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Alan Stern

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2017-01-01

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2017-01-01

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1. “a high accuracy, high speed tracking on the sky, which we were involved in a couple of failed spacecraft. There's a couple of spacecraft were launched and then they stopped talking to the ground, coupled by US and coupled by NASA and coupled by our colleagues in Britain. The realization was if the thing is alive but the radio system is broken. So it transmitters, say, died, but the receiver is still alive. Maybe we can still figure out what happened. Maybe it's just stuck. We could send a command on stick it. But we need to know what's going on. So if the thing is still alive up there, then the telecom system is partly awake and the reference frequencies from their oscillators are leaking out from the spacecraft. The thing is that the leakage is tiny. It's a millionth of a watt coming out of the spacecraft and orbit a thousand kilometers away.”

   2017-01-01 · a16z Podcast · a16z Podcast: New Year, New Horizons -- Pluto! · IDENTIFIED FROM THE TRANSCRIPT · source

2. “We placed the hydraulics. So, when it happened, another kind of wrinkle in the technology story. Was that over the era from the 1970s to the 1990s and 2000s, the progression of the disk drive industry to ever increasing capacity had led to the sophistication of these electric stepper motors for controlling the drive on the oak of the magnetic readers going in and out? And they had a step with increasing precision, and they had to do it through precise rotation of the motor. And it had to do it quickly, the quicker the better because they were increasing speeds and densities. And so what happened was that this drive industry spawned a technology for the electric stepper that was for purposes of industrial control. And so now instead of something that was a cubic centimeter in size and your little disk drive, you could buy something that was the size of a Volkswagen and would turn the dish. And they did. We replaced the hydraulics with electric steppers. And the dish woke up. We were able to do not only”

   2017-01-01 · a16z Podcast · a16z Podcast: New Year, New Horizons -- Pluto! · IDENTIFIED FROM THE TRANSCRIPT · source

3. “And so what that spawned was a succession of research into means of isolation and protection really excision. How do you eliminate without destroying what you're looking for the unwanted interference? And that became a research project for me, a couple of students that I had pioneered some very nice solutions, as well as Mike's ability to develop, to implement those. And it was Mike, though, that heard about electric stepper motors.”

   2017-01-01 · a16z Podcast · a16z Podcast: New Year, New Horizons -- Pluto! · IDENTIFIED FROM THE TRANSCRIPT · source

4. “Who was their chief engineer that knew the most about it and had been using the dish up until and still did from time to time? So Mike and I developed a really lifelong friendship and the desire to keep the dish alive. And so what we found was that there were a couple of things that were in need. Clearly, one was the control and the other was the receivers. Those receivers could be a relatively low performance. They were good at the time, but they were unsuitable for listening for alien signals on the sky or looking for subtleties within the galactic background. And so we needed to demonstrate that if you had the right receiver, you had in this environment enough sensitivity to with that dish to make a difference. One of the big concerns was that that dish is sitting fully visible from”

   2017-01-01 · a16z Podcast · a16z Podcast: New Year, New Horizons -- Pluto! · IDENTIFIED FROM THE TRANSCRIPT · source

5. “Yeah, along about the same time I stopped work with SETI, I still carried that nagging sense that, gee, I really should be looking for something anyway. And so this is sitting up there, you know, fallow. And I started asking around and I was led to SRI and a colleague over there, Mike. Last name is Cousins, Mike Cousins,”

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6. “Yeah, it was a very dangerous job to have, which was the anti-aircraft control guy who sat in that seat moving that thing around. Because if something went wrong, you probably weren't going to survive it. Anyway, how they got approval to stick that. On the dish In this era of litigious conservatism, I don't think that would have ever happened. But that desperation being what it is and innovation being the better part of valor, they did. But by the 1970s, the technicians that knew how to prepare that were retiring.”

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7. “Computer was restarted. The real concern was we were on a timeline. It was everything on the spacecraft's run autonomously. And in order for the encounter sequence to proceed with the science that we intended to obtain, that timeline needed to start. Only it was like 30 hours from when the fault occurred. So to their extraordinary credit, the operations team was able to do that. They restarted the timeline just moments, minutes before it was needed to get it on track to do the encounter in the way that captured all of the scientific opportunity.”

