Introduction

Alright. Thank you. Thank you very much for having me. I look forward to talking about the SpaceX Mars architecture and what I really want to try to achieve here is to make Mars seem possible. Make it seem as though it's something we can do in our lifetimes and that you can go to Mars. Is there really a way that anyone could go if they wanted to? I think that's really the important thing.

First of all, why go anywhere? The... I think there's really two fundamental paths. History will bifurcate on two directions. One path is that we stay on Earth forever and then there will be some extinction event eventually. I don't have an immediate doomsday prophecy, but eventually history suggests that there will be some sort of doomsday event. The alternative is to become a spacefaring civilization and a multiplanetary species which I hope you would agree is the right way to go. Yes? ((applause)) That's what we want. ((applause))

So how do we figure out how to take you to Mars and create a self-sustaining city? A city that is not an outpost, but a planet in its own rights, and thus we could become a truly multiplanet species.

Which planets could we pick?

There are-- sometimes people wonder, what about other places in the solar system? Why Mars? Well, just to provide some quick perspective, this is what actual scale of what the solar system looks like. We're currently in the third little rock from the left. That's earth. Yeah, exactly. And our goal is to go to the fourth rock on the left, which is Mars. But you can get a sense for the scale of the solar system, how big the sun is, Jupiter, Neptune, Saturn, Uranus, and then the little guys on the right are Pluto and friends. This sort of helps see it, not quite to scale, but gives a better sense for where things are.

Our options for going-- for becoming a multiplanetary species within our solar system are limited. We have in terms of nearby options, we've got Venus, but Venus is a high-pressure and super-high-pressure hot acid bath. So that would be a tricky one. Venus is not at all like the goddess. This is no way similar to the actual goddess. So it's really difficult to make things work on Venus. And Mercury is also way too close to the sun. We could go to one of the moons of Jupiter or Saturn, but those are much further out from the sun and a lot harder to get to. This leaves us with one option to become a multiplanetary species, and that's Mars.

What about the moon?

We could conceivably go to our moon, and I have nothing against going to our moon, but I think it's challenging to create a -- to become multiplanetary from the moon, because it's much smaller than a planet. It doesn't have an atmosphere. It's not as resource-rich as Mars. It's got a 28-day day. Whereas the Mars day is 24.5 hours. And in general, Mars is far better suited to be ultimately scaled up to be its own self-sustaining civilization.

https://www.youtube.com/watch?v=H7Uyfqi_TE8&t=5m27s

Just to give some comparison between the two planets, they're actually remarkably close in a lot of ways. In fact, we now believe that early Mars was a lot like Earth, and in fact if we could warm Mars up, it would once again have a thick atmosphere and liquid oceans. So where things are right now, Mars is about half again as far from the sun as from the earth. So there's still decent sunlight. It's a little cold, but we could warm it up. It has a very helpful atmosphere, which in the case of Mars being primarily CO2, nitrogen, argon and some other trace elements means that we can grow plants on Mars just by compressing the atmosphere. And it has nitrogen too, which is very important for growing plants.

Mars

It would be fun to be on Mars, because it has gravity which is 37% that of Earth. You would be able to lift heavy things, bounce around and have a bunch of fun. The day length is remarkably close to that of Earth. We just need to change that bottom row because currently we have 7 billion peope on Earth, and 0 people on Mars.

There's been a lot of great work by NASA and other organizations in early exploration of Mars and understanding what Mars is like, where could we land, what's the composition of the atmosphere, where is there water or water-ice I should say? We need to go from these early exploration missions to actually building a city.

The issue that we have today is that, if you look at a venn diagram, there's no intersection of sets of people who want to go and people who can afford to go. In fact, right now you can't go to Mars for infinite money. Using traditional methods, you know, if you take an Apollo-style approach, an optimistic cost number would be about $10 billion per person. For example, the Apollo program, the cost estimates were somewhere between $100 to $200 billion USD in current dollars, and we sent 12 people to the surface of the moon. Which was an incredible thing and I think the greatest achievements of humanity. But that is a steep price to pay for a ticket. That's why these so-called only just barely touch in the venn diagram. You can't create a self-sustaining civilization if the ticket price is $10 billion per person. What we need is a closer, to move those circles in the venn diagram closer together. If we can get the cost of moving to Mars to be roughly equivalent to the median house price in the United States, which is around $200,000, then I think the probability of establishing a self-sustaining civilization is very high. I think it would almost certainly occur.

Not everyone would want to go. In fact, I think a relatively small number of people from Earth would wat to go. But enough would want to go, and who could afford the trip, that it would happen. People could get sponsorship. I think it gets to the point where almost anyone if they saved up and this was their goal that they could ultimately save enough money to buy a ticket, and move to Mars. And Mars would have a labor shortage for a very long time, so jobs would not be in short supply on Mars.

Getting to Mars

It's a bit tricky because we have to figure out how to improve the cost of trips to Mars by 5 million percent. This is not easy. It sounds like virtually impossible. I think there's ways to do it. This translates to an improvement of about 4.5 orders of magnitude. These are the key elements needed in order to achieve the 4.5x order of magnitude improvement. Most of the improvement would come from full reusability, perhaps 2-2.5x orders of magnitude. The other 2x orders of magnitude would come from refilling in orbit, propellant production on Mars, and choosing the right propellant.

Full reusability

Full reusability is really the super hard one. It's very difficult to achieve reusability even for an orbital system. That challenge becomes even greater for a system that has to go to another planet. As an example of the difference between reusability and expendibility in aircraft, and in fact you could use any form of transport- like a car, bicycle, or horse, if it was single-use then nobody would use them because it's too expensive. With frequent flights, you could take something like an aircraft which costs $90 million dollars and if it were single-use you would have to pay $500k per flight. But you could actually buy a ticket on Southwest right now from LA to Vegas for $43 dollars not $500k dollars including taxes. That's a massive improvement right there. That's a 4x order of improvement right there.

Reusability is harder when you apply it to Mars. The number of times that you can reuse the spaceship is, the spaceship part of the system, is less often because the Earth-Mars rendezvous occurs roughly every 26 months. You get to use the spaceship part roughly every 2 years. You get to use the booster and the tanker as frequently as you like. That's why it really makes a lot of sense to load the tanks into orbit, with the tanks dry, and then have really big tanks that you can refill in orbit and maximize the payloads of the spaceships so that when you go to Mars you have a really large payload capability.

