 Welcome to the Penultimate Hangout on Air for the NASA Space Systems Engineering course that we're running with the Sailor Foundation. We're here today with Dr. John Mather and Systems Engineer Mike Menzel of the James Webb Space Telescope. And I will allow them to introduce themselves in just a moment, but we may put a hold on things while we see if David Rose, our presenter and Hangout on Air leader extraordinaire, will come back online shortly. Gentlemen, would you like to introduce yourselves? Yes, sure. Good morning. I'm John Mather. I'm a senior project scientist for the James Webb Space Telescope. I've been here at NASA Goddard since 1976, doing a variety of different things, starting with the Cosmic Background Explorer project and now working with a very large crowd of people around the world to make sure that we're doing the right thing for the next great observatory in space, the James Webb Space Telescope. And good morning. My name is Mike Menzel. I'm the James Webb mission, the Systems Engineer for the James Webb Space Telescope. I've been here at NASA for I guess about 10 years and I've been working on the James Webb for almost 15 years. I was a Systems Engineer even on some of the conceptual design studies. So I consider myself very fortunate to be in this job and we're looking forward to getting the next great observatory up there. David, go ahead. You've come back. Welcome. They've just introduced themselves and we're live. All right. I am so sorry about that, everyone. Internet can be a fickle thing sometimes, but thank you for taking over, Sean. And thanks for just rolling it with it. Dr. Mather and Mike, I really appreciate it. So I guess we'll just get right into the questions now. So the first one, maybe the two of you can talk about. So as students have gotten to know you throughout the course, your guest interviews, which have been great. You've both talked about the interplay or relationship between scientists and engineers at NASA. But could you talk about how often your two groups actually work together? I guess in the context of James Webb, are there prearranged meetings or how often do scientists and engineers meet up? What about the two of you specifically? Do you meet more often because you are maybe the respective heads of the units and then kind of disseminate that information to your groups later or how does that work? Go ahead, John. Well, okay. I work primarily with the other scientists on the project and so I don't see Mike all that frequently, but some of my team of leading scientists do see Mike every day. So many meetings are prearranged and scheduled because there's a sort of pulse and cycle in the process. People need to talk to each other and having some prearranged moment is always a good thing. And on my part, I think I make sure that the scientists are invited to just about, if not all, my technical meetings. They're certainly welcome to all. About the only meetings that we have that don't involve the scientists on my part are things that deal with personnel matters. But other than that, all the scientists are invited to my meetings and my interactions and as John said, I deal with scientists like Mark Clampen almost on a daily basis and his deputies. And I'm very lucky because most of the scientists here at Goddard have flight experience and they are themselves world class systems engineers. So the interaction I have with them is very, very frequent and daily. That's great. Thanks, Mike. Mike, perhaps you can, do you know if that's typical, I mean you have experience outside of NASA as well. Do you think NASA operates very similar to other organizations or does it differ in that respect? No, I think that I've worked for commercial DoD and NASA and I think that NASA is very unique in that respect. That the interaction with scientists on NASA on civil space missions is much more open, much more frequent with the scientists. DoD missions, you generally have a special program officer, that's an intermediary, things like that. And there's generally a little more compartmentalization. And on commercial it's even a little less frequent. So I think NASA really is unique in that the scientists and engineers really interact more than on any other arena that I've seen. Let me add that there's one particularly important factor about this which is that we scientists are pushing NASA and our contractors to do things that have never been done before. So quite often we encounter technical difficulties that are really tough. And so it takes a wide range of points of view and knowledge to try to solve big problems. We ask for the impossible and sometimes we actually get it. That's great. So I guess another question then. So I mentioned how Mike you came from commercial organizations and now are at NASA. And so your experiences is unique in that sense that you've been working on James Webb but not exclusively with NASA. And so do you think the two of you have different perspectives on the project because the different pathways that you got there? John you came from working on Kobe and then went straight to James Webb. And the success of Kobe is obviously wanting the Nobel Prize. And then Mike you've had the experience seeing JWST progress from multiple. So I guess John maybe you can start with that. Yeah sure. I guess the thing about systems engineering for scientists is that we have to imagine a project that's never been done and try to imagine how building blocks could be found and organized and put into a system that could actually do the job. So we have to be conceptual systems engineers before we actually know whether anything can really happen. So after we sort of design in our minds a system that could possibly do the job then we say okay can all these boxes be built? Can we build the mirrors? Can you understand how to make a great sun shield that will unfold in space and all these things that seem impossible at the beginning? Then say okay engineering teams, systems engineers are other ways to do these things. You know I think the scientists count on the systems engineers to know what's possible in every domain. And from my perspective