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8. “Made that happen. That isn't that isn't that's not something that's supposed to have happened right now. That shouldn't have happened right now. We know what this stuff does. Why is this a problem? And why didn't we find it when we ran the rehearsal? In other words, six months ago, we did exactly the same thing. We ran exactly the same programs. We sent the exact same update command to flash. Why wasn't it a problem there? It turned out that six months ago, the picture of the sky was dark. There was nothing but black in a few stars. So the JPEG compression took a whole lot less time. Right. So it could finish in time. It was done when the flash commands came in. This time unbelievable. All the stars.”

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9. “So Saturday morning, we're about to go to Baltimore. My wife, Margot, and I for the encounter. A lot of the members of the team are already there. And it's the Saturday morning. We're having breakfast. And I don't normally even open my laptop to see messages. And I do. And there's one from Alice, and she says, we have a conference call in an hour to discuss the spacecraft went safe. When the spacecraft goes safe, those are not good words because it meant that something went wrong and the spacecraft tucked its head under its wings and shut everything off and tried to find out where Earth was and turned on a tone that said one of several things happened and it's up to you to figure out what it is.”

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10. “Its destination. And so Yes, every, it's called the annual checkout. The spacecraft's in hibernation. Once a year we wake it up. We exercise a set of tests. We transmit to it. We do performance evaluation like we were going to do the occultations tests and we make sure that everything's running okay. And so once a year for the nine years we went through the annual checkout plus we did two rehearsals where we ran the whole process of occultation and radiometric measurement in rehearsal”

    2017-01-01 · a16z Podcast · a16z Podcast: New Year, New Horizons -- Pluto! · IDENTIFIED FROM THE TRANSCRIPT · source

11. “Unbelievable. So we got one of these incredibly rare oscillators. We've got the sort of mix of old and new plutonium. We've got the FPGA that's got five gates left over on it. And you launch the sucker. So now we're going to take years. It is almost a decade, right? Before it gets to its destination. And so you're testing the communication all along.”

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12. “And we want one. One of these US. Where do you get one? Right. And it was the same story like with the plutonium. We started looking for suppliers that didn't exist. There was a French company that was making them, and they'd gone bankrupt. Gave him like three years. And so here we are six months before launch. We have to actually have one of these things to integrate into the payload. And that company delivered five. We tested the five. Two were okay. Two Met specs. And they were put”

    2017-01-01 · a16z Podcast · a16z Podcast: New Year, New Horizons -- Pluto! · IDENTIFIED FROM THE TRANSCRIPT · source

13. “It was, yeah, I count that. Among the top 10, Hashemi stories of all time. Anyway, to do that, you needed the ultra-stable oscillator. And I maybe had rambling on here, but Because the Cold War when it went over when that happened, the former Soviet Union was disassembled. The market in USOs disappeared.”

    2017-01-01 · a16z Podcast · a16z Podcast: New Year, New Horizons -- Pluto! · IDENTIFIED FROM THE TRANSCRIPT · source

14. “So, what I have is I have a million to one in Salino's ratio sampled to a precision of part in 10 to the 13th. Basically, you can measure a gnat's eyebrow at a billion miles with that thing. And that's what we did.”

    2017-01-01 · a16z Podcast · a16z Podcast: New Year, New Horizons -- Pluto! · IDENTIFIED FROM THE TRANSCRIPT · source

15. “That is a lot The way we sample it is we have a clock that's running the sampler on the broadband channel. It's running a 10 million samples a second. That clock is derived from an oscillator on board. That oscillator itself is what we call USO, an ultra-stable oscillator. That oscillator's quartz. It's a slice of quartz encapsulated in a glass sarcophagus, carefully suspended and thermally insulated and kept at temperature barely changing by a thousandth of a degree. And as a consequence, it doesn't change its frequency by one part and 10 to the 13th. That's one tenth of a trillionth of the frequency.”

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16. “3.7 billion miles out in a system that captures this, those waveforms are sampled with noise that's one thousandth of the amplitude of that signal. So it's like you see a sine wave. And you sampling it many times per cycle, each dot is a sample value, has noise associated with it associated with the receiver's noise and the sky noise and this noise from coming down the radio path from the earth. You're going through three and a half billion miles of solar wind and plasma irregularities. It's extraordinary that all that happens and you still get a signal where the amplitude is noisy only a thousandth of the waveform. Now the power which is the square of that you square the amplitude of the voltage squared is power. So a thousand squared is a million. So we got signals that were a million to one above the noise power. It's at Pluto at Pluto. So what you can do with it.”