Refilling in orbit

Refilling in orbit is one of the essential elements of this. Without refilling in orbit, you would have a half-order of magnitude impact on the cost. By half-order of magnitude, I think the audience mostly knows, but it means that each order of magnitude is a factor of 10. So not refilling in orbit would mean a 500% increase in the cost per ticket. It also allows us to build a smaller vehicle and lower the total cost, although this vehicle is quite big, but it would be much harder to build something that's 5-10x the size of this one.

It also reduces the sensitivity of performance characteristics of the booster rocket and tanker. If there's a short-fall in the performance of any of the elements, you can actually make up for it by having one or two extra refilling trips to the spaceship. This is really fortunate towards reducing the susceptibility of the total system to performance shortfalls.

Propellant

And then, producing propellant on Mars is actually really obviously important. If we didn't do this, it would have at least a 0.5x order of magnitude impact on the cost of the trip, so a 500% increase in the cost of a trip if we were not to produce propellant on Mars. It would be pretty absurd to try to build a city on Mars if your spaceship just kept staying on Mars and not going to Earth. It would be a massive graveyard of ships. You would have to do something with them. It wouldn't make sense to leave spaceships on Mars. You wat to build a propellant station on Mars and send your ships back. And Mars happens to work out well for that, because it has a CO2 atmosphere, it has water-ice in the soil, and with H2O and C2O you could do CH4 methane and oxygen O2.

Picking our propellant is also important. Think of this as maybe having three main choices. They have their merits. Kerosene or rocket-propellant-grade kerosene which is also what jets use. Rockets use a very expensive highly refined form of kerosene. It helps keep the vehicle size small, but because it's a very specialized form of jet fuel, it's quite expensive. The reusability potential is lower. It's very difficult to make kerosene on Mars because there's no oil. So really difficult to make that propellant on Mars. And then propellant transport is pretty good, but not great.

Hydrogen, although it has a high specific impulse, is very expensive and incredibly difficult to keep from boiling off. Liquid hydrogen is very close to absolute zero as a liquid. So the insulation required is tremendous. The cost of-- the energy cost on Mars of producing and storing hydrogen is very high. When we looked at the overall optimization of the system, it was very clear to us that methane actually was the clear winner.

It would require maybe anywhere from 50 to 60% of the energy on Mars to refill propellants using the propellant depot. And the technical challenges are a lot easier. So we think methane is a lot better almost across the board. We started off by thinking that hydrogen would make sense, but ultimately we came to the conclusion that the best way to optimize the cost of unit mass to Mars and back is to use an all-methane system, or technically deprior methologs.

So those are the four elements that need to be achieved. Whtaever architecture, or system is designed, whether by SpaceX or anyone, we think these are the four features that need to be addressed in order for the system to achieve low cost per ton to the surface of Mars.

Mission overview

And this is a simulation of the overall system: https://www.youtube.com/watch?v=0qo78R_yYFA

https://www.youtube.com/watch?v=H7Uyfqi_TE8&t=21m15s

What you saw there is really quite close to what we will build. It will look almost exactly like what you just saw. These are not artist's impressions. The simulation in that video was made from the SpaceX CAD models. It's not just "well this is what it might look like", it's also "this is what we are planning to make it look like".

In the video, you got a sense for what the system architecture looks like. The rocket booster in the spaceship takes off and loads the spaceship into orbit. The rocket booster then comes back. It comes back quite quickly within about 20 minutes. It can actually launch the tanker version of the spacecraft, which is essentially the same as the spaceship, but filling up the unpressurized and pressurized cargo areas with propellant tanks. They look almost identical. This helps lower the development cost, which obviously will not be small. And then the propellant tanker goes up, it goes up multiple times, anywhere from 3 to 5 times to fill the tanks of the spaceship in orbit. Once the tanks of the spaceship are full, and the cargo has been transferred, and we reach the Mars rendezvou timing, which as I mentioned is roughly every 26 months, that's when the ship would depart.

Over time there would be many spaceships doing this trip at the same time, I think upwards of 1,000 spaceships or more waiting in orbit. And so the Mars colonial fleet would depart en mass. Kind of like Battlestar Galactica, if you've seen that; good show. A bit like that. It makes sense to load the spaceships into orbit- because you have 2 years to do so. And then make frequent use of the booster and the tanker and get really heavy reuse out of those. And then with the spaceship you get less reuse, because you have to ask how long it lasts, well maybe 30 years, and that might be 12 to maybe 15 flights of the spaceship at most. So you really want to maximize the cargo of the spaceship and reuse the booster and the tanker a lot. The ship goes to Mars. It gets propellant replenished at Mars, and then it returns to Earth.

Vehicle design characteristics and performance

So going into some of the vehicle design characteristics and performance. I am going to gloss over, I'll only talk a little bit about the technical details in the actual presentation, and then I'll leave the detailed technical questions to the Q&A that follows.

https://www.youtube.com/watch?v=H7Uyfqi_TE8&t=24m30s

This is to give you a sense of size. It's quite big. ((applause)) The funny thing is that I think in the long-term the ships will be even bigger than this. This will be relatively small compared to the Mars interplanetary ships of the future. It kind of needs to be about this size because in order to fit 100 people or thereabouts in the pressurized section plus carry the luggage and all the unpressurized cargo for building propellant plants, building pizza joints, iron foundries, you name it, we need to carry a lot of cargo. So it roughly needs to be on this order of magnitude. If we say that, the minimum threshold for a self-sustaining civilization on Mars would be 1 million people and you could only go every 2 years, if you have 100 people per ship, then that's 10,000 trips. So I think at least 100 people per trip is the right order-of-magnitude. I think we might end up expanding the crew section of the ship and ultimately end up taking more like 200 or more people per flight in order to reduce the cost per person.

10,000 flights is a lot of flights. So you probably want on the order of 1,000 ships in your fleet. It will take quite a while to build up to 1,000 ships. And so I think, if you, when would we reach that 1 million person goal from the point of when the first ship goes to Mars, it seems somewhere between 20 to 50 total Mars rendezvous. So it's probably between 40 to 100 years to achieve a fully self-sustaining civilization on Mars.