I think that I just second everything John said. The different perspective I've seen is mainly has not been so much with regard to system engineering discipline. The actual things systems engineers do. But there are certain contractual environments that have to be you know that are obviously different. When you work for the contractors that you're concerned about things like the points of contact for official communications, things like that. And you obviously have to worry about cost and schedule and you know items like that. But in general everything John said is just the same. It really wasn't that big a difference between going from the contractors to going from NASA from me. Just some certain contractual nuances other than that the engineering is the engineering. That's great. So another, I think we kind of mentioned it during when Lisa Guara had her hang out on air. The subject of when James Webb kind of got threatened to shut down for a while. How did that affect you two personally? I mean did you continue your jobs as normal hoping that everything would pick back up and you just saying or did you kind of have to cool things off and find other projects to keep you busy? Well in my part anyway I just kept right on working as hard as I could. Our job is to keep the project going. And one of the most important parts of keeping the project alive is to keep it alive. You don't stop. So I guess Satchel Page was quoted saying don't look behind somebody might be gaining on you. So we don't look back. We just keep on running as fast as we can as well as we can. And it's actually somebody else's job to save the project. Our job is just to make the project happen. And from my perspective my whole team was still dedicated and committed to the project. We kept working as if it was going to go on. In fact many of us, many of the leads had to deal with the independent review teams during that time. So we were totally immersed in it and totally immersed in trying to answer the questions of these review teams in addition to the work that we had to do to keep it going. So a question that we just got in through the hangouts from Angelique and she asks So in Unit 3 about the project life cycle from pre-phase A through F and so she's asking what's the duration of each phase for James Webb and what phase is the project in now? Well the duration for each phase has probably been approximately three years for each of the major phases. That's the time period between the major reviews like the systems design review, the preliminary design review and this critical design review. And right now we've passed our mission, our systems level CDR, and we're in what we call phase D. We're actually building hardware, in fact many of the items, many of the more complex items have already been built, manufactured and tested. The mirrors of the telescope are all done, they're in storage right now. All have been tested, they've all passed their tests and we've just received and integrated all four of the science instruments here at Goddard. So technically we're in phase D and it's approximately three years per phase. Is that pretty typical again from your experience? Well it may be typical for NASA, I have some commercial experience and that would not be typical for commercial. But remember that as John said James Webb is the first of its kind, it's one of a kind. So we're treading on new ground here. So for something that's first of its kind and new, it wouldn't be atypical. So the Webb Telescope is planned to be 23 years from the first conversation about it to launch. The COBE project was 15 years, many projects are much smaller and they go much more quickly. If you don't have to invent as many new technologies and don't have to push the state of the art quite so far then you can go quicker. And if the budget is smaller you can go quicker because you have more local autonomy and a budget commitment can actually be made that stands and when NASA says this is the project we can go forward. So there are projects that are done in just a few years but those are less common nowadays because we've done the easy ones in the past. John, do project lifecycle phases, do they affect scientists the same way that they do engineers? Does your role change or do you talk about different things to go along with phases just like engineers work on different things for each phase? Sure, the project cycle changes completely. At the beginning let's draw something on the whiteboard and see if we could imagine how to put the boxes together that would make something happen. Now the project has grown so large we have well over a thousand people working today and most of them I don't know personally. So as you go from let's have a project to we have a project to we're about to launch the people change everything changes. So now scientists for instance are busy thinking about how are we going to run the observatory make sure that everything is ready to turn on the software that the scientists are ready to make their proposals all those things are things we didn't have to think about 15 years ago. That's great. John maybe you can give, there's a ton of great material and students have been exposed to it throughout the course but perhaps you can kind of give just an overview of the major advances of James Webb that the Hubble wasn't able to do but then also if you can talk about maybe perhaps the potential limitations of James Webb and maybe the most difficult things to achieve that you want to. Okay well the web telescope is conceived basically as a successor for the Hubble telescope pushing beyond where the Hubble can go. So when the Hubble Observatory had been up for five years committees were formed and people said well what's the next thing to do. So they identified that the infrared region was the place to go because the Hubble could not observe infrared past about 1.7 microns wavelength and it can't because it's warm it emits infrared light itself. So and we could also see from the Hubble data that Hubble was too small to see far enough away back towards the earliest moments of the universe. So there are questions that were hot