 The next talk will be in English, obviously, and it will be about a very specific, a very special and very interesting topic, Frank Wunderlich-Pfeiffer. He is a journalist. He works for Gullim.de, but he's also a podcaster, and he will explain to us how we could make space exploration cheaper. And very interesting topic, please give a warm applause to our next speaker. Okay, well, it seems to be on. Hello. It's not rocket science. I actually planned to give this talk without mentioning rockets, but then we got some new pictures and I ended up deciding against that. So just ahead of Christmas, Space X released new pictures from the new test spacecraft, and this is going to be the Starship test spacecraft. It's very much the same as Grasshopper that we had in 2012, so really don't expect this to be any more than an ugly test bed of a rocket that is flying a bit up and a bit down just to shake things down and see if the technology works. But the interesting thing was that they changed the technology they used to build this spaceship. And if you remember back two years or something like that, Space X presented a large carbon fiber tank, a fuel tank that would be primary structure of the new spacecraft. And now he said, nope, we're going to make it out of steel. Steel is known as a heavy material. Usually when you use steel, you have something like a huge building, maybe a ship or something like that. It's not something that you would use to build something as delicate and light as a spacecraft. In spacecraft, you usually use aluminum or carbon fiber or anything to make things as light as possible. And that's not what they did here. Or so it seems. It seems to be that using steel cannot possibly result in something like a light spacecraft. But actually you can use internal pressure within the tanks to stabilize it. And at least Elon Musk said, and I didn't have time to actually check that because it was just before Christmas and there was a lot to do in the meantime, that at high temperatures at least, steel is about as tough as carbon fiber. And the new spacecraft of Space X is supposed to withstand reentry heats, though quite high and so steel could actually make sense. Well, why am I telling this story? Because it seems like steel is the right choice in this case. It reminded me of something else. The X-33 Venture Star, and this was supposed to be the next Space Shuttle. Back in the 1990s, early 2000s, kind of looks like the Space Shuttle and was supposed to be single-stage to orbit. Now there's a lot of things wrong with this whole concept, especially because it's single-stage to orbit. The rocket equation does not take kindly to people trying to put something from the ground up into orbit. There are a lot of rockets that could actually do it. You could take a rocket and without any kind of staging you could put several tons into a low Earth orbit. But it doesn't make sense because you can put a second stage on top of it and double or triple the payload even for low Earth orbits, and you couldn't reach any higher orbits with a single-stage spacecraft like this one. But the reason why this one never flew, this was supposed to be a one-third scale model of the real thing, was something else. And we will talk about that. After a little quote of Richard Feynman, yes, reality is an important thing, and public relations are not quite important enough to go beyond the limits of laws of nature. And single-stage to orbit doesn't quite work. This demonstrator here was almost finished, all the components were there, and the problem was with this large blue thing, that's the hydrogen tank. These hydrogen tanks, you see, it's two tanks and there are two sections to it with a loop in between, and it's a very complicated shape, and you wouldn't use that sort of shape in a normal tank. When they decided, well, those tanks, they have to be extremely light because it's supposed to go to space, it has to be extremely light to go to space, and so they made it out of carbon fibre, and they ran it to trouble. They couldn't get it tight, they had leaks all the time, and also it was not as light as they thought it would be, because the shape is complicated and carbon fibres are actual fibres, and they are only strong in one direction, in the direction of the fibre and not perpendicular to it, and so they ended up using a lot more mass than they would have thought, especially in those low barriers. This was so obvious to the engineers that there was a group of engineers within the company that built it, that they built a second tank, and they made it out of aluminum alloy. The tank itself was heavier than the carbon fibre tank, but the lobes, they saved so much more weight on the lobes that it came out to be almost the exact same thing, but that was when the project was cancelled, because essentially it wasn't high-tech enough. They were so concentrated on proving the principle of carbon fibre, technologies for cryo tanks, that they can project in the end, which is quite a difference compared to SpaceX, who just thought, well, we can make it out of steel, and steel works at least. Steel is not the first time that it's being used. In fact, this is the factory of the Atlas rockets, the early Atlas rockets, and this is China material and it is actual steel, and those are the balloon tanks that are under pressure, and if you go search on the web, you can find a nice video how they don't work. There's a video where one of those rockets is upright and it loses pressure inside and it just collapses like a tin can without pressure inside of it, and the way, this is actually a very nice technology, it's pretty