1 00:00:09,257 --> 00:00:10,684 Welcome to our next talk. 2 00:00:10,684 --> 00:00:13,960 This is Anja Kohfeldt. And she will be talkin about "Lasers in Space". 3 00:00:13,960 --> 00:00:17,397 Please give her a warm round of applause. 4 00:00:22,674 --> 00:00:28,294 Anja: Ja, hello everybody I also would like to welcome you to my talk. 5 00:00:28,294 --> 00:00:30,421 As the Angel already said. 6 00:00:30,421 --> 00:00:32,304 It is about lasers in space 7 00:00:32,304 --> 00:00:36,487 and they more than just: "Pew! Pew!" 8 00:00:36,742 --> 00:00:40,360 So that's what I want to talk about. 9 00:00:40,360 --> 00:00:42,876 I'm a scientist at the Ferdinand-Braun-Institut in Berlin. 10 00:00:42,876 --> 00:00:45,308 And I am a member of the Quantus Project group. 11 00:00:45,308 --> 00:00:52,025 The Quantus Project has the main goal, to build an optical atom interferometer, in space. 12 00:00:52,025 --> 00:00:58,048 And there we started at the drop tower in Bremen and now we are heading toward our sounding rocket 13 00:00:58,048 --> 00:01:02,643 which will be launched in november next year. 14 00:01:03,512 --> 00:01:08,932 In order to build this atom interferometer, we have to cool down atoms 15 00:01:08,963 --> 00:01:13,513 and for that we semiconductors(?) or we need lasers, at a specific wave length. 16 00:01:13,543 --> 00:01:16,955 And my job in this project is to build these laser modules. 17 00:01:16,955 --> 00:01:19,555 So now you know what I'm doing. 18 00:01:19,555 --> 00:01:22,212 My motivation for this talk today is: 19 00:01:22,243 --> 00:01:24,644 At first lasers are cool! 20 00:01:24,659 --> 00:01:26,600 I think everybody will agree to that. 21 00:01:26,600 --> 00:01:28,337 I hope so. 22 00:01:28,337 --> 00:01:31,454 In the past years there have been a lot of projects concerning lasers. 23 00:01:31,454 --> 00:01:40,018 For example building lasers cutters or building laser projectors, or pimping you laser pointer to laser gun, burning stuff. 24 00:01:40,018 --> 00:01:44,549 There are some pictures I found on the web. 25 00:01:44,549 --> 00:01:47,189 And than there is the space side. 26 00:01:47,220 --> 00:01:51,749 This whole space stuff got more and more affordable in the previous years. 27 00:01:51,749 --> 00:01:56,339 There is more and more private activity in the space sector. 28 00:01:56,366 --> 00:01:58,363 For example private companies building launching systems. 29 00:01:58,363 --> 00:02:07,532 But there are also a lot of student and university programs to build there own satellite to make science in space, science in micro gravity. 30 00:02:07,532 --> 00:02:16,256 And I think when we just follow this development there also will be 31 00:02:16,256 --> 00:02:22,048 more, yeah, there also will be some hacking possible in space in the next years. 32 00:02:22,186 --> 00:02:25,067 There is also a personal motivation. 33 00:02:25,067 --> 00:02:30,066 Whenever I tell somebody that I am building lasers for space applications, there is always this: 34 00:02:30,066 --> 00:02:32,068 "Oh, you are building orbital death lasers!" 35 00:02:32,068 --> 00:02:35,035 No, I don't. 36 00:02:35,035 --> 00:02:40,753 [Someone booing in the audience, causing the others to breaks out into laughter.] 37 00:02:40,753 --> 00:02:45,074 Actually I'm very happy that I don't do that. 38 00:02:45,074 --> 00:02:50,387 This talk will be about other applications of lasers in space. 39 00:02:51,940 --> 00:02:55,917 When you google lasers in space, you find a lot pictures like that. 40 00:02:55,917 --> 00:02:59,001 And they are beautiful. They really are. 41 00:02:59,001 --> 00:03:01,349 They have lasers, they have space. 42 00:03:01,349 --> 00:03:06,554 But I won't talk about that, because these lasers are on earth. 