 Welcome to subunit 4.2, concept of operations. So concept of operations or a conop sometimes shortened or to tell you the truth sometimes flipped around and called an operations concept just to confuse people. They all mean the same thing, but it's a description of how the system will be operated during its mission phases in order to meet the stakeholder expectations that you define in your needs goals and objectives. The importance of a concept of operations is multifold, right? It provides an operational perspective on how the system is going to be used. It stimulates requirements development related to the stakeholders or the users of the system. It reveals requirements and design functions as you consider different ways that the system might be used that might draw out different sets of requirements. Sometimes systems are used to do many different functions. So we'll talk about that. And it also serves as a basis for key operations documentation that will have to be done later. A concept of operations is a high level document. Later in the design, you'll be developing very specific operations documents that will say minute to minute, maybe how you're going to operate the system. But this one is first to lay out an overall perspective on a concept of operations. Information that you'll typically find in a concept of operations includes a description of the major mission phases for a NASA mission. It will include things like launch and on-orbit operations, maybe contingency or emergency operations, science data return, different phases of the mission. It'll also, you'll see in a concept of operations, an operations timeline, kind of from launch through the mission, when will different things be happening. It'll give you sometimes an end-to-end communication strategy, meaning how will you communicate back and forth, especially at NASA where we're flying these things in space. What will be the style of communication, the systems that you'll interact with to get data back and forth from the ground of the spacecraft during launch, during on-orbit operations, and all different phases of the mission. It'll provide a command and data architecture where it'll show, again, maybe how data will flow even on the ground to get data from where it maybe comes into an antenna on the ground all the way back to a mission control center or to a science facility where the scientists will be trying to process that data. A concept of operations will also identify operational facilities that are required. Maybe there are some to process a satellite to prepare it for launch. Maybe there are some that are needed to communicate it. You see mission control in Houston for the space station. There's got to be some operational facilities. And so those will be identified in an ops concept. Integrated logistics support, if there's any logistics required, and that's for missions that require maybe some resupply or resources to be supplied during the mission. Definition of critical events. For the space station, for example, that might include times when the astronauts do an extravehicular activity when they leave the spacecraft and go outside. The con ops is going to give you those critical events. So you might have to provide additional support or things to make sure that those critical events go safely. So you want to define those. Every mission we fly at NASA, it starts out early in its development with the thought about how are we going to operate it. We have some high level objectives we'd like to meet. Now we've got to go through and say what are the systems that would be used and how would they operate. And so early on, I'm actually a project manager on a mission that's just in the early phases. We're in the phase B or the early development phases. And we're having a concept of operations working group that's meeting probably every week with all of the people involved in the mission to flush out our concept of operations. It's a key product that we develop early in the life cycle. And so if you look at this first chart, I'm going to use this shuttle as an example. It could be a little confusing because there's another term used when we're developing early on. It's called an architecture. And an architecture is really all the subsystems and elements that make up this system. So if you look at this chart, you might look at there's a space shuttle with solid rocket motors and an external tank. And that's a system. It's a bunch of things that are going to come together to operate. The operations concept or concept of operations, people use it either way. So that concept of operations is really how it's more the story. How are you going to operate? And so it's less about the physical vehicle that you see here or the architecture. And more about how that architecture allows you to perform operations or goes through a series of operations to complete its mission, to operate as a system and to meet its end objective. And so just looking at this example here with the space shuttle, you have a system, a space shuttle with an external tank and two solid rocket motors. And it's going to go through different phases of operation. So initially, and it's not even shown here on the chart is, it's got to go through a ground processing operation. It doesn't start out at a launch pad. It's got to go through some process. The shuttle maybe has flown before. It's landed. It's got to be cleaned and inspected. Parts have to be rebuilt and redone. And there's a whole set of processes that have to happen to get it to a launch pad. When we think about a concept of operations, it can reach all the way back to that early part of the, for a reusable mission like the space shuttle into that part where you're going to do all the ground processing. What are the operations that have to happen to be able to get this thing out to the launch pad? It's got that large crawler that has to bring it out. But there's this whole concept of how you're going to process it, move it to the pad. And in a concept of operations, you're even thinking about very simple things. Am I going to bring it to the pad, launch stack vertically up and down? Am I going to lay it down, bring it to the pad, and then lift it up? And when you watch different launches around the world, you'll notice that the ground processing concept of operations or how they do it is done very differently. Whether you're the European Space Agency or whether you're the Russians, and you'll see the Russian rockets are rolled out on railroad cars and then stacked up or lifted up at the launch pad. And so there's very different ways of approaching this concept. Does the cargo, the satellite that it's going to carry, get put in at another facility? Or do you wait until you get to the launch pad before you put the cargo in? If so, that may drive you to do different kinds of facilities that you might have to develop, right? So if you're going to take this vehicle to the launch pad and then put all the cargo on board, you might have to have clean room facilities out at the launch pad to allow you to bring this up and stack it while the vehicle is on the launch pad versus if you were to do that in another building. So that's exactly why we do concept of operation development early on. It's to flush out the requirements that we might have for some of the systems that are going to be required. So if I'm going to do all the payload processing