light, and it has been used again, it has been used again in the upper stage, the Centaur upper stage also for the Atlas rocket, and they use steel tanks, this is the hydrogen steel tank, and this rocket stage is extremely light, even for today's standards, they kept building this stage since the 1960s and Centaur stages are used to this day and they still use steel because the balloon structure is quite light. In fact, it's today one of the lightest upper stages there are. I mean I'm not going to complain too much about the area in the upper stage, which is a huge compromise and really inhibits its performance, but we'll come to that. It's a very simple material and it has a great history, but if you want to build something cheap you better build it in large numbers. Atlas rockets were built in large numbers in a factory like that and you can see, yes, they headed down to the science to a real factory, but there's a reason for that and that reason is not space exploration. Atlas rockets were used to go to space, first American astronauts, John Glenn, who actually orbited the Earth, went on an Atlas rocket and the actual payload of these rockets are nuclear bombs and that's a huge tradition, most rockets going to space usually had nuclear bombs on top of them. That's not just true for North Korea, it's true for almost any spacefaring nation that started out except for exotics like maybe New Zealand, who recently started their own space program and started building their own rockets, they actually just went to space and never had nuclear bombs on top of them. But if you replace the nuclear bomb with an extra rocket stage and a satellite or space probe, you can get it to orbit and essentially what NASA did here was to use the surplus, the production facilities from the military to build their own rockets. Obviously they built about 400 something rockets of this type and they didn't quite need as many of those for spaceflight, some of them were actually scrapped, a lot of them during the shuttle program. If you build so many rockets you can build them cheaply. I think their production cost was originally something like 6 million dollars but there's a lot of inflation since that time, they were quite cheap anyway. That's because of mass production. The problem with mass production is that especially these days when you have larger rockets and we have for the first time since 1990, since the end of the Cold War, we have launched worldwide 100 rockets this year. That is not very suitable for mass production like this one. So the alternative is instead of building the rockets in mass production, you can at least build the most important, most expensive components in mass production and some nice examples of those are of course the Soyuz rockets where they built the burning chambers and the nozzles which are delicate parts really on mass. Every Soyuz rockets, when you look at it from behind, has 20 such burning chambers and five sets of turbo pumps to deliver the fuel to them. And of course we all know about the Falcon Heavy, 27 engines in the first stage. Having so many small engines means that you can build one engine every three days or something like that and that really cuts down on production costs. Especially compared to other rockets that are more current. ESA did the same thing. This is an area for four rockets which was back in its day the cheapest rocket there was and really disrupted the transportation of satellites into space as much as SpaceX did back in the 2000s. So ESA with the early area in rockets really changed the game there and they did it by putting a lot of identical and small engines. These are eight Viking engines. In the first stage there's one Viking engine in the second stage and there's another stage that is fueled by hydrogen and a different rocket engine. It's very much the same concept as SpaceX used and for some reason they forgot all about it. The next rocket was Ariane 5. Ariane 5 consists of two solid boosters, one big engine, the Vulcan engine and the large central stage and another stage with yet another different engine. These rockets are built and launched about six every year. So every two months or so you build one engine. That's very different than building one engine every three days. That's what makes it so expensive and there are some TV documentaries where you can see the production process of these engines and there's a lot of hand work. There are for example about 500 injection nozzles inside of this engine and well there are two or three engineers in the room and one of them is watching the other one while he is taking each injection nozzle and screwing it into the plate by hand. There's not a lot of automation you can do when you build six of those engines every year and six of those rockets every year and that's a big reason why this has become quite expensive and it had to be subsidised. Each rocket launch of those is subsidised by about 20 million euros just to not actually be competitive but to be just not quite so expensive that it's worth to develop a new rocket at least until SpaceX came along. Next rocket is going to be Ariane 6 and it's not going to be that much better especially if you have a look it's going to be in two different flavours the one with just two solid boosters Ariane 6, A62 and the A64 is the big one essentially it's the same rocket just with smaller solid boosters but you notice the actual payload on top is five tons this one is ten tons and you wouldn't think that somebody would come up with this idea and say hey that's a good idea because the solid rockets are the cheap part of the entire rocket so by leaving