Thank you very much for the kind introduction. It's an honor to be here. This is an incredibly beautiful theater. It's amazing to be in a place design by Christopher Wren. Speaking of Brunel, I'm a big fan of Brunel, I have five boys and I really wanted to name one of them Brunel.. or Isambard. No luck. Hopefully, one in the future.
I guess I'll just tell you the story of how I came to be here. The various things that I did and maybe why I did them. Hopefully, that's a bit helpful, and then we're going to have quite a long question and answer session, so feel free to ask me any question no matter how provocative or challenging to what we're doing. I'm actually always interested in negative feedback.
I did start out in South Africa, went to Victoria Boys' High, and then left, actually by myself, to go to Canada and then the US to college. Graduating from undergrad I had to make a decision. One path would have led to Wall Street and I guess quite a big salary, and the other was to do grad studies and try to figure out a technical problem and I didn't much like the first one. So, I decided to go out to Silicon Valley and go to Stanford and try to work on ultra-capacitors for use in electric vehicles, and I do actually think there's potential for a significant breakthrough in that area and actually have an energy storage mechanism that's better than batteries. It's not necessary for transport to go electric but I think it is something that would accelerate that. So, I was about to get into grad studies and then it was clear the Internet was going to be something that would be very important to the future, so I thought, well, I can either spend five years in a graduate program and discover that the answer is that there is no way to make a capacitor work, and perhaps get some nice papers published and that kind of thing, but that would be a most unfortunate situation, I thought. You know, one of the possible things to do is determine that success is not one of the possible outcomes, and I could not actually bracket the uncertainty on that.
So, I thought, I can either do that, or I can work on building elements of the Internet that - and this was in 1995, so nobody had actually made any money on the Internet but I thought the Internet would be something that would fundamentally change the nature of humanity. It was like humanity gaining a nervous system. All of a sudden, any part of humanity would have access to the collective knowledge, and that's true. It's really quite a remarkable transformation. In the past, if you wanted access to a lot of information, you had to be close to a big library or something - like the great Bodleian library nearby - but that would be the only way to gain access to information. Now with the Internet, with everything online, you can be somewhere in the jungles of South America and if you've got access to an Internet connection, you've got access to essentially all the world's information, with a tremendous amount of analytical power behind that. I think it has literally gone from a situation where people would communicate almost like via osmosis - if you can imagine a simple multi-cellular creature that would communicate via quite slow chemical signals - and now any part of humanity knows what every other part of humanity is immediately, it's pretty incredible.
So anyway, I wanted to be a part of building that, so I decided to start a couple of Internet companies. That actually worked out reasonable well. The first one helped bring the media companies online and then, we solved that, we started another company that you may have used, called Paypal and that we sold for a large amount of money to eBay and that left me in the fortunate position of having the capital to pursue the two other things that I thought would most affect the future of humanity. Being, sustainable energy - both the consumption and production of energy in a sustainable manner - which I think is arguably the most pressing problem of the 21st century, and then the other one, which is the extension of life beyond Earth.
The one I did first was the space company and the genesis of that is kind of interesting as, at first, I didn't think it would be possible to create a rocket company. I thought what would really make a difference is to have a mission to Mars, a small payload to the surface of Mars, that would get the public excited - to reignite the passion for space exploration such that we could go beyond what we did with the Apollo program. "I thought it was quite sad that the Apollo program represented the high water mark of space exploration. It was not something I was able to witness in real time, because I was -2 when they landed." It just seemed as though, if I thought about the future, one where we were a true spacefaring civilization out there exploring the stars and making the things real that we read in science fiction books movies, that seems like a really exciting future. That made me feel good about the future, and one where we're forever confined to Earth made me feel a bit sad. What I was trying to figure out is, how do we reverse that? Like I said, at first it didn't seem like it would be possible to start a space company because it seemed like the province of governments.
So my first thought was, if we could do a philanthropic mission to Mars and get the public excited about the idea of going there and then that would lead to an increased budget for NASA and then we could go there. That might, hopefully, work. I figured out how to compress the cost of the spacecraft and the communications systems and the payload and so forth. It would have been a small greenhouse, about a meter across, with seeds in dehydrated nutrient gel, that would land, and you'd hydrate the gel upon landing and you'd have this great shot of green plants against a red background. In the US, that's called the money shot. The public tends to respond to precedents and superlatives. This would be the first life on another planet. The furthest that life has ever traveled and I thought, okay, that would get people pretty excited and maybe they could envision people being there. We would certainly be able to figure out a lot of engineering insights into what it took to maintain planet life on the surface of Mars.