on people's minds after the Hubble went up where we knew we could never answer them with Hubble. So what are they? Number one how do the first objects form after the Big Bang? Hubble saw that they were much farther away. Galaxies look like many of them are already fully formed even at the most distant reaches that Hubble can see. So number two how are the stars and galaxies formed as they merge together? Galaxies probably grow by small things joining together to make big ones. So theme number two how does that happen? Probably farther away than what Hubble can see. Number three how are the stars born nearby? The stars are born in the Milky Way where we live about two or three of them per year and some of them are happening nearby like in Orion there's a beautiful nebula in the sword of Orion and that's where they are happening now. So we like to look inside places like that to see stars being born. And finally how do planetary systems evolve? As we now know planetary systems are common. Many stars out there have them and there are about as many stars as there are planets and many are expected to have earth sized planets at about the right temperature to support life. So this leads to our final big theme which is how does that happen? How are planets set up so that they could possibly support life? So we can study that either in the solar system by looking into a little residue from the formation of the solar system or by looking at other planetary systems around other stars. That's great. Thanks. So another question that we just got in and can start with this but I think both of your perspectives would be great. Perhaps they're different maybe they're the same I don't know but Sergio asks what's the most exciting technology that was being implemented specifically for the James Webb? Well, I'll start. There are a couple of exciting technologies. The one that I like to chat about is the wave front sensing and control. The telescope itself is bigger than the launcher that's taking it up so we have to fold it up in a very complex manner. So that means you take a perfectly good telescope, you test it on the ground, you align it on the ground, it works great and then you bust it up. You bust it up, you fold it up, you put it in orbit and now you've got to realign it on orbit. And the kind of neat thing about the techniques that we're using is they were actually developed to fix the Hubble Space Telescope on orbit. So in part you could say some of the technology developed to fix Hubble because of that Hubble error actually enabled larger telescopes like Webb to go into space and I always thought that was kind of neat. The other thing that kind of consumes a lot of my time is the fact that the telescope has to be cryogenic as John just said. It has to be cool or it would glow brighter than the things it's looking at. So we have a telescope where about 3.5 metric tons of hardware has to be cooled below 55 degrees Kelvin, only 55 degrees above absolute zero. Materials change, properties change and that makes life for us engineers very interesting. So those would be my answers as to the cool technology. And what about you John? Well I think I concur with Mike about the coolest part but another thing that people worry about obviously is the fact that we have to unfold this gigantic thing in space and Mike mentioned that we have to do that and then align it but even just getting it to unfold reliably is something we're not that accustomed to. Nobody ever needed a sun shield as big as a tennis court the way we do and so here we have to not only make this huge set of five sheets of plastic but fold them up and then unfold them in space and be sure that it will work. So this is a tremendous challenge for engineering and for the test program and every possible thing that could go wrong has to be imagined so we have review groups to tell us where we might have made a mistake and we don't always like that but we definitely need to know the answer so that's a critically important part of our project is making sure that this huge thing will unfold in space and behave properly. Thanks so I mean I guess that kind of you know you mentioned you have to test it on the ground to make sure it's on space once it gets to the location and I mean that has to do with the fact of the placement of James Webb which is so unique as well right so far away so that kind of leads into another question that a student asks and they said they understand that James Webb is not expected to have any in-situ service once it has launched but has any contingency plan been given at least making some sort of servicing available should the need arise in the future for instance will there be any valves so coolant or fuel could be added should you know some intrepid explorers wish to venture out there X number of years from now when that seems more feasible Right now we're putting fiducials on the telescope to aid in any potential future docking mechanisms that might come we're putting alignment targets on the launch vehicle ring that would be the sturdiest place to grapple an observatory like James Webb should there be a technology like that in 2018 for that kind of thing but for the moment that's what we're doing we're putting you know these alignment targets on it to aid in a potential docking I mean I guess from both of your perspectives maybe this is more an engineering thing how likely does that seem that one day I mean do you think if you have to guess right now do you think one day someone will go out there to visit James Webb Well there are certainly engineering challenges right now I'm not and I'll make it clear we're designing James Webb we're taking all the precautions and designing it such that we don't need a servicing mission it would be very challenging right now just to imagine that we'd be able to go out there in 2018-2019 I'll say that and there's a lot of you know a lot of problems that would have to be overcome not the least of which is if there was a problem with James Webb you'd want to have a call-up mission relatively quick or you'd have to have a situation where the Webb might have to be survive in