43 00:03:06,554 --> 00:03:10,304 They are guiding the stars very often or laser shows. Both applications. 44 00:03:10,304 --> 00:03:14,403 Very useful, very nice pictures. Here they are. 45 00:03:14,403 --> 00:03:17,837 Okay? Nice. 46 00:03:19,207 --> 00:03:25,757 So, I would like to talk about a little laser 101. 47 00:03:26,456 --> 00:03:28,346 Telling what is a laser? What can you do with a laser? What is space? 48 00:03:28,346 --> 00:03:30,365 And, well, as I said already, the applications of it. 49 00:03:30,365 --> 00:03:35,366 Lasers. Laser: "light amplification of stimulated emission of radiation" 50 00:03:35,366 --> 00:03:37,292 Yeah, ok. We knew that. 51 00:03:37,292 --> 00:03:41,031 It's a device emitting monochromatic and coherent light. 52 00:03:41,031 --> 00:03:44,037 And that's nothing else but: 53 00:03:44,037 --> 00:03:49,331 Light with the same wavelength, in the same direction and the same polarization. 54 00:03:49,331 --> 00:03:55,064 With that properties you can focus photons on a very, very small area, 55 00:03:55,064 --> 00:03:58,032 because there are lot of photons doing the same thing. 56 00:03:58,032 --> 00:04:01,268 And that's why you have a very high power density 57 00:04:01,268 --> 00:04:08,115 and that is why you can use lasers for example for welding, for cutting 58 00:04:08,115 --> 00:04:14,064 or for delivering data over very, very long distance 59 00:04:14,064 --> 00:04:16,315 What do you need to build a laser? 60 00:04:16,315 --> 00:04:18,515 You need active medium. 61 00:04:18,515 --> 00:04:24,730 This active medium, or the electrons in this active medium, are stimulated by a pump. 62 00:04:24,730 --> 00:04:29,590 This either an optical pump or an electrical pump or whatever pump. 63 00:04:29,590 --> 00:04:36,954 And you need a resonator to sort the right photons. 64 00:04:36,954 --> 00:04:44,365 And when it comes to the classification of lasers, you basically vary the active medium. 65 00:04:44,365 --> 00:04:49,797 So for example there are solid state lasers, where you use a crystal. 66 00:04:49,797 --> 00:05:03,449 A very good example for a solid state laser is the neon doped XXX XXX laser. The YaC Laser, as we are used to call that. 67 00:05:03,449 --> 00:05:11,781 This laser or this type of laser is used industry, but you also find it in laser-light-shows. 68 00:05:11,781 --> 00:05:15,549 There are a lot of applications for that. 69 00:05:15,549 --> 00:05:18,396 In contrast there are semi-conductor lasers. 70 00:05:18,396 --> 00:05:20,314 They are a lot smaller. 71 00:05:20,314 --> 00:05:28,000 You see, the green one on the left is the YaC Laser, in the center you find the semiconductor laser. 72 00:05:28,000 --> 00:05:33,415 They a are a lot smaller, they are cheaper, they are more efficient. 73 00:05:33,415 --> 00:05:39,447 And you can tune the wavelength over a certain range. 74 00:05:39,447 --> 00:05:46,980 As an example here, there is the indium gallium nitride laser, which you will find in you Blue-Ray-Player 75 00:05:46,980 --> 00:05:54,897 or the aluminium gallium arsenide diode, which is commonly used in DVD-Players, and stuff like that. 76 00:05:54,897 --> 00:05:57,764 I think everybody owns at least one of them. 77 00:05:57,764 --> 00:05:59,514 There are gas lasers. 78 00:05:59,514 --> 00:06:01,565 For example helium-neon-lasers. 79 00:06:01,565 --> 00:06:07,963 The helium-neon-lasers built in the current wave mode. 80 00:06:07,963 --> 00:06:11,881 And it's now used, for example for calibration or in schools. 81 00:06:11,881 --> 00:06:16,999 And the CO2 laser is one with very, very high power density. 82 00:06:16,999 --> 00:06:20,294 It's a pulse laser, used for example for welding. 83 00:06:20,294 --> 00:06:30,013 And there are the dye lasers, which can tune the wave length on a very, very long range. 