Zubrin's take on Elon's Mars plans

Elon Musk has revealed his true nature over the last year.  I used to admire him, believing that he wished to make the world a better place.   I no longer think that.  Nevertheless,  I am going to continue to report news and opinions about SpaceX's Starship,  as I have been a keen follower since it was first announced nearly ten years ago, and because I believe that mankind should go to Mars.

Starship remains far ahead of any competitor.  There's the DreamChaser, but it's been in development for 20 years, and its first lauch has just been postponed again.  Jeff Bezos's New Glen reusable booster has only just had one launch, which wasn't completely successful.  Unlike SpaceX, which has landed its booster, and will soon land Starship, New Glen has yet to return safely to base.

Starship had its first successful flight two days ago, after several failures.  SpaceX's development method is to test its rockets in action, see what's wrong, fix the issues, and then test again.  It's taken 10 Starship launches to get its first success, and there is still a long way to go.  Reusable rockets are essential, to cut costs, and for Starship, that means getting the heatshield tiles to work.  Perhaps another 10 launches will be needed for the technical problems with the heatshield to be solved.  A first step will be to launch Starship and let it land at Starbase, rather than into the sea, so that the engineers can see what's wrong by inspecting the damage to the tiles, the hull and the fins.

Despite the technical difficulties, I have no doubt that Starship will over the next couple of years become as reliable a workhorse as the Falcon 9.  But will it be the foundation for a Mars city?  Well, probably not.  

I've talked before about Zubrin's plans.  He points out that there are no great grasslands or oceans on Mars, and that we can't colonise it in the same way the New World was colonised.  We will have to grow all our food inside domes or caverns.  The initial populations on Mars will be limited by this.  He also argues that a "Starboat" (a rendering is shown below), about 1/5th the size of the Starship, would be much more practical, because the energy needs to produce propellant for Starship for the return journey to Earth would require 60,000 square metres of solar panels, which by themselves would need 3 Starships, and therefore another +-20 launches of refuelling tankers.  A Starboat would require only 1/5 of that.  In addition, a "Starboat" could be lifted  fully fuelled from Earth into orbit by a Starship, ready to head to Mars, and would not require in-orbit propellant transfer.

Musk is fixated on having just one workhorse: Starship.  Yet it has already morphed into 4 distinct variants:  the passenger Starship; the fuel tanker; the cargo version with its huge bay door; and the Moon landing vehicle.  One more wouldn't make much difference.

A concept for "Starboat"

Here is a video about Robert Zubrin's take on Musk' Mars plan.

Will we get to Mars?  Yes.  Will Mars have a million inhabitants by 2060?  I doubt it.  

But the first scientific bases will expand, and eventually there will be small towns with a few thousand inhabitants living in domes and caverns.  It will take decades to reach a Martian population of a million.

Meanwhile, the need to make it all work will be powerful technological driver, providing incentives to develop the technology needed for a space civilisation, all of which will be good for Earth.  Think for example of the need for vat meat and fish, for air and water purification systems, for workable, safe, small nuclear reactors, for plant varieties which can flourish in very different conditions from on Earth, and for more efficient, cheaper and faster transportation between Mars and Earth.  Just as space has already led to incredibly useful new technologies on Earth--solar panels being just one--so will Mars lead to improvements in Earth-based technology and science.

An interview with Robert Zubrin about Mars

 A fascinating interview with Robert Zubrin.  The most interesting bits are about how frontier societies drive technological innovation.  Also, about why the USA is English-speaking not French (I didn't see that coming!)

How to get to Mars

Another excerpt from Robert Zubrin's The Mars Dream is Back

The SpaceX Plan

While there should be fair competition for all mission hardware used by the human Mars exploration program, it is a foregone conclusion at this time that the best launch system for the effort will be the SpaceX Starship. This soon-to-be operational system will offer comparable lift capacity to the SLS but with at least twenty times the launch rate and two orders of magnitude lower cost. We therefore assume that Starship will be selected as the program launch booster.

After payload delivery to low Earth orbit (LEO), however, there are a number of ways that the mission could proceed. SpaceX’s own proposed mission plan would be to fly the Starship to LEO along with 100 tons of cargo, and then refuel it with 600 tons of methane/oxygen bipropellant delivered to orbit by six tanker Starships. This would provide it with sufficient propellant to fly to Mars on a six-month Conjunction-class trajectory, aerobrake into Mars orbit, and then land on Mars. After unloading its cargo, the Starship could serve as the home for a very substantial crew for a year and a half, during which time it would be refueled with some 600 tons of methane/oxygen bipropellant produced from Martian carbon dioxide and water. This would be enough to fly back to Earth on a six-month trajectory carrying the crew and ten tons of cargo.