    2017-01-01 · a16z Podcast · a16z Podcast: New Year, New Horizons -- Pluto! · IDENTIFIED FROM THE TRANSCRIPT · source

17. “And it flies at an angle and it flies into the shadow of Pluto as seen from the Earth. And so that's the occultation. On the way in to the shadow and then coming out on the other side. And then in those moments before ingress, as we call it, an egress, the refraction of those four signals through Pluto's atmosphere has the effect of shifting the frequency of the received signal. And that's because the direction of the ray bends slightly and you're getting the Doppler from a slightly different direction than you were before. So what we do is we capture that central thousand hertz and we sample it into the waveform that is present in the signal and the waveform has got a lot of amplitude. In other words, we've sent 20,000 watts on an aperture that's about 70 meters in diameter. So the instantaneous power in the beam is huge. It's over a million watts per square meter. At Pluto, which is...”

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18. “So we transmit from the Earth with the Deep Space Nets stations, which are three of them that ring the Earth, and we use two of them because at the time of the encounter, Pluto is up above the horizon for Goldstone, California, and Canberra in Australia. They have antennas that are two sizes, one's a 70 meter diameter and the others are 34s. They all have these 20,000 watt transmitters. So during the occultation portion of the flythrough of the encounter, we had four of those transmissions going simultaneously, actually five, and I'll tell you about the fifth is the bystandic one. So the 70 and a 34 from each of the two stations transmitting at frequencies that are within this one kilohertz of each other, spaced about 100 hertz apart to the spacecraft. What's going to happen is as the spacecraft flies to Pluto and then pass”

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19. “On non-used gates. Lord knows how that actually the routing worked. But again, that was Mark's magic, be able to kind of groom the routing. You do these nets first and then you do the next set and you just sort of layered and you don't give it all at the same time and you just try to slowly ease its way into completion. It's hurting cats, but you get them all into the corral.”

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20. “It works. It fits. We've demonstrated it across the board. There are no test procedures that show any vulnerability. We've stressed it, temperature, radiation. I mean, we've done all that stuff. So you got a choice. You can take it as it is and waive the margin or give us the other chip. So they waived the margin. Then they said, well, actually, there are a couple of other functions that this ought to have. Do you think you can fit them in? And somebody says, I'll take a look. I said, are you kidding? He said, no, I think so. I think so. So he did. And there were a couple of just simple protocol acknowledgements on the communication link that they wanted to see to make sure that the thing was handshaking correctly. So it was that he had five gates left. And that's the way we”

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21. “The other was that Mark says, you know, I have a very strict discipline about how I code. There are certain choices you can make in the language of the code that are absolutely guaranteed to fail. He said, you only know that Woodsy lore by, you know, a lifetime of trial and error and mostly error. This is a discipline you have to have. He said, students, PhD students at Stanford in electrical engineering are too clever. They see the opportunity to recast an algorithm into a more efficient form and they'll do that. They can't resist doing that. Steve said, that's the problem. Mark took over the code and with Kamakshi's interaction, they succeeded in getting the first to test module to work and then the succeeding modes went.”

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22. “He's out of Texas, right? Yeah. So Mark shows up and we wants to know what's going on. What are we doing? So Kamakshi's there. You know, we give him a story, we give him a story, we tell him what's going on. Two things really important happened. One is Mark became really fond of Kamachi.”

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23. “And until already my hackles are up, right? I'm real prickly about this, right? The guy who is head of evaluation was a former Stanford graduate student not too long ago, who is now the payload chief engineer. And Mark, Mark Taffley. And we became close friends quickly. It was amazing how that compatibility seemed to kick in. So Mark went back and he recommended to Bill Gibson, the program manager, you know, that Stanford needed help, but they didn't need, it wasn't probably a good idea to take the whole project away and give it to somebody else. So how can we help them? Well, Southwest had a FPGA programmer for space flight qualified solutions, Mark Johnson, Mark say motorcycle riding, guitar plane, leather jacketed, tattooed.”

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24. “Yeah, yeah. And after, and not it wasn't the whole design, it was just a small test piece that uses maybe a tenth of the hundred thousand gates. It didn't work. There was something fundamentally broken in the process of how that language assembled in to code that was then dropped onto the device. It's something fundamental we didn't understand. After a year, the program manager that oversaw the entire spacecraft, Glenn was the payload guy. And there was a manager at Southwest San Antonio, which had responsibility for the whole program. He's getting worried. He's saying, Stanford doesn't look like it's going to succeed. We're going to have to do something. So he sends a SWAT team in to reveal what you're coming to fixers.”