So, I got through most of that, but the thing that I got hung up on was the rocket. Getting there in the first place. The US options from Boeing and Lockheed were simply too expensive. I couldn't afford them. So, "I went to Russia three times to negotiate purchasing an ICBM." Of course. Desperate times call for desperate measures. I did three visits there and at the end of it, I was able to negotiate a price actually, to buy three of them - three of the largest ICBMs in the Russian fleet - but they were still pretty expensive and by the third trip I actually came to the conclusion that I was operating under the wrong premise. That I was actually mistaken about the willingness to send people to Mars to expand the space frontier. In retrospect, it was quite silly of me to think that people were not interested in such a thing or had lost the will to do this. In fact, people had thought that it was not possible for an amount of money that would materially effect their standard of living. So I came to the conclusion that even if we succeeded in doing this mission, that wouldn't be enough. That would perhaps add a little bit more to the will to do it, but it wouldn't make it clear to people that there was a way. This is the case of almost the opposite, "if you can show people that there is a way, then there is plenty of will."
So, after that third trip, I had learnt a lot more about rockets at that point, and I held a series of meetings - just sort of brainstorming sessions - with people from the space industry, to try to understand if I was missing something fundamental about the ability to improve rocketry. This is where I think it is helpful to use the analytical approach in physics, which is to try boil things down to first principles and reason from there, instead of trying to reason by analogy. The way this applied to rocketry was to say, okay, well, what are the materials that go into a rocket, how much does each material constituent weigh, what's the cost of that raw material, and that's going to set some floor as to the cost of the rocket. That actually turns out to be a relatively small number. Certainly well under 5% of the cost of a rocket and, in some cases, closer to 1% or 2%. You can call it, maybe, the magic wand number. If you had piles of the raw materials on the floor and you just waved a magic wand and rearranged them, then that would be the best case scenario for a rocket. So, I was able to say, okay, there's obviously a great deal of room for improvement. Even if you consider rockets to be expendable. That's what I mean about thinking about things from a first principles standpoint. If, on the other hand, I just analyzed it by analogy and said, okay, what are all other rocket companies - what do their rockets cost, what historically have other rockets cost, and that would be sort of an analogy thing, but it really doesn't illustrate what the true potential is. I think a first principles approach is a good way to understand what new things are possible. This is a good framework. It doesn't mean you'll be successful, but it means that you can at least determine if success is one of the possibilities. That is important, I think.
So, I started SpaceX and initially decided to make a small rocket called the Falcon 1 that was capable of putting about a half a ton into orbit. This did not go smoothly. It was quite difficult to attract the key technical talent and, of course, I was quite ignorant of many things. I made lots of mistakes along the way. The first three flights of the Falcon 1 failed, or rather, they certainly didn't get to orbit. The second and third flights arguably got to space but they did not reach full orbital velocity. Fortunately, the fourth flight worked. If it hadn't, SpaceX wouldn't be around, because I'd basically run out of money. So that was a bit of a nail biter. Thank goodness. In fact, this all happened in 2008, so there was really no ability to raise outside money in a meaningful way in 2008 because of the financial crisis. You can imagine trying to go to raise money and saying, well yes, we've just had four failures and the world is in financial ruin, but would you like to give us some money? It would be a definite no. So, fortunately, that succeeded and we were able to go from the Falcon 1 to begin designing the Falcon 9 which is an order of magnitude larger vehicle and, in fact, has over 20 times the payload. It's got a payload to orbit of over ten tons. That actually has gone a lot better because we had the experience of Falcon 1 to go by. The reason we started with Falcon 1 was that I thought we would make a lot of mistakes and if we're going to make a lot of mistakes then it's best to make those mistakes at a smaller scale rather than at a large scale. That seems to have worked, because going to Falcon 9 we've had four flights of Falcon 9 and all four of them have been successful. So I think that principle seems to have worked reasonably well. Touch wood, five flights coming up soon.
And then we also developed the Dragon spacecraft because, somewhat optimistically, NASA announced they were going to retire the space shuttle and they didn't have the budget to develop a cargo transport capability to the space station via the normal large government way, and so they put it out to bid to commercial industry, for the first time in NASA history. It's a big step. We were lucky enough to win one of those contracts and then the other company wasn't able to execute, so they got cut, and so we ended up being the primary means of transporting cargo to and from the space station. We just did the first two space station resupply missions this year, and thankfully both of those worked. Going from there, NASA then said, well, what about astronaut transport? So they put out a big competition and awarded two contracts for astronaut transport, one of which went to Boeing - they got a slightly larger contract - and one to us. Hopefully, in about three years, we'll have Dragon version 2 and the next generation of Falcon 9 rocket, transporting astronauts to and from the space station.