84 00:06:30,013 --> 00:06:35,180 They are very often used for spectroscopy, for example. 85 00:06:35,180 --> 00:06:43,366 So whatever you want to do, you have to chose your laser your laser type with your application. 86 00:06:43,366 --> 00:06:49,564 And they vary a lot in their output power, in there mode, whether they are pulsed or not pulsed 87 00:06:49,564 --> 00:06:54,449 and their wavelength, but also in their size and complexity, yeah. 88 00:06:54,449 --> 00:06:57,604 And you just have to chose the right one. 89 00:06:57,604 --> 00:07:03,165 This is important especially when we are going to space. 90 00:07:03,165 --> 00:07:06,541 Here are some common applications for lasers. 91 00:07:06,541 --> 00:07:09,004 You use them in measuring, in optical data transmission, 92 00:07:09,004 --> 00:07:16,365 they are used in the multimedia sector and also in the production sector. 93 00:07:16,365 --> 00:07:22,133 But not only at home, or industrial or in medicine, but also in space. 94 00:07:22,133 --> 00:07:24,998 So space, here we are. 95 00:07:24,998 --> 00:07:31,515 The common definition of space is: "Hundred kilometres above the sea level." 96 00:07:31,515 --> 00:07:36,882 But whenever there is, for example an Apollo astronaut, when they are talking about space, 97 00:07:36,882 --> 00:07:44,172 they are talking about 50 miles, which is an older definition of space, based in the US. 98 00:07:44,172 --> 00:07:49,116 You can go to space via satellite, you have the space station 99 00:07:49,116 --> 00:07:56,456 and sometimes at the space station you have an operator, like a person operating your experiment. Might be useful. 100 00:07:56,456 --> 00:08:05,400 There have been orbital experiments. Especially the times with a space shuttle. 101 00:08:05,400 --> 00:08:12,974 And there are sounding rockets, which are rockets going up up to approximately a thousand kilometres max, 102 00:08:12,974 --> 00:08:20,333 and falling down, but in the meantime you can perform experiments in zero gravity. 103 00:08:20,333 --> 00:08:23,282 Why do you want to go to space? 104 00:08:23,282 --> 00:08:25,950 Well, there are a lot of reasons. 105 00:08:25,950 --> 00:08:33,531 For example the observation of distant galaxies, the earth weather, 106 00:08:33,531 --> 00:08:38,297 there are communication satellites, just to transfer data, 107 00:08:38,297 --> 00:08:41,563 you can or you want to perform science up there. 108 00:08:41,563 --> 00:08:45,998 For example because of the lack of gravity or the lack of atmosphere. 109 00:08:45,998 --> 00:08:53,497 There is navigation and there is also the military purpose, you can't deny that. 110 00:08:53,497 --> 00:08:57,333 But it's not that easy going to space. 111 00:08:57,333 --> 00:09:00,199 Whenever you want to go there, there are a lot of restrictions. 112 00:09:00,199 --> 00:09:02,366 For example the size and the weight. 113 00:09:02,366 --> 00:09:14,198 When you want to launch something into space, you have costs approximately four to five thousand dollar a kilo. 114 00:09:14,198 --> 00:09:19,665 Although this price is decreasing, it's still high enough. 115 00:09:19,665 --> 00:09:27,223 You are very limited in you power consumption, cause you don't have, i mean 116 00:09:27,223 --> 00:09:29,880 it's a closed system, right? You have you solar panel, but that's it. 117 00:09:29,880 --> 00:09:36,602 And sometimes some other energy sources, which may disappear after a while. 118 00:09:36,602 --> 00:09:43,781 Everything you want to send up there has to survive the launch and sometimes it has to survive the landing. 119 00:09:43,781 --> 00:09:47,870 When it's coming back to earth, there might be applications where you might use that. 120 00:09:47,870 --> 00:09:50,296 Very often there is no operator. 