So this is the cross-section of the ship. In some ways it's really not that complicated. It's made primarily of an advanced carbon fiber. The carbon fiber part is tricky when dealing with deep cryogens and trying to achieve both liquid and gas impermeability and not have gaps or cracks occur due to repressurization that would make the carbon fiber leaky. So this is, this is a fairly sophisticated technical challenge to make cryogen tanks out of carbon fiber. It's only recently that we think the carbon fiber technology has got to the point where we can do this without having to create a liner or metal liner or other liner on the inside of the tanks which would add mass and complexity. Particularly tricky for gaseous repressurization. The fuel and oxygen, we gassify them through heat exchange in the engine and use them to pressurize the tank. We gassify the oxygen and use that to pressurize the oxygen tank. The fuel tanks are also pressurized through this method as well. And this compares to-- this is a much simpler system than what we have with Falcon9 where we use helium for pressurization and we use nitrogen for gas thrusters. In this case, we would use autogenously pressurized, and then use gaseous methane and oxygen for the control thrusters. So really you only need two ingredients for this, as opposed to four ingredients in the case of Falcon9, and actually five if you consider the ignition liquid. It's sort of complicated liquid to ignite the engines which isn't really reusable. In this case, we would use spark ignition.

Vehicles by performance

https://www.youtube.com/watch?v=H7Uyfqi_TE8&t=29m

So just to give you a sense of vehicles by performance, both current and historic... I don't know if you can read that. In expendible mode, the vehicle we are proposing would do 550 tons, and about 300 tons in reusable mode. That compares to Saturn V max capability of 135 tons.

I think this really gives a better sense for things. The white bars show the performance of the vehicles. In other words, the payload to orbit of the vehicle. What it represents is what is the size efficiency of the vehicle. And mostly including ours that are currently flying, incuding those; the performance bar is only a small percentage of the actual size of the rocket. With the interplanetary system initially to be used for Mars, we have been able to, we believe, massively improve the design performance. It's the first time the rocket performance bar will exceed the physical size of the rocket.

This gives you a more direct comparison. This is the-- the thrust level is quite enormous. We're talking about a lift-off thrust of 13,000 tons. It's quite tectonic when it takes off. It does fit on pad 39A which NASA has been kind of us to allow us to use. They kind of oversized the pad for Saturn V, and as a result we can do a much larger vehicle on that same launchpad, and in the future we hope to add additional locations, probably adding one on the south coast of Texas. This gives you a sense of the relative capability if you can read this slide.

These vehicles have very different purposes. This is really intended to carry huge numbers of people, ultimately millions of tons of cargo to Mars. So you need something quite large in order to do that.

Raptor engine

Okay, so let's talk about some of the key elements of the interplanetary spaceship and rocket booster. We decided to start off the development with what we think are the two most difficult elements of the design. One is the raptor engine. This is going to be the highest chamber pressure of any kind ever built, and probably the highest thrust to weight.

It's a full-flow stage combustion engine which maximizes the theoretical momentum that you can get out of a given source fuel and oxidizer. We subcool the oxygen and methane to densify it. Compared to when, propellants usually used, used close to their boiling point. In our case, we load the propellant close to their freezing point. That can result in a density improvement of 10 to 12% which makes an enormous difference in the actual results of the rocket. It also gets rid of any cavitation risk for the turbopumps and it makes it easier to feed a high-pressure turbopump if you have a very cold propellant.

Really one of the keys here is the vacuum version of raptor having a 382 second ISP. This is really quite critical to the whole Mars mission. We can get to that number, or within a few seconds, or maybe even exceed it slightly.

The rocket booster in many ways is a scaled-up version of the Falcon 9 booster. You will see a lot of similarities such as the grid fins, plus plastering a lot of engines at the base. The big difference being that the primary structure is an advanced form of carbon fiber rather than aluminum lithium and that we use otogeneous pressurization and we get rid of the helium and the nitrogen.

The interstellar colonial transport uses 42 raptor engines. It's a lot of engines. We use 9 on a Falcon 9. With Falcon Heavy, which should launch early next year, there's 27 engines on the base. So we've got pretty good experience with having a large number of engines. It also gives us redundancy, so that if some of the engines fail, you can still continue the mission and be fine. The main job of the booster is to accelerate the spaceship to around 8,500 kilometers per hour.

For those who are less familiar with orbital dynamics, it's all about velocity and not about height, so really that's the job of the booster. The booster is like the javalin thrower. It's going to toss the javelin, which is the spaceship. In the case of other planets, though, which have a gravity well which is not as deep as Earth, such as Mars, the moons of Jupiter, conceivably one day maybe even Venus-- and Venus will be more tricky-- but for most of the solar system, you only need the spaceship. You don't need the booster if you have a lower gravity well, such as on the Moon, Mars, or any of the moons of Jupiter, or Pluto--- you need just the spaceship. The booster is there just for heavy gravity wells.

And then we will soon be able to optimize the propellant for boost-back and landing, to get it down to about 7% of the lift-off propellant load. We think that with some optimization we might be able to get it down to about 6%. We are now getting comfortable with the accuracy of the landing. If you are watching the accuracy of the Falcon 9 landings, you will see that they are getting increasingly closer to the bulls eye. We think that particularly with the addition of some thrusters for maneuvering, we could put the booster right back on the launch stand. Those fins at the base are essentially centering features to take out any minor position mismatch at the launch site.

So that's what it looks like at the base. We think we only need to gimble or steer these central cluster of engines. There are only 7 in the center cluster. Those would be the ones that move for steering the rocket. The other ones would be fixed in position, which would give us the best concentration, we could max out the number of engines because we don't need to leave any room for gimbling or moving the engines. And again, these are designed so that you could lose the engines during lift-off or at any time during flight and yet still continue the mission safely.

Spaceship design

For the spaceship itself, in the top we have the pressurized compartment. I'll show you a fly-through of that in a moment. Beneath that, we will have the unpressurized cargo, which will be really flat packed and in a dense format.

And then below that is the liquid oxygen tank. The liquid oxygen tank is probably the hardest piece of this whole vehicle because it has to handle propellant at its coldest level, and the tanks themselves actually form the airframe. The airframe structure and the tank structure are combined, as they are in all modern rockets. In aircrafts for example, the wing is actually a fuel tank in wing shape. So it has to take the thrust loads of ascent, the loads of re-entry, and then it has to be impermeable to gaseous oxygen which is tricky. And non-reactive to gaseous oxygen. That's the hardest piece of the spaceship itself. So that's why we have started on that element as well, and I will show some pictures later.

Below the oxygen tank is the fuel tank. The engines are mounted directly to the thrust cone on the base. And then there are 6 of the high-efficiency vacuum engines around the perimeter, which do not gimble. And hten 3 of the sea-level versions of the engines, which do gimble and provide steering. We can do some amount of steering if you are in space by doing differential thrust on the outside engines.

