Natalya Bailey: Rocket Engines and Electric Spacecraft Propulsion | Lex Fridman Podcast #157 | Transcription

Transcription for the video titled "Natalya Bailey: Rocket Engines and Electric Spacecraft Propulsion | Lex Fridman Podcast #157".


Note: This transcription is split and grouped by topics and subtopics. You can navigate through the Table of Contents on the left. It's interactive. All paragraphs are timed to the original video. Click on the time (e.g., 01:53) to jump to the specific portion of the video.


Intro (00:00)

The following is a conversation with Natalia Bailey, a rocket scientist and spacecraft propulsion engineer previous data MIT, and now the founder and CTO of Axion Systems, specializing in efficient space propulsion engines for satellites and spacecraft. So these are not the engines they get us from the ground on Earth out to space, but rather the engines that move us around in space once we get out there. Quick mention of our sponsors, Monk Pack, Low Carb Snacks, for Sigmatic Mushroom Coffee, Blinkist, and Aptosummarizes Books, and Sun Basket, Meal Delivery Service. So the choice is snacks, caffeine, knowledge, or a delicious meal. Choose what's in my friends, and if you wish, click the sponsor links below to get a discount and to support this podcast. As a side note, let me say something about Natalia's story. She has talked about how when she was young, she would often look up at the stars and dream of alien intelligences that one day we could communicate with. This moment of childlike cosmic curiosity is at the core of my own interest in space and extraterrestrial life, and in general, in artificial intelligence science and engineering. Amid the meetings and the papers and the career rat race and all the awards, let's not let ourselves lose that childlike wander. Sadly, we're on Earth for only a very short time, so let's have fun solving some of the biggest puzzles in the universe while we're here. If you enjoy this thing, subscribe on YouTube, review it on Apple Podcast, follow on Spotify, support it on Patreon, or connect with me on Twitter at Lex Friedman. And now, here's my conversation with Natalia Bailey.

Outer Space And Exploration: Concepts And Controversies

Is there intelligent alien life? (01:45)

You said that you spent your whole life dreaming about space, and also pondering the big existential question of whether there is or isn't intelligent life, intelligent alien civilizations out there. So what do you think? Do you think there's life out there? Intelligent life. Intelligent life, that's trickier. I think looking at the likelihood of a self-replicating organism given how much time the universe has existed and how many stars with planets, I think it's likely that there's other life, intelligent life, I'm hopeful, you know, I'm a little discouraged that we haven't yet been in touch. Allegedly, I mean, in our dimensions in Estonia. It's also possible that they have been in touch and we just haven't were too dumb to realize they're communicating with us. And whichever is the Carl Sagan idea that they may be communicating at a timescale that's totally different. Like their signals are in a totally different timescale or in a totally different kind of medium communication. It could be our own, it could be the birth of like human beings, like that, whatever the magic that makes us who we are, the collective intelligence thing, that could be aliens themselves, that could be the medium communication. Like the nature of our consciousness and intelligence itself is the medium communication. - And like being able to ask the questions themselves, I've never thought of it that way. - Like actually asking the question whether aliens exist might be the very medium by which they communicate. It's like they send questions. - So some, this like collective emergent behavior is the signal. - Is the signal, yeah. So how can you say? - It's interesting, yeah. - Because maybe that's how we would communicate. If you think about it, if we were way, way smarter, like a thousand years from now, we somehow survive. Like how would we actually communicate? In a way that's like, if we broadcast the signal, you know, and then it could somehow like percolate throughout the universe. Like that signal having an impact on-- - Multiverse. - Multiverse, of course. That would have a signal, an effect on the most possible, the most, the highest number of possible civilizations, what would that signal be? It might not be like sending a few like stupid little Hello World messages. It might be something more impactful. Where it's almost like impactful in a way where they don't have to have the capability to hear it. Like forces the message to have an impact. - Right. My train of thought has never gone there, but I like it. And also somewhere in there, I think it's implied that something travels faster than the speed of light, which I'm also really hopeful for. - Oh, you're hopeful. Are you excited by the possibility that there's intelligent life out there? Sort of you work on the engineering side of things. It's this very kind of focus pursuit of moving things through space efficiently. But if you zoom out, one of the cool things that this enables us to do is find, I forget even an intelligent life, just life on Mars or on Europa or something like that. Does that excite you? Does that scare you? - Oh, it's very exciting. I mean, it's the whole reason I went into the field. I'm in is to contribute to building the body of knowledge that we have as a species. So very exciting. - Do you think there's a life on Mars? Like no longer, well, already living, but currently living, but also no longer living. Like that we might be able to find life. There's some people suspect basic microbial life. - I'm not so sure about in our own solar system. And I do think it might be hard to untangle if we somehow contaminated other things as well. So I'm not sure about this close to home. - That'd be really exciting.

The Drake equation (06:20)

- Yes. - Do you think about the Drake equation? Much of what? - That was what got me into all of this, yeah. - Yeah, 'cause one of the questions is how hard is it for life to start on a habitable planet? Like if you have a lot of the basic conditions, not exactly like Earth, but basic Earth-like conditions, how hard is it for life to start? And if you find life on Mars or find life on Europa, that means it's way easier. That's a good thing to confirm that if you have a habitable planet, then there's going to be life. And that like immediately, that would be super exciting 'cause that means there's like trillions of planets with basic life out there. - Though of all the planets in our solar system, Earth is clearly the most habitable. So I would not be discouraged if we didn't find it on another planet in our solar system. - True, and again, that life could look very different. It's habitable for Earth-like life, but it could be totally different. I still think that trees are quite possibly more intelligent than humans, but their intelligence is carried out over time scale that we're just not able to appreciate. Like they might be running the entirety of human civilization, and we're just like to don't realize that they're the smart ones. - Maybe that's the alien message that's in the trees. - It's in the trees. Yeah, it's not in the monolith in the Utah deserts in the trees. - Right, yeah. - So let's go to space exploration. How do you think we'd get humans to Mars? - I think SpaceX and Elon Musk will be the ones that get the first human setting foot on Mars, and probably not that long from now from us having this conversation. Maybe we'll inflate his timeline a little bit, but I tend to believe the goals he sets. So I think that will happen relatively soon. As far as when and what it will take to get humans living there in a more permanent way, I have a glib answer, which is when we can invent a time machine to go back to the early Cold War and instead of uniting around sending people to the moon, we pick Mars as the destination. So really, I say that because there's nothing truly scientifically or technologically impossible about doing that soon, it's more politically and financially and those are the obstacles I think to them. - Well, I wonder of when you colonize with, more than I say five people on Mars, you have to start thinking about the kind of rules you have on Mars. And speaking of the Cold War, who gets to own the land, you start planting flags, and you start to make decisions. And like SpaceX says, it's probably a little bit trolly, but they have this nice paragraph in their contracts where it's like, it talks about that like human governments on Earth or Earth governments have no jurisdiction on Mars.

Competition, ColdWar (09:23)

Like the rules, the Martians get to define their own rules. It sounds very much like the founding fathers for this country, that's the kind of language. It's interesting that that's in there and it makes you think perhaps that needs to be leveraged. You have to be very clever about leveraging that to create a little bit of a Cold War feeling. It seems like we humans need a little bit of a competition. Do you think that's necessary to succeed in getting the necessary investment? Or can the pure pursuit of science be enough? - No, I think we're seeing right now the pure pursuit of science, I mean, that results in pretty tiny budgets for exploration. There has to be some disaster impending doom to get us onto another planet in a permanent way. I don't know financially, I just don't know if the private sector can support that. But I don't wish that there is some catastrophe coming our way that spurs us to do that. - Yeah, I'm unsure what the business model is for colonizing Mars. - Yeah, exactly. - Yeah, like there is for, we'll talk about satellites. There's probably a lot of business models around satellites, but there's not enough short-term business. I guess that's how business works. Like you should have a path to making money in like the next 10 years. - Well, and maybe even more broadly and looping back to something we said earlier, I don't know that getting humans off this planet and spreading like bacteria is what we're supposed to be doing in the first place. So maybe we can go, but should we? And I'm probably an unusual person for thinking that in my industry because humans want to explore. But I almost wonder, are we putting unnecessary obstacles? Like we're very finicky, biological things in the way of some more robotic or more silicon-based exploration. And yeah, do we need to colonize and spread? I'm not sure.