two of those solid rocket boosters you can reduce the cost of the rocket by about 20 million euros or something like that but you lose half of the payload while when you have a big rocket when you use four boosters you can get about twice the payload for a marginal price increase. I've been told that the A62 will cost about 40% less than the Ariane 5 rocket so it's going to be about 90 to 100 million euros for a performance similar to a Falcon 9 rocket. That is about as expensive as well 50 or 60 million euros it's not going to be very cheap and of course the A64 is going to be 120 or 130 million euros and it doesn't look like this is going to be a very nice prospect for being competitive. What also struck me is people are actually using this one. When you have five tons of payload that you can bring into space but by just using 20 million euros or maybe 30 million euros in addition to that you can double it that means you're actually wasting a lot of payload mass. That means it's pretty expensive to get a satellite into orbit but getting five tons more into orbit when there's a rocket already going can be quite cheap and even whenever you use the small variant of this rocket means that you're wasting a lot of money and a lot of space in your rocket. Another problem is this is an outdated graphic but the whole production is distributed all over Europe. This is actually a point of pride for the producers so you can find every part of it. This is the Volkheim engine and you can see here where all the components of the Volkheim engine are made. This is actually no longer current because as far as I know the oxygen pump will be built in Germany and they traded it for some plans that were later announced between all this where Germany was supposed to build casings for this motor and so on and so forth. There's a lot of political to and fro. This is the case in Europe between different European countries in the United States. You have something similar between the different states in the US and it really increases cost who would have thought. Volkheim engine if you have a problem with thrust well what could it be well maybe it's the turbine. The turbine drives the pumps for the fuel pumps, the hydrogen pumps and the oxygen pumps and so you call up Sweden while check your turbine and maybe you find out no it has nothing to do with the turbine. It's actually the hydrogen pump so you have to call to France or maybe it's the gas generator in this case you're lucky because it's also in France but it could be the oxygen pump and it's not actually made in Italy anymore so you have to call Germany and so on and so forth and that's just for one engine and if you have any problem with this rocket you're very likely to have to call another company in another country probably in a different language and yes it's a bit of a miracle that it works at all but it works but it's not cheap and everybody in ESA is aware if you talk about if you talk to people who are working on these rockets they know very well they could be much cheaper. Well let's talk about different rockets. This is the rocket that was used to launch the latest Mars space probe. This is Mars insight and you might think well it's a big rocket but it's like a really small space probe surely this must be some figment of the imagination probably it's much bigger and the artist made a mistake but no no it's really that small and it's about I think seven or eight hundred kilograms and this rocket the way it's configured here could at least put another one point five tons more to Mars so there was room there was a lot of room to occupy this and you know you could you have one point five tons so what do you do you put a different space probe maybe into it and send it also to Mars because finally have a chance to get a big chunk of metal or something to Mars anything you want what did NASA do well they send two small CubeSats to Mars and they're quite proud of it and I can understand that especially the teams that built those they are quite proud of it and quite rightfully so because it's the first time that a small CubeSat was sent to Mars so far away and transmitted data and that worked very well but what about the other 1.5 tons as a matter of fact you could have put at least one maybe two or even three additional lenders on Mars on the same rocket there's a lot of waste going on in this space and we're not even talking about the price of this rocket yeah when you have so much mass you could change the way you build such probes or satellites because right now the reason why this is 800 kilograms is because when they constructed a space probe they tried to save as much weight as possible and a lot of effort is put into every single satellite every single space mission to save weight every kilogram counts or so it seems but if you look at a rocket like this is 1.5 tons that are wasted essentially so what was your point in saving all this mass there isn't very much to it also remember that a lot of rockets are built with a launched not in a maximum configuration so you could with very little extra expense increase the payload instead you could choose a different concept and right now there are not many manufacturers that do this on a large scale but there's one manufacturer that I found where that I interviewed where they do it on a small scale this is it's burn space technologies and this is one of the satellites they built and doesn't show up very nicely here unfortunately it's a satellite about this big half a meter weighs about 70 kilograms and they actually launched one of those already and it's a modular system it's just a box it's