Elon Musk has just explained his updated plans for Mars colonization to an audience at the 68th International Astronautical Congress.
Based on the various comments and questions I see pop up in the comment fields, I want to clarify some misunderstandings.
Why BFR will Replace Falcon 9
To many it seems illogical why a huge rocket like the BFR will replace the Falcon 9. I’ve seen arguments that most launches don’t need huge payload capacity.
That is why the Space Shuttle hardly ever saw any use. It could launch massive payloads but at a high cost. This meant people would rather use a smaller cheaper rocket such as the Soyuz for launching satellites.
It is also the main reason companies such as RocketLabs with their small Electron rocket exists. With satellites getting ever smaller, it is more beneficial for small satellite makers to hitch a ride on an electron rocket to get to the particular orbit they want to be in rather than hitch a ride with a Falcon 9, delivering another larger satellite to another orbit.
This is all logical, but only for non-reusable rockets. With fully reusable rockets we have to think about this in an entirely different way.
Falcon 9 is only partially reusable. The booster, which is the first stage of the rocket can be landed and reused. However the fairing, and upper stage is not reused. This means only about 70% of the cost of the rocket can be reused.
That prevents a 10 times or 100 times sort of cost reduction we are after. The BFR however is being designed to be fully reusable. So despite being a significantly more costly rocket to build than the Falcon 9, it will be much cheaper to operate.
Elon Musk tried to illustrate this difference with airplanes. He pointed out that if you bought a tiny airplane to be used only once, it would cost you a lot more than if you simply rented a huge jumbo-jet for a trip.
That means even a small cheap rockets like the Electron most likely wont be able to compete on price per launch with the BFR. I am not talking cost per Kg, but cost per launch! Each launch of the Electron requires building a whole rocket. That is expensive. Each launch of the BFR requires mainly servicing the rocket, managing the launch pad and refueling it, which is much cheaper. BFR also uses methane fuel rather than refined kerosene which is significantly cheaper.
No We are Not Abandoning Earth
A common opinion among many commenters on Musk’s plans is that he is somehow trying to run away from the problems on Earth. He has repeatedly stated that is not what this is about. When Elon Musk talks about not keeping all the eggs in one basket and saving the human species, he is not referring to our current global climate change. In fact he is doing his best to combat this with Tesla and Solar City, to replace our fossil infrastructure.
In Musk’s world, global warming is a short term problem, which isn’t even an existential threat. More hurricanes, rising sea levels and some failed crops around the world, will surely affect millions and hurt the economy badly, but in no way does it doom the human race.
Elon Musk is talking about much bigger threats than this, such as e.g. a massive asteroid hitting the earth and wiping out all life. There is no way to protect against that by simply burning cleaner fuels.
Now people might argue there is no imminent threat of that. The problem is that should we discover a huge asteroid or rough planet on a trajectory to earth, we would simply not have time to colonize another planet, even if we had a 50 year warning. Colonizing Mars and making it self sustainable will take a very long time. As Musk pointed out it will require at least 1 million people to be self sustainable. That is going to take a very long time to achieve.
Global warming will be a solved problem on earth or it will already have played itself out, long before we have achieved this.
How is Fuel Production on Mars Possible?
I’ve seen people skeptical of the ability to produce fuel on Mars. In fact this idea is not new, but initially proposed by Robert Zubrin in his Mars Direct plan. Some seem to think this involves building some large factory on Mars, and think it would be much simpler to simply send an extra fuel tanker to Mars.
However Mars Direct was all about low cost and simplicity. Zubrin observed how Norwegian polar explorers beat the British by using much smaller expeditions utilizing local resources. The British had huge ships with lots of supplies. Norwegians relied more on hunting and they used dogs for pulling sleds that they later eat, after recommendations from Inuits.
Zubrin concluded that most of the Mars missions when he proposed Mars Direct got too complicated and costly because they relied on bringing absolutely everything from Earth to Mars.
Zubrin’s plans was not about building complicated industrial infrastructure on Mars, but finding the simples possible way of utilizing local resources on Mars. He concluded that there was a simple way of doing this by utilizing the Sabatier chemical reaction.
CO₂ + 4H₂ → CH₄ + 2H₂O
This is quite an old well established chemical reaction which is easy to do. You really just need some steel pipes and heat everything to 800° celsius. Zubrin has already built and demonstrated such a reactor in small scale. You bring Hydrogen from earth in tanks and suck in Carbon dioxide from the atmosphere with a compressor.
Alternatively one could dig up ice on Mars, melt it and produce hydrogen from it through electrolysis. But that requires more equipment.
The point is, none of this requires huge factories and infrastructure. Zubrin’s plan dependent on a tiny space ship compared to the enormous BFR which Elon Musk proposes.
People easily think that because most production on earth happens in huge factories it has to do so on Mars. Remember that is due to economics of scale. Chemical factories in particular can cut costs a lot by going bigger. However this doesn’t mean that production of chemicals or fuels actually requires such large units. We can do most chemical processes in substantially smaller facilities.
Remember a Methane producing facility on Mars, typically has two years before next mission arrives to produce enough fuel.
How Will This Change The Space Industry?
While many of the effects are hard to predict, the dramatic decrease in launch costs a reusable BFR will cause, will dramatically change the way we thing about the space industry and how it operates. So much of how we do things today is a result of extremely expensive launch costs.
Satellites are very expensive partially because they have to be very durable as they cannot be repaired or replaced easily. We might see that change when launching a new satellite is much cheaper.
Satellites design is complicated because they need to fit into relatively small space when launched. The BFR has huge amount of cargo space and can afford much larger designs, which doesn’t need complicated engineering to fold out.
A single BFR space craft has almost the same space as the International Space Station. It means we can quite quickly build a space station of the same size or larger with just a single launch. That simplifies design when you don’t have to couple together lots of small modules.
With much cheaper launches it will open up the ability for a whole host of new business opportunities which did not exist before. Cheap computers paved the way for new services and products big mainframes could not give us such as a smart phone in your pocket to check your current location on an interactive map.
Space Mining becomes a more realistic opportunity with cheap launches. There is vast wealth on asteroids which is not accessible to us today because it is too expensive to get there. Valuable metals such as platinum and gold is typically hidden in deep layers of rock on earth. Iron has to be processed from rock. On asteroids these sorts of valuable metals tend to exist in big chunks in pure form.
Just one small asteroid could contain platinum quantities worth $50 billion. If utilized this would of course cause platinum prices on earth to drop dramatically, causing profits on asteroid mining to fall. However that would be a good thing. Cheap platinum on earth would open up a lot of new technology opportunities. The main reason we don’t have hydrogen fuel cells cars today, despite the technology having been around for decades, is because they require expensive platinum. If it was cheap, fuel cells would also be cheap to make.