Ship capacity

The net effect is a cargo to Mars of up to 450 tons depending on how many refills you do with the tanker. And the goal is at least 100 passengers per ship, although ultimately I think we will see that number grow to 200 or more.

https://www.youtube.com/watch?v=H7Uyfqi_TE8&t=39m30s

This chart is a little difficult to interpret at first. We decided to put it there for folks watching the video afterwards for people who want to take a closer look, analyze some of the numbers.

year	trip time (days)
2020	90
2022	120
2024	140
2027	150
2029	140
2031	110
2033	90
2035	80
2037	100
AVERAGE	115

(TMI DELTA V: 6 km/sec; Mars Entry Velocity: 8.5 km/sec)

The column on the left is probably what's most relevant, which gives you the trip time. Depending on which Mars-Earth trip time you're aiming for, the trip time at 6 km/s departure velocity can be as low as 80 days. Over time, I think we could improve that. Ultimately I suspect that you would see Mars transit times as low as 30 days in the more distant future.

It's fairly manageable compared to trips that people used to take in the old days, where they would routinely do sailing voyages that would be 6 months or more.

Heat shield and arrival

On arrival, the heat shield technology is extremely important. We have been refining our heat shield technology using our Dragon spacecraft. We're now on version 3 of PICA, which is phenolic-impregnated carbon ablator heat shield tech. It's getting more robust with each new version, with less ablation, more resistance, less need for refurbishment. The heat shield is basically a giant break pad. So the goal is to figure out how good you can make this, and minimize the cost of refurbishment and make it so that you can have many flights with no refurbishment at all.

Crew compartment fly-through

https://www.youtube.com/watch?v=H7Uyfqi_TE8&t=41m10s

This is a fly-through of the crew compartment. I wanted to give you a sense for what it would feel like to actually be in the spaceship. In order for this to be appealing, and to increase that portion of the venn diagram of people who want to actually want to go to Mars, it has to be really fun and exciting. It can't feel cramped or boring. The crew compartment, or the occupant compartment is setup so that you can do zero g games, you can float around, there will be movies, electro-polls, cabins, a restaurant, it will be really fun to go to Mars. You're going to have a great time.

Propellant plant on Mars

https://www.youtube.com/watch?v=H7Uyfqi_TE8&t=42m35s

The propellant plant on Mars. This is one of those slides that I won't go into a great detail here, but you can take a look offline. The key point being that the ingredients are there on Mars to create a propellant plant with relative ease. The atmosphere is primarily CO2. And there's water-ice almost everywhere. You have CO2 + H2O to make 2O2 plus CH4 which is our methane, using the Sabatier reaction. The trickiest thing is really the energy source, which we think we can do with a large field of solar panels.

Cost

https://www.youtube.com/watch?v=H7Uyfqi_TE8&t=43m15s

To give you a sense of the cost, really the key is making this affordable to almost anyone who wants to go. We think that based on this architecture, this architecture assuming optimization over time, the very first flights would be fairly expensive, but the architecture allows for a cost per ticket of less than $200,000, maybe as low as $100,000 over time depending on how much mass a person takes. Right now, we're estimating $140k per ton to the surface of Mars. So if a person plus their luggage is less than that, taking into account food consumption and life support, we think that the cost of moving to Mars will ultimately drop to under $100,000 dollars.

So funding.. we've thought about funding sources. We could steal underpants, launch satellites, send cargo to astronauts at the International Space Station. Of course, kickstarter and crowdfunding. Followed by profit.

It's going to be a challenge to fund this endeavour. We do expect to generate positive cash flow from launching satellites and servicing the space station for NASA, transferring cargo to and from the International Space Station. And then, I know there's a lot of people in the private sector that are interested in helping fund a base on Mars. And then perhaps there will be interest from the government sector side to also do that.

Ultimately this is going to be a huge public-private partnership. That's how the United States was established, and many other countries around the world. I think that's how it will happen. Right now we're trying to make as much progress as we can with the resources that we have available and just sort of keep moving both forward and hopefully I think as we show that this is possible, that this dream is real, not just a dream but that it is something that is being made real, I think the support will snowball over time.

The main reason why I am personally accumulating assets is in order to fund this. I really don't have any ohter motivation for accumulating assets except to make the biggest contribution I can towards making life multiplanetary. ((applause))

Timelines

https://www.youtube.com/watch?v=H7Uyfqi_TE8&t=46m30s

I am not the best at this sort of thing. ((laughter)) But ((more laughter))... just to show you where we started off, in 2002, SpaceX basically consisted of carpet and a mariachi band. That was it. That's all of SpaceX in 2002. As you can see, I am a dancing machine. I believe in kicking into self-events with mariachi bands.

That was what we started off with in 2002. I thought we had maybe a 10% chance of doing anything at all, or even getting a rocket to orbit, let alone going beyond that and taking Mars seriously. I came to the conclusion that if there wasn't some new entrant into the space arena, with a strong ideological motivation, then it didn't seem like we were on a trajectory to ever be a spacefaring civilization and be out there among the stars. In 1969, we were able to get to the moon. The space shuttle was able to get to low earth orbit, and hten it was retired, and that trend line is down to zero now. I think what a lot of people don't appreciate is that technology does not automatically improve. It only improves if a lot of really strong engineering talent is applied to the problem that it improves. There are many examples in history where civilizations have reached a certain technology level, and then fell below that only to recover millenia later.