AI in Space (12:20)

- What do you think is the role of AI in space? Do you, in your work, again, we'll talk about it, but do you see more and more of the space vehicles, spacecraft being run by artificial intelligence systems more than just like the flight control, but like the management? - Yeah, I don't have a lot of color to the dreams to have about way in the future and AI, but I do think that removing, it's hard for humans to even make a trip to Mars much less go anywhere farther than that. And I think we'll have more, this again, I'm probably unusual in having these thoughts, but perhaps be able to generate more knowledge and understand more if we stop trying to send humans and instead, I don't know if we're talking about AI in a truly artificial intelligence way or AI as we kind of use it today, but maybe sending a Petri dish or two of stem cells and some robotic handlers instead if we still need to send our DNA because we're really stuck on that, but if not, maybe not even that Petri dish. So I see, I think what I'm saying is, I see a much bigger role in the future of AI for space exploration. - It's kind of sad to think that, I mean, I'm sure we'll eventually send a spacecraft with a fish and propulsion, like some of the stuff you work on out that travels just really far with some robots on it and with some DNA in a Petri dish and then human civilization destroys itself and then they'll just be this floating spacecraft that eventually gets somewhere or not. That's a sad thought, like this lonely spacecraft just kind of traveling through space and humans are all dead. - Well, it depends on what the goal is, right? Another way to look at it is we've preserved, it's like a little time capsule of knowledge, DNA, that we've, that will outlive us. - Well, it's beautiful. How I sleep at night.

Becoming an astronaut (14:41)

- So you also mentioned that you wanted to be an astronaut. - Yes. - So even though you said you're unusual in thinking like, it's nice here on earth and then we might want to be sending robots up there. You wanted to be a human that goes out there. Would you like to one day travel to Mars? You know, if it's, if it becomes sort of more open to civilian travel and that kind of thing, like are you like vacation wise? Like if you talk, if we're talking vacations, would you like the vacation on earth? The vacation on Mars. - I wish that I had a better answer, but no. I wanted to be an astronaut because I, first of all, I like working in labs and doing experiments and I wanted to go to like the coolest lab, the ISS and do some experiments there. That's being decommissioned, which is sad, but you know, there will be others, I'm sure. - The ISS is being decommissioned? - Yes, I think by 2025, it's not going to be in use anymore, but I think there are other, there are private companies that are going to be putting up stations and things. - So it's primarily like a research lab essentially. - Yes. - A research lab in space, that's a cool way to say. It's like the coolest possible research lab. - Yes. - That's where I wanted to go. And now though my risk profile has changed a little bit of three little ones and I won't be in the first 1000 people to go to Mars, let's put it that way. - Yeah, Earth is kind of nice. We have our troubles, but overall it's pretty nice. Again, it's the Netflix. Okay, let's talk rockets. How does a rocket engine work or any kind of engine can get us to space or float around in space? - The basic principle is conservation of momentum.

Conservation of Momentum (16:36)

So you throw stuff out the back of the engine and that pushes the rocket and the spacecraft in the other direction. So there are two main types of rocket propulsion. The one people are more familiar with is chemical because it's loud and there's fire. And that's what's used for launch and is more televised. So in those types of systems, you usually have a fuel on an oxidizer and they react and combust and release stored chemical energy. And that energy heats the resultant gas and that's funneled out the back through and nozzle directed out the back. And then that momentum exchange pushes the spacecraft forward.

Difference in liquid and solid fuel (17:32)

- Is there an interesting difference in liquid and solid fuel in those contexts? - They're both lumped in the same. So chemical just means that the release of energy from those bonds essentially. So a solid fuel works the same way. And the other main category is electric propulsion. So instead of chemical energy, you're using electrical energy. Usually from batteries or solar panels. And in this case, the stuff you're pushing out the back would be charged particles. So instead of combustion and heat, you end up with charged particles and you force them out the back of the spacecraft using either an electrostatic field or electromagnetic. But it's the same momentum exchange and same idea of stuff out the back and everything else goes forward. - Cool. So those are the big two categories. What's the difference maybe in the challenges of each, the use cases of each and how they're used today, the physics of each and where they're used, all that kind of stuff. Anything interesting about the two categories that distinguishes them besides the chemical one being the big sexy flames and-- - Yeah, fire. - Fire. - Yeah. - Chemical is very well understood. In its simplest form, it's like a firework. So it's been around since 400 BC or something like that. So that even the big engines are quite well understood. I think one of the last gaps there is probably what exactly are the products of combustion, are modeling abilities kind of fall apart there because it's hot and gases are moving and you end up kind of having to venture into lots of different interdisciplinary fields of science to try to solve that. And that's quite complex, but we have pretty good models for some of the more like emergent behaviors of that system anyways. But that's I think one of the less unsolved pieces. And really the kind of what people care about there is making it more fuel efficient. So the chemical stuff, you can get a lot of instantaneous thrust, but it's not very fuel efficient. It's much more fuel efficient to go with the electric type of propulsion. So that's where people spend a lot of their time is trying to make that more efficient in terms of thrust per unit of fuel. And then there's always considerations like heating and cooling, it's very hot, which is good if it heats the gases, but you know, bad if it melts the rocket and things like that. So there's always a lot of work on heating and cooling and the engine cycles and things like that. And then on electric propulsion, I find it like much more refreshingly poorly understood. - Last more mysteries. - Yeah, I think so. One of the classes I took in college spent, we spent 90% of the class on chemical propulsion, and then the last 10% on electric. And then professor said like, we only sort of understand how it works, but it works kind of and it's like that's, that's interesting.

Ion engines (21:09)

- Yeah, and you know, even an ion engine, which is probably one of the most straightforward because it has just an electrostatic engine, but it has this really awesome combination of quantum mechanics and material science and fluid dynamics and electrostatics and it's just very intriguing to me. - First of all, can you actually zoom out even more, like 'cause you mentioned ion propulsion engine is a subset of electrical. So like maybe is there a categories of electric engines and then we can zoom in on ion propulsion? - Yes, so sure. There's the two most kind of conventional types that have been around since the '60s are ion engines and haul thrusters. And ion engines are a little bit simpler because they don't use a magnetic field for generating thrust. And then there are also some other types of plasma engines but that don't fit into those two categories. So just kind of other plasma like a Vazimir engine, which we could get into. And then those are probably the main three categories that would be fun to talk about. Oh, and then of course the category of engine that I work on, which has a lot of similarities to an ion engine but could be considered its own class called a colloid thruster. - Colloid, cool. Okay, so what is an ion propulsion, I imagine? - Okay, so in an ion engine you have an ionization chamber and you inject the propellant into that chamber and this is usually a neutral gas like xenon or argon. So you inject that into the chamber and you also inject a stream of really hot, high energy electrons and everything's just moving around very randomly in there and the whole goal is to have one of those electrons collide with one of those neutral atoms and turn it into an ion. So kick off a secondary electron and now you have-- - Plasma. - Yes. - Okay. - And now you have, and now you have a charged, xenon or argon ion and more electrons and so on. And then some fraction of those ions will happen to make it to this downstream electric field that we set up between two grids with holes in them. And in terms of area, the same amount of those ions also runs into the walls and lose their charge and that's where some of the inefficiencies come in but the very lucky few make it to those holes in that grid and there are two grids actually and you apply a voltage differential between them and that sets up an electric field and a charged particle in an electric field creates a force. And so those ions are accelerated out the back of the engine and the reaction force is what pushes the spacecraft forward. If you're following along and tallying these charges, now we've just sent a positive beam of ions out the back of the spacecraft and for our purposes here, the spacecraft is neutral. So eventually those ions will come back and hit the spacecraft because it's a positive beam. So you also have to have an external cathode producer of electrons outside the engine that pumps electrons into that beam and neutralizes that. So now it's net neutral everywhere and it won't come back to the spacecraft. So that's an ion engine. - What temperature are we talking about here? So in terms of like the chemical base engines, those are super hot. You mentioned plasma here. How hot does this thing get? I mean, is that an interesting thing to talk about in a sense that is that an interesting distinction or is heat, I mean, it's all gonna be hot? - No, so it's important, especially for some of these smaller satellites, people are into launching these days. So it's important because you have the plasma, but also those high energy electrons are hot. And if you have a lot of those that are going into the walls, you do have to care about the temperature. So having trouble remembering off the top of my head, I think they're at like 100 electron volts in terms of the electron energy. And then I'd have to remember how to convert that into Kelvin. - Can you stick your hand in it? Is that not temperature? - No, not recommended, yeah. - Okay, so what's a colloid engine?

