Visions of Space Colonization: Jeff Bezos vs Elon Musk

Reflections on Space Exploration after the Unveiling of Blue Moon

Jeff Bezos recently (May 2019) unveiled a lunar lander, called Blue Moon, being developed by his space company Blue Origin. With it he gave more details about his vision for space exploration with some thinly veiled jabs at Elon Musk competing vision of Mars colonization.

They are following quite different strategies, but as a SpaceX and Elon Musk fan I would like to make the case that Elon Musk’s vision may be easier to get fired up about Bezos may in fact have a better thought out vision.

But first let us look at the different development strategies pursued by each company.

Blue Origin vs SpaceX Style of Development

A problem with Blue Origin is that we don’t know much about how it operates internally so there will be some guessing I have to do here.

SpaceX has a move fast and break stuff, iterative approach. They prefer to build things at smaller scale or in simplified version, test it out, sort of problem and then head on to the next iteration with a larger or more sophisticated model. SpaceX is famous for hiring people who actually built rocket stuff in the garage. They want hands on people, not just theoretical guys. It shows in how they use a company usually building water towers to make their Starship model to test hopping. SpaceX does quick and dirty prototypes rapidly using whatever tools or materials that will get the job done.

They are willing to change course rapidly. Starship was originally planned with carbon composite parts, now they are pursuing steel, despite actually having built huge carbon composite tanks and tested them. It is a wild west company unafraid to test and fail. And they must be doing something right because they are getting results at a staggering pace with way smaller investments than any old Space company or NASA. Falcon Heavy e.g. started development around the same time as SLS, but has already been flying for over a year. SLS may still be years from finished. It has cost more than 15 billion dollars to develop thus far and will cost around 2 billion per launch. Yet Falcon Heavy cost 0.5 billions to develop in total, which is 4 times less than a single launch of SLS! And the SLS is not a significantly more capable rocket. Falcon Heavy has about 60% of the payload capacity as the SLS.

The raptor full flow methalox (methane fuel, liquid oxygen oxidizer) engine is another impressive example. This is one of the most impressive engines ever built, and it has been developed by basically a newbie in the rocket industry in record time.

Rabbit vs the Turtle

If SpaceX is the rabbit, moving fast and frenetically, Blue Origin may very well be the Turtle. As we know from the story, the Turtle ended up winning in the long run.

So why am I saying this? Because if you look at everything Blue Origin has been doing and there is a clearer overall plan to what they do. Here are some examples: SpaceX developed the Kestrel and Merlin 1D engines which are both kerosene engines. Then they made three rockets Falcon 1, Falcon 9 and Falcon Heavy all utilizing these engines. Yet these engines and rockets are complete dead ends. Starship is not really reusing any of this technology. It will use an entirely different engine, using a different fuel, which means different tanks, different forms of pressurization, cooling etc.

Contrast this with Blue Origin. Their New Shepard is fundamentally a scaled down version of the second stage of their much larger New Glenn rocket, being developed. They developed a Hydrolox (hydrogen fuel, liquid oxygen oxidizer) engine for it, the BE-3. The same engine will be used for the New Glenn second stage. Blue Origin never spent much time on dead end technology like Kerosene engines.

This is where the fuel choices of SpaceX and Blue Origin start diverging because they have fundamentally different goals. Both chose Methane or something similar like liquid natural gas for the first stage booster. That is the lowest stage of the rocket which lifts up the second stage. It is what both of the companies land or plan on landing.

For this reason both of them end up choosing Methane as fuel and develop Methalox engines. For first stage it is better choice than Hydrogen because of higher fuel density it gives higher thrust. First stage boosters need a lot of thrust to fight gravity. Kerosene would in principle have been an even better choice due to its high density. However Kerosene is bad for reuse, as it leaves sooth in the engine which has to be cleaned out. You also cannot use it to pressurize the fuel tanks. For methane and hydrogen though as the liquid heats up it turns into a gas and increase pressure in the tank. Thus it is easy to create a pressure in methane and hydrogen tanks for pushing out the fuel.

It is on the second stage where choices diverge. Using methane for the second stage simplifies things. So that would be a good reason, but that is not why Elon Musk picks Methane. He is going to Mars, and you can make Methane on Mars because there is a pure CO2 atmosphere there. Either you could bring Hydrogen to react with the CO2 to make Methane or you perform electrolysis on ice you have dug up from the Martian surface and melted. It is easier to store the fuel and it gives more thrust than hydrogen which Elon Musk will need to get Starship off Mars.

Jeff Bezos in contrast is not going to Mars. He is going to the moon, and there is no carbon on the moon in any form. Thus producing methane on the moon is impractical. It would require bringing carbon in some form from the earth. Water does exist on the moon however in the form of large quantities of ice. Ice can be melted and one can perform electrolysis to generate hydrogen and oxygen. All that is required is electric power, which could be provided by solar cells.