121 00:09:50,296 --> 00:09:55,875 Like no one pressing buttons. So everything has to run autonomously. 122 00:09:55,875 --> 00:10:04,963 And your stuff needs quite a long life time, cause you don't want to switch parts once a year on a satellite. 123 00:10:04,963 --> 00:10:09,770 So you normally don't do that. 124 00:10:09,770 --> 00:10:13,414 So, as I said in the beginning, I'm a scientist. 125 00:10:13,414 --> 00:10:16,052 And this is a lab. 126 00:10:16,052 --> 00:10:19,889 It's not my lab, I'm very happy about that. 127 00:10:19,889 --> 00:10:25,832 But this is an experiment quite close to that what we want to do. 128 00:10:25,832 --> 00:10:31,953 And as you might assume, this is not a good idea to launch that. 129 00:10:31,953 --> 00:10:33,980 It won't hold. 130 00:10:33,980 --> 00:10:38,665 It won't survive the launch and probably it won't work up there. 131 00:10:38,665 --> 00:10:43,248 So what did we do? You have to choose an appropriate technology. 132 00:10:43,248 --> 00:10:45,385 That's why we are using semiconductors for exmaple. 133 00:10:45,385 --> 00:10:48,157 They are much smaller, they are much more energy efficient. 134 00:10:48,157 --> 00:10:53,705 You have to space qualify all the components you are using. 135 00:10:53,705 --> 00:10:56,531 You have to take care of the materials you are using. 136 00:10:56,531 --> 00:11:03,199 You can't use whatever a XXX for example, because you have this out gassing problem. 137 00:11:03,199 --> 00:11:07,749 Your device has to operate in vaccum, very often at least. 138 00:11:07,749 --> 00:11:11,546 You have to minimize everything. 139 00:11:11,546 --> 00:11:14,082 You want to fix every part. 140 00:11:14,082 --> 00:11:22,367 You don't want to much movable parts. Because there won't be anybody to fix your setup, afterwards. 141 00:11:22,367 --> 00:11:26,564 And you have to work in a clean environment, when you integrate something. 142 00:11:26,564 --> 00:11:29,417 Dust is a problem, for example. 143 00:11:29,417 --> 00:11:32,915 You don't want to have any particles around. 144 00:11:32,915 --> 00:11:37,689 You have to test and characterize everything and once again and once again. 145 00:11:37,689 --> 00:11:43,876 And you have to document everything. Like more than everything. 146 00:11:43,876 --> 00:11:46,615 So this are some pictures of my lab. 147 00:11:46,615 --> 00:11:56,582 On this side, you see a characterization setup. 148 00:11:56,582 --> 00:12:00,115 In our lab, it's not clean room, yet! 149 00:12:00,115 --> 00:12:04,583 We are not working on a satellite mission, it's just a sounding rocket. 150 00:12:04,583 --> 00:12:08,084 But we wear these funny lab coats and funny hats. 151 00:12:08,084 --> 00:12:11,451 So maybe you see that person there in the middle, it's a colleague of mine. 152 00:12:11,451 --> 00:12:14,902 If you see that: "Hello!" :) 153 00:12:14,902 --> 00:12:19,964 And on the other side it's the integration station, of our lasers. 154 00:12:19,964 --> 00:12:25,415 And some setup around to characterize everything. 155 00:12:25,415 --> 00:12:29,020 So, just to show the result of our effort. 156 00:12:29,020 --> 00:12:35,785 It's a semiconductor based master oscillator power amplifier, of the size of that. 157 00:12:35,785 --> 00:12:41,263 Its like 8 centimetres long and 2.5 centimetres wide. 158 00:12:41,263 --> 00:12:48,248 It has nor movable parts and it's a specific wavelength, cause we need that for our application. 159 00:12:48,248 --> 00:12:51,780 We want to cool down rubidium. 160 00:12:51,780 --> 00:12:56,281 It has an output power greater than 1.2 Watts. 161 00:12:56,281 --> 00:12:57,743 So, how much is that? 162 00:12:57,743 --> 00:13:01,299 Well, a laser pointer has a 1 milliwatt. 