Conic theory (26:07)

- So the same rocket people that came up with with these ideas for electric propulsion, probably in the middle of last century, also realized that there's one more place to get charged particles from if you're going to be using electric propulsion. So you can take a gas and you can ionize it, but there are also some liquids, particularly ionic liquids, which is what we use that you also can use as a source of ions. And if you have ions and you put them in a field, you generate a force. So they recognize that, but part of being able to leverage that technique is being able to kind of manipulate those liquids on a scale of nanometers or very few microns. So the diameter of a human hair or something like that. And in the 50s, there was no way to do that. So they wrote about it in some books and then it kind of died for a little bit. And then with silicon, MEMS, computer processors and when Foundry started becoming more ubiquitous and my advisor started at MIT, kind of put those ideas back together and was like, hey, actually there's now a way to build this and bring this other technique to life. And so the way that you actually get the ions out of those liquids is you put the liquid in again a strong electric field and the electric field stresses the liquid and you keep increasing the field and eventually the liquid will assume a conical shape. It's when the electric field pressure that's pulling on it exactly balances the liquid's own restoring force, which is its surface tension. So you have this balance and the liquid assumes a cone when it's perfectly balanced like that. And at the tip of a cone, the radius of curvature goes to zero right at the tip. And the radius, sorry, the electric field right at the tip of a sharp object would go to infinity 'cause it goes as one over the radius and one over the radius squared. And instead of the electric field going to infinity and maybe like generating a wormhole or something, a jet of ions instead starts issuing from the tip of that liquid. So the field becomes strong enough there that you can pull ions out of the liquid. - What is the liquid? What are we talking about? - So there's a bunch of different ones. - You can do it with different types of liquids. It depends on how easily you can free ions from their neighbors and if it has enough surface tension so that you can build up a high enough electric field. But what we use are called ionic liquids and they're really just positive. They're very similar to salts, but they happen to be liquid over a really wide range of temperatures. - This sounds like really cool. - Yeah. - Okay, so how big is the cone over here? What's the size of this cone that you noise that ion? - So if you have a cone that's emitting pure ions, I can't remember if it's the radius or diameter, but that emission is happening from, of that cone is something like 20 nanometers. - Oh, as a magic something's like a big air. - So this is tiny, tiny, hence the only being able to do it recently. - Yeah, that's right. - So this is all controlled by a computer, I guess. Like, or like, how do you control, how do you create a cone that generates ion that is scale of nanometers, exactly? - So the kind of main trick to making this work is that physically we manufacture hundreds or thousands of sharp structures and then supply the liquid to the tips. So that does a few things. It makes sure that we know where the ion beams are forming so we can put holes in the grid above them to let them actually leave instead of hitting. - That's cool. - But it also reduces the actual field we have to, the voltage we have to apply to create that field because the field will be much stronger if we can already give the liquid a tip to form on. And those tips we form have radii of curvature on the order of probably like single microns. So we are working at a little bit larger scale but once we create that support and the electric field can be focused at that tip, then the tiny little cone can form on that. - So there's something in them, there's an already like a hard material that like gives you the base for the cone and you're pouring like a liquid over it, whatever. - From the bottom, yeah, it's porous. So we actually supply it from the back of the chip and then liquid forms on top on that structure. And then you somehow make it like super sharp, the liquid. So the ions can leave. - And then we've applied that field to get those ions in that same field then accelerates them. - That's awesome. And there's like a bunch of these. - Yeah, I should have, I should have brought something. So we-- - You could just pretend that you have some nanometer cones on the table again. - Actually, you know, kind of about this scale, we build, we call them thruster chips and it's just a convenient form factor and it's a square centimeter. And on each square centimeter today, we have about 500 of the actual physical, we call them emitters, those physical cones. And we're working on increasing that by a factor of four in the coming months. - In size or in the density? - In number, in the density, the number of emitters within the same square centimeter chip. - So that thing, 'cause I think I've seen pictures of you with like a tiny thing in your hand, that must be the, okay, so that's an engine. - So that is kind of the ionization chamber and thrust producing part of it. What's not shown in that picture is the propellant tank. So we can keep supplying more and more of the liquid to those emission sites. And then we also provide a power electronic system that talks to the spacecraft and turns our device on and off. - So that's the colloid engine? That's the core of the colloid engine. - It's the way I've been talking about it. It's more of ion electrospray. Colloid tends to mean like a liquid droplets coming off of the jet. But if you make smaller and smaller cones, you get pure ions. So we're kind of like a subset of colloid, yes. - What aspects of this? You said that it's been full of mystery from the physics perspective. What aspects of this are understood and what are still full of mystery? - Yeah, recently we've been understanding the kind of instabilities and stable regimes of how much liquid do you supply and what field do you apply and why is it flickering on and off or why does it have these weird behaviors? So that's in the past just a couple years that's become much more understood. I think the two areas that come to mind as far as not as well understood are the boundary between, we actually use kind of big molecular ions. And if you're looking at the molecular scale, you have some ions that you've extracted and they're in this electric field. One ion, it's a big molecule, it's getting energy from the electric field and some of that energy is going into the bonds and making it vibrate and doing weird things to it. Sometimes it breaks them apart and then zooming out to the whole beam. The beam has some behaviors as this beam of ions and there's a big gap between what are those, what, how do you connect those and how do we understand that better so that we can understand the beam performance of the engine. - Is that a theory question or is that an engineering question?