Then we've got Falcon Heavy which is about three times the capability of the Falcon 9 and that will hopefully launch in a year or two. That will actually be the most powerful rocket in the world by a factor of two. So we're making, sort of, steady progress. The Falcon Heavy, to put that into perspective, has about 60% of the capability of the Saturn V moon rocket. So, if you were to combine two flights of Falcon Heavy, with orbital rendezvous and docking, you could actually send people back to the surface of the Moon. Now we're really talking about advancing the frontier, which I think is quite important.
The really major breakthrough that's needed in rocketry, the pivotal one which we're aspiring to make, is to have a fully and rapidly reusable rocket. This has not been achieved before. The space shuttle was an attempt to achieve that, but it was not a successful attempt, unfortunately. The main tank of the space shuttle was through away every time, which was also the primary ascent aeroframe. Even the parts that were reusable were so difficult to reuse, for the space shuttle, that it ended up costing four times more than an expendable rocket of equivalent payload capability. It was the right goal, but didn't hit the target. I think this is actually incredibly important. I think it may not be completely intuitive, but I think if one refers to other modes of transport, it makes more sense. All other modes of transport are fully and rapidly reusable. That applies to a bicycle, a horse, a plane, ships. In fact, in normal life, it would be quite silly to discard your horse after every ride, you know, or dump the plane after you flew it. The cost of a 747 is about $300 million, and you'd need two of those to do a round trip from Los Angeles to London, but I don't think anyone has paid half a billion dollars to do that. Nor would one want to. There'd be a lot of travel by boat and train and that sort of thing, if that was the true cost.
So it's extremely important in rocketry to achieve full and rapid reusability. This is not an easy thing to do because of Earth's gravity well and just the basic physics of things. There have been many attempts to create a reusable rocket, but they've all sort of been cancelled along the way once people realized they would not succeed. In fact, usually they got cancelled quite some time after it became obvious that they would not succeed. But, the essence of the problem is, if you design an expendable rocket and do quite a good job of it, you'll get about 2% to 3% of your liftoff mass to orbit. Then if you say, well, how much mass is needed to return that rocket and be able to fly it again quickly? Well, about 2% to 3%. So you basically get nothing to orbit. That's how it's been in the past. In order to do something useful, what you have to figure out is, how do you get a much larger percentage to orbit? Let's say, ideally, on the order of 4% of your liftoff mass to orbit, in an expendable configuration, and then compress the reusable elements down to about 2%, so you have a net payload to orbit of 2%, and then you could really have something that's quite useful.
The cost of the propellant is only about, let's say, 0.3% of the cost of the vehicle. Take Falcon 9 for example, which uses quite expensive fuel, relatively speaking. I think there are lower cost options. The cost of reloading propellant on Falcon 9 is about $200,000 and the cost of the rocket is $60 million. It's just like a plane. If you were to refuel a plane, not very expensive. If you want to buy a new plane, very expensive.
At this point, I am reasonably confident that it can be done and now it's a question of executing to make that design work and seeing if there are any gotchas, and there will probably be a few craters along the way. I'm not expecting this to be a smooth journey. So long as the rocket doesn't land on anyone, we'll be fine. So that's really what SpaceX is focused on right now. Scaling up the size of the rockets and trying to achieve this full and rapid reusability. If you're curious, we're fairly public about things, you can just follow it on the SpaceX website. That's what we're doing on the SpaceX side.
Then, in parallel, we've got Tesla, which is developing electric vehicles. That's a whole separate story line. Tell me if I'm going on too long and stop me at any point. "Feel free to leave if I'm getting boring." I won't be offended. With Tesla, the goal is to try to create electric vehicles that are more compelling than gasoline vehicles as a product. The fundamental issue we have in energy and transport is the tragedy of the commons. We've got this CO2 capacity of the oceans and the atmosphere that is unpriced, or mostly unpriced. It's almost like we're dumping garbage in the atmosphere and nobody's paying for garbage collection. It's a most unfortunate situation. There are quite significant invested interests in oil and gas and coal, with enormous amounts of money. It's quite a difficult battle to fight. You can't expect them to simply roll over and commit suicide or something. They will fight hard and they have been. So, unfortunately, it requires fighting hard back and creating products, in the absence of there being a tax on CO2, that don't rely on the economics of using hydrocarbon fuels, verses electric cars. That was our goal, in terms of from the beginning, and I'm really excited to see that we've started to achieve that goal with the Model-S. As was mentioned, the Model-S was recently awarded top honors by - was awarded car of the year and automobile of the year - and that was against a very difficult field of gasoline cars. I'm hopeful that this will be seen as a pivotal moment in transport where people finally appreciate that an electric car could be better than a gasoline car.