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25. “didn't have a lot of transistors in a chip, and they had vacuum tubes, and they were doing radar on planes, and they wanted to be able to reject the clutters and the jamming, and so they wanted to be able to filter. And so Hogemeier had developed these computationally efficient techniques for filtering linearly and using vacuum tubes. And Kamoxi's design was, I think this could work if we did it this way. So she did. Then I had another couple of students that tried to take that and drop it down into a programmable device, FPGA. And well, so ACTAL gives you all of the tools. And they'll even give you a course in how to do it. And they give you the development environment, and they give you program languages and they give you simulators. They give you routers. They give you the emulator to test it. A couple of students, one after the other, went through that whole process, got it down into the chip, actually bought some chips and the programming stations, and we burned them in and we turned them on.”

    2017-01-01 · a16z Podcast · a16z Podcast: New Year, New Horizons -- Pluto! · IDENTIFIED FROM THE TRANSCRIPT · source

26. “Which is basically 10,000 to 1 reduction in bandwidth. And we got to make that reduction. We have to throw away all that other stuff and pick that one band that we need. And we have to do that in such a way as to guarantee linearity in the process. That filter has to be perfect. It has to suppress the album by the noise inside the band has to be flat and has to be linear. These are called FIRs, finite impulse response filters. But a 10,000 element FIR is unimplementable. There is no algorithmic stability that you could possibly find in any computing technology even today that would do that. So Kamakshi's task was to figure it out and do it in a way that was not computationally expensive. And she did. She discovered a old radar idea by RCA employee Glenn Hogemeier, who was working in the 1950s and 60s.”

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27. “Just sitting there unused, and we were fine, we had 50, now we have to stuff it into one. And we said, well, we're not sure we can do this. And they said, well, I don't think you have a choice. So I had a student at the time who had designed the signal processing for this application. This was Kamakshi, Shiva Ramakrishnan. Kamakshi's wanted to take on a challenge. We said, well, this is a challenge. We've got a signal that's coming in in this big wide bandwidth. It's four and a half megahertz. And this actual signal is about kilohertz.”

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28. “You got one. FPGA. Now, we knew that we were at the time about 50 50. Now that we could put half of the design in one and half of the other and they could talk to each other and it would be all just fine. And that was good from a lot of reasons because one of the design guidelines from the mission is that you have to have a margin of gates in these FPGA that is high enough to give you assurance that the implementation in the gate is going to be successful. One of the biggest problems in implementing an FPGA design is routing and being able to successfully route to all the gates in this million point gets exponentially more complicated as you get closer and closer to the top of the line. And so they say NASA guidelines is you need at least, we would like you to have 25% margin minimum number is 15%, which means 50% of million gates, 150,000 gates.”

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29. “That's right. But it will turn out that it will be the case that you'll get three or two essentially all the time. So those are limited in capacity. At the time, I think you could get a million gates and one of the highest density octel you could get for this case, which is, you know, it has to be spaceflight qualified. So we had been offered the opportunity to implement in two of these. And as you say, Frank, as the power budget was reduced and the scope was re-evaluated, they came back to us and said, well, guess what? We really have to have one. It's just one. Wow.”

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30. “Yeah, you have to have a radiation tolerant implementation. And that was possible in a signal processing element called a FPGA, which are field programmable gatorays that Actel was making. And they were based on a technique of hardened by design, but also what they call triple redundancy. You have each element in each gate in the array is triply implemented, and you vote them in pairs. So if all three agree, fine. If two agree, you chose that one, right? And if none of them agree, well, you've got a problem.”

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31. “Right. We were initially offered a chance to implement our new technology for acquisition of the signal that was transmitted from the Earth to the spacecraft. Like I said, we had a sponsored research development program. We knew how to do it. We thought we could fit it into a signal processing system, but it would require in the existing technology of the early 2000s. These have to be radiated.”

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32. “Yeah. Well, let's work our way back to the impact on the communication systems, right? Because you had assumed a power budget, assuming fresh plutonium from the Department of Energy, and you got kind of tired plutonium from a variety of sources. And now you have a much lower power budget.”

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33. “You won't have the power that you expected. We had maybe thought we'd start out with like 300 watts and we didn't, we started maybe with 280, 275. And by the time we get there, it's pushed down to 245. There was a succession of compromises and brokered deals, but... Eventually it all kind of worked.”