Material science (34:45)

- Theory, definitely. We're, Axion is a startup and we're more in the business of building and testing and observing and characterizing and we're not really diving much into that theory right now. - Okay, so zooming out a little bit on the physics, apologies for the way too big of a question, but to you from either, you mentioned Axion as more sort of an engineering endeavor, right? But from a perspective of physics in general, science in general or the site of engineering, what do you think is the most to you, like beautiful and captivating and inspiring idea in this space? In this space, and then I'm gonna zoom out a little bit more, but in this space, I keep budding up against material science questions. So I, over the past 10 years, I feel like every problem or interesting thing I want to work on, if you dig deep enough, you end up in material science land, which I find kind of exciting and it makes me want to dig in more there. And I was just, even for our technology, when we have to move the propellant from the tank to the tip of the emitters, we rely a lot on capillary action and you're getting into wedding and surface energies. - At a scale of like, no, scape. - Yeah, I mean, if you look further, it's quantum too, but it all is, you know. - Is it a capillary action at the quantum level? - Yeah, so I would, it all comes back to me to material science. There's so much we don't understand at these sizes. And I find that inspiring and exciting. And then more broadly, you know, I remember when I learned that the same equation that describes flow over an airfoil is used to price options, the black-tuals equation. And it's, you know, just a partial differential equation, but that kind of connectedness of the universe, you know, I don't want to use options pricing and the universe in the same. But you know what I mean? This connectedness, I find really magical. - Yeah, the patterns that mathematics reveals seems to echo in a bunch of different places. - Yes. - Yeah, there's just weirdness. It's like, it really makes you think, I think through definitely living in a simulation. Like, whoever programmed it. - I like that that's your conclusion. - It's using, I don't know, it's using like shortcuts to program it. Like, they didn't, they're just copying pieces and so it's got different parts. - Yeah, think of something new or just paste from over there. - They won't notice. - My conclusion from that was, I'm gonna go interview for finance jobs. So I had like a little detour. - That's the backup option. So in terms of using Collet engines, what's an interesting difference between a propulsion of a rocket from Earth when you're standing on the ground to orbit? And then the kind of propulsion necessary for once you get out to orbit or to like deep space to move around? - Yes, the reason you can't use an engine like mine to get off the ground is, you know, the thrust it generates is instantaneous thrust is very small, but if you have the time and can accumulate that acceleration, you can still reach speeds that are very interesting for exploration and even for missions with humans on them.

Nuclear power (38:10)

An interesting direction, I think we need to go as humans. Exploring space is the power supplies for electric propulsion are limiting us in that, you know, solar panels are really inefficient and bulky and batteries, I don't know when anybody's ever gonna improve battery technology. I know a lot of people that work on that. And nuclear power, we could have a lot more powerful electric propulsion system so they would be extremely fuel efficient, but more instantaneous thrust to do more interesting missions if we could start launching more nuclear systems. - So like something that's powered, nuclear powered, that's the right way to say it. - Yeah. - But is it a small enough container that could be launched? - Yeah, so I mean, as a world, we do launch spacecraft with nuclear power systems on board, but size is one consideration. It hasn't been a big focus, so the reactors and the heaters and everything are bulky and so they're really only suitable for some of the much bigger interplanetary stuff. So that's one issue, but then it's a whole like rat's nest of political stuff as well. - I heard, I think Elon described, or somebody, but I think it was Elon that described the EV tool like electrical vertical take off on landing vehicles, so basically saying rockets, obviously Elon is interested in electric vehicles, right? But he said that rockets can't. In the near term, it doesn't make sense for them to be electric. What do you see a world with the rockets that we use to get into orbit are also electric-based? - It's possible you can produce the thrust levels you need, but you need a much bigger power supply and I think that would be nuclear. And the only way people have been able to launch them at all is that they're in a 100 times redundancy safe mode while they're being launched and they're not turned on until they're farther off. So if you were to actually try to use it on launch, I think a lot of people would still have an issue with that, but someday. - It's an interesting concept, nuclear. It seems like people, like everybody that works on nuclear power has shown how safe it is as a source of energy. - Oh, right.

Nuclear power in transportation (41:16)

- And yet we seem to be, I mean, based on the history, based on the excellent HBO series. I'm rushing with the Chernobyl. It seems like we have our risk estimation about this particular power source is drastically inaccurate, but that's a fascinating idea that we would use nuclear as a source for our vehicles. And not just in outer space. That's cool. I'm gonna look into that. That's super interesting. - Well, just last year, Trump eased up a little bit on the regulations and NASA and hopefully others are starting to pick up on the development. So now is a good time to look into it 'cause there's actually some movement. - Is that a hope for you to explore different energy sources that the entirety of the vehicle uses something like, like the entirety of the propulsion systems for all aspects of the vehicle's life travel is the same or electric, is it possible for it to be the same? Like the cool lit engine being used for everything? - You could and you would have to do it in the same way. We do different stages of rockets now where once you've used up an engine or a stage, you let it go because there's really no point in holding onto it. You wouldn't necessarily wanna use the same engine for the whole thing but the same technology, I think would be interesting. - Okay, so it's possible. All right, but in terms of-- - Yeah, comes down to the power source. - The power source, that's really interesting.

Modern Space Exploration Techniques And Controversies

Suitability of modern electrical propulsion (42:51)

But for the current power sources and its current use cases, what's the use case for electric? Like the cool light engine, can you talk about where they're used today? - Sure, so chemical engines are still used quite a bit once you're in orbit but that's also where you might choose and said to use an electric system and what people do with them and this includes, the ion engines and hauthresters and our engine. It's basically any maneuvering you need to do once you're dropped off. There's, even if your only goal was to just stay in your orbit and not move for the life of your mission, you need propulsion to accomplish that because the Earth's gravity field changes as you go around in orbit and pulls you out of your little box. There are other perturbations that can throw you off a bit. And then, most people want to do things a little bit more interesting, like maneuver to avoid being hit by space debris or perhaps lower their orbit to take a higher resolution image of something and then return. At the end of your mission, you're supposed to responsibly get rid of your satellite whether that's burning it up but if you're in geo, you want to push it higher into graveyard orbit. - Was geo, what's-- - So lower orbit and then geosynchronous orbit or geostationary orbit.

Lower orbits and graveyard orbits (44:13)

- And there's a graveyard? - Yeah, so those satellites are at like 40,000 kilometers. So if they were to try to push their satellites back down to burn up in the atmosphere, they would need even more propulsion than they've had for the whole lifetime of their mission. So instead, they push them higher where it'll take a million years for it to naturally deorbit. So we're also cluttering that higher bit up as well but it's not as pressing as Lea, which is low Earth orbit, where more of these commercial missions are going now. - So how hard is the collision avoidance problem there? - We said some debris and stuff. So how much propulsion is needed? How much is the life of a satellite? It's just like a crap trying to avoid like what's going there. - I think one of the recent rules of thumb I heard was per year, some of these small satellites are doing like three collision avoidance maneuvers. So that's not too bad. - Yeah, but it's not zero and it takes a lot of planning and people on the ground and none of that really, I don't think right now is autonomous. - Oh, that's not good. - Yeah, and then we have a lot of folks taking advantage of more is lawn, cheaper spacecraft. So they're launching them up without the ability to maneuver themselves and they're like, well, I don't know, just don't hit me. - And three times a year, that could become affordable if it's like, if it gets hit, maybe won't be damaged. Kind of thing, that kind of logic. - Affordable in that instead of launching one satellite, they'll launch 20 small ones. Yeah, so if one gets taken out, that's okay. But the problem is that one good size satellite getting hit, that's like a ballistic event that turns into 10,000 pieces of debris that then are the things that go and hit the other satellites. - Yeah.