So we went from 2002 where we began, where we were basically clueless. With Falcon 1, the smallest orbital rocket that we could think of, which would deliver 0.5 tons to orbit. And then 4 years later, we developed the upper stage, the airframes, the launch system, and so on, and had our first attempted launch in 2006 which failed. That lasted about 60 seconds unfortunately. It was 2006, four years after starting, it was when we got our first NASA contract. I am incredibly grateful to NASA for supporting SpaceX despite the fact that our rocket crashed. That was one of the worst points of my life. Thank you very much to the people that had the faith to do that, thank you. ((applause))

2006 followed by a lot of grief. Finally the fourth launch of Falcon 1 worked in 2008. We were down to my last pennies. I thought we had only enough for 3 launches. They all failed. We were able to scrape together some money for a fourth launch, which finally succeeded in 2008. That was a lot of pain. At the end of 2008 was where NASA awarded us the first major operational contract for resupplying the space station with cargo and taking cargo back. In 2009, we did our first launch of Falcon 9, version 1, and that had about a 10 ton to orbit capability, so it was about 20x the capability of Falcon 1 and was assigned to carry our dragon spacecraft. Then in 2010 was our first mission to the space station, so we were able to finish the development of Dragon and dock with the space station in 2010... so, sorry, 2010 was expendible dragon, and 2012 was when we delivered and returned cargo to the space station. 2013 is when we started our vertical takeoff and landing tests. 2014 was when we were able to have our first orbital booster to have a soft landing in the ocean. The landing was soft, but then it fell over and exploded. For 7 seconds the landing was soft, at least. We also improved the capability of the vehicle from 10 tons to about 13 tons to LEO. In 2015, last year, in December, that was definitely one of the best moments of my life when the rocket booster came back and landed at Cape Canaveral. That was really something. ((applause))

I think that really showed that we could bring an orbit-class booster back from a very high velocity all the way back to the launch site and land it safely with almost no refurbishment required for re-flight. If things go smoothly, we hope to launch one of our used boosters in a few months for its second flight.

In 2016 we demonstrated landing on a ship in the ocean. This was important for the very high velocity geosynchronous missions, and less important for Falcon 9 because about roughly 25% of our missions are sort of servicing the space station, and then there's a few other low earth orbit missions, but most of our missions perhaps 60% of our missions are commercial geo missions so we have to do these high-velocity missions that have to land on a ship out at sea, which don't have enough propellant on board to bring it back to the launch site.

Next steps

Looking into the future, what are the next steps? We were intentionally fuzzy about this timeline. We are going to try to make as much progress as we can, obviously with a very constrained budget. We're going to try to make as much progress as we can on the elements of the interplanetary transport booster and spaceship. And hopefully we will be able to complete the first development spaceship in maybe about 4 years from 2016, and start doing sub-orbital flights with that.

Actually it has enough capability that you could maybe even go to orbit, if you limit the amount of cargo with the spaceship. You have to really strip it down, but in tanker form it can definitely get to orbit, can't get back but it could get to orbit. Actually I was thinking maybe there's some market for really fast transport of stuff around the world, provided we could land somewhere that noise is not a big deal (rockets are very noisy). We could transport cargo to anywhere on earth in 45 minutes at the longest. Most places on earth would be maybe 20 to 25 minutes. Maybe if we had a floating platform out off the coast of, say, New York, say 20 to 30 miles out, you could go from, you know, New York to Tokyo in about 25 minutes. Across the atlantic ocean in 10 minutes. Really most of the time would be spent getting to the ship, and then it would be really quick after that. There's some intriguing possibilities here, although we're not counting on that.

Development of the booster-- we actually think the booster part is relatively straightforward, because it amounts to a scaling-up of the Falcon 9 booster. We don't see a lot of showstoppers there.

Timeline

Trying to put it all together and make this work for Mars-- if things go super well, it might be in the 10 year timeframe. I don't want to say that's when it will occur. There's a huge amount of risk. It's going to cost a lot. There's a good chance we wont succeed. But we're going to do our best and try to make as much progress as possible. We're going to try to send something to Mars on every Mars rendezvous from here on out. Dragon 2, which is a propulsive lander, we plan to send to Mars in a couple years and then do probably another Dragon mission in 2020. We want to establish a steady cadence that there's always a flight leaving, like a train leaving a station, with every launch rendevouzs we will be sending something to Mars, certainly the Dragon spaceship but hopefully the big spaceship. This way, if people are interested in putting payloads on Dragon, then you know you can count on a ship that is going to transport at least 2 to 3 tons of useful payload to the surface of Mars on a regular schedule. ((applause))

That's part of the reason why we designed Dragon 2 to be a propulsive lander. As a propulsive lander, you can go anywhere in the solar system. You could go to the moon; you could go to, well, anywhere really. Whereas if something relies on parachutes or wings, then you can pretty much only-- well if it's wings, you can only land on Earth because you need runway and most places don't have runways yet. And anywhere that doesn't have a dense atmosphere, you can't use parachutes. But propulsive works anywhere. So dragon should be capable of landing on any solid or liquid surface in the solar system.

Raptor engines

I was really excited to see that the SpaceX team managed to do the raptor engine firing in advance of this presentatio a few days ago. Thank you to the Raptor team for really working 7 days a week to try to get this to work in advance of the presentation. I really wanted to show that we have made some hardware progress in this direction. Raptor is a really tricky engine. It's a four-flow stage combustion engine; I'm amazed it didn't blow up on the first firing, but fortunately it was good.

https://www.youtube.com/watch?v=H7Uyfqi_TE8&t=59m

It's interesting to see the (?) bands forming. ((applause)) Yeah. So the um and part of the reason for making the engine sort of small... raptor, while it has 3 times the thrust as the Merlin engine, it's actually only about the same size as a merlin engine because it has 3x the operating pressure, which means we can use a lot of the production techniques that we have honed with merlin for the raptor engines too. We're currently producing merlin engines at almost 300 per year. We understand how to make rocket engines at volume. So even though the Mars vehicle uses 42 raptor engines on the base and 9 on the upper stage-- so 51 engines to make-- that's well within our production capabilities for Merlin, and this raptor engine is similarly sized as merlin except for the expansion ratio, so we feel confident that we will be able to make this engine at volume at a price that doesn't break our budget.

Carbon fiber tank

We also wanted to make progress on the primary structure. This is a very difficult thing to make, is to make something out of carbon fiber, even though carbon fiber has incredible strength-to-weight. When you put in super-cold liquid oxygen and liquid methane, particularly liquid oxygen into the tank, it's subject to cracking and liquid. It's a very difficult thing to make. The sheer scale of it is challenging. You have to lay out the carbon fiber in an exact way on a huge mould, then you have to cure that mould at a high temperature, it's just really hard to make large carbon fiber structures that can do all of those things and carry incredible loads. So that's the other thing we wanted to focus on; the raptor engines and building the first development tank for the Mars spaceship.

https://www.youtube.com/watch?v=H7Uyfqi_TE8&t=1h4m40s

This is really the hardest part of the Mars colonial transport spaceship. The other pieces we have a good handle on, but this one is tricky. So we wanted to try this out first. You can get a sense for the size of the tank. It's really quite big. Big congratulations to the team that worked on this, they were also working 7 days a week to get this done before IAC conference. The initial test with the cryopropellant was quite positive, we have not seen any major issues or leaks yet. This is what the tank looks like on the inside. You can get a real sense for just how big this tank is. It's actually completely smooth on the inside. But the way that the layers of carbon fiber reflect light, it makes it look faceted.