This mission plan offers a number of advantages. First and foremost, it requires use of only a single flight system that is already in an advanced stage of development and scheduled for use as part of the Artemis Moon program as well. Thus, the same team and infrastructure used to operate Artemis could support the Mars program simultaneously, offering both programs large cost savings. Second, the payload delivered to the surface of Mars is enormous relative to competing approaches, and so is the potential crew size. Elon Musk advertises Starship as a transport capable of delivering 100 colonists to Mars at a time. Such a large number would neither be necessary nor desirable for an exploration mission, but a crew of twenty or so might be readily accommodated. This would be around four times the size of the crew proposed in most other credible Mars mission plans. Moreover, the entire crew would be landed on Mars, where they all would be available to support the field exploration effort, and where they all could avail themselves of natural gravity and substantial radiation protection offered by the Martian environment. Unlike typical NASA mission designs, no one would be left on an orbiting mothership doing nothing useful except for minding the store, while undergoing extensive deconditioning from extended exposure to zero gravity and soaking up cosmic rays. Furthermore, there would be no mission-critical Mars orbit rendezvous on the return leg of the mission.

There are difficulties with this plan, however, which stem from the same source as the problem with SpaceX’s lunar mission architecture: the Starship is way too heavy to serve as an optimal ascent vehicle. By a rough estimate, to make the 600 metric tons of propellant required to refuel the Starship once on Mars within a year and a half would require a power source with an average round-the-clock output of 600 kilowatts. A solar array that could do that would cover 60,000 square meters — that’s over 13 football fields in size — and weigh about 240 metric tons. It would require three Starship flights just to deliver such a solar array to Mars, and it would then be a major burden to deploy and maintain. A more practical alternative would be to use nuclear power. We could imagine a plausible reactor design at this power level with a mass of about ten tons. (See Endnote 2.)

From a technical point of view, nuclear is the far superior alternative to supply the required surface power. However, to achieve the necessary compact size and weight, space nuclear reactors require the use of either plutonium or highly enriched uranium, which are both controlled substances. Thus the government will need to be involved. This poses issues, because the Department of Energy is afflicted by all the same bureaucratic pathologies as NASA, if not more so. A reactor development program done in-house at the modern DOE would never produce a working system on the timeline required for a human Mars mission program. Instead, it would have to be a commercially-led effort with the DOE playing a supporting role.

 

The Starboat Plan

There is another way to mitigate the energy production problem. We could achieve a very large reduction in the amount of propellant needed by introducing an additional flight element, which I call a Starboat. This could be a vehicle of similar type to the current SpaceX Starship but scaled down by about a factor of five in mass. This could play numerous roles that would correct the weaknesses in the SpaceX plan. For example, it could do a direct return from the Mars surface to Earth using 120 tons of propellant or perform a low-Mars-orbit rendezvous using just 50 tons of propellent, with a single tanker in low Mars orbit being able to support five such return flights. It could also be lifted to Earth orbit fully fueled by a single Starship and sent directly to Mars with five tons of cargo without any Earth-orbit refueling, or 25 tons of cargo with a single tanker refueling. This would eliminate the problem of needing to launch seven Starships (the mission vehicle plus six tankers) within a single launch window as is required by the SpaceX plan. If, as assumed in these examples, the Starboat is used as the interplanetary flight vehicle, the crew size would have to be reduced from twenty to four or five, but that might well be appropriate for initial missions that will need to be conducted before all the base infrastructure is up and running.

Alternatively, instead of putting a tanker in low Mars orbit, a Starship fully fitted out for crew could be stationed there, and the Starboat only employed as a reusable shuttle between the surface and orbit. In that case, the plan could retain the ability to employ twenty-person crews, as they could ride out and land Mars along with 100 tons of freight on a standard Starship, only needing to accept the closer quarters on the smaller vehicle during a short Mars-to-orbit flight on the return leg.

The development of the Starboat would also fix the excessive launch problem with the SpaceX Artemis mission plan. The current plan requires 200 tons of propellant to be delivered to low lunar orbit to fuel the Starship on a roundtrip sortie to the lunar surface. At one fifth the size, a Starboat could make the same trip with only 40 tons of fuel. Similarly, the propellant requirement for a round trip from the Gateway to the lunar surface would be reduced from 400 tons to 80. And this could be further reduced by another factor of four when and if lunar oxygen production becomes operational. (See Endnote 3.)

The Starboat could also serve as the upper stage of a reusable first-stage booster in the same class as the Falcon-9, Neutron, and New Glenn boosters, