 Welcome to NASA and the Seller Foundation's Space System Engineering Course Unit 1, What is System Engineering? The unit objectives for Unit 1 include, explain systems engineering in the context of the aerospace industry, discuss the need for systems engineering, give an overview of the NASA system engineering engine and its associated processes, identify the attributes of system engineering. Unit 1.1, common definitions of system engineering. Today we're going to talk about system engineering, what it is, what does the system engineer do when they come to work every day and specifically how does it apply to the missions that NASA does for the in the aerospace community. So a lot of the other material you're going to see in the course going forward will get into the specific processes, the tools that are used by system engineers in their daily life but today we're going to kind of back up and just talk in general what is system engineering all about. A system is an integrated composite of people and people in a lot of cases in system engineering, you're talking about all your discipline engineers, you have thermal engineers and power engineers and a variety of people that are involved in a system. You can't forget, sometimes people think of system as the product which you see on the slide as well. The product is the actual physical hardware and software that you're going to develop as part of the system but the people are just as important to developing a system engineering concept. So people and products and then you see processes on the slide as well. So all three of these are kind of key to putting together a system engineering process and to managing a system development activity. So all of these are combined to satisfy some need or goal or objective that you set out for the system. So we'll talk more about that but the goal is to kind of set a site where you want to get what does the system need to look like, how is it going to operate and then what are the people, products and processes I need to put in place to make all of that happen. The term system engineering really was developed in the 1940s. So there was people doing system engineering forever, right? Anytime there was a big project, when the Egyptians built pyramids, they had to have some processes, they had to have some way to communicate because the system was too big for any one or two people to be able to kind of manipulate the whole thing and make it work. So when you have these big teams, you need to have standard processes and tools. So system engineering has been around a long time but the formalizing of it really developed in the U.S. in the 1940s, so kind of in the World War II era. And the Nike Missile Program in the 1940s was kind of the first program where people started to use the term system engineering. The Nike Missile Program for the Army was a way to try to defend the country from jet aircraft that might attack. Jet aircraft were being developed and the threat of jet aircraft couldn't be met by the traditional ground to air missiles that were available. So you needed high speed, highly accurate missiles and that was going to be a very complex program that involved a lot of different technologies coming together. And so the idea was it's a very hard problem to solve. You needed to bring together a team of engineers and then you had to have engineers who would kind of make sure they were coordinated and that a system was developed out of it. Bringing the importance of this anti-missile system to the protection of the free world, the Army is pursuing the development of Nike Zeus on a high priority basis. When it comes to NASA's history, our first big effort in system engineering was Apollo. In the Apollo program you were bringing together elements from around the country and a lot of different systems and capabilities had to be brought together to make it work. And so system engineering at NASA really started to be formalized during the Apollo era. And at this point and if you go online there are many sources, the NASA system engineering handbook is available many different places online where you can see all the different ways now that we have formalized that methodology and that's again what you're going to be learning in this course. System engineering is a rigorous approach to designing, creating and operating a system and you know there's other things too. You're trying to optimize the system to meet the requirements and the goals that you set for it. Let's just talk about the two words. So first this involves engineering. So system engineering at its core is engineering work. So engineering being the application of physics and math and science to solving some problem. There's something that needs to be done and engineers step in and use the laws of physics and mathematics to go ahead and find some solution for it. And there's all kinds of different disciplines may be involved. So depending on the problem there might be chemists involved, there might be metallurgists involved. But the end goal is to engineer a solution to some real-world problem. And so there's a couple examples on that chart. Something like building the Hubble Space Telescope Mirror that you see on the one side or on the other side you see some folks at a Marshall Space Flight Center trying to build a new type of lunar lander. And so in either case you've got a team of people coming together and they're starting to look at the different ways to make this system work. Now a lot of engineering can happen at the very basic level. So some engineers are only working on maybe the design of a battery for a spacecraft. Some engineers are only working on how to build the thermal coatings that go on the outside. Those very specific engineers that are working in their disciplines, that engineering can happen at a small scale level with small teams. And they can make changes just based on their experiences and develop a better and new product based on their experiences. But when it comes to bigger things, not just maybe a small application, engineering can become more and more complex. So if you go to the next chart, you see that the next part of system engineering is the word system. And so as problems become more complex, the engineering techniques and the processes you need to use also become more complex. The number of people involved becomes more complicated. Here you see an example of the space station. So the space station is an example of a large system. You see that there's one element of it is the space station itself, the thing that's in Earth orbit. That's allowing crew to be on board and running experiments and doing all kinds of cool and neat things. But that's only one part of the space station system. What you see on the rest of the chart is all of the other elements that make up the system. There are cargo vehicles delivering cargo to the station that are coming from all over the world, Japan and Europe, from commercial vendors from the Russians. There's also crew vehicles coming back and forth, the Soyuz capsule delivering crew and returning them back to Earth. There's also a lot of other elements of this system. You see some large communication satellites in the background. Those have to be the relay data from the space station down to Earth so that people can communicate with that crew on board. There's also many facilities spread out around the world that have to be integrated together to make the station operate, to send information up to the station, to take the data from the station and send it out to the scientific community that needs to see it. So in this case, you've got a very large system that has to be coordinated with thousands of people that have to make this thing work. And this is where system engineering comes into play. And so system engineering, it really adds a discipline when you get to these large scale projects. So as engineering has become more and more complicated over the years, the idea is mature, that you need tools to do this. You need processes. And those processes need to be standardized so that everyone speaks the same language. Everyone uses terms that everyone else can understand. And so that's a lot of what you're going to learn in this course is, what are those terms and what are those processes that everybody uses? The system engineering approach consists of identifying and quantifying system goals. And so at the beginning, we'll talk that you start with an abstract idea. You'd like to maybe learn more about the universe and how planets around other stars might be able to be seen from Earth. And so I've got this goal. I've got this very high level thing that I'd like to achieve. Now I have to break that down and understand, how can I develop a system to actually do that? So I'm going to use an example here. You see some pictures on the slide that maybe remind you of the space shuttle in some way. Maybe not exactly what you remember the space shuttle looking like, but we're going to walk through this process. And at the beginning, you've got this high level goal that you'd like to achieve. And maybe you have many different ways of developing a system to meet that high level goal. So it says, a creation of alternative systems and design concepts. So along the way, as you try to meet this goal, you may try out a lot of different ways and a lot of different systems that might be able to achieve that goal. Now you want to go through a number of trade studies. So the system engineering approach consists of performing trade studies, design trades, where you're starting to look at, well, which one of these potential systems might be the best at meeting that goal? What's the optimal way of achieving what I'd like to achieve with the system? So the system engineering approach consists of selecting and implementing that best design. Best is maybe some subjective, some objective. You have certain things like, in the case of what you see here, this was actually some early design work for the shuttle. You have some best might be, it has to be able to carry the most payload up into space if it's a space shuttle. But then best might be, you think it's the safest way of doing it. So there might be some subjective and objective ways that you're going to consider, what's the best way? And once you've selected an approach, you're going to go through and do some verification of that design. I'll talk more about the term verification all the way, but verification says if I build that system, as I'm building it, I want to check to make sure that in the end, it's going to meet all of the requirements. Can it carry all that payload to space? Is that shuttle going to do all the things? Can it carry seven crew members? Is it going to do all the things that I set out for it to do when I first wrote down my goals and my requirements up front in this process? And so as you go further into the process, you've verified that the system is developing the way you want it to to meet that high level set of goals. And then at the end, you're going to say, okay, I've got this vehicle, I've built it. Now, can it meet the goals that I set out for it at the beginning? So we're going to learn about a term called validation where at the end, you want to know, will it operate the way I said it should when I set out to build this system? And so we'll learn about verification where along the way you're seeing if it'll meet each individual requirement such as how much mass can it take to orbit? And then we're going to validate the entire system to say, as a system, does it do all the things? Does it operate the way that we expected it to? We'll talk about one of the major processes of system engineering. It's kind of the largest abstraction of system engineering is, how do you move from an idea to a system that's completed and operating? And so here you see the Mars Curiosity rover. And we're going to use that as an example to kind of walk through very quickly to describe the process of system engineering. In the upper left-hand corner, you see the initial requirements that the scientific community came up with to come up with a new rover to send to Mars. They said, gee, we'd like to learn more about the geology of Mars, more about the atmosphere of Mars. And we'd also like to know if Mars could have had life on it at some point in the past, was the environment conducive to having some form of microbial life developed and survived? And so when you're doing system engineering, you take those initial ideas, and now the first step is going to be to look to see if there are any tools out there that already can do what is needed to be