Thus for Bezos making hydrogen rocket engines make sense. In this regard Jeff Bezos approach seems well planned. He made New Shepard with a Hydrogen engine, BE-3, which is the same engine which will be used in the upper stage of New Glenn. Another variant of this, the BE-7 is a hydrogen engine (Hydrolox) which will be used for his lunar lander, Blue Moon.

From this we can see that, while SpaceX moves faster than Blue Origin, it also makes more detours. Blue Origin goes to a larger degree straight for the technologies it is going to need for its future plans.

If Jeff Bezos manage to meet his schedule of launching New Glenn in 2021, he will be ahead of SpaceX. Sure, SpaceX will still have their powerful Falcon Heavy, rocket but it represent technologies Elon Musk will abandon as soon as Starship flies.

New Glenn will be able to outcompete Falcon Heavy. Just like Falcon Heavy, it has reusable boosters, but it has several advantages over FH:

1. The fuel, natural gas, is cheaper and more plentiful than the RP-1 (kerosene) fuel used by Falcon Heavy.
2. It can be reused more times. Natural gas is easier on the engines than RP-1.
3. More untapped potential. Falcon Heavy specs today is based upon years of iterations with improvements. New Glenn in contrast will not be exploiting its full potential. It has more advance rocket engines, which has more opportunities for further tweaking and optimization.
4. Much larger fairing. The New Glenn has a much bigger diameter, which means payloads can be bigger. This is a big deal, as payload size rather than weight is often a limiting factor.

However nothing is certain in this race. SpaceX should not be underestimated. At times they move forward at unreal speed. They are further along with the raptor engine development than Blue Origin with its BE-4 despite Raptor being a far more advance and complicated engine to make.

Blue Moon Lander vs Apollo Lander and Starship

There are some difficulties in making comparisons between all of these as Starship is the second stage of Musk’s next rocket. However it is not just a stage. It also has the capacity to land on any planet. Thus it is a combined second stage, capsule and lunar lander of sorts.

Blue Origin’s lunar lander in contrast is not made for reentry on earth, nor does it serve as a rocket stage. Rather it is a payload a space vehicle.

However when comparing with the Lunar Lander from the Apollo mission it does share some characteristics with Starship:

1. I can in principle be refueled. The Apollo Lunar lander used hypergolic propellant, which there is no chance will be produced on the Moon or Mars. At least not in the near future.
2. That means like Starship it can in principle be reused. However it will in principle be limited to missions on the moon, or possibly travel to low earth orbit.

Blue Moon also offers a number of other clever designs utilizing the fact that it is using Hydrolox. If you look at a rocket before launch it looks like it is venting steam. That is typically very cold hydrogen or oxygen gas being released causing water condensation. Why are they releasing fuel and oxidizer? Isn’t that a waste?

The reason is that both are cryogenic. They are super cooled to be liquified. However it is impossible to keep them cool indefinitely. They get gradually heated which causes some of the liquid to be converted into gas which expands and causes great increases in pressure. To not blow the tanks, the need to vent some of these gases continuously to relieve pressure.

The Blue Moon lander makes sure the gas that needs venting is not wasted. Gasified hydrogen is led past the oxygen tanks to cool them to reduce the need for venting the oxygen tanks. After that hydrogen and oxygen is not actually released but rather fed into a fuel cell, where electricity and water is produced. This give large amounts of electricity production for the lander and removed the need for solar cells.

It is also a more versatile vehicle than the Apollo lander. The apollo lander was just made to land astronauts on the moon. Blue Moon in contrast can instead be used to deliver a variety of payloads instead. That makes is possible to use it commercially. Any company or research organization which wants to deliver rovers, or other equipment to the lunar surface could pay Blue Origin to make the delivery.

This is important if we are to see sustained missions to the moon. Apollo offered no alternative usage of the rocket at competitive prices. Hence when the huge expense could no longer be justified, we stopped visiting the moon.

With Blue Moon we can imagine starting to build infrastructure on the moon. We could deliver equipment for fuel production, and perhaps parts for creating more permanent settlements, or for instance BigLow style inflatable habitats. This could allow astronauts to spend longer time on the moon before returning to earth.

If the refueling capability is built on the moon we could imagine refueling the lander and using it to go on excursion to different parts of the moon. Astronauts could then spend months on the moon and go on exploring large areas.

Bezos vs Musk Vision for Space Colonization

On the face of it Mars is a better place to colonize than the Moon. It has all the same resources (at least in terms of atoms) as the earth has. Thus we could in principle build up a very similar industrial base to the one found on earth. Moon has no carbon so this make growing plants or producing plastic, and a wide variety of chemical difficult.

The moon also has issues like abrasive moon dust and two-week long day and night cycles. A Mars day in contrast is roughly the same as on Earth.

So long term I would say Mars is a better vision. It is also a place that I think appeal more to humans. It has a sky, while the moon has none and looks grayish. Not an inviting place.

However the moon has a massive advantage. It is just 3 days travel away from earth, while it takes around 6 months to go to Mars. A round trip to the moon is thus around 6 days and a round trip to Mars is 1 year. Except it gets even worse. You can’t go to Mars whenever you want. You got to wait for the planets to align properly. That gives you a window to go every 4 years.

