan Berck: In SPARTAN, you would think there’d be, you know, at least half or maybe more electrical engineers, but we’re actually mostly aerospace and mechies, but they fully train them on the power system and they understand everything they need to know. Um, and of course as an electrical engineer, you know, I have a, a leg behind the mechanicals when it comes to the thermal system, but um, they train me on everything I need to operate the vehicle safely.
Krista Farrell: Yeah, I would echo that. I’d say even if you don’t have ops experience, um, or you dunno what it’s like to be a flight controller, we can definitely train you on that. We can train you on the technical side of what the ISS is, but we also do spend a lot of time helping you develop your communication skills, your leadership and team coordination skills. So if you’re interested in applying, come join us.
Joe Scalora: USA jobs.
Host: <laugh>, you, you mentioned the communication skills are, are there a lot of communication skills you need for like communicating, say with the flight director or with other consoles as as things are going on?
Krista Farrell: Absolutely. I say that is probably one of the things we have to spend the most time working with the ADCO trainees on. Um, you need to be concise, um, because especially when things get really busy, there’s a lot of people who want the flight director’s bandwidth. Um, but you also to be very clear, so you have to be able to take what can be really complex technical topics and boil them down into what flight and the rest of the flight control team really need to know. You also have to, um, be good at listening, I think is another key part. So active listening, um, not just kind of half tuning into what other people say, but really processing what they’re saying, um, and thinking about, uh, what that means for you.
Logan Berck: And then I think another aspect, especially for SPARTAN, you have to be able to communicate for a very wide audience. So we have partners in the commercial industry that are listening to our loops that we coordinate with. We have partners in, uh, Europe and in Japan and in Russia. And we have to be able to communicate in a way that they’re all going to understand that even if English isn’t their first language, um, or you know, different levels of people even here at JSC may not know all the details. Like a flight director, like if I give them some acronym of a hardware, they may not know what it is, but if I say a motor controller instead of an RJMC, they’re gonna know exactly what I’m talking about. And so being able to communicate to, um, your backroom, but also the other FCRs, but also the flight director and knowing when to kind of, uh, code switch between the different people you’re talking to, um, is a really huge skill.
Host: That makes so much sense. Well, thank you all for coming here today. I really appreciate you, you coming on and, and telling us more about what it is you do as the motion controllers in mission control. So thank you all.
Logan Berck: Thanks for having us. Yes, thanks.
Host: Thanks for sticking around. I hope you learned something new today. This is the first in a series of podcasts we’re doing, highlighting the roles of all the different consoles in ISS Mission Control. Be on the lookout for more mission control centric episodes in the coming months. Our full collection of episodes is on nasa.gov/podcasts. You can also find the many other wonderful podcasts we have across the agency there as well. On social media we’re on the NASA Johnson Space Center pages of Facebook, X and Instagram use hashtag #askNASA on your favorite platform to submit an idea or ask a question, just make sure to mention it’s for Houston We have a podcast. This interview was recorded on December 16th, 2024. Thanks to Will Flato, Daniel Tohill, Courtney Beasley and Dominique Crespo. Special thanks to Chelsey Ballarte, Jayden Jennings and flight Director Paul Konyha for helping us plan and set up these interviews. And of course, thanks again to Krista Farrell, Joe Scalora and Logan Berck for taking the time to come on the show. Give us a rating and feedback on whatever platform you’re listening to us on and tell us what you think of our podcast. We’ll be back next week.