some kind of less than nominal state for quite a while so I think the probability of that might be might not be too great getting a servicing mission out there that would be the fairest thing I could say It's tough in any respect even for you know visionary scientists to project that far out in the future where things will be so I think Mike this is probably another question for you this is in regards to team rapport and engineering and just how much does that affect the progression of a project how well a team works together is it can you overcome big differences relatively easy do people understand the job needs to get done even though they don't work together well or is that a huge detriment to a team if they don't have strong rapport with each other well first it is a huge detriment if they don't but I think that I've been lucky the whole engineering team has been lucky we understand the historical significance of a project like this I think most of us engineers feel lucky that we're on something of this significance so based on that you know most of us have found ways to overcome our differences like that and just realize that hey we have a launch date we're going to make it and the technical problems are so daunting we don't want to let the normal you know mundane squabbling stuff get in the way I think you know the squabbles always come up they're usually very well intention some of the biggest squabbles I end up with are having two, three brilliant people in my office who all want to say something different and we find our ways to get around that my personal way to try to get around that is to dwell on facts, reduce the squabble to something that can be analyzed with data that way emotions get out of the squabble and all the parties can look and say yeah we think that's the right answer so in short you know I think that James Webb is pretty lucky in that but having a team that works together for missions like these are extremely important if you get you know a lot of key contractors or key partners that don't get along that could be a nightmare and what about for you John are there similar issues with scientists well there could be but mostly they're not with our current team of scientists people behave very well and again as Mike says we like to focus on the facts and try to figure out what to do based on everything that we know and can anticipate rather than just trying to argue about stuff we have a plan and we follow the plan and we do have meetings of scientists to make sure that they're all aware of what's going on fortunately we've not had to have disputes where we had to vote we have a science team structure so we could vote if we need to but they all almost always agree about what needs to be done and they just all have their own jobs within that team and so they keep on doing them it's been remarkably non-controversial within the project team so this is I guess a non-James Webb specific question perhaps maybe John you can try and tackle this one first but Heidi asks can you talk about any exciting advancements in space travel just in general any research projects working on getting us farther or faster into other that you know of I guess the big thing that's coming up in our future is the desire to go to Mars and so we need a couple of important advancements in space travel one is solar electric propulsion or some kind of electric propulsion because we want to get there faster it's dangerous for people to be exposed to the space environment and cosmic-grade bombardment for long periods of time so the quicker is good so we need the electric propulsion systems which have what we call a specific impulse so you can require less fuel to go and the other one is really big rockets we no longer have the Saturn 5 that it took to get to the moon but we would need multiple ones of that category so now we're building the space launch system which is the big rocket of the future so eventually we will be able to undertake very major programs of space travel we are fond of that idea because we could imagine flying much bigger telescopes in fact astronomers like to say we travel at the speed of light we receive signals from distant places and try to figure out what they are so if we have the great new launch vehicle we would be able to build an even much larger telescope than the James Webb which would be capable of for instance examining Earth-like planets orbiting other stars to determine if they're alive so that would be really cool and so that's a different kind of space travel what about Mike you have any I mean even just your personal things that you get excited about do you know of any advancements that are going on? yeah I'd like to add to what John said I think electric propulsion is a very neat thing and that should be what we concentrate on the one other thing that aspect of what John was talking about if you were to have electric propulsion you can fire the thrusters continuously at least that would be the goal right now the way we get to planets and the way we navigate in space is we fire a thruster for a couple of seconds to an hour and then we coast there which takes a long time there's a spacecraft that's on its way to Pluto right now that's been heading there for almost 20 years I think if you were to have an electric propulsion system that could fire continuously even at low thrust the propulsion would start building up and you would very quickly reach some very high velocities it's a classic college assignment but I think that with very reasonable continuous thrust you would get to Pluto inside a month so that could be a very neat thing the other neat thing that I'd like to see is some technologies to develop to build these big telescopes on orbit you'd be able to test them in the environment and let's face it when you build these spacecraft quite a bit of the mass, quite a bit of the work that you do is just to enable the telescope to survive the first 10 minutes of its life, the launch if you could assemble these things in orbit you could be building very very big telescopes you could test them in the environment they were meant to be operated in I