All Astronautical Evolution posts in 2017:

Scenario Block Diagram Analysis of the Galactic Evolution of Life (Nov.)

Comments by Alex Tolley (Oct.)

Elon Musk’s “Great Martian” (Oct.)

Elon Musk’s Mars Plans: Highlights from His Second Iteration (Sept.)

What is a Supercivilisation? (Aug.)

Quantifying the Assumptions Behind the METI Debate (July)

Five Principles of a Sustainable Manned Mars Programme (June)

Pale Red Dot: Mars comes to Oxford (May)

Back to 2016:

Elon Musk and Mars: Looking for a Snowball Effect (Oct.)

New in 2020:

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AE posts:

2022: What’s to do on Mars?…

2021: New space company Planetopolis…

2020: Cruising in Space…

2019: The Doomsday Fallacy, SpaceX successes…

2018: I, Starship, atheism versus religion, the Copernican principle…

2017: Mars, Supercivilisations, METI…

2016: Stragegic goal for manned spaceflight…

2015: The Pluto Controversy, Mars, SETI…

2014: Skylon, the Great Space Debate, exponential growth, the Fermi “paradox”…

2013: Manned spaceflight, sustainability, the Singularity, Voyager 1, philosophy, ET…

2012: Bulgakov vs. Clarke, starships, the Doomsday Argument…

2011: Manned spaceflight, evolution, worldships, battle for the future…

2010: Views on progress, the Great Sociology Dust-Up…

Chronological index

Subject index

General essays:

Index to essaysincluding:

Talk presented to students at the International Space University, May 2016

Basic concepts of Astronautical Evolution

Options for Growth and Sustainability

Mars on the Interstellar Roadmap (2015)

The Great Sociology Debate (2011)

Building Selenopolis (2008)


Issue 136, 29 September 2017 – 48th Apollo Anniversary Year

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Elon Musk’s Mars Plans: Highlights from His Second Iteration

What he said

Today, Elon Musk presented the second iteration of his strategy for opening up the Solar System, and especially Mars, at the IAC in Adelaide. The video is well worth watching in its entirety.


His talk was more convincing than last year’s, partly because it came after what has so far been a highly successful year for SpaceX, rather than on the heels of the second explosion in two years with the loss of the Amos-6 satellite, and partly because the plans themselves have made significant concessions to reality.

Musk made a good start with a “brief refresher” on why space is so important:

“I think, fundamentally the future is vastly more exciting and interesting if we’re a spacefaring civilisation and a multi-planet species than if we’re not. You want to be inspired by things. You want to wake up in the morning and think, the future’s going to be great, and that’s what being a spacefaring civilisation’s all about. It’s about believing in the future and thinking that the future’ll be better than the past, and I can’t think of anything more exciting than going out there and being among the stars. That’s why.”

The most important part of the updated design of what he’s still calling the “BFR” is how he’s going to pay for it: by using the same basic booster and spacecraft as his main commercial workhorse in near-Earth space – launching satellites and servicing the ISS. It’s been obvious for a long time, to me at least, that coordination between exploration/settlement and commercial flights in low Earth orbit and the Earth-Moon system is the key to progress, so I’m extremely glad that SpaceX have now taken this point on board.

He showed his 12-metre diameter cryogenic oxygen tank being tested to destruction, and emphasised the importance of its innovative carbon-fibre construction for building lightweight vehicles. The Raptor engine, he claimed, had the highest thrust to weight ratio of any engine ever made. And after 16 successful landings of Falcon 9 rockets in a row, he felt confident that another major technical element of a Mars flight had been achieved, or, in his technical jargon, there would be “minimum pucker-factor on landing”.

High precision automated rendezvous and docking, with transfer of propellant, is another ingredient. Dragon 2, which is due to begin launches next year, will be able to dock directly with the ISS without needing the use of the Canadarm to berth it into position.

This smaller iteration of the BFR booster is designed to lift a spacecraft of 150 tonnes to LEO (rather than the 300 of last year’s presentation). The vehicle is to be 9 metres in diameter, have a mass of 4400 tonnes, and be driven by 31 Raptor engines with a combined lift-off thrust of 5400 tonnes (i.e. 53 MN). The passenger capacity of the spacecraft on top is still nominally 100 people per flight to Mars.