SmallSat revolution (46:18)

- Do you see a world where like in your sense, in your own work and just in the space industry in general, do you see that people moving towards bigger satellites or smaller satellites? Is there going to be a mix? Like what's, and what do we talk, what does it mean for a satellite to be big and small? What's that? - So big, the space industry prior to, I don't know, 1990, I guess the bulk of the majority of satellites were the size of a school bus and costs a couple of billion dollars and now, you know, our first launches were on satellite the size of shoe boxes that were built by high school students. So that's a very different, you know, to give you the two ends of the spectrum. Big satellites will, I think they're here to stay, at least as far as I can see into the future for things like broadcasting. You want to be able to, you know, broadcast to as many people as possible. There, you also can't just go to small satellites and say Moore's law for things like optics. So if you have an aperture on your satellite, you know, that just, that doesn't follow Moore's law, that's different. So it's always going to be the size that it will be, you know, unless there's some new physics that comes out that I'm not aware of, but if you need a resolution and you're at an altitude, that kind of sets your size of your telescope. But because of Moore's law, we are able to do a lot more with smaller packages and with that, you know, comes more affordability and opening up access to space to more and more people. - Well, what's the smallest satellite you've seen go up there? I go, what are the smallest kind of shoe boxes? - Yeah, so I think, you know, the smallest, they're smallest common form factor can fit a softball inside. - Wow. - So that's 10 centimeters on each side. - So cool. - But then there are some companies working on, you know, fractions of that even. And they're doing things like IOT type application. So it's very low, you know, bandwidth type things, but they're finding some niches for those. - You mean like there's a business, there's a thing to do with them. - Yes, either. - Like what do you do with a small satellite like that? - You can, you know, track a ship going across the ocean. Like if you need to, if you're just pinging something, you know, you can handle that amount of data and those latencies and so on. - You have to have propulsion on that. You have to have a little engine. - No, those are just, you know, letting fall out of the sky. - Okay. - Yeah. - But what, so what kind of satellite would you equip a colloid engine on? - Anything that's bigger than probably about 20 kilograms, anything that needs to stay up for more than a year or anything somebody spent more than like 100K to build are kind of the ways I would think about it. - That's a lot of use cases. What's a small set? Like what category? - Small sets actually very big. I think it's like 700 kilograms or, kidding, my microphone. Maybe a thousand kilograms down to 200 kilograms or people have their own kind of definitions of how they break them up. But small set is still quite large and then it's kind of also applied as a blanket term for anything that's not a school bus size satellite. We need to get our jargon straight industry.

The future of space exploration (49:56)

- So what do you see a possible future where, you know, there's a few thousand satellites up there now, a couple of thousand of them functioning. Do you see a future where there's like millions of satellites up in orbit or forget millions, tens of thousands, which it seems like where the natural trajectory of the way things are going now is going. - Tens of thousands, yes. The two, you know, buckets of applications. One is imaging and the other is communication. So imaging, I think that will plateau because one satellite or one constellation can take an image or a video and sell it to, you know, infinity customers. But if you're providing communications like broadband internet or satellite cell or something like that, satellite phone, you know, you're limited by your transponders and so on. So to serve more people, you actually need more satellites and perhaps at the rate, you know, our data consumption and things are going these days. - Yeah, I can see tens of thousands of satellites.

The flat earth argument (51:11)

- Can I ask you a ridiculous question? - Yes. - So I've recently watched this documentary on Netflix about flat earthers that, you know, that people that believe in a flat earth. As some, as somebody who develops propulsion systems for satellites and for spacecraft, what's to use the most convincing evidence that the earth is round? - Probably some of the photos taken from the moon. - Photos from the moon? Okay, so it's not from the satellite space. - Yeah, I think seeing that perspective, maybe I'm just, I'm answering to personally 'cause I really love those photos. - 'Cause they're beautiful, yeah. - I really like the ones that show the moon and the lunar lander and they're taken a little bit farther back. So you see earth and first you're like, "Wow, that's tiny and we're insignificant." And that's kind of sad, but then you see this really cool thing that we landed on another, you know, planetary body and you're like, "Oh, okay." - Can you actually see her? I don't know about the pictures. - Yeah, I'll send you that picture. - 'Cause I love the pictures or videos of just earth from more, from orbit and so on. - Right, yeah. - That's really beautiful. That's like a perspective shifter. That's the pale blue dot, right? It probably appears tiny. - Yeah, and just that, you know, juxtaposition of the insignificance, but-- - You're in another-- - You build this really cool thing. - Yeah, take the picture. - I just love that. Yeah. - Oh, that'd be cool. I personally love the idea of human stepping out of Mars. I'm such a sucker for the romantic notion of that and being able to take pictures from Mars next to Mars. - So you would go? - I would be, what did you say? You said you wouldn't be-- - Not in the first thousand. - The first thousand. Which, it's funny because to me, that's brave to be in the first million. I think when a declaration of independence was signed in the United States, that was like two million people. So I would like to show up when they're signing those documents. - Okay. - So maybe the two million-- - Oh, that's an interesting way to think about it. 'Cause then we're participating in citizenry and defining the direction. - So it's not the technical risk. You just don't wanna show up somewhere that's like America before. - Yeah, because it's, from a psychological perspective, it's just gonna be a stressful mess as people have studied, right? It's like, it's people, most likely, the process of colonization like looks like basically a prison. Like you're in a very tight and close space with people. And it's just a really stressful environment. You know, how do you select the kind of people that will go and then there'll be drama? There's always drama in this. And I just wanna show up when there's some rules. But I mean, you know, it depends. So I'm not worried about the health and the technical difficulties. I'm more worried about the psychological difficulties. And also just not being able to tweet. Like, what are you gonna, how are you? - Yeah. - There's no Netflix. So yeah, maybe not in the first million, but the first 100,000. It's exciting to define the direction of a new, like how often do we not just have a revolution to redefine our government as you know, smaller countries are still doing to this day? - Start over. - But literally start over from scratch. There's just our financial system. It could be like based on cryptocurrency, you could think about like how democracy, you know. We have now the technology that can enable pure democracy, for example, if we choose to do that. - Mm, yeah. - As opposed to representative democracy, all those kinds of things. So we talked about two different forms of propulsion, which are super exciting.

Propellantless Propulsion (55:12)

So the chemical base, that's doing pretty well. And then the electric base is, are there types of propulsion that might sound like science fiction right now, but are actually within the reach of science in the next 10, 20, 30, 50 years that you kind of think about? Or maybe even within the space of even just like, like even ion engines, is there like breakthroughs that might 10x the thing? Like really improve it? - So, you know, the real game changer would be propellantless propulsion. And so every couple of years you see a new, now a startup or a researcher comes up with some contraption for producing threats that didn't require, you know, we've been talking about conservation and momentum mass times velocity out the back. - Because there's usually a mass. - Mass, that's what. - Yes. Exactly. And you have to, you know, carry that up with you or find it on an asteroid or harvest it from somewhere if you didn't bring it with you. So not having to do that would be, you know, one of the ultimate game changers. And I, you know, unless there are new types of physics, I don't know how we do it, but it comes up often. So it's something I do think about. And, you know, the one, I think it's called the chasmere effect. If you can, if you have two plates and the space between them is on the order of these, like the wavelength of these ephemeral vacuum particles that pop into and out of existence or something, I may be confusing multiple types of propellantless forces, but that could be real and could be something that we use eventually. - What would be the power source? - Yeah, the most recent engine like this that was just debunked this year, I think, in March or something was called the M drive. And supposedly you used a power source, so, you know, batteries or solar panels to generate microwaves into this resonant cavity. And people claimed it produced thrust. So they went straight from this really loose concept to building a device and testing it. And they said, we've measured thrust and sure on their thrust balance, they saw thrust and different researchers built it and tested it and got the same measurements. And so it was looking actually pretty good. No one could explain how it worked, but what they said was that this inside the cavity, the microwaves themselves didn't change, but the speed of light changed inside the cavity. So relative to that, you know, their momentum was conserved. And I don't, you know, I, whatever. But finally someone, I think at NASA, built the device, tested it, got the same thrust, then unhooked it, flipped it backwards and turned it on, but got the same thrust in the same direction again. And so they're like, this is just an interaction with the test setup or, you know, some of the chamber or something like that. So, forward it again, but, you know, it would be so wonderful for everybody if we could figure out how to do it, but I don't know. - That's an interesting twist on it, because that's more about efficient travel, long distance travel, right? That's not necessarily about speed. That's more about enabling like less-- - Yeah, so hook that up to the nuclear power supply. There you go. - Okay.