Going into the future, our goal with Tesla is to keep refining the technology, increasing the scale of production, and make a mass market electric car that almost anyone can afford. That's step three on the strategy. Step one was high price, low volume. Step two was mid price, mid volume. Step three is low price, high volume. We're now at step two and we want to progress to step three as soon as possible. We do get quite a bit of criticism at Tesla for creating the Roadster, which we did in collaboration with Lotus. People were complaining, well, why are you making this expensive sports car. With the implication that we thought there was a shortage of sports cars for rich people and we were racing to meet that unmet need. The real reason is that, any car that we make at low volume, which is the first version of the technology, is going to be expensive. It didn't matter what that car looked like. So if we made something that looked like a very standard Toyota Corolla or a Ford Fusion or something like that, and it would have cost, say, $70,000. Nobody will pay that for what looks like a mid-sized economy sedan. They just won't. Or very few people would, but people are willing to pay $100,000 for a fast sports car. That's why we started off at that level, and with another big design iteration and an increase in volume, so we had economies of scale, we were able to create the Model-S, and with another order of magnitude increase in volume and another big design revision, that's what will allow us to cut the price in half again. Tesla also supplies power trains to Mercedes and Toyota, and we'll perhaps do that for other car companies, in an effort to help them accelerate the transition to electric vehicles.
That's Tesla and SpaceX and I should mention Solar City. One must generate electricity in a sustainable way, as well as consume it in a sustainable way. People will say, well, don't electric cars create pollution at the power plant level? It should be noted that, for any given source fuel, it is always better to generate the power at the power plant level and then charge electric cars and run them, for any given source fuel, because power plant are much more efficient at extracting energy than internal combustion engines in a car. They are at least twice as efficient and usually more like three times as efficient. So, for any given source fuel, even if the whole world were always going to be powered by hydrocarbons, it would still make sense to do electric cars. But, of course, we must find a sustainable means of generating energy as well, and I think that the most likely, well, the main candidate for sustainable energy generation is actually solar. I think that this is actually rather obvious because the Earth is almost entirely solar powered today, as it is. We'd be a frozen ice ball at, I don't know, three or four kelvin, if it weren't for the sun and our entire system of precipitation is powered by the sun. The ecosystem is almost entirely, 99.999% powered by the sun, except for some chemotrobes at the bottom of the ocean. It's rather obvious that one should try to take a little portion of that energy, and it's actually not much, and convert that into electricity for use by society.
I'm quite confident that solar power will be the single largest source of electrical energy for humanity in the future. It will be combined with other things, of course, such as hydro power, geothermal, and I actually think nuclear is not a terrible option, so long as you're not located in a place that's susceptible to natural disasters. That, also I think, defies common sense. So long as there are not huge earthquakes or weather systems that have names coming at you, then I think nuclear can be a sensible option. There are much safer and better ways of generating nuclear energy - I'm talking fission here - than existed in the past when nuclear reactors first came out. At some point in the future it would be nice to make fusion work, of course. That'd be quite good, but in the mean time I think indirect fusion, being solar power, is a good thing to do. That's what Solar City is doing, it's really trying to improve the economics of solar power, and they're doing a great job. I don't run the company, so the credit really goes to the two key guys who run that company. They're doing a great job of really accelerating the good option of solar power in the United States, and hopefully they'll come to the UK as well.
That's about it. So we have Q and A.
[Question about energy concentration and the role of robots in the future.] Absolutely. In fact, the energy density, basically the amount of energy you can store in a given amount of mass or volume, has been a fundamental constraint on electric cars for a while and that's correlated to some degree with the cost per kWh, the cost of storing that energy in the car. With the advent of lithium-ion technology, that I think, is really what enabled a compelling car and lithium-ion batteries continue to improve. Roughly, on average, maybe 8% or 9% per year. Which, when compounded over several years, ends up being a meaningful improvement. As mentioned in my talk, even if there was no fundamental improvement beyond lithium-ion batteries, I think we could still take all terrestrial - all ground transportation could go electric. We do need a further breakthrough for aircraft, where the energy density requirements are at least 2 to 3 times more significant but, even with current generation lithium-ion, we could go to mass market with ground vehicles. In fact, our focus is really more on reducing the cost of the battery pack than improving the energy density.