This has massive implications when using a reusable rocket. Ironically Mars gets worse in relation to the moon if you have access to a fully reusable space craft. If SpaceX builds one reusable Starship, the have the choice of sending it back and forth between Earth and Mars on a 4 year schedule. In that same time period they could send the same Starship 4 * 60 = 260 times back and forth to the moon!

Fuel costs are minimal expense, which means you can essentially do 260 launches to the moon for the price of one launch to Mars. That means you can build up infrastructure on the moon far more rapidly than on Mars. It will take many decades before Mars will catch up with the Moon. Once you have built up sufficient local industry on Mars, it can perhaps start to gain on the Moon.

However here is a big difference between Bezos and Musk. Bezos does not really believe in the Moon as a place to live on. Instead Bezos talks about Space stations, specifically rotating O’Neil cylinders.

These are large rotating structures. The rotation simulates gravity. The benefit of this approach over living on the Moon or Mars, is that you can pick whatever gravity you want. This allows us to offer the same gravity as on the Earth. Humans may get health problems over time living in such low gravity as exists on Mars. That is a big advantage of space stations.

O’Neil imagined using the moon as a staging ground for building his cylinders. He imagined building the space stations at larange points. These are points between the moon and earth where objects remain fixed relative to the earth and the moon, due to gravity from both celestial bodies canceling each other out.

This offers some great opportunities. Parts for a space station could be sent to a larange point using a mass driver (essentially a big cannon) and assembled there. The parts would not drift away from each other by going into orbit. Thus you can spend all the time shooting up parts into roughly the same location and they will stay there indefinitely.

At this point you may wonder, why don’t see use mass drivers on earth to get parts cheap into space? The simple answer is: atmosphere. Accelerating objects to high velocity on earth causes massive air resistance. That is why e.g. rockets launched from earth do not go at full speed. They keep their velocity below terminal velocity, to avoid too much air resistance. This problem does not exist on the moon.

You would not need to have a complex sophisticated industrial base on the moon to do this. You would simple manufacture the big heavy and simple structural parts of the space base on the moon. More complex and advance parts could be made on earth. The point is just to avoid launching too much material in terms of mass from earth.

The first stage to get this going could be for the moon to sell manufacturing services for satellites to earth companies. All advance electronics and instruments for the satellites could be made on earth, while the simpler structural parts could be made on the moon: such as struts, joints, antennas etc. This could drive the further development of an industrial base on the moon which later could be utilized for space base construction.

It may seem far fetched. But remember we are getting 260 times as much cargo to the Moon each years as to Mars. So if we can afford colonizing Mars, we can certainly afford building up quite an industrial base on the moon.

Space Colonies vs Mars Colonies

It is likely easier in the short term to setup some smaller Mars colony than to build a large space colony. However once you get to the point where you can actually mine asteroid and process material from them in space, space colonies will have a huge advantage over any settlement on a planetary surface.

Minerals are more readily available on asteroids than on planetary surfaces. On plants gravity tends to pull the heavier useful metals and minerals into the planet core. Thus the stuff we really want is in low concentration on the surface. On asteroids in contrast because they have low gravity and no other other complex environments chemically altering minerals, means that a lot of metals exist in high concentrations and often in pure form.

The other advantage is that the bases themselves and the asteroids are existing in a low gravity environment, which makes it cheap for move large quantities of mass around. Hundreds of tons of asteroid matter can be moved with small rocket engines. During construction of the space stations huge structures can be moved around with minimal energy needs. You don’t need enormous cranes like on earth to hold things up, because there is no gravity to fight, pulling things down.

Cargo can be moved between space bases at low cost. Of course building things in space is not something we have much experience with, so we need to create a whole new set of construction vehicles and methods. On Mars in contrast we have the benefit of being able to build in similar fashion to how you build on Earth.

However there is a much bigger potential for amazing things once we master building large structures in space. The abundance of resources in the asteroid belt and the ease of transportation opens up for amazing possibilities which does not exist on Earth or Mars. There is a greater opportunity for creating affluent societies in space.

E.g. a single asteroid of modest size can contain more platinum than has ever been mined on earth. If very expensive materials on earth become abundant and cheap in space it opens up opportunities for building things in entirely new ways. E.g. one of the major obstacles towards making hydrogen fuel cells for cars economical, is the need for expensive metals like platinum. If platinum was abundant and cheap, making fuel cells would also become cheap.

Citizens in space colonies could thus produce and consume things that would be prohibitively expensive for earth citizens to have.

Then there is the question of whether there really will be different citizens. Jeff Bezos seems to suggest nobody would permanently live in these space colonies. They are simply temporary areas of residence. Like a recreational thing. He suggests all the worst kinds of polluting and industry would exist in these colonies rather than on earth.

I am not entirely convinced of this. There may not be a cheap and effective method of moving goods and materials from space onto earth. Nor am I entirely convinced heavy industry cannot be made safe and clean on earth. It is mostly a question of money and technology. If we can build enormous space bases, then surely we should be able to handle waste and pollution effectively on earth.