think that could be very neat we got a long way to go for that but I'd really love to see technology start progressing that way definitely exciting things you know only progressing I would imagine I guess another question related now to the project and Angelique asks well, sorry so if you have a meeting about a key decision point like a critical design review who and how many people are invited to that specific meeting well, yeah for most of the design reviews we have we have an independent review board these are people who are not on the project they're experts from all over NASA and academia and industry and there's probably about 20 to 30 review board members for some of the larger project level reviews we have quite an audience there and in terms of presenters usually at these big events there's probably about 20 or 30 of the lead engineers presenting and defending the designs to this review board so the bigger reviews the critical design reviews, the preliminary design reviews those kind of things are generally big events and when you're building an eight billion dollar observatory that has to work right you definitely welcome these you welcome more eyes on this to make sure you're doing the right thing great so then another I personally don't know about this, maybe you guys do but Heidi asks what is NASA's assessment or stance on the practicality of the space elevator concept that John maybe do you have okay well I don't know what NASA's stance is on it I know it's a wonderful idea which when it was first imagined maybe 50 years ago was clearly impossible because there were no materials strong enough to possibly do it now we have carbon nanotubes and other amazingly strong materials which make it possible in principle but it's still so far from practical that I don't give it much thought I hope that somebody does but I don't know how to do this one what about do you have any engineering expertise that would make this a reality Mike no I first became I became aware of the space elevator was actually a problem on a qualifying on a qualifying stand that I had and it was neat to think that physics allows for such a thing and it does I will say aside from the technological challenges of it I would want to invoke a discipline engineering use and look at the various failure modes of such a thing building something like that has to be very robust to failure and I also remember on this qualifying exam that I took they actually part of the problem was to discuss the outcomes of the failure of this thing that were kind of interesting so I guess another question for you Mike engineering specific student wants to know what's the typical ratio on any given project of systems engineers to technical engineers and how does that ratio change with the complexity and size of a project yeah first before I get the complexity and size which obviously the ratio must go up with complexity and size the answer that question is really a function of the time period of the project when you start out the project the ratio could be as high as one to one 50% of your engineers could be systems guys looking at how to formulate requirements how to do conceptual design studies in the phase that I'm in right now which is post critical design review you generally have around between 20 and 15% that those kind of numbers for that which is typical and then when you get to the testing and the verification of the system that that ratio would go up again so averaged over the time period of a project it probably is around 20% and for a system that is complex the ratio would go up for a system that is high it would go up and it does depend in part on what you characterize as systems engineers to if you include the illities the specialties in systems engineering those numbers tend to be a little high higher than that things like radiation survivability those kind of disciplines if you lump them into systems engineering the numbers go up a little in terms of complexity this is where it gets a little interesting if your system is a one of a kind and never been built before those ratios can become skewed and generally the numbers the percentages would be higher for systems engineering disciplines there because you're considering things you know the what if scenarios you're covering new ground and you have to make sure that that ground is covered adequately so my quick answer is probably an average of 20% for complex new systems that have never been done before higher than that thanks Mike so John we have a question specifically for you Arvind asks what are your thoughts on the bicep 2 result oh bicep 2 for the people that don't know is a measurement of polarization of the cosmic microwave background radiation and the polarization appears according to the team to have a pattern that indicates that there were gravitational waves in the primordial material in the first trillionth of a trillionth of a trillionth of a second of the universe so I would say that all eyes are on that team and many other teams are now trying to measure the same information so it's such a spectacular result that we all really basically want to know is it true that's our number one question so I think it's been the sort of really subject for literally hundreds of scientists and engineers around the world dozens of teams hunting for this information for a long time so I'm holding back opinion about whether it's true until we can see a confirmation but either way it's spectacular that you could possibly even know something about that earliest moments of the universe by measuring microwave radiation coming to us pretty amazing so another question from James Webb Brian asks so James Webb has stood a lot of criticism for budget delays so looking back maybe we'll start with you Mike and then we'll get to John but looking back what do you think could have been done differently to minimize those budget constraints and delays and things like that I get to ask this question a lot and I don't really have a good answer James Webb is going where no telescope has gone before the only way most engineers find out the right answer is by probing it's the wrong