So, I think we're actually in a pretty good spot and I am reasonably optimistic that there will be a breakthrough in high energy density capacitors. It's sort of interesting. If you do the basic physics on the energy density potential of a capacitor, using naturally occurring materials, it's quite hard to beat lithium-ion batteries, but if you can figure out a way to make - unnatural materials I suppose, that are accurate at the molecular level then I think you can have some fairly significant breakthroughs. The ability to do that was developed in the photonics arena and applying those photonics breakthroughs to capacitor technology is what has the potential for a really big breakthrough there. So, I think we may see something on that level, but it isn't entirely required for cars.
For rockets, well, there's no way to make a rocket electric. That's for sure. Unfortunately, Newton's third law cannot be escaped - I think. Certainly, there'd have to be a few Nobel prizes awarded if there was a way to get around it. That'd be really convenient. I do think it's possible, with a really efficient combustion rocket, to achieve the settlement of Mars. I think we'll probably want to switch to methane - either methane or hydrogen, they're kind of the best two choices, and probably slightly leaning in the direction of methane because it's easier to handle than hydrogen. Methane is CH4 verses H2. Both can be produced on the surface of Mars, which is important. I should say that I'm quite confident at this point that it is possible to create a self-sustaining civilization on Mars using only a methane or hydrogen based launch system - it needs to be a fully reusable methane or hydrogen based launch system and it can be done. The key I was trying to figure out was, with volume, is it possible to get the cost of moving to Mars down to under half a million dollars, which is I think is - no-one can argue about the exact threshold, but I think that is about the threshold which enough people would save up money and move to Mars. I mean, that's how America got created, basically. "They can come back if they like, if they don't like it, of course. You get a free return ticket. There's sometimes a debate about going to Mars one-way and whether that makes things easier, and I think for the initial flights perhaps, but long term, to get the cost down, you need the spacecraft back. Whether the people come back is irrelevant, but you must have the ship back because those things are expensive. So anyone who wants to return can just jump on." But until a few years ago, I wasn't sure that success was one of the possible outcomes and now I'm quite sure that success is possible. Of course, there's a long way between possible and making it real, but I believe it is possible.
And then robotics, right. I think one can accomplish a lot with robotics. I do slightly worry about, if robotics get too good, what's the point of us? I think, either robotics get so good and there's not much point to us, I guess, I don't know, or they're not as good as us, in which case, we need to go. I'd advocate the second. Hopefully, in the future, there's not some AI apocalypse.
[Question about Reaction Engines SABRE and the original Tesla prototype.] We still have the original mule one of Tesla Roadster and here I should give credit to a small company in southern California called AC Propulsion that had a vehicle called the T-Zero. Our very first mule was really taking a Lotus Elise and jamming an AC Propulsion power train into it and then making it drive. We originally thought that - it's another example of making some dumb mistakes but the thought at the beginning of Tesla was to use AC Propulsion's power train in a Lotus Elise and to get to market fast with an electric car. As it turned out, the AC Propulsion power train didn't really work, very well, and was not scalable for production - had a lot of issues - and so we had to completely redesign the power train and then, the Elise, because our car ended up being 50% heavier and had different weight distribution, and low points, we invalidate all the crash structure and had to completely redesign the chassis. In the end, I think about 7% of the parts were in common with the Elise. So, almost nothing, but we actually inherited some of the limitations of the Elise. Long winded answer, I'll try to be less long winded in my answers.
"With respect to air breathing hybrid stages, I have not seen how the physics of that makes sense. There may be some assumptions that I have that are incorrect, but really, for an orbital rocket, you're trying to get out of the atmosphere as soon as possible because the atmosphere is just as thick as soup when you're trying to go fast, and it's not helped by the fact that the atmosphere is mostly not oxygen." It's 80% nitrogen. So, mostly what you're air breathing is chaff, not wheat, and having a big intake is like having a giant brake. The braking effect tends to overwhelm the advantage of ingesting 20% oxidizer. You could just make the boost stage 5% to 10% larger and get rid of all the air breathing stuff and you're done.