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34. “Actually, we were still a bit short. And the DOE said, Well, you know, we have put aside a few extra pellets for the next space mission. We might be willing to trade those for some new ones that would come along. And the problem is that the ones we have put aside are now a bit old.”

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35. “Glenn became our program manager, the program manager of the mission at the time became ill, and they were looking for somebody to step into John's ample shoes. And Glenn was asked and he agreed. Glenn brought to the mission that same quality of statesmanship and problem solving that he demonstrated in the brokering of the plutonium. And it really eased so many problems that occurred along the way that had to do with funding, irregularities, recalcitrants on the part of the U.S. Congress and the White House and all of those other problems that pop up day to day that you would otherwise, any one of which could have stalled us for too long. Glenn made work of. And I think we all credit him with making this possible.”

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36. “For the missing piece of it. It wasn't the entire piece, but it was about half. So that was brought over to the processing facility that could package it, which was not shut down. And they did that. They packaged it, put it up, tested it, blinked out the licenses. It was all under extraordinarily short fuses. The last time that that happened for the Cassini mission, the license itself took like three years, maybe pushing four. And we had to have it in under six months.”

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37. “Thank God. And there are quite a few that do that we don't want to, and some that have done so that we have had an excess of it, the Russians, under this former Soviet Union, made a significant amount of plutonium, and they had it in storage, and it was my understanding that what Glenn discovered was that the Soviets or the Russians now were anxious to maybe use it as a marketable option, that they were looking for cash. They desperately needed the cash. They would have possibly entertained an buy offer from a variety of vendors, and the US did not want that to happen because they didn't want it to fall in the wrong hands. So Glenn, brokering through the US State Department, got the U.S. to make an offer to the Russians to buy their plutonium for this mission.”

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38. “Well, and they actually put that capability in there in case the thing is going in the wrong direction after a launch failure. So you want to be able to mitigate that threat, boom. So you have to prove that if you do that, that the plutonium won't disperse, it'll fall down and intact and in such a way that it won't be potentially harmful, all that. In addition, now the thing has been shut down. And so Glenn Glenn, to his extraordinary credit, got into motion and he started discussing with the U.S. State Department alternative sources of this rare and precious quantity called plutonium, which you probably understand is actually one of the reasons why it's scarce is that it's nuclear fuel. In addition, it's nuclear bomb fuel.”

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39. “That's right. And then they tell you this might not be possible. So we had at the time, the project had assigned a liaison to the Department of Energy within the program, the spacecraft was being developed by APL, Johns Hopkins Applied Physics Lab. And Glenn Fountain was the person who was in charge of this process of acquisition of the RTG and mitigating problems that would come along with getting the license. You need a license for this from the Department of Energy. And it has to go through a whole lot of layers, including a congressional and approval and environmental impact studies and people who had protested the launching of plutonium before because other spacecraft had had it. But there were a lot of protests about putting that on a rocket and sending it up in the air.”

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40. “Yeah. So you have to build this thing that's never been built before. You're racing against time because otherwise the atmosphere you want to observe isn't there. The radiation processing plant springs a leak.”

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41. “Because you have a window that you can get to Pluto, right? We had a launch window that was narrow. For a lot of reasons, one was we were looking for a gravity assist at Jupiter, which would have boosted the arrival time by about four or five years. It also was true that we were afraid Pluto has sort of an elliptic orbit, that the high point in the orbit, the apogee, it's colder significantly than in the perigee, which is the closest part. And it had just passed the warmest part. And so what happens if the model for Pluto at the time was kind of like a comet? So when it got warm, the atmosphere would bloom. When it got cold, the atmosphere would collapse. And if there was going to be an atmosphere there that we were going to measure its temperature and pressure, we dogged on, well better get up there before too much time had passed because it was very likely to collapse sometime soon.”

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42. “Of the system? Oh, sure. There's a bunch of plutonium isotopes. The longest lived ones are about a quarter of a million years, but they're also the ones that don't generate as much heat because they're not popping off as much, okay? The ones that are the hottest are the ones that are the shortest-lived, and they're about 84 years. So what you want to do is you want to get a fresh supply of plutonium, sock it on a spacecraft, send it off so that in the first year or so you don't lose more than a few 10% of the power. In our case, that process got started. There's a plutonium processing facility that the U.S. Department of Energy maintains, and that there was in about halfway through the process, there was a leak that was discovered in the radioactive leak. And they shut down the process of production indefinitely.”