Beyond Mars

What about beyond Mars? As we thought about this system, and the reason why we call it a system; and the reason why I don't like calling things systems is because everything is a system including your dog... it's, that, it's actually more than a vehicle. There's obviously the rocket booster, the spaceship, the tanker, and the propellant plant- the actual propellant production facility. If you have all of those four elements, you can actually go anywhere in the system by planet hopping or moon hopping. By establishing a propellant depot in the asteroid belt or on the moons of Jupiter, you could make a flight from Mars to Jupiter with no problem. Even without a propellant depot on Mars, you could do a fly-by of Jupiter without a propellant depot, so, by establishing a propellant depot let's say, on Enceladus or Europa or any of the few options-- and then another one on Saturn's moon Titan, and perhaps another one further out on Pluto or elsewhere in the solar system-- this system really gives you freedom to go anywhere you want in the greater solar system. You can travel out to the Kulper belt, the oort cloud, I wouldn't recommend this for interstellar journies, but this basic system provided we have refilling stations along the way would mean full access to the entire greater solar system ((applause)).

Q&A

https://www.youtube.com/watch?v=10gECHeMSds&t=1h4m16s

A: Alright, so, any questions that I could answer?

((applause))

Q: Hello. Yeah. Derek Sandlers.

A: I can't see a thing, by the way. So, I wont try to look at you.

Q: Okay. Derek Sylers, NASA spaceflight dot com. Could you talk a little bit about, from the video it looks like launch site 39A is going to be the launch site. Could you talk about some of the modifications to the pad and where the booster and spacecraft might be built?

A: Sorry, could you speak just a little bit louder?

Q: On the video it showed launching from launch site 39A. Talking about initial test flights, booster construction sites, and where the spacecraft will be built since it seems to be too large to transport by road or terrestrial transport?

A: Yeah, so we are expecting to do initial flights from 39A. We plan to setup 39A so that it could launch either Falcon Heavy or the interplanetary system. The-- it's quite a big launch site. We can do that. The construction of the ship and booster, you're right it is quite big, you can't transport that on the road. I think we would probably look at construction of the booster and the spacecraft we're actually looking at Louissiana as a possibility and um I think we're going to end up constructing the booster and spacecraft in probably multiple states and then do final assembly at the launch site.

Q: Thank you.

Q: Right here. Hi Ellen. Over here. Right here.

A: Okay, great.

Q: Very nice to meet you. My name is Alto. Three weeks ago I was at Burning Man in the Nevada desert.

A: Great.

Q: And it felt like I was in Mars. It was a dusty storm it was really cold at night and there was no water. There was one problem at Burning Man. With a population of only 75,000 there was a lot of shit. And there was no water to take it into the rivers which is kind of what we do today for current sanitation systems. So I was like, is this what Mars is going to be like? Just a dusty waterless shitstorm? So I was like, hey Ellen, are you working on sustainable sanitation? Are we gonna have toilet in Mars that doesn't use water? Today on Earth, there are 3 million people that don't have---

A: Guys I have to say, let's keep this -- no essays, only questions.

Q: Alright. So are you working for a toilet on Mars?

A: Yeah. I think Mars actually has a good amount of water and water-ice. I don't think we're going to suffer a water shortage on Mars. The main problem on Mars is actually going to be energy. There's plenty of water because of massive amounts of ice. It's really about getting huge numbers of solar panels out there and potentially doing geothermal energy. And ultimately, I think it might be nuclear, certainly if you built nuclear on Mars, I think that might be up to the public to decide. Alright, next question?

Q: I'm George Gordors from MITSTDM and ... alive... Elon, the first humans on mars, will be in the history books as we all know. Who should these men and women, and maybe children be? Who should these people be cutting the light of humanity to Mars for all of us? Thank you.

A: Well I think the first journies to Mars are going to be really very dangerous. The risk of fatality will be high. There's no way around it. I would not suggest sending children. It would be basically, are you prepared to die? If that's okay, then you know, you're a candidate for going. But really this is less about you know who goes there first or, .. the thing that really matters is making a self-sustaining civilization on Mars as fast as possible. This is different from Apollo. This is really about minimizing existential risk and having a tremendous sense of adventure. I mean the thing that Mars really represents-- there's the whole life insurance and protecting life and ensuring that the light of consciousness is not extinguished, which I think is incredibly important; backing up the bioshpere-- and to be clear, this is not about everyone moving to Mars, it's about becoming multiplanetary. I think earth will be a good place for a long time. But it's just, the probable lifespan of human civilization will be much greater if we were a multiplanetary species. Now, that's the defensive argument. But the art of finding the most compelling-- is that, it would be an incredible adventure. I think it would be the most inspiring thing that I could possibly imagine, and life needs to be about more than just solving problems every day. You need to wake up and be excited about the future, be inspired and want to live. ((applause))

Q: Thank you very much.

Q: Hey Elon. Kid Rock at Global Space something dot com. Everybody give up for Elon please. This guy inspires the shit out of us. Come on. I've got a gift for you it's a comic book called The future of fusion. It's about the first man on Mars. It looks like you. I can't get past El Chappo's militia, though. So I don't know should I just throw this on to the stage.

A: Sorry?

Q: My question is can I give you this gift. The future of fusion. Thank you sir.

A: Sorry could you-- lright thank you.

Q: Lauren Brush from The Verge. You talk about how the Mars colonization architecture is meant to serve as a backup plan?

A: Man, there's so many mics here.

Q: Yeah if you can see me.

A: Okay.

Q: Mars architecture is supposed to serve as a backup plan for humanity, but you didn't touch much on how you will keep humans safe on the way over there from either deep space radiation or how they will live on the planet. Could you give just some insight into the life support systems, habitats, stuff like that?