[Question about the US energy boom.] That's a good point. "New technology and innovation can have a downside and one of the downsides is people are able to extract far more hydrocarbons than we thought were possible." Once you start getting into deep methane, or deep natural gas, you're actually tapping into things that are not related to dinosaur fossils. Methane is a naturally occurring gas. There are places in the solar system where the atmosphere is primarily methane. So, it does not require an organic origin. If we dig too deep for methane, we're actually going to a level that has never been seen before, not even in the very earliest history of Earth. So that's very dangerous I think. That's why I think it's important for electric cars to be able to compete without an economic benefactor. But, I think, it is very dangerous to be extracting vast quantities of hydrocarbons from deep within the Earth and putting them in the atmosphere. Sooner or later, something very bad will happen. There are a lot of people, particularly in the US, who are vehemently against electric cars and sustainable power, and it's quite difficult to reason with them, actually. They'll say, well, some scientists don't think it's a problem and I'm like, okay, well, you can find someone reputable who will disagree with anything. This actually reminds me of the tobacco industry where, for the longest time, there were actually - you'd see ads where they would claim that tobacco is healthy for you - I know, hard to believe these days. There were these reports, where there seemed to be some correlation between lung cancer and smoking, and they were like, our scientists have conducted experiments and they show there is no relation between those, it's complete nonsense. It got to the point where almost any reasonable scientist would say, yes, of course, smoking causes lung cancer and all sorts of other bad things. Not definitively, but it's extremely likely, and yet the tobacco industry would still say, oh, scientists disagree, because 1% or 2% of the scientific community didn't feel that way. The public just hears: scientists disagree. They don't hear: 99% of them think it's stupid. It's definitely a tough thing and hopefully that transition occurs before it's too late. There's already quite a bit of momentum in the direction of climate change, and accelerating the removal of hydrocarbons from the crust and placing them in the atmosphere is, I think, just very unwise. That's why I think it's the biggest problem of the 21st century.
[Question about future projects and failure.] I think I'm going to stay on electric cars and rockets for a while. It was actually never my intent to run Tesla, because running two companies is quite a burden, actually. I sometimes run into people who think, oh, if you're CEO of the company then they sort of imagine themselves, if they were CEO of the company, they would grant themselves lots of vacation and do lots of fun things. It's doesn't quite work that way. What you actually get is, a distillation of the worst things going on in the company. So, the idea of taking on something more, is very frightening. Possibly, at some point in the future, certainly not the near term, there's an opportunity to create an electric jet, eventually. I do think I want to create an electric jet that is really exciting. Something that would be supersonic, vertical takeoff and landing, pure electric, and just a big leap forward. I'm quite confident it's doable, provided that there's a rough doubling of the energy density in batteries or capacitors. Basically, around the 500W/kg level is where it starts to make sense. I do think there's the possibility of a fifth mode of transport which I've mentioned tangentially, which I call the Hyperloop. I'd like to publish something about that, maybe in the next month or two, once Tesla is at steady state production, and I want to flesh it out a bit so that I can pre-address some of the rebuttals that people will come up with, rather than just put it out there and then have the rebuttal occur and have an unaddressed rebuttal. I guess a way to think of it is, it's like a cross between a Concorde and a rail gun.
[Why are your rockets so much less expensive?] The full answer is quite complicated and requires at least some understanding of how rockets work, but if you divide a rocket into the cost of the engines, the air frame and the electronics, and then the launch operation itself, those are the marginal cost drivers and then there's the fixed cost of the company, which you divide over the number of launches that take place, but just looking at the marginal cost drivers, it means you have to make a significant advancement in engines, air frame and electronics and launch operation. In fact, it would be easy to point out one of those areas but success in one of those areas would only have a small effect. So, let's say you had free engines, well that would only reduce the cost of the rocket by, probably, 30% - the cost of launch by 30%. That's not a huge breakthrough. Or free electronics. Or free air frame. You actually have to compress all of them quite a bit, and then, like I said, you have to make them reusable.
I can give an illustrative example in the air frame. That may be helpful. The normal way that a rocket air frame is constructed, is machined iso-grid. That's where you take high strength, aluminum alloy plate and you machine integral stiffeners into the plate. This is probably going to go slightly technical, but imagine you have a plate of metal and you're just cutting triangles out of it. That's normally how rockets are made. Most of a rocket is propellant tanks, these things have to be sealed to maintain pressure, and they have to be quite stiff. The approach that we took is, rather, to build it up. To start with thin sections and friction stir weld stiffeners into the thin sections. This is a big improvement because if you machine away the material you're left with maybe 5% of the original material. So, a 20 to 1, roughly, wastage of material, plus a lot of machining time. It's very expensive. If you can roll sheet, and stir weld the stiffeners in, then your material wastage can be 5%. That's the inverse, essentially. Instead of having a 20 to 1 ratio, you have got 1.1 ratio. Instead of having 95% wastage, it's 5% wastage. It's a huge improvement. You can actually improve the mass fraction too, because if you have stir welded stiffeners, you can increase the profile and improve the geometry of the stiffeners so you can have something which is, say, 5cm tall whereas, if you machined it from a plate, it'd be limited to the thickness of the plate which may only be 2cm or 3cm tall. You actually end up with something which is both more advanced, in that it is better mass fraction, but is also a fraction of the cost. That's one example, but there are many such things.