163 00:13:01,299 --> 00:13:06,414 An illegal laser pointer has 100 milliwatt. 164 00:13:06,414 --> 00:13:10,708 And this is ten times stronger. 165 00:13:10,708 --> 00:13:13,066 And the efficiency we have now is 22%. 166 00:13:13,066 --> 00:13:22,664 When we fuck of the wavelength, when we don't care about that at all, than we can achieve an even higher efficiency and a higher output power. 167 00:13:22,664 --> 00:13:27,397 But in our application the wavelength is mandatory. 168 00:13:27,397 --> 00:13:31,883 So now, when it comes to testing you need some documents telling you, what to test. 169 00:13:31,883 --> 00:13:34,365 And how to test and so on. 170 00:13:34,365 --> 00:13:44,520 So, there are a couple of standards and most of the standards are based in the military sector. 171 00:13:44,520 --> 00:13:51,401 The standard which is very important for us is, for example, the MIL-STD-883. 172 00:13:51,401 --> 00:14:00,129 Which describe test methods of micro circuits and thats a really huge document. 173 00:14:00,129 --> 00:14:05,444 It's about 630 pages thick. 174 00:14:05,444 --> 00:14:15,367 And it describes the purpose of a test, the apparatus, the test conditions and the procedure and the failure criteria 175 00:14:15,367 --> 00:14:19,929 ...of environmental tests, of mechanical tests and of electrical tests. 176 00:14:19,929 --> 00:14:22,915 So in this picture down there you see our laser system. 177 00:14:22,915 --> 00:14:27,939 The silver cube is the entire laser system, we have in our experiment. 178 00:14:27,939 --> 00:14:33,963 It contains 8 lasers and a spectroscopy module and a switching module. 179 00:14:33,963 --> 00:14:38,218 And this setup is on a shaker. 180 00:14:38,218 --> 00:14:44,963 So here we are performing a random vibration test on acceptance level. 181 00:14:44,963 --> 00:14:51,177 And we passed. So I'm very, very happy about that. 182 00:14:51,177 --> 00:14:53,962 And of course there a lot more tests we have to perform. 183 00:14:53,962 --> 00:14:56,729 But it looks good, so far. 184 00:14:56,729 --> 00:15:03,998 So now we have our hardware, what else can we do with that than building weapons and atom interferometers? 185 00:15:03,998 --> 00:15:11,834 Of course we have the interferometer is a very common application. 186 00:15:11,834 --> 00:15:18,048 Just to name the LIDAR system, it's a combination of radar, but with light. 187 00:15:18,048 --> 00:15:23,265 And this one is used for as alterometer(?) for example. 188 00:15:23,265 --> 00:15:30,146 Or to map surfaces. For example of some distant planets, of the moon, of the earth, of whatever. 189 00:15:30,146 --> 00:15:36,397 Systems are sending out a beam 190 00:15:36,397 --> 00:15:41,580 and they are analysing the reflected beam concerning the phase shift 191 00:15:41,580 --> 00:15:48,999 and than they now how far the reflector is away. 192 00:15:48,999 --> 00:15:54,950 And with that you can measure very precisely distance. 193 00:15:54,950 --> 00:16:04,935 You need that for example in docking operations. In the picture up there you see the ATV satellite docking station. 194 00:16:04,935 --> 00:16:16,538 I think it was in 2007. You have several other satellites, for example mapping the planet. 195 00:16:16,538 --> 00:16:19,178 Ant there is also another mission I would like to point out. 196 00:16:19,178 --> 00:16:24,550 This is the LISA mission, which wants to point out gravitational waves. 197 00:16:24,550 --> 00:16:30,799 Unfortunately the LISA project cut down. And now it's just LISA Pathfinder. 198 00:16:30,799 --> 00:16:35,911 A proof-of-concet mission, which is scheduled in 2015. 199 00:16:35,911 --> 00:16:40,836 But there are of course a lot of more applications, I just picked out some which I fond interesting. 