Musk made a telling comparison from the aircraft industry which concluded: “It’s really crazy that we build these sophisticated rockets and then crash them every time we fly. This is mad. So… I can’t emphasise [enough] how profound this is, and how important reusability is.”

Refilling the tanks of the 150-tonne spacecraft once it is in orbit can get it all the way to Mars. A single refilling in elliptical orbit would allow it to fly to the Moon and back without needing a propellant plant on the Moon. The result could be the creation of a lunar base: “It’s 2017, I mean, we should have a lunar base by now. What the hell’s going on?”

Back on Mars, Musk mentioned the Sabatier process for manufacturing propellant from locally sourced carbon dioxide and water. The propellant plant would be powered by a large solar array, not the nuclear reactor originally proposed by Robert Zubrin.

“That’s not a typo… [laughter] although it is aspiration” – the next slide showed the first cargo flights to Mars taking place in 2022 using the first two ships of this type. The first manned flight would use the 2024 opportunity with two manned ships plus two cargo ships. Construction is on schedule to begin in the second quarter of 2018. He was fairly confident that SpaceX would be able to build and launch the first vehicles within 5 years or so.

An interesting point: the goal of the initial missions would be to locate water and to build the propellant plant and associated solar arrays. Scientific exploration was not mentioned. I find this to be an excellent advance over previous science-motivated thinking. The priority is to get a firm economic and technical foothold, from which scientific exploration can then be based. The space agency attitude of putting government science first risks losing the whole programme after half a dozen flights when the government loses interest, as happened with Apollo.

Musk concluded his presentation with a portrayal of point-to-point transport anywhere on Earth using the BFR system, and exploiting the value of space as zero-friction transport medium. Journeys to anywhere on the planet could be made within an hour, mostly around half an hour in duration (excluding transport to and from the spaceport, car parking, security checks…).

What he did not say

There was not yet any mention of space tourism as the largest potential growth market for passenger transport into LEO. Maybe Musk is saving that for next year. By that time, barring any further accidents, we can expect that SpaceX will have flown its first astronauts into orbit. And the initial flights of the Falcon Heavy will have brought plans for a circumlunar private passenger flight much closer.


A few years ago SpaceX announced a partnership with Bigelow Aerospace: SpaceX to provide the passenger transport to and from LEO, and Bigelow to provide the in-orbit accommodation. Hopefully this will be realised in the next few years, freeing the space passenger transport industry from its dependence upon a single destination.

There was no further mention of the private-public partnership mode of operation which Musk was so keen on last year. It seems that he has finally realised that his plans are incompatible with the government space agency culture, and that with careful coordination of profit-making and non-profit-making work they might not even need any public subsidy.

Musk did not respond to any of the criticisms which have been levelled at his architecture, notably by Robert Zubrin in The New Atlantis. Zubrin takes issue with the unnecessarily large size of spacecraft and its integral propulsion unit that is landed on Mars, and with the aspiration to cut Earth-Mars journey times down to around three months.

Nor was there any mention of how much, if any, consideration had been given to artificial gravity on the long interplanetary crossings, and why it had been rejected. I believe there’s room for a competitor to construct an alternative architecture with this feature added, which would make Mars accessible to a wider variety of people.

When settling Mars with large numbers of people (tens of thousands up to a million), the issues of local food production, human waste recycling and microbiological health in a low-buffer system really do need to be tackled. I believe there needs to be a parallel project carried out on Earth which addresses this problem, as I argued recently in Principium issue 18.

Clearly, this is not a transport issue, and it is in the nature of SpaceX to focus on transport. But it is a set of problems that SpaceX’s potential customers would need to solve, and unless they can achieve this the Mars transport architecture might end up without any customers. SpaceX should therefore at least be aware of whether progress is being made, and who is making it.

But in summary and setting criticisms of points of detail aside, it has to be said that Elon Musk has once again enormously advanced the subject of Mars exploration and colonisation.

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