Space Exploration: Project Initiatives And Private Sector Involvement

Project Breakthrough Starshot (58:58)

But still in terms of speed, in terms of trying to, so there's recently, already I think been debunked or close to being debunked, but the signal, a weird signal from our nearby friends, nearby exoplanets from Proxima Centauri, a signal that's 4.2 light years away. So, you know, the thought is, it'd be kind of cool if there's life out there, alien life, but it'd be really cool if it could fly out there and check. And so what kind of propulsion, and do you think about what kind of propulsion allows to travel close to the speed of light, or you know, half the speed of light, all those kinds of things that would allow us to get to Proxima Centauri in a reasonable, in a lifetime? - You know, there's the project breakthrough star shot. - Yeah. - That's looking at sending those tiny little chip sets. - And like accelerating really fast. - Yeah, using a laser, so launching them, and then while they're still relatively close to the earth, blasting them with some, I forget what, even what power level you needed to accelerate them fast enough to get there in 20 years. - Super crazy sounding, but a lot of people say that's the legitimate, like it's crazy sounding, but it can actually pull it off. - Yeah, I love that project because there are a lot of different aspects, you know, there's the laser, there's how do you then get enough power when you're there to send a signal back? No part of that project is possible right now, but I think it's really exciting. But do you see like human, like a spacecraft with a human on it, so it's like a heavy one? Being like us inventing new propulsion systems entirely. Like do you ever see that in the radar of propulsion systems like that, or are they completely out there in the impossible? - Well, we're going to quickly leave the realm of what I can describe with any credibility, but I think because of special relativity, if we tried to accelerate some mass close to the speed of light, it becomes infinitely heavy, and then we'd have to harness a lot of suns to do that. Or you know, it's just that math doesn't quite work out, but in my child's heart, I believe that we're missing something, whether it's dark matter or other dimensions, and if you can just have some anti-matter and a black hole and then ride that around and somehow turn that into some-- - Mess with gravity somehow. - Yeah, I feel like we're missing lots of things in this puzzle and that-- - I wonder how hard that puzzle-- - Yeah, right, well I can speak with confidence as a descendant of apes that we don't know what the hell we're doing. - Yeah. - So we're really confident, like physicists are really confident that we've got most of the picture down, but it feels like, oh boy, it feels like that we might not even be getting started on some of the essential things that would allow us to engineer systems that would allow us to travel to space much, much faster. - Yeah, and there's even things that are much more commonplace that we can't explain, but we've started to take for granted like quantum tunneling, you know, just things like, oh, the electron was here with this energy and now it's here with this energy and it's just tunneling. But so we're missing a lot of the picture, so yeah, I don't know to use your same question from earlier, I don't know if you and I will see it, but yeah, someday. - You're the co-founder of just like we've been talking about X-ion systems, would you say space propulsion company?

The vision that propels allofX. (01:03:08)

- Yes. - Broadly speaking. So how do you, big question, how do you build a rocket company from like a propulsion company from one person, from two people to 10 people plus? And actually, you know, take it to a successful product. - Yeah, well, I think the early stage is quite, I'm not supposed to use the word easy when you work in rocket science, but straightforward. When you're working on something, you know, sexy, like an ion engine, it's more straightforward to raise money and get people to come work for you because the vision's really exciting. And actually that's something I would say is very important throughout is a really exciting vision because when everything, you know, goes to crap, you need that to get people getting themselves out of bed in the morning and thinking of the higher purpose there. And, you know, another thing along the way that I think is key in building any company is the right early employees that also have their own networks and can bring in a lot of people that, you know, really make the whole greater than just the sum of the early team. - How do you build that?

Building a great team is all about your network. (01:04:43)

Like, how do you find people? It's like asking, like, how do you make friends? But is it luck? Is there a system? Like how in terms of the people you've connected with, the people you've built the company with, is there some thread, some commonality, some pattern that you find it to be to hold for what makes a great team? - I think, you know, personally, a thread for me has been my network and being able to draw on that a lot but also giving back to it as much as possible and like an unsolicited sort of way, like making connections between people that, you know, maybe didn't ask but that I think could be really fruitful. And even, you know, weirder than that is just really getting, you know, having weird uncomfortable conversations with people like at a conference and getting over the small talk quickly and getting to know them quickly and having a relationship that stands out and then being able to call on them later because of that. And I think that's been because I'm introverted and I, you know, wanna poke my eyes out instead of go and do small talk. And so I huddle in a corner with one person and, you know, we talk about aliens or things like that. And so, you know, that's all to say that, you know, having a strong network I think is really important but a genuine one. And let's see, other ways to build a rocket company, kind of making sure you're paying attention to this, sweeping trends of the industry. So everybody just cares about cost and being able to get out ahead of that and even more than we ever thought we'd need to as far as what we needed to price our systems at, you know, people for, since the start of the US space industry, they've been paying 20, 25 million in adjusted dollars for an ion engine and seeing that now people are going to wanna pay 10K for an ion engine and just staying out ahead of that and those kinds of things. So, you know, being out in the industry and talking to as many people as possible.

Will SpaceX's innovation be the death of theirs intro. (01:07:06)

- So there's a drive, I mean, I suppose SpaceX really pushed that. - It's frustrating for me. - So SpaceX really pushed this, the application of, I guess, capitalism of driving the price down of basically forcing people to ask the question, can this be done cheaper? This can lead to like big problems, I would say, in the following sense, I see this in the car industry, for example, that people have, it's such a small margin for profit, like they've driven the cost of everything down so much that there's literally no room for innovation for taking risks. So like cars, which is funny because not until Tesla, really, which is one of the, in a long, long time, one of the first successful new car companies that's constantly innovating, every other car company is really boring in terms of their technological innovation. They innovate on design and style and so on, that people fall in love with a look and so on, but it's not really innovation. The, in terms of the technology, and it's really boringly the same thing, and they're really afraid to have taken risks. And that's a big problem for rocket space too, is like if you're cutting out costs, you can't afford to innovate, to try out new things. And that's definitely true with ion engine then, right? So, but what, so how do you compete in this space? Do you, by the way, see SpaceX as a competitor? And what do you say in general about the competition in this space, is it really difficult as a business to compete here? No, I don't see SpaceX as a competitor, and I see them as one day, not too long from now, a customer, hopefully. I mean, to compete against that, I think you just have to do things in an unconventional way.

Why SpaceX isn't a threat to AllofX. (01:09:18)

So, bringing silicon MEMS manufacturing to propulsion. NASA doesn't make ion engines using a batch mass of a produceable technique. They have one guy that's been making their ion engines for 20 years, like bespoke pieces of jewelry. So, bringing things to what you're trying to innovate to make them, in our case, more cost effective, was really key. I like the idea of somebody putting out ion engines on like Etsy. Yeah, my advisor at MIT, the thruster chip I was holding at you would wear one as a lapel pin. But in general, just on the topic of SpaceX, 2020 has seen some difficult things for human civilization. And it's been a lot of, first of all, it's an election year, there's been a lot of drama and division about that.