200 00:16:40,836 --> 00:16:48,544 Spectroscopy is also a very nice application. 201 00:16:48,544 --> 00:16:59,780 When it comes to spectroscopy, you analyse the beam concerning of the absorption or reflecting photons coming back. 202 00:16:59,780 --> 00:17:09,054 So you are also sending up a laser beam and it comes back and you simply look what is coming back. 203 00:17:09,054 --> 00:17:15,116 And with that you can analyse matter with a chemical composition of matter around. 204 00:17:15,116 --> 00:17:26,168 For example on Curiosity, the Mars rover they are looking for methane gas by spectrography. 205 00:17:26,168 --> 00:17:34,653 So they have at least two spectrometers on board of this little guy. 206 00:17:34,653 --> 00:17:43,542 And another application which gains more and more importance in space are optical atomical clocks. 207 00:17:43,542 --> 00:17:53,551 It's a time keeping device, but optical clocks operating with lasers are even more precise than radio operated ones. 208 00:17:53,551 --> 00:18:01,499 And there are some new generations of optical atomic clocks, cause they are even more precise in space. 209 00:18:01,499 --> 00:18:10,385 For example there is the ACES mission, which is a french mission, which was scheduled at the end of this year. 210 00:18:10,385 --> 00:18:17,795 Unfortunately a newer launching date, but I think it won't be launched next year. 211 00:18:17,795 --> 00:18:20,902 Maybe you know even more than I do. 212 00:18:20,902 --> 00:18:31,070 And there is also another mission called X quest, which is still in preparation. 213 00:18:31,070 --> 00:18:36,153 So, this is everything I have on measurement. 214 00:18:36,153 --> 00:18:43,685 Free space optical communication is maybe an application3, most of you know what it is. 215 00:18:43,685 --> 00:18:46,502 You have your optical carrier, the laser beam, 216 00:18:46,502 --> 00:18:52,283 and you modulate you data either with phase shifting or with binary on-off keying. 217 00:18:52,283 --> 00:18:57,380 The binary on-off keying is the most common one. 218 00:18:57,380 --> 00:19:03,319 Compared to the commonly used RF-transmission you can go over longer distances, 219 00:19:03,319 --> 00:19:07,986 it needs less power and you have a higher transmission rate. 220 00:19:07,986 --> 00:19:11,585 Still it depends on the weather and the atmosphere on earth, when you want transfer data down to earth. 221 00:19:11,585 --> 00:19:21,379 As an example I can name the Laser Communication Terminal. 222 00:19:21,379 --> 00:19:28,784 It's build from TISAD(?) and it was first tested on the satellite ARTEMIS. 223 00:19:28,784 --> 00:19:36,603 It had a downlink and an intersatellite bandwith of 50 Mbps. This was in 2001. 224 00:19:36,603 --> 00:19:50,473 In 2008 there was another inter-satellite connection between XXX and XXX and they received 5.5 Gbps. 225 00:19:53,838 --> 00:20:05,937 There's also another US mission ongoing. It's called the lunar laser communication demonstrator mission. 226 00:20:05,937 --> 00:20:11,386 On the lunar atmosphere dust environment explorer. This was launched in September this year. 227 00:20:11,386 --> 00:20:24,216 And in October they received a downlink of 622 mbps. So this is state of the art right now. 228 00:20:24,216 --> 00:20:29,914 So, that's everything I have... I still think lasers are cool! 229 00:20:29,914 --> 00:20:35,085 And I hope you agree with me that there are a lot of applications for lasers in space. 230 00:20:35,085 --> 00:20:48,474 And I also think that reaching space is challenging, but it's not impossible. It's pretty doable actually. 231 00:20:48,474 --> 00:20:58,308 There are some initiatives for non-professionals or for - I'm not sure how to call that - for you, for everybody. 