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43. “Or maybe not for the instruments. They're body mounted, unlike a lot of other spacecraft. This means that all of the instruments are not all facing the same direction at the same time. So you can only use one or two at the same time, as it turns out.”

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44. “Oh, Chris Pluto is roughly 37 right now, 40-ish AU out from the Sun 40 times the distance. You can't use solar power because the square of the distance. And so 40 squared is 1600. So you get 1,600th of the power of the Sun that you would get at the Earth's orbit. And that's not enough. So common of these deep space missions is to use an electric source called an RTG, a radiothermal electric generator, which uses radioactive nucleides to generate the heat, which is presented to a thermopile that generates the electricity. We use a radioactive element called plutonium to generate the heat, and that generates about 250 watts for us of power.”

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45. “Well, the pioneers are out there further. Yeah. But this is the furthest radio occultation experiment that's ever been done. And the furthest by static radar experiment that's been done. In a way, they're a lot of firsts associated with this”

    2017-01-01 · a16z Podcast · a16z Podcast: New Year, New Horizons -- Pluto! · IDENTIFIED FROM THE TRANSCRIPT · source

46. “Static radar experiment that would characterize the surface to an even greater degree. And in the ensuing years we had students develop the technology, we had them build it, we had them test it, it was integrated into the spacecraft. And you pretty much know the rest of the story. We got our data back. We got an exquisite profile of Pluto's temperature and pressure. We did radiometry measurements and discovered some really quite surprising things like the night side is a whole lot warmer than the day side and we got the bisatic signal, which is itself kind of a small miracle.”

    2017-01-01 · a16z Podcast · a16z Podcast: New Year, New Horizons -- Pluto! · IDENTIFIED FROM THE TRANSCRIPT · source

47. “And so we proposed in the early 90s to develop the technology. NASA has a program for technology development that is applicable to future missions. And so they gave us the support to build prototype receivers that would do this, would be able to capture a narrowband signal and record it and send it back with the opportunity to extract those properties that allow us to do the inversions. That resulted in a sequence of proposals. And so we teamed with a group at Southwest Research, led by Alan Stern, to do this new Pluto mission they could call New Horizons. We became the radio science experiment called Rex that had the objective of doing the radio occultation of Pluto's atmosphere and Charon, which doesn't have an atmosphere, and to do what we call radiometry to measure the temperature of Pluto using the radio antenna and to do an additional experiment where we bounce signals off the surface of Pluto called a biological”

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48. “A novel architecture for the acquisition of the signal Going to have to be transmitted from the Earth, not to spacecraft. It's going to have to receive on this spacecraft. It means the receiver is going to have to be modified. They don't like to do that. They like to fly things that have flown before. They don't like novelty. But if we want to do this, we're going to have to do the modification.”

    2017-01-01 · a16z Podcast · a16z Podcast: New Year, New Horizons -- Pluto! · IDENTIFIED FROM THE TRANSCRIPT · source

49. “And their specialty, Lens specialty with Professor Echeland at the time, was to do what they call radio occultation. It's a process by which radio signals transmitted from one direction and like refracted or diffracted in an atmosphere or soft of rings or some other Process on a planet and is received on the spacecraft or vice versa. And using that, you can extract the properties of the refractor. And in this case, we get from that, we can recover the temperature and pressure profiles of the atmospheres of the objects. And so that was our plan for Pluto. When Pluto mission was announced, initially there were several incarnations of it. And one of the early ones was in the mid-1990s. And Len Tyler at the time said, you know, I have done every occultation of every planet in the solar system except Pluto. It was still a planet then. Right.”

    2017-01-01 · a16z Podcast · a16z Podcast: New Year, New Horizons -- Pluto! · IDENTIFIED FROM THE TRANSCRIPT · source

50. “And promoting that got me an invitation to be a NASA fellow, an RC fellow at the Ames Center which was then pioneering the work on the development of the study instrument. So that got me to Stanford working with Professor Alan Peterson, who was then leading the signal processing group in the Department of Electrical Engineering. And Alan and I became responsible for the 10 million point Fourier transform analyzer that we built for the SETI project and its prototype that has then since been used and thinking other versions for the search that they've conducted ever since. But I haven't been involved since the late 80s when I started working more seriously with the space sciences group and electrical engineering under Professor Tyler there. And it was his interest to do a radio science experiments in the outer planets, which attracted me very much.”

    2017-01-01 · a16z Podcast · a16z Podcast: New Year, New Horizons -- Pluto! · IDENTIFIED FROM THE TRANSCRIPT · source