a box with lots of little components inside of it that can be put into different places and this means that you waste a lot of weight because when you construct a satellite you have to make sure that all the mass is distributed equally evenly and you have to look at every system that works correctly with all the other systems and as soon as you have to change something you have to start essentially start the construction all over again because you now have to shift all the weight the whole weight distribution inside of it if you don't want to waste any mass what you can do is you can just put some weights into the satellite box and shift them around each time you have to change your component and you can do this and they do it by for example taking their batteries and putting them into a different spot and the spot is already designated it's not it's not like there's it's not so tightly built that there's no room to put it elsewhere they just made room for it that means the box is bigger that means that the whole the whole satellite will weigh more and you will need more mass to achieve the same the same goals but it gets cheaper because now you can have your box and build it for different configurations and just qualify it once and when you have to change something you change it and you're not leaving the scope that you qualified your box for your entire satellite for also what they do is they use very simple technology when you look at this the camera and it doesn't show up very nicely here but if you see it in person it really looks like somebody took a regular photo lens and put it into a satellite and you could be forgiven for thinking that because that's what they did it's a photo lens that's about this big 10 centimeters across and it's enough that from a 500 kilometer high orbit you can take pictures with a resolution of about five meters in many other satellites they're especially built optics just for this but you can use commercially available technology just like for common consumer grade camera we have to check that it actually works in vacuum because there might be some sealant some lubricant or something like that they evaporates in a vacuum and may evaporates in a vacuum it there's a little fine mist might deposit on the lens and fog them up or something like that you have to check all that but you can make it quite cheap that way it is also a very nice piece this the Star Trekor they use Star Trekors are essentially cameras that look at star constellations and from these star constellations you can tell that where where your satellite is pointing and what it essentially is it's a camera and a fairly small camera at that and what they use is a little board and this looks like the camera board you would have in one of your smartphones and that's because that's what it is they essentially used camera board from a smartphone put different lens on top of it much better lens higher gets more light on the sensor and the hardware cost is quite cheap it's like few dollars the problem here is you have to do all the engineering you have to do the software and this is what costs the money here another example is reaction wheels reaction wheels are a wheel that you spin and because you speed you spin the wheel in one direction the satellite will tend to spin in the other direction and that way you control you can control how the satellite is pointed in space and usually you would take a reaction wheel and make it so you can it works in space in vacuum that's a problem because you have to have some sort of lubrication because you have to spin those wheels and they will touch something and there should not be too much friction between it well on earth here we have solved these problems we have a lot of absolutely fine lubricants that can work for years on end no problem but in vacuum it's a different story so instead of trying to find a vacuum capable lubricant or something like that they just put a box in around it wasted another one or two kilograms of mass and put air into it and solve the problem that way which is very elegant and easy solution to a problem that you would normally have to solve especially when you look at missions like the Capra space telescope recently or the Dawn mission they had huge problems because they were in vacuum and in vacuum you don't get to have the luxury that when you have a static charge it eventually dissipates you know you have an electric charge and because air conducts electricity very badly but at least a bit eventually when you have something that's electrically charged it will it will well dissipate the charge and it will equalize we have it in vacuum this doesn't happen and the only way it can happen is through discharges and it turns out in these ball bearings that you have you have very small differences between the ball bearings and the walls of micrometers and when you have micrometers you can get extremely high field strength just from small voltages like one or two volt difference between the ball bearing and the center of the wheel and you can get arcs and these arcs can melt the ball bearings and cause higher friction and they found out the hard way by essentially essentially screwing up several missions after a couple of years and they only found out by looking at when the reaction wheels failed in space and solar storms and the solar storms consist of charged particles and they charged up the the satellite and caused this disarcing to happen and I really like that kind of modular approach even though it's much more expensive in terms of the mass but it will cause much less engineering can be qualified much more easily for