232 00:20:58,308 --> 00:21:05,043 For example the amateur radio satellite organizations. They are worldwide. 233 00:21:05,043 --> 00:21:13,408 There are for example the rexusbexus experiments. These are sounding rockets and balloon experiments for students. 234 00:21:13,408 --> 00:21:23,146 There are for example the cubesat projects. They design satellites of the size of one liter, like that size. 235 00:21:23,146 --> 00:21:29,077 And they can go as piggyback payload, for example on commercial satellites. 236 00:21:29,077 --> 00:21:34,264 So this is an opportunity to get to space pretty cheap. 237 00:21:34,264 --> 00:21:42,300 I also want to name the Google Lunar X Prize with the part-time scientists as the last German team (I think). 238 00:21:42,300 --> 00:21:55,627 They want to build a lunar rover and there are also a lot of other initiatives and projects which you can find. 239 00:21:55,627 --> 00:21:57,700 Thank you. 240 00:21:57,700 --> 00:22:04,441 [Applause] 241 00:22:04,441 --> 00:22:07,568 Thank you very much, Anja. Thank you very much. 242 00:22:07,568 --> 00:22:14,275 Now if you have questions, could you please line up at the microphones so we can record it? 243 00:22:14,275 --> 00:22:18,013 Our signal angel, do we have questions from the internet? 244 00:22:18,013 --> 00:22:21,967 - No, not right now... OK, then let's start with microphone 1. 245 00:22:21,967 --> 00:22:31,920 There is basically one thing: The French device is going to be launched in 2016. - OK. 246 00:22:31,920 --> 00:22:47,511 And another thing... it's a double question actually. First of all: Why do you go in microgravity with [?] What do you promise yourself from that? 247 00:22:47,511 --> 00:23:00,810 The plan is to find the answer to the question whether Einstein's equivalence principle is still correct. 248 00:23:00,810 --> 00:23:09,508 The main goal is to go up with 2 species up there, measuring the gravitation, and compare that. 249 00:23:09,508 --> 00:23:23,092 And we need to go to space because it's more precise measuring up there. You have a longer measuring time. 250 00:23:23,092 --> 00:23:36,693 And another thing: I happen to know some friends of mine who work scientifically with lasers, and the alignment ends up to be depending on everybody working on that field... 251 00:23:36,693 --> 00:23:45,280 ...professors touching random stuff and the experiment is ruined. How exactly do you harden a setup for launch? 252 00:23:45,280 --> 00:23:52,585 I mean you have the G-loads, you have vibrations, you have random stuff happening... So how do you do that? 253 00:23:52,585 --> 00:23:56,809 I mean it's a quite sensitive setup if I'm not wrong. 254 00:23:56,809 --> 00:24:16,148 It's a very sensitive setup, that's true. But when you know that it has to work autonomously from the beginning, you can design it to make it independent of professors running around touching things, for example. 255 00:24:16,148 --> 00:24:31,367 Yeah, that's not the thing... How do you cope with misalignment for example. I mean you will have some mirrors, some beamsplitters or whatever... and if they get moved, that's it. 256 00:24:31,367 --> 00:24:41,416 - We use very very small components like very very small lenses and we glue them, we fix them on a bench, so you can't align them anymore. 257 00:24:41,416 --> 00:24:55,500 When we are integrating our stuff, then we're aligning that actively. So the laser is switched on and then we align the components that the output is what we expect it to be. 258 00:24:55,500 --> 00:24:59,102 OK, let's have a question from the other microphone over here. 259 00:24:59,102 --> 00:25:05,030 First of all, thanks a lot for the straight overview talk. I just have a very quick remark about the Lisa mission. 