What does Yael think about private sector doing space exploration? (01:10:14)

There's been riots of all different reasons, racial division, there's been obviously a virus that's testing the very fabric of our society. But there's been really, for me, these super positive things, which inspire me things, which is SpaceX and NASA doing the first commercial human flight launching humans to space and did it twice successfully. What is that? Did you get to watch that launch? Did you, what does it make you feel? Do you think this is first days for a new era of space exploration? Yeah, I did watch it. We played it outside on a big screen at our place. And I was a little, they kept saying, Bob and Doug, Bob and Doug and astronauts usually are treated with a little bit more fanfare. So it felt very casual, but maybe that was a good thing. Like this is the era of commercial crude missions. It was a little bit more, what is it? What's this name, Chris Hadfield playing guitar? Yeah. It's more, it's a different flavor to it of-- Yeah, exactly. More like fun, playful, celebrity type-- Yes, exactly. Astronaut versus the aura of the magical sort of heroic element of the single human representing us in space. Yes. Yeah. I think that's all for the better though. It's so cool that it's such a commonplace thing now that we send. You know, I can't believe that sometimes I'll have to, you know, you don't even realize that astronauts are coming and going all the time, you know, splashing back down. And it's just so common now, but that's quite magical, I think. So yes, we did watch that. I love, love, love that we finally have that capability again to send people to the space station. And it's just really exciting to see the private sector stepping up to fill in where the government has pulled back in the US. And I think pulled back way too soon as far as exploration and science goes. Probably pulled back at the right time for commercial things and getting that started, but I'm really happy that it's even possible to do that with private money and companies.

Support And Inspirational Stories

Government funding (01:12:42)

Do you like the kind of the model of competition of NASA funding? I guess that's how it works is like they're providing quite a bit of money from the government and then private companies compete to be the delivery vehicles for the whichever the government missions, like NASA missions. Yes, I think for this type of mission is a little bit kind of straddles, commercial and science. So I think it's good, but I do in general feel like we've pulled back too much on NASA's role in the science and exploration part. And I think our pace is too slow there, for my liking, I suppose. What do you mean on a scientific, okay, so did you have, I mean, on the cost thing, do you feel like NASA was a little too bureaucratic, in a sense, like too slow, too heavy, cost-wise in their effort? Like when they were running things purely without any commercial involvement. So I suppose it's more that I just want the government to fund. I see, yeah. And maybe NASA's not the best organization to do it rapidly, but I think that, you know, again, depending on the goals, we're just kind of at the very starting point of space exploration and science and understanding. So we should be spending more money there and not less. And other countries are starting to spend more and more and I think we'll fall behind because of that. So you have quite a bit of experience, first of all, starting a company yourself, but also I saw maybe you can correct me, but you have quite a bit of knowledge of, just in general, the startup experience of building companies that you've interacted with people. Is there advice that you can give to somebody to a co-founder who wants to launch and grow a new company and do something big and impactful in this world? Yes, I would say, you know, like I mentioned earlier, but make sure the vision is something that, you know, we'll get you out of bed in the morning and we'll get, and that you can rally other people around you to achieve. 'Cause I see a lot of folks that sort of cared about something or saw a window of opportunity to do something and, you know, startups are hard and more often than not just being opportunistic isn't going to be enough to make it through all the really crappy things that are going to happen. But the vision just helps you psychologically to carry through the hardships, the you and the team. Yeah, you and the team, yeah, exactly. To kind of younger people interested in getting into entrepreneurship, I would say, you know, stay as close to like first principles and fundamentals as you can for as long as you can, because really understanding the problems, you know, if it's something scientific or hardware related or, even if it's not, but having a deep understanding of the problem and the customers and what people care about and how to move something forward is more important than taking all of the entrepreneurship classes in undergrad. So being able to think deeply, yeah. Yeah, exactly. Yeah, but have you been surprised about how much pivoting is involved? Like basically rethinking what you thought initially would be the right direction to go?

stress on her first three years at Ripple and the risks worth taking (01:16:42)

Or is there, if you think deeply enough that you can stick in the same direction for long enough? So our, you know, our guiding star hasn't changed at all. So that's been pretty consistent, but we within that, we flip flop on so many things all the time and, you know, to give you one example. What's, do you stop and build a first product that's well suited to maybe a smaller, less exciting segment of the market? Or do you stay head down and focus on, you know, the big swing and trying to hit it out of the park right away? And we've flip flop between that. And there's not a blanket answer and there are a lot of factors, but that's a hard one. I think one other piece for the aspiring founder, spending a lot of time and effort on the culture and people piece is so important and is always an afterthought and something that I haven't really seen like the founders or executives at companies purposefully carve out time and acknowledge that yes, this is going to take a lot of my time and resources and then, but you see them after the fact trying to repair the, you know, bro culture or whatever else is broken at the company. And I think that it's starting to change, but just to be aware of it from the beginning is important. - All right. I guess it should be part of the vision of what kind of place you wanna create. What kind of like human beings? - Yeah, exactly. Like you can't wait five, 10 years and then just slap an HR person onto trying to fix it. Like it has to be thoughtful from the beginning. - Yeah. Don't get me started in HR people. Don't leave HR to HR people, but I'll just leave it that you didn't say it. I said it. Okay. Yeah, HR's actual HR is really important. As is so important. - Yes, but so more a lot. - Culture, support. - Yeah. - And then I also was surprised. Like I thought you could say, here will be our culture and our values and that it was kind of distinct from who I and my co-founder were as people. And I was like, no, that's not how that works. We just kind of like ooze out our behaviors and then the company grows around that. So you have to do a lot of like introspection and self work to not end up with a shitty culture. - It's kind of a, it's a relationship, but it's supposed to relationship with two people. It's relationship with many people. - Yeah. - And you communicate so much indirectly by who you are. You have to be. - Yes. - You have to live it, yeah. As somebody, I think about this a lot 'cause generally I'm full of love and all those kinds of things. But like I also get like really passionate and when I see somebody in the context of work, especially when I see somebody who I know can do a much better job and they don't do a great job, I can lose my shit in a way that's like Steve Jobsian and you have to think about exactly the right way to lose your shit if you're going to or if at all. You have to really think through that 'cause it sends a big signal. You know, sometimes that's okay. Like if you do deliberately, like if you're going to do it deliberately, if you're going to say like I'm going to be the kind of person that allows this and pays the cost of it, but you can't just think it's not gonna have a cost. - Yes, this was like the first thing I worked on with my leadership coach was to how not to just snap people when they were being an idiot. And first I got really good at apologizing. That was the first step because it was gonna take longer to fix the behavior. And then I'm actually a lot better at it now and it started with things. She's like every time you walk through a doorway, think, you know, calm and take breaths before responding. And there were all sorts of these little things we did and it was mostly just changing the habit. - Yeah. Boy, it's a long road. - Yeah. - So people love it when we talk about books. Is there books maybe three or so technical fiction philosophical that had an impact on your life and you might recommend? And for each, is there an idea or so that you take away from it? - Yes. So I've been a voracious reader all my life. And I'm always reading like three or four or five books at a time. And now I use Audible a lot too and podcasts and things like that. So I think the first one that stands out to me is 10, it's a novel, "Tender is the Night" by Fitzgerald. And I read it when I was much younger but I went back and read it recently and it's not that good.

F. Scott Fitzgerald story on introspection and loss of greatness (01:22:02)

So I'm not sure why it has such an important place in my literary history. But I love Fitzgerald as an author because he's very, he has very like flowery prose that I can just picture what he's saying but he does it in such a creative way. I remember that one in particular 'cause it, you know, I read a ton as a kid too but it kind of set me, is like the beginning of my adult reading life and getting into classics. And I kind of, I do feel like I, they seem intimidating maybe. And then I realize that they're all just like love stories. So. - Yeah, isn't everything the most stories? - Yeah, it's really. - That's the bottom. - Even, you know, I don't know. I was surprised that even like a lot of the Russian authors, you know, they're all just love stories. - Where demons are pretty simple. There's not much to work with. - So I think maybe that was it. It made like that whole world less intimidating to me and cemented my love for reading. - People should have just approached the classics. Like there's probably a love story in here. - Chickflits, yeah. - It's true. So it somehow boils down to a chickflits. So I just relax and enjoy the ride. - And then. - So what else? - Changing gears quite a bit. The beginning of infinity. Do you know what? By David Deutsch. So he's a physicist. I think it came by a juror Oxford. And so I was introduced like more formally to a lot of the ideas. Like a lot of the things we've talked about, he has a lot more formalism and physics rigor around.