continued for new missions for reuse. Finally I want to talk about two missions that really kind of took this approach from India. India has actually a fairly unknown but quite viable space program and what they did they send one mission to the moon and another one to Mars and what those are is essentially satellite that they already had like telecommunication satellite and they made room for cameras and other instruments. When they send it to to the moon this worked quite well they had about 80 kilograms of payload in there of scientific payload. When they send it to Mars they had a bit a somewhat bigger problem and the problem was it takes more energy to get to Mars and the Indian rockets the heavier Indian rockets were not quite reliable enough when they when they started to launch this and so they had to use a small rocket and these satellites were built for the small rocket but they were built to go to a geostationary orbit. Now it turns and the geostationary orbit is the orbit that you use for TV satellites kind of orbit that where the satellite just stays on one spot in the sky. Now it turns out any satellite that can do that they can get into this kind of orbit has enough energy and enough fuel to get to the moon or even get to Mars because it's quite demanding mission. The problem then is only to get into an orbit around the moon or around Mars and so getting to Mars is not the problem getting into a good orbit around Mars that is that was the problem and actually this is Mangalyan that's the that's the Mars mission only has I think 12 kilograms of payload on board because of that because they really had to use most of the fuel just to get into any kind of orbit. So okay I hope you have some questions so I can answer them. Yeah first of all thank you so much for this talk hopefully there are some questions from the audience please don't be shy. Yes. Hi thank you for the talk my question will be you said that mass production of the rocket engines allows you to cut down costs so why do they even use bigger engines? The original reasoning was that you only have one one engine so only one engine can fail. Okay thank you. That is essentially that was the reasoning they used for a very long time and it was supposed to be man rated so people were supposed to go on these of course it's also woman rated it's a it's a pretty old concept so yeah they still call it man rating and they hope to improve the reliability of the whole system but it turns out that a lot of the a lot of the rockets that you actually used a lot of engines were just as reliable as rockets that used just a single engine and one in one stage and area and four itself was a pretty good example for that even though I have had a lot of I did a lot of talking to people from ESA and CNS and others and a lot of people would tell me oh that's you cannot use nine engines like in Falcon 9 rocket that would be too unreliable but actually okay in the Falcon 9 they had a different trick and they made sure they could still launch with or they could have one engine fail and still continue to continue to launch unlike area and four where occasionally they had failures I think they had one or two failures of engines and that actually aborted the mission because it wasn't made for that okay thank you yeah thanks for your question next question over there and one reminder you can also ask questions yeah from the internet if you're watching the stream so please contact our signal engine what type of justifications do the space shakers you give for not filling up the payloads do they risk you know satellites interfering with each other or anything like that in in this case they didn't give any kind of sophistication instead they launched it from the west coast of the United States and said look it's the first time we launched a rocket from a west and interplanetary space probe from the west coast of the United States of course they could only do this because they have had so much performance margin and usually you would go for the east coast and launch the rocket towards the east which is along with the rotation of the earth and get an additional boost of speed just from the rotation of the earth and they just said well we don't need that so we can also launch it from the west coast and now they made a big deal of yeah it's the first time that we had an interplanetary mission from the west coast but it's well it's quite disingenuous thanks for your question next one yes thanks for the great talk and you meant you were talking about the problems with friction and lubrication and the interesting solution that you showed near the end of your talk I'm curious what kind of solutions did they use for friction other than that other than putting it in a can that was pressurized how do you prevent the evaporation of lubricant or do they use some method that doesn't use a lubricant I think they found lubricants that work quite well or I think they're also they're also ceramic ball bearings that they are now using and they also have the added advantage they don't conduct electricity so you don't get the arcing that led to the failure of Kepler and dawn so ceramic ball bearings don't need to be lubricated I think no I'm not entirely sure but I think they have they have vacuum capable lubrication lubrication thank you thank you for your questions I think if no one now is like jumping up and saying yes I have another one then you would post the event and thank you for your talk it was incredibly interesting all these awesome rock and science pictures incredible incredible thank you for that so give a very warm round of applause for our speaker