260 00:25:05,030 --> 00:25:17,619 I'm very happy to announce that just recently we got fully funded by the European Space Agency and in 2034 we will fly with a 1.2 billion dollar budget. 261 00:25:17,619 --> 00:25:21,994 - Which mission? 262 00:25:21,994 --> 00:25:26,746 - The Lisa mission. 263 00:25:26,746 --> 00:25:29,894 Congratulations. Go ahead, please. 264 00:25:29,894 --> 00:25:42,151 My question is about... when you shoot something up and make experiments, you probably won't shoot one satellite for only your project. 265 00:25:42,151 --> 00:25:58,157 So are you working together with other departments and then you... like everyone gets one square meter for his experiments and then you shoot them up and all experiments run independently on one satellite? 266 00:25:58,157 --> 00:26:15,148 - It depends on what you are doing. In our experiment we have one rocket just for our experiment, but it's not just an [...] institute building that stuff. It's a cooperation of a lot of institutions and universities. 267 00:26:15,148 --> 00:26:26,590 And when it comes to these experimental satellites, they very often go as piggyback payloads, that means you have a commercial satellite. 268 00:26:26,590 --> 00:26:37,973 For example a communications satellite which is launched anyway and they're normally much smaller, so they're sitting just on the side and wait for the launch. 269 00:26:37,973 --> 00:26:59,314 When we're talking about piggyback payloads: Don't you have space trash problems because you can't just say people can go and shoot stuff up there if there is one space trash problem anyway? 270 00:26:59,314 --> 00:27:02,630 - I'm not sure I got the question... 271 00:27:02,630 --> 00:27:10,529 You say for example I could just build something and shoot it up as a piggyback payload... 272 00:27:10,529 --> 00:27:16,280 - Well, it's unfortunately not that easy of course. But it's not impossible. 273 00:27:16,280 --> 00:27:25,951 Like some years ago or some decades ago, it was impossible for a private person to even think about building your own satellite. 274 00:27:25,951 --> 00:27:35,696 But you need some funding, you need a group basically and maybe you're lucky and you'll get to your goal at the end. 275 00:27:35,696 --> 00:27:45,513 - So I can't just... if I get to build the rocket myself and shoot it up... Is it allowed? Just from the law? 276 00:27:45,513 --> 00:27:47,365 - I don't think so... 277 00:27:47,365 --> 00:27:49,758 - OK. 278 00:27:49,758 --> 00:28:00,901 - I have one question: You mentioned the mission concerning analyzing the moon dust and this moon mission. 279 00:28:00,901 --> 00:28:10,480 But you didn't mention who was the partners - is it a project by ESA, is it a project of a cooperation of several agencies or is it a private... 280 00:28:10,480 --> 00:28:12,066 - It's a NASA project. 281 00:28:12,066 --> 00:28:26,086 - Ok, thank you. And then another question: A lot of [?] come down by Gigahertz and those frequencies are also reserved for astronomers. 282 00:28:26,086 --> 00:28:42,940 Do we have some feedback from the astronomer community, are they concerned that their frequency will be less and less laser communication we will get... other optical applications or other laser applications? 283 00:28:42,940 --> 00:28:53,019 What's the standing point of the astronomy community? Because they're also using the high frequencies in the 5.5 Gigahertz. 284 00:28:53,019 --> 00:28:59,833 Um, I have no feedback on that... 285 00:28:59,833 --> 00:29:05,318 OK. Any more questions from the internet? How about our signal angel? 286 00:29:05,318 --> 00:29:06,852 No questions from the internet. OK. 287 00:29:06,852 --> 00:29:13,436 Then, Anja, once again: Thank you very much!