The Beginning of Infinity extreme love for learning (01:23:48)

And so I got introduced to more like jargon of how to think about some of these ideas. You know, like memes and DNA as ultimate meme. The concept of infinity and objective beauty. But he has a really strong grounding in physics. - He has a rigorous way of talking about these like big topics. - Yeah. So that was very mind opening to me to read that. But it also, I think is probably part of why I ended up marrying my husband is related to that book. And then I've had some other really great connections with people because I had read it. And so had they. - I thought you turned that book into a love story. - I did. - No. - It's good, it's good. Your robot has a heart. - Exactly. - And okay, the third series is, it's just, it's Harry Potter. - Of course, which somehow connects to, I haven't read Harry Potter. I'm really sorry. - Oh no. - Forgive me, forgive me. But I've read Tolkien, but just Harry Potter, just haven't gotten to it. But your company name is somehow, I think, connected to Harry Potter, right?

Harry Potter (01:25:12)

- I feel you heard this. - My, I always feel like I have to justify my fandom. The first three books came out when I was 10. So I went along this journey with Harry, age wise. And I read them all like nine or 10 times, all seven books. And I think anything that just keeps you reading is what's important. And you know, I have loles where I don't feel like reading anything. So I'll reread a Harry Potter or a, you know, trashy detective novel or something. And I don't really care. And that's why I mention Harry Potter, because it, you know, whatever just keeps me reading, I think is important. And it was a big part of my life growing up. And then yes, Axion, the official story of the naming of the company is that Axion is like a concatenation of accelerate and ion, but it actually came from Accio, the summoning charm. And then we just added an N and it was perfect. - What's the summoning charm? Is this one of the spells? - Yeah, it probably most notably, Harry uses it to summon his broomstick out of his dorm room when he's battling a dragon somewhere else. So he says the spell and the broomstick comes to him. So summoning in that way. Okay, there we go. - This is brilliant.

How to be a good reader (01:26:45)

So the big thing is that it's something that you've carried with, it's like your safe place you return to. Something like the Harry Potter. - That, you know, I reread them still. Whatever keeps me reading, I think is, is the most important thing. - Okay, I got it. So, yeah. I'm actually the same way in terms of the habit of it. It's important. It's important to just keep reading. But I have found myself struggling a little bit too, because I listen to a lot of audio books now. I've struggled to then switch back to reading seriously. It's just, it reads so many papers, reads so many other things. It feels like if I'm going to sit down and have the time to actually focus on the reading, I should be reading like blog posts or papers or more condensed kind of things. - Yeah. - But there's a huge value to just reading long form still. - Yeah, and you know, my husband was never that into fiction, but then someone pulled him or he heard, you know, you learn a lot of empathy through reading fiction. So you could think of it that way. - Oh yeah, that's kind of what, yeah, yeah. And it's also fiction is a nice, I'm like not less so with nonfiction, is a chance to travel. I see it as kind of traveling. - Yeah. - Because you go to this other world and it's nice because it's like much more efficient. You have to get on a plane, you know, and you get to meet all kinds of new people. It's like people say they love traveling and I say I love traveling too. I just, yeah, read fiction. - I told my three year old that that was why we read so much 'cause we, you know, see the places in our mind and I'm like, it's basically like, we're watching a movie. You know, that's how it feels. And she's like, I prefer watching Frozen with popcorn. Was it her first one? - Yeah, all right. - It was her response. - Well, the, yeah, it's a good point. But yeah, there's some power to the imagination, right? - Yeah. - That's not just like watching a movie because something about of our imagination, 'cause it's the words in the world that's painted somehow mixing in with our own understanding of our own hopes and dreams, our fears. It like mixes up in there in the way we can build up that world from just the page. - Yeah, you're really creating the world just with the like prompts from the book, right? Yeah. - Yeah. That's different than watching a movie. - Yeah, which is why it hurts sometimes to watch the movie version. And then you're like, that's not at all high. - Yeah. - Imagine it. - Well, we kind of brought this up in terms of the, depending on what the goals are. Let me ask the big, your friends with Manolis, he's obsessed with this question.

Philosophical Reflections And Appreciation

The meaning of life (01:29:31)

So let me ask the big, ridiculous question about the meaning of life. Do you have, you ever think about this one? Do you ever ponder the reason we're here? The sense of the vapes on this spinning ball in the middle of nowhere? - Yeah, I don't think one ends up in the field of space propulsion without thinking of these existential questions. Yeah, all the time. - Or build the business. - Yeah, I know, right? Yeah, we've touched on a lot of the different pieces of this, I think. So I have a bunch of thoughts. I do think that the goal isn't, the meaning isn't anymore just to be like a petri dish of bacteria that reproduces and, where survival and reproduction are the main objectives. And maybe it's because now we're able to answer these, ask those questions. That's maybe the turning point. And instead, I think it's really the pursuit and generation of knowledge. And so if we're taken out by an asteroid or something, I think that it will have been a meaningful endeavor if somehow our knowledge about the universe is preserved somehow. And the next civilization isn't starting over again. - So that's interesting. I always, yeah, I resonate with that. I always loved the mission of Google from the early days of making the world's sort of information and knowledge searchable. I always loved that idea. I was donated, as people should, to Wikipedia. I just love Wikipedia. I feel like it's the, that's one of the greatest accomplishments of just humanity of us together, especially Wikipedia. And this opens, like, in this open community way, putting together different knowledge, just like on everything we've talked about today, I'm sure there's a Wikipedia page about ion engines. And I'm sure it's pretty good. - Yeah. - Like, it's, I don't know, that's incredible. And obviously that can be preserved pretty efficiently, at least Wikipedia. I know you'll be like, the human civilization is all like burning up in flames as there's this one USB drive slowly traveling out. - Yeah, yeah, yeah, yeah, yeah. - Yeah, yeah, yeah. - Yeah. - That's on, from the beginning of our chat, that one lonely spacecraft just needs Wikipedia. And then it will have been a civilization well spent. - So pushing that knowledge along, - Yeah. - Through like one little discovery at a time is one of, is a core aspect to the meaning of it all. - Yes. - And I also, I haven't yet figured out what the connection, you know, an explanation I'm happy with yet for how it's connected, but evolving beyond just the survival piece too. I think like we touched on the emotional aspect, something in there about cooperation and love. And so I, in my day to day, that just boils down to, you know, the pursuit of knowledge or improving the human condition and being kind. - Love and knowledge. - Yeah, exactly. So I'm pretty at peace with that as the meaning right now. Makes sense to me. - While you work on, - Yeah, exactly. - spacecraft propulsion. - Yes, exactly. - Like literal rocket science. Natalia, this is an amazing conversation. You work on such an exciting engineering field. And I think this is like what 20th, 21st century will be remembered for is space exploration. So this is super exciting space that you're working on. So, and thank you so much for spending your time with me today. - Thanks for having me. This was fun.

Podcast sponsors (01:33:52)

- Thanks for listening to this conversation with Natalia Bailey. And thank you to our sponsors, Monk Pack, Low Carb Snacks, Four Sigmatic Mushroom Coffee, Blinkist, An App that summarizes books, and Sun Basket, Meal Delivery Service. So the choice is snacks, caffeine, knowledge, or delicious meal. Choose wisely, my friends. And if you wish, click the sponsor links below to get a discount at to support the podcast. And now, let me leave you with some words from Carlos Sagan.


End (01:34:20)

All civilizations become either spacefaring or extinct. Thank you for listening and hope to see you next time.

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