done. So if you look in this case, there are other rovers that have gone to Mars. So could those rovers do the science that's being asked for? Could they answer the questions that you've come up with? And so there was the Sojourner rover, many in the late 1990s, early 2000s. There was the Spirit and Opportunity rovers. So you can look at the science from those rovers and say, could they help us in answering these basic questions? The first step of system engineering is, is there some way to get this information without having to even build the system? Maybe we can just use an existing system. So in this case, the answer was no, that the existing rovers weren't capable enough to do the kinds of investigation that the scientists wanted to do on Mars, so a new rover would be required. You'll see that there's now the designing phase. You take this idea, you don't have an existing system that could perform the job, and you develop a new system. So you have to design it, you look at different ideas, how big should it be? Should it be a wheeled vehicle? Should it have tracks on it instead? So now the system engineering process is going through and doing trade studies, doing analysis of alternative options on how to perform this mission. And you're looking at which one is maybe most cost effective, which one can be done the quickest from a schedule standpoint, and which one would require new technology. And in the case of adding new technology to a mission, it might make it very capable, but it also might add risk that if the technology isn't matured on time, your whole mission might be set back. So you follow it along that you go through a design phase, you come up with your concepts, you start to put out drawings of what this thing might look like. Maybe you look at two or three alternatives designs and you pick which one you think is most optimal for how you're gonna do it. You see that you also might do testing. So here you see a prototype of the Mars rover, and you see they're looking at the mobility system, the wheels. How are they gonna design the wheels? How is it gonna move over the surface to be able to go into the rugged terrain that they wanted to explore with this new rover? And so they aren't building the spacecraft yet, but they're building parts of it in a demonstration mode where they can test it on the earth and make some decisions about how to go forward. So you'll see that after you've come up with your design and you've done some prototyping, you're now ready to build the flight system that you're gonna use. So this is all part of the system engineering process from idea all the way through now to actually building the vehicle that you're gonna send into space. So you see them working on the front end of the rover here and getting the drive system ready for testing. And so this is the integration of a vehicle, the actual development of a vehicle. After you've done a lot of pre-work to get to this phase. And so a lot of people think that this is where most of the time and effort is spent is actually building the vehicle. But the system engineering tools and processes will tell you that all of that front end work you did, looking at alternatives, doing trade studies, looking at different technologies, coming up with different designs and trading them off, that's the most critical part of the process because changing things back in that early part of the process when you're working with designs and you're working with drawings, the cost of making changes is very small and you can try to optimize your design. Once you start actually making the vehicle, any changes that have to be made because maybe the vehicle isn't meeting the requirements, it's not working the way you thought it would, those changes are gonna be very expensive if you have to go back and change drawings and remanufacture components. And there could be a lot of ripple effect on your ability to meet your schedule, your ability to stay on budget. So it might be deceived into thinking that NASA spends most of its time building vehicles, we actually spend most of our time designing vehicles and that's where system engineering tools really come in handy. So if you go down to the lower left hand corner, you see that after we build a vehicle, it has to go through a whole series of tests. A lot of these tests involve putting the spacecraft or in this case the rover into an environment very similar to what it'll be like on Mars. And so there are large chambers where you could reduce the pressure, change the atmospheric components, put the sunlight onto the vehicle the way it would be coming if the vehicle was on Mars. And that's what you see here is that you see a person inside the chamber testing to make sure that the brightness of the sunlight or the artificial sunlight in the chamber matches up with what you would expect at Mars before they run some type of environmental test where they might lower the temperature to be like Mars at night to see how the rover would survive at night. All part of the system engineering process. Again, making sure that the rover will work the way it's required to work to meet that high level set of goals that you set out for it at the beginning. So you've designed it, tested it, you got it ready for launch and now you're gonna operate the system. And so the end of the system engineering process has to do with actually operating a system all the way through to the end of its life and then decommissioning it. So you'll learn a lot more about how these phases are translated into a whole lot of terms. The beginning parts are called phase A and phase B the designing phases, the building phases move in and the final designs phase C the building of the vehicle phase D and integrating it and the phase E operation. So there's all kinds of terms that will come up but put it in the context of system engineers really work through a formal process to take an idea and generate an operational system that's really the key. Click on the icon to read the art and science of system engineering and that'll provide you some more information about background on system engineering. And once you've read that, come back to this video and click on the link for understanding the value of system engineering, again, some additional work to help you understand the concepts.