or the satellite processing somewhere else and then bring it to the launch pad ready to go and encapsulate it in a faring, well, then I've got to build certain facilities to support that. I have to interface with the satellite at different points to get data from it. So this concept of operations of how you're going to do it is going to drive out a lot of systems requirements. And so that's why when you're in phase A, you're developing a concept of operations that will help you in developing those initial set of requirements. So for this example, now you've got the shuttle to the pad and this kind of walks through. It's a visual and a lot of times the concepts of operations who use a chart just like this where you'll try to draw out what are the major phases of this mission, whether it's the launch phase. In the case of the shuttle, it's got these phases where it has to have the solid rocket motors fall away and parachute back because the concept says that they will be reusable. And so you had to design something that could be reusable. You want this system to be as reusable as possible. You have to be able to get the orbiter into space safely with the crew and be able to get that external tank, that orange tank, to fall away once you reach orbit about eight minutes after launch. And so that concept is really kind of saying, well, how do I go through this launch phase? How do I, you know, what are the steps that are going to be along the way? Got to go through high dynamic pressure heating regimes. And so I'm kind of looking at this whole concept of how I'm going to get the orbit and then how am I going to operate on orbit? And so in the world, the concept of operations underneath every concept are what are sometimes called design reference missions. So design reference missions may reflect one phase of this concept. So for the shuttle, you may have a launch design reference mission, which goes into much more detail about all the small things that might happen during the launch phase as you were sending to orbit. You may have a separate design reference mission that describes what you're going to do on orbit and what are the operations that this vehicle is going to have to perform. And one of the things about the space shuttle is that its nominal mission, maybe when it was first built, was to take a cargo up into space and drop it off in orbit and come back. And as time went by and the shuttle system was matured and the concept of an international space station was developed, now all of a sudden another design reference mission was required to say, how about we take that same space shuttle and operate it in a much higher inclination orbit and use it to bring elements of the space station up and put them on orbit and bring the crew back and forth to that space station. Now there are a lot of nuances there, right? Because the initial design reference mission only included a stay on orbit that was long enough to go up deploy a satellite and then maybe do some research on the space station and come back. Or on the space shuttle and come back. And that was all limited by the amount of resources available. So maybe the shuttle could stay on orbit for two weeks, maybe three weeks at the most. But now when you're going to the space station, you're going to dock to another vehicle, you're going to leave the shuttle, you're going to power most of its systems down, and you may stay on orbit for quite a long time. You're not using the shuttle as your primary vehicle. But now the designers had to think about from a requirement standpoint for that design reference mission, how could the shuttle survive on orbit for a longer period of time? Were there issues that are caused by either thermal stresses or radiation or anything else that for the shorter design reference mission that originally had been used, how would they translate into this longer design reference mission where you were on orbit for a longer time, docked to another vehicle? And so each time you design one of these new design reference missions, again it can help draw out all the requirements to make sure the vehicle is going to be able to support, the systems will support that operation. So here at the end you see the shuttle re-entering the atmosphere, a whole other design reference mission can be related to coming back through the atmosphere, both the upper part of the atmosphere where there's high heating. And then there's probably even another design reference mission you could build just to talk about the aerodynamic regime when there's enough air pressure now to actually use control surfaces like ailerons and elevators and things like that. So in the shuttle design, you could have many different design reference missions that can support one large concept of how this vehicle will operate the performance mission. So that's kind of even played out more on the next page. If you look at the next slide, you'll see that here you show the shuttle and this nominal mission of taking something to orbit and coming back, sure that's the nominal mission, that's how we like to operate each time. But there are parts of the concept that also have to take into consideration anomalous performance, right? So every satellite is always going to have times when it has a bad day and you want to know that you understand those bad day scenarios as well and how to operate successfully through them. So you see in this chart that not only do you have the nominal shuttle concept of operations where it goes to orbit and then comes back down and lands at the end of the mission, but you see other concepts here or design reference missions from that concept where it maybe has to abort during launch and come back and land at the landing site. That's going to add a whole other set of requirements. And so thinking about that concept, oh, I need a runway at the Cape and what are the loads on the vehicle? How do I get it safely down at different parts of the orbit that lift off? And so the other thing is at some point it will be impossible as you're going through that concept to say, I can't turn around and go back to the Cape because think of it, the shuttle gets to orbit in only eight minutes. So it's not very far into Ascent before there's no way it's going to be able to turn around and glide back to the Cape. But remember it doesn't have engines. That was an early trade study which shouldn't have engines. A jet engine, so the decision was no. And so now you've got this vehicle that's a glider. At some point it won't be able to glide itself all the way back to the Cape if a problem happens during Ascent. So you see another design reference mission here that says abort across the Atlantic Ocean. So now at some point instead of aborting back to the Cape you're going to abort and try to land somewhere overseas. So you have to have runways in place overseas that are okay to land a shuttle on. Not all runways are good for shuttles. And so you have to have special facilities out there so that the capability is in place. So by working through a concept of operations of what happens if we have a bad day? What are the options? Then you can start to drive out requirements. It helps you drive out requirements on your systems and it helps you drive out interface requirements where two systems have to work together. There are no additional resources for this subunit. Feel free to skip ahead to the next video.