[Question about adapting to climate change.] I think the thing we need to do is, we need - the best thing to do to achieve that - would be a carbon tax. The market system will work extremely well if it has the right information - to work. If we just apply a tax to carbon and then dial that up according to whatever achieves the target maximum carbon proportion in the atmosphere that's, I think, the right way to go. Countries really need to act unilaterally. We can't have this thing where such and such country isn't doing it, I'm not doing it. Well, okay, set a good example and hopefully, over time, other countries will fall in line, or get ostracized. I think that's probably the smart move, and then we can avoid - there's no need for subsidies and special incentives which are really a backwards way of trying to deal with the lack of a carbon tax. I think, in the good scenario, the best possible scenario would be that something like that is instituted. We're still going to have a significant increase in the amount of carbon in the atmosphere, temperatures are still going to rise, sea levels are still going to rise but - the Dutch can manage, you know, with - a lot of dyke companies will, you know, there's a lot of options in the dyke business. I think, if we take action reasonably soon, we can avoid a calamitous outcome. If we only take action towards the end of the century, then it's going to be extremely bad. I don't think people quite appreciate the fact that there's the momentum of climate change, you know. Even if we immediately stop all carbon production, the momentum will still carry forward and increase the temperature, raise water levels, make storms more powerful, all those things. I'm trying.. what's the good outcome? The good outcome is, we do carbon tax, we minimize the carbon production, we move to sustainable transportation and energy production, which I said, is going to be like solar, wind, geothermal, hydro, and some nuclear, I think we have to accept that nuclear is a good option, in certain places. I actually think that the most likely outcome is a reasonably good one where there's damage but we recover. I actually think that will occur. I'm quite optimistic about the future. I'm not suggesting complacency in the least, but I'm optimistic about the future.
[Question about humanity being confided to Earth due to lack of energy.] I actually think, as long as the sun is shining, we'll be fine. If humanity had to get all of its energy from the sun, it could do so. There's truly an astounding amount of energy that comes at us from the sun. It's interesting - if you took the land area used by nuclear plants, including the stay-out zones and everything, and said, okay, what generates more power, the nuclear power plant or just covering it with solar panels? In most cases, it's solar panels. Just the area used by the nuclear power plant, in solar panels would generate more energy because you actually have to have a big stay-out zone, you can't just put a nuclear power plant in the outer suburbs, with a bunch of people around it, so you have to have this big clear zone and so, they use a lot of area. But just to give you a sense of how much power can come from the sun, this is literally true, what I've just said.
[Question about Mars vs elsewhere in the solar system.] Just by process of elimination. Mercury is obviously just way too close to the sun. They may be some mere habitable zone on the back side of Mercury, but I think one's sort of asking for trouble on that one. Venus would be a lesson for what Earth could become in worst case scenario. A superheated, high pressure - and, in the case of Venus - acid bath. It's literally a high pressure, high temperate acid bath. Definitely not a good place. I think the longest that even any probe has lasted on Venus is measured in hours. The Moon is close, but it's a very small rock, you know, that's just circling Earth, with no atmosphere, very limited amounts of water ice that are in permanently shadowed craters, and it's got a 28 day rotational cycle which isn't great for plants. It would be quite tough to make a self-sustaining civilization on the Moon. So then, coming to Mars, it's definitely a fix-er-up-er of a planet. It's not perfect, but feasible. It's got a rotational period of 24.5 hours - remarkably similar to Earth. It's got just under half Earth's gravity - so it's a lot closer gravitationally. It's got a lot of water ice - almost all of Mars has water, bound up in ice form, in the soil. The soil has turned out to be non-toxic, it's be found by probes that we've sent there. If you had a greenhouse and some fertilizer, and you just warmed things up and pressurized it a little bit, then you could grow plants on Mars. Mars has a CO2 atmosphere which plants like to consume. Plant's consume CO2 and, on net, give you oxygen. I think it's very doable to create a self-sustaining Mars base and then, ultimately, terraform the planet to make it like Earth - so we could just walk around outdoors. Obviously, that's a longer term project, but it is within the realm of possibility. Going beyond that, you're going to Jupiter and the asteroids. You could potentially do something on the moons of Jupiter or Saturn, but that's way harder than Mars.