answers it's very difficult to cost something and to cost something accurately when it's never been built before and the only way you get it right is by trying some avenues if they work, if they don't they keep trying I can say that the solace I take is that the next 6 meter cryogenic deployed telescope will have the benefit of our mistakes to get the costing a little right or better so I don't I could think of some rather small or picky stuff but when the initial cost estimates were made for a system like James Webb it's hard to know whether or not you've got everything you certainly won't find all the technical risks cost risks or schedule risks until you try so there are some minor things but I wouldn't want to get into the minor things I think in terms of in terms of the big things the big cost items we've done a pretty good job and where we've had to make corrections we've made the corrections maybe I could add that when our project did face difficulties we had external review boards and Mike described external review boards the summary answer I would give that they told us was did great work and you didn't ask for enough money so why didn't we ask for enough money that's a human question and I don't think anyone could really answer that one do you think any part of that is past experience where asking for too much money has led to a project being shut down or not granted so is that any part of that you know experience from back with how much the ask is that's a good question I think this is a part of human history that goes back probably many thousands of years I imagine being the architect building the pyramids I would say well how much does that cost Mr. Farrow and I wouldn't really know the right answer so I think it's a challenge when you've never been somewhere before so certainly but it's a competitive environment that all projects are done in and everybody's thinking well is that other person is that other project going to get chosen instead so it's not like this is a big surprise really but it's nevertheless for each project is somewhat different story and one thing I'll add to that because John alluded to it there may be a tendency for projects to do that but that's why we have what we call advocate review boards independent review boards and if they see us getting you know too optimistic in our cost estimates they try their best to flag it and you know James Webb has been through a lot of in since its inception it's been through a lot of these independent review boards and these are non quote non advocates people that are looking for the mistakes when you're just doing something this new and you know this novel it's hard to see the mistakes until you make it I'm sure it's easy from you know outside critics to be very critical of those sort of things but I mean as you both mentioned it's groundbreaking technology one of its kind it's you know like you both have said there's there's absolutely no way to know many of these things so another question that we got sorry I'm just trying to find it this is shifting on me so in terms of James Webb again are there any systems that have no redundancies and so it this is from Rob and he asks in other words are there any functions that absolutely must work or for the projects or else it'll fail entirely the as John alluded to earlier the deployments have they have to get it right now where we we've added redundancy to deployments where it makes sense loader windings things like that the traditional redundancies that systems engineers would add when it comes to a lot of mechanical systems so you got to watch out because sometimes when you think you're adding a redundancy you're adding two parallel mechanisms to do a deployment you're in fact adding more failure modes than you're eliminating so it's very hard on a lot of deployments to get it to where it's we can take away all kinds of single point failures so the quick answer is the deployments have to go right and we've added redundancy everywhere where it makes sense to have redundancy for those deployments John do you have any other things or is that the one key thing that you agree with I think that I completely agree with Mike on that one I did however want to add a point about cost estimation we've named our telescope for James Webb who was the administrator who went to Jack Kennedy and said this is what it takes go to the moon with their approval program within a decade and he had a sufficient sense of systems engineering to say what if I don't have enough money and so the story goes that he doubled the budget in the taxicab on the way to see the president and then it was enough but he realized I think he was able to do the risk analysis and say if I don't have enough money this is a complete disaster for the entire nation and so it's better not to go than it is to get halfway so I think that's a lesson we should all remember if something really matters you should get what it takes as soon as you can so I guess along keeping up with the new technology theme and unexpected consequences I guess how I think it's hard for a lot of people who don't have this visionary or all this engineering expertise to kind of translate those visions into a real life structure but I guess what is the general process like of creating new technology for James Webb there was the brilliant mirrors that were never done before how does something like that happen you have to just predict and have knowledge of a wide variety of things and kind of guess how they will react and test them out from there well maybe I should do that we actually started immediately when the project was conceived in 1995 to think about all the inventions that we had to have and as soon as money was available to start inventing them we started having competitions sponsored through NASA headquarters where all the companies that said we could do that for you had a chance to say what they could do and so we ran these competitions and selected winners and eventually got what we needed but sometimes it takes a long time I think there were 12 different contracts to different companies that promised that they should be able