A: Um, sure. My feel on the radiation thing is that there's some risk of radiation, but it's not deadly. There will be some slight increase of risk of cancer. But I think it's relatively minor. You need to have some shielding particularly if there's a solar flare or sort of a big-- any kind of solar storm, we would want to point the ship at the sun and maximize the shielding effect. Point the rear of the rocket at the sun, and maximize the shielding; and have the passengers cluster around a column of water. Once you are on Mars, you cut your radiation in half because you have the planet shielding you, and then there's at least some atmosphere. And then I think you construct over time an artifical magnetic field to deflect high-energy particles. So I actually think the radiation problem is often brought up, but I don't think it's too big of a deal. And then there's what's happens once people are there? The goal with SpaceX is to build the transport system. It's like building the Union Pacific railroad. And once that transport system is built, then there's a tremendous opportunity for anyone who wants to go to Mars and create something new or build the foundations of a new planet. So who wants to sort of be among the founding members of a new planet and build everything from iron foundries to the first pizza joint? One or more. And then things on Mars that people can't even imagine today, that might be unique to Mars. And, but that's really where a tremendous amount of entrepreneurship and talent would flourish, just as happened in California when the Union Pacific railroad was completed. And when they were building the Union Pacific, people said it was a super dumb idea because "there is hardly anybody living in California". But now today we have sort of at least, U.S. epicenter of tech development and entertainment and it's the biggest state in the nation. But you need that transport link. If you can't get there, none of those opportunities exist. Our goal is just to make sure you can get there.

Q: Thank you.

Q: Hi Elon. My name is Anatasia. I would like to ask you the following thing. I am Russian. A lot of people here are from many different countries. You're going interplanetary but you're not going international. When are you gonna hire people from other countries than the U.S.? ((applause))

A: Yeah so I think people are a bit confused about this. Unfortunately this is not up to us. The U.S. government regulations make getting a job in the U.S. hard as it is, but if you're working on rocket technology then that's considered an advanced weapons technology, so even a normal work visa is not sufficient, unless you get special permission from the Secretary of Defense or the Secretary of State. So, I want to be clear. This is not out of some desire of SpaceX to just hire people with greencards. It's because we're not allowed to do anything else. I mean, I think this is not a wise thing-- not a wise policy for the U.S. because there's so many talented people all around the world that we would love to have work at our company. Unless they somehow get a greencard, we're just legally prevented from hiring anyone. But for example this is not the case at Tesla, where we're about 25% of our engineering team is from outside the U.S. and even 30%. Because we don't have the ITAR restriction. I really wish we could do more at SpaceX but our hands are tied.

Q: Thank you.

Q: Hey Elon so can we for the SpaceX improbability drive, looking forward to that, but you often talk about wanting to inspire the masses and pushing technology forward, and I'm developing a series with Funny or Die which is like the top comedy site founded by Will Ferrell---

A: Quick questions, not essays.

Q: Yeah yeah, quick question. It's kind of about sending the first person to Mars, but kind of like that first monkey that got shot into space, they are never coming back, it's going to be a one-way trip---

A: Not necessarily.

Q: Well, maybe. So you mathematically determine the world's most expendible human to make the journey, and it's Michael Cera. I wanted to see if this is a project you might have any interest in supporting. Funny or Die just drove 31 million views to a like Hillary Clinton ... a few days ago..

Q: Stop.

A: I think it's pretty important to give people the option of returning. The number of people who would be willing to move to Mars is much greater if they know they have the option of returning, even if they never actually return. Most of the people that went to the original english colonies in North America never returned to Europe even once. But some did. And just knowing that if you don't like it there that you can come back, makes a big difference to people's willingness to go in the first place. And in any case, we need the spaceship back, and it's coming back, so you can jump onboard or not. It's cool. You get a free return trip if you want. ((applause))

Q: Hi Elon. Cameron Ashguard here from the outer space education alliance. Over the years, we've watched in admiration as you've drawn up great blueprints of how we're going to get to Mars. I'm curious what kind of initiatives in mind for answering the question of why an increasing public interest and desiring a thing that is so vast and complex.

A: Exactly. That's what I really want. That's why I started off the talk saying what I really want is an intersection of sets of people who want to go and who could afford to go. So anything that can be done to increase the desire of people to go to Mars, is I think a good thing. There's been a lot of Mars shows, Mars movies and some TV shows that I know are getting written; and you really want to create the dream of Mars in people's minds and have it like it's the new frontier. Make it exciting. Make it fun. Make it as desirable as possible. I think this is where the entertainment industry could play a huge role in just imagining and putting that dream in people's heads and showing them what it could be like. I think this is something that appeals to anybody with an exploratory spirit. If you're an explorer, if you want to be on the frontier and you want to push the envelope and be where things are super exciting even if it's dangerous, then that's who we're appealing to here. Anything that anyone here could do to in that direction would be great. Getting people excited about going, getting the public behind this, and the truth is that right now on Earth you can basically go anywhere in 24 hours. I mean anywhere. You could get-- you could fly over the antartic pole in 24 hours and parachute out if you want. You could get parachuted to the top of Mount Everest from the right plane. You can go to the bottom of the ocean. Earth from a physical standpoint, you can go anywhere. There is no real physical frontier on Earth anymore. Space is that frontier. So I think it's going to appeal to anyone with that exploratory spirit.

Q: Thank you very much.

Q: Hey. Hello. I'm Laura. Back here. Eli.

A: Man, it's really hard to figure out where the disembodied voices are coming from.

Q: Like I was wondering, I wanted to ask you, for some normal people like me, what would it take physically, do you need some requirements or something to get to Mars?

A: Sorry, I can't hear you.

Q: Yeah like, if normal people want to travel to Mars, do we need some specific requirements or do normal people can go there?

A: We're trying to make it such that anyone can go.

Q: Yeah but do we need like a lot of training or something special?

A: Nope. Maybe a few days of training. ((laughter))

Q: Yeah..... Also, ...

A: I mean, you could train more if you want. ((applause))

Q: Also, I wanted to ask you, on behalf of all the ladies, can I go upstairs and give you a kiss? A good luck kiss? ((hoots))

A: Ha. Sounds great, I don't have them here, but thank you, appreciate the thought.

Q: Hi. Jeff How, Space Is Over, on your right. Question on the resources-- how much resources are you putting into this development right now in terms of funding, resources and employees? And how do you expect that to change as the development on the booster ramps up?

A: Well right now resources are being put into the interplanetary transport system are pretty low, certainly under 5% of the company. We're maybe spending a few tens of millions of dollars on it right now. It's relatively small. But then as we finish the development of the sort of the final version of Falcon 9 which should be sometime next year, and dragon 2, and get the reusability of the booster stage and the reusability of dragon 2 sorted out, we'll gradually apply more resources to the interplanetary system. Hopefully over time we'll be able to have most of our engineering team-- well we will have, within um, a year and a half to 2 years, we should have most of SpaceX engineering working on the interplanetary system and spend more on the order of a couple hundred million dollars per year maybe up to $300 million per year on the interplanetary system. So not a lot relative to the overall thing-- and in order to make this whole thing and work reliably before it starts generating some sort of positive cashflow, it's probably an investment on the order of $10 billion dollars. It's a lot of money to get there.