[Question about commercial entities taking over from space agencies doing space science.] I think space exploration is going to be a mixture of private and government activities. In fact, for SpaceX, there are many things we want to do to enable scientific missions and enable NASA and JPL and ESA and others to be able to do much more for a given budget. In fact, we've had a number of conversations with JPL, which is located quite close to SpaceX, about using our Falcon rocket and Dragon spacecraft - version two of the Dragon spacecraft will have propulsive landing capabilities, so version two of the Dragon spacecraft will be able to land on any liquid or solid surface in the solar system. There's potential to turn that into a generalized science instrument delivery platform, for anywhere in the solar system. You could see then how one could figure out how to do a sample return. You know, if you were to land Dragon and have a smaller sample return rocket housed within the Dragon spacecraft, that could return some martian regolith, that'd be pretty cool. So, we're exploring some ideas there and I think we'll see at least some science missions being done in the future - maybe a lot of them. We're still at the early stage but we do have JASON-3 which a joint NASA-ESA mission that's going to be launched on one of our rockets in about two years and, of course, we're resupplying the space station. So, I think it's going to be a mixture of government and commercial. I'm for whatever means will make it happen. I'm not hot over government or commercial, just whatever works for all practical purposes.
[Question about exploiting Mars.] I don't think it's going to be economical to mine things on Mars and then transport them back to Earth because the transport costs would overwhelm the value of whatever you mined, but there will likely be a lot of mining on Mars that's useful for a Mars base, but it's unlikely to be transferred back to Earth. I think the economic exchange between a Mars base and Earth would be mostly in the form of intellectual property. Anything that can be transmitted by photon, that's the most likely exchange of things that will occur. I don't think we need to worry too much about the exploitation of Mars, essentially. I mean, that would be a high class problem to deal with, for sure.
[Question about biofuels and electric grid upgrades.] I'm not the biggest fan of biofuels because I try to look at things and just calculate the basic physics of it, really elementary stuff, and say, okay, well, what percentage of the incident sunlight is bound up in usable chemical energy and then once you have that chemical energy, how much of that is then translated into electricity? You have to compare that total efficiency with just having solar panels. Unless I've made some really dumb mistake, which is possible, you're about a hundred times off with biofuels. I mean, at least two orders of magnitude. What it boils down to is what's square meter per electricity generated? With the best case biofuel - take every assumption and maximize it, so don't say, don't worry, maybe somebody could invent something better, say what is the best - just envelope the whole thing. Say you had unbelievably efficient plants. I mean, you can't violate any laws of thermodynamics, but assuming that you're at the limits of thermodynamics in all those cases, then biofuels - at least your land-based biofuels - there's no way this makes sense. You end up being around, maybe, 0.2% efficient in turning sunlight into electrical energy, whereas commercial solar panels are 20% efficient. So why would you ever do biofuels? It's not as though there are large swaths of arable land unused. You have to say, well, if you go with biofuels, it's going to either result in wilderness being cultivated or an increase in food prices. You can also say, is it possible, if you stopped all food production in the world, to generate enough energy to meet the world's needs? Like, yeah, you could probably - it's about right, actually, if you stopped all food production you could just about meet the world's energy needs. Now, there is a possibility of ocean-based, because Earth's surface is mostly ocean. So, if you could find a way to - maybe some sort of ocean algae-based solution where you're unconstrained by surface area, although I still think you'd have to compare that to a bunch of floating solar panels and I think you still lose on floating solar panels. I don't see how it would make sense.
At some point, there will have to be improvements to the electricity grid, but because there's a huge disparity in the peak energy use during the day and the energy use at night, and most charging of electric cars occurs at night - we have a quite strong empirical basis for concluding this, because we can look at all our customers and plot their energy usage and it's very predominately at night. It's basically just like your cell phone, you go home, you plug it in and it charges overnight. The electricity grid has to be sized for the worst second of the worst day of the worst year with some power plants not functioning. Well, that's how the electricity grid should be sized. Sometimes it doesn't work out that way. Most the time you have huge amounts of excess capacity. In the US there was a study done - there's studies done on all sorts of things, some of them are complete nonsense, I love the words 'studies say..' but I think this study is probably accurate - that you could replace about 70% of the passenger miles - in the United States, at least, I don't know how to apply that to Britain - but about 70% of the passenger miles with no change to the grid. Assuming charging predominately at night. If you combine that with increased use of solar panels on houses and businesses, you have localized power generation, and the nice thing about solar power is it tends to match energy usage. Just generating power during the day and that's when you tend to use the most power. Particularly on summer days when you have air conditioning running. Air conditioning is a huge consumer of electricity. You generally only need it when it's warm and sunny - that's when you need it most. I think we're okay on the grid front, at least for the near future, it's only going to become a problem once, let's say, electric vehicles are at least approaching 10% or 20% of the vehicles on the road and then, I think, you'll be able to address the problem on a fairly localized basis.