to do this and only one in the end was able to do the job for the mirrors so that's basically what we had to do was outline what we needed to have invented and then arrange for it to get invented and developed and proven out eventually to what we call TRL-6 which is a NASA term that means it's tested in the relevant environment so that we would be sure that it would work and then from Mike what about from your perspective is it ever difficult trying to from an engineer's perspective is it ever here's this idea now go make it is that ever a challenge dealing with unknowns and things that don't exist and therefore don't really have much context I suppose? Absolutely that's why I like the job that I do but you start with conceptual design here's some designs of systems that could get the ultimate job done and what's standing in between me and doing each of these different concepts and that's where you start identifying the new technologies that John spoke of and one of the things we did on James Webb is once we started to identify these new technologies these enablers of getting the mission that we wanted we started to do the technology development early that was a lesson learned from Hubble and other missions and we started to have special reviews to make sure that the progress of the tech development was on schedule we called it a TNAR a technology non-advocate review to make sure that the new inventions were progressing at the right level and that's also the reason why in the system engineering process you have things like phase A studies conceptual design studies that are meant to flesh out the technologies that are standing between you and success and the new technologies making sure there's time to develop them and assess their risks and so I guess we're going to kind of take it back previously when we were talking about the space elevator you had mentioned when you were talking about that you had to conceive of the failures and you had mentioned you had to do a report where you had to do an exercise where you can see so another question after hearing that was what would those exercises look like where you can see failures and maybe not just for the space elevator but for any potential idea or project such as that well there's actually a process in system engineering called failure modes and effects analysis and that is a systematic way of working through the functions and the things that have to go right for success and methodically saying okay if this step doesn't go right what happens if that fails what are the effects of that failure and you start assessing the ramifications of that failure and you go through it systematically that process identifies areas that could be single point failures and then you start asking yourself well how do I mitigate that how do I either trade that failure out of the system redesign the system to eliminate it or how do I find a way to rationally deal with such a failure if and when it happens that kind of thing so there is a very methodical process that we go through and it's been around for quite a while and like I said it's called failure modes and effects analysis thanks so another question for both of you perhaps John you can start with this one so Arvind he asks again ask on one nugget of advice most important thing to your successors on practical complex basis and missions what would that be I would say you have to look for things that are difficult and worth doing at the same time and so quite often we're limited by what we think is currently available and we should be thinking about what do the laws of nature allow us to to accomplish so for instance if we say we need to have a great telescope that's say 20 meters across an aperture we shouldn't say we can't afford it we should say what steps do I need to take so I can get there and I think that applies in practically every area of human endeavor if we want to have a great objective that everyone knows is difficult we'll break it down into parts see if we can do the systems engineering of dividing into manageable pieces and then do those steps thanks John what about for you Mike it's simple find out and get some really good people around you make sure you get really good ideas don't be afraid of criticism don't be afraid to try and have a thick skin it's really that simple don't be afraid to try something new I think that's great I think as with the whole of the course the space engineering course that I put together exactly what you said as well as the course material concepts that could be applied to space engineering or any other profession that people go into just having that perseverance absolutely key I'm sure so another question from AJ and he asks I'm not too sure if either of you know about this one but he mentions that on Thursday April 10th two days from now NASA is going to make available to the public at no cost more than a thousand software programs with its release of a new online service and has you know your team at Goddard or anyone that you know have made any contributions to this new public space software I don't know about it I think it's a great idea and if we've developed stuff we are basically required by Congress to give it out to people because they paid for it the public paid for it so we like to commercialize our developments and makes them available to everyone we extend that to science results as well and the data that come from our space missions all become public yeah well I guess there's not a we can move on to the next subject and I guess John made us another question for you but someone asks what is the life expectancy of James Webb we are planning to we're guaranteeing that it will run for five years of operations and we're carrying fuel for ten years of operations and I think we can run for a lot longer than that because we have some reserves in the fuel budgets so that we could for like a long long mission that's what I hope what about so we kind of mentioned the differences between Hubble a while ago but another student asked a question about the differences of James Webb to the Keck telescope do you have any general knowledge on that yeah I can say a few words the Keck telescope is already in existence has been on the ground for many many years already and it was a pioneering observatory in using a set of adjustable mirrors to simulate a single continuous perfect primary mirror so we basically adopted that idea and put it into space and we have very much profited from that they're showing here on the picture an image of our telescope which has 18 segments I believe the Keck telescopes have 36 but at any rate we follow that same idea and learn how to as Mike said to focus it after launch so by the way on the ground people are now building much larger telescopes even than the Keck telescope 20 30 40 meter and aperture because that's possible on the ground then they're using these techniques to compensate for the turbulent earth's atmosphere so tremendous results should come from those telescopes as well we designed the Webb telescope to do things that no telescope on the ground could possibly ever do because they can't see through the infrared admission of the atmosphere so they're very complimentary when we see something with the Webb telescope or with the Hubble telescope we follow and we come up with the biggest things we have on the ground thanks John so Mike this is perhaps a question more geared for you and asks does systems engineering help us to design any system from basic idea to real system in any sort of engineering whether it be aerospace, mechanical, electrical essentially what are the applications of systems engineering outside of space systems engineering well the quick answer is yes it helps in just about anything and you know systems engineering as I understand it was probably was invented by the military for non-space applications it's the genesis of systems engineering actually predated space application so the methods are essentially universal in a sense as an engineer you find the needs of your users you translate them into engineering type requirements you start building the system to fulfill those requirements you do models or pre-dix and make sure you got the system right and it's optimal and then you test it and hand it over to the user those fundamental tenets of systems engineering are used in just about anything you know I was speaking to John earlier about I began my life as a communications engineer so you know telephony systems and things like that all use systems engineering weapon systems use systems engineering that's where it was actually kind of invented as a discipline so the quick answer is yes systems engineering the process is kind of universal for engineering so I mean I guess you had mentioned I think a lot of student engineering background and are approaching this from a number of different angles are currently engineers are wanting to be engineers and you had mentioned you started off as communications engineer so can you talk a little bit more about your transition to systems engineer and is your path typical or just more elaborate on that well my path I started out in a company called RCA Astro in New Jersey and it was typical they would recruit systems engineers from the folks that had been about ten years in the business building hardware building software you know for flights and I always wanted to expand I'm kind of a generalist and I wanted to get into systems engineering so that's kind of the way that I was brought up and the way that I'm comfortable with that I would endorse starting off at a product that actually let's say goes into space structures GNNC that kind of thing and then moving into systems engineering after about ten years after you had a couple flights under your belt so that was typical at RCA and it was a method that produced some really you know some good systems engineers I had colleagues that were really fantastic at this and most of the systems engineers that I know in the space business at least came from these product areas the one difference that I'll just quickly state is when you move from a product like communications I was an antenna designer into systems the things that you got to kind of get used to is you go from an area that's very structured when you build a product you're given the requirements and someone says build this and you know you build it as a systems engineer you're generally your job can be described as transferring chaos into order you have a bunch of amorphous desires for you know what the scientists or the public may want and somehow you got to bring order to that so that you can go to the product guys and say hey you build this you build that you build that when we put it all together it's going to work so that was the big difference between the two you know at least the transition I had to make in life glad I made it thanks Mike so we probably have time for one more question and John we can go back to this one and obviously Mike if you have anything to add after that but John you had mentioned the question about the life expectancy and you had mentioned that there is a minimum of five years so what is the end-life plan for James Webb especially if fuel is left after that five years will it remain in space and just continue going because it can or is it going to be brought back down? Actually the Webb telescope will be disposed of in interplanetary space the orbit is unstable and if we just stop thrusting the telescope will go into interplanetary space so our aim is to use the observatory until we run out of fuel that's the plan So disposing of it interplanetary space is that a new concept from an engineering standpoint or has that been around for a while? No, no nature is going to dispose of it quite nicely so it's like John said the L2 point is what they call metastable and if you stop doing thrusts every 21-22 days you'll eventually get to a point and it'll just shoot out we probably will save just a little bit of propellant just so we could try to direct the direction that it's going to but nature is going to do all the work for us Is that an ideal and life plan to bring something back down to Earth or is that just because of the location that happens to work out that way? Well, you know, at a middle