Q: Hi Elon. My name is Zach. I'm a space enthusiast and a local idiot for rooster teeth. I was just wondering you know, can you talk a little bit about the future of humans in space and are you going to go to Mars? Cause I would hate to put all this work and then not go.

A: Yeah, I would definitely like to go to orbit and mabye visit the space station and then ultimately go to Mars. I got to make sure that, if something goes wrong on the flight and I die, then I want to-- that there's a good succession plan and that the mission of the company continues and that it doesn't somehow get taken over by investors that just want to maximize the profit of the company and not go to Mars. That would be my biggest fear in that situation.

Q: Thank you so much.

Q: Hi, Mr. Musk? This is Nancy Warsohl with Aerospace Education Alliance. I know you have been talking about getting to Mars. Can you see me here?

A: Yes. I can. I can see your arms.

Q: Alright. So. And I know we need to get first to Mars. But I have a question. In the back of your head, have you been thinking about interstellar travel?

A: Interstellar, yes. I think that if we were to do interstellar travel then the best way to do it would be with an anti-matter drive, that would give you the best mass efficiency would be antimatter. But even in a best case situation, that's a very long journey even to get to Proxima Centauri. I think that the key thing is to establish a base on Mars. As soon as there is a base on Mars, there's a very powerful forcing function for improving space technology. Right now there just isn't that forcing function. All we do is very local stuff in earth orbit. So as soon as we've got a base on Mars, we can see a base on the moon but certainly one on Mars, which creates a very powerful forcing function for making space technology better every year and that is what will lead us to interstellar travel. I think that doing interstellar travel right off the bat would be very tricky. If you are developing an aircraft, you really want to start small, and then maybe to a 707, and then to a 747, but trying to build a 747 right off the bat would be a tall order.

Q: Right I agree. But do you thnk it's something we need to start talking about?

A: Yeah I think it's definitely worth talking about. The technical solution like I said is I think optimally it's antimatter.

Q: I see. Yes. Thank you for coming to IDC 2016 by the way.

A: Thanks for having me.

Q: I was curious to know if you have ever considered the idea of using cycler or some recycler on a routine basis to go to Mars? And if yes, why did you not go for it?

A: Yeah I think the-- when we do the, when we try to figure out the best cost to mass ratio for Mars, I mean you could do a cycler, but our calculations at least show that it's better to go directly there and not have a cycler. The transit time actually matters quite a lot for reuse of the spaceship. So if you can reuse that spaceship very frequently, then your cost per ton to Mars drops a lot. Now we could be wrong about that, and it could turn out that having a cycler is a good idea to do. But I consider that to be a future potential optimization, along with having a propellant depot on the moon. That might make sense, but say put that in the category of future optimization.

Q: Thank you.

Q: Hello Elon, Tim Dodd here from The Everyday Astronaut with Spaceflight Now. Now in the animation you showed passengers loading up on to MCT or the ICT. And then going into orbit.

https://www.youtube.com/watch?v=Oq-ObkCD4XU&t=1h28m50s

A: We're thinking about names, yeah...

Q: and then going into orbit...

A: The name thing is really hard. We're thinking about maybe for the name of the first ship that goes to Mars not the name of the whole ship line or whatever necessarily, but the first trip that goes to Mars, my current favorite is "Heart of Gold" from Hitchhiker's Guide to the Galaxy. I think we will probably name the first ship to Mars "Heart of Gold" and I like that it's driven by infinite probability because I think our ship is also extremely implausible. I like the infinite probability drive. The acronym is not the best.

Q: You show it going into orbit with the 100 passengers and then refuelling it 3 to 5 times and then doing the Mars injection.

A: Right.

Q: Are you going to do a fully-fueled ICT and then put passengers on board?

A: So, right. It depends on how quickly we do the propellant replinsihment and how many missions are pure cargo versus have people on board. If we can do the refuelling very quickly, then we can send people up there and complete the refueling process in a few weeks. If we're loading spacecraft into orbit with crew comparmtents a year in advace, you would wat people on board then. So we would probably launch a mission that just transfers people. So it would wait until the spacecraft is fully fueled, then launch another one that transfers people from tanks empty to one with tanks full.

Q: That makes sense, thank you.

Q: Hello Elon, I think what you presented was incredible. I have a startup. I have my own electric bus. I have my prototype outside.

A: Space questions only.

Q: I have it outside. It's a 30 ton electric bus. It's just outside.

A: This is the IAC, space questions oly.

Q: Hi Elon my name is ....

A: One or two more questions only.

Q: Lunar missions instead? Do you intend to be the first man on Mars?

A: I think it's good for there to be multiple paths to Mars. I wouldn't suggest anything or any attmept at planetary travel to be caceled. I think it's good to have multiple irons in the fire. A big part of me today was coming here to encourage the international community to build architectures like this. I think it's much better for the world if there are multiple companies or multiple organizations building interplanetary spacecraft. The more the better. I think anything that improves the probability of the future is good, and multiple companies doing that I think would be great. So I wanted to come to describe the architecture in the hopes that this would encourage companies and organizations from around the world to perhaps do something like this or maybe they've got a better architecture. This is why I wanted to do this at IAC to really encourage people to compete with SpaceX or potentially team-up and get people to think in general about doing this.

Q: You could use more funding from NASA. Will you be the first person on Mars?

A: I don't think so. Maybe. I'm not really sure. I don't know. There are pros and cons to that. If I-- I would definitely need to have a pretty good succession plan because the probability of death is quite high on the first mission. I would really like to see my kids grow up.

A: Sorry we're out of time. Got to make room for a new session. Sorry guys. Thank you for coming. Thank you. Good night.

Q: Wait Elon one last question.

Links

https://www.reddit.com/r/spacex/comments/54j2y4/rspacex_official_mars_architecture/

https://www.reddit.com/r/spacex/comments/54rrnb/spacex_interplanetary_transport_system/

https://www.reddit.com/r/worldnews/comments/54tqbs/elon_musk_plans_to_get_humans_to_mars_in_six/

https://www.reddit.com/r/spacex/comments/590wi9/i_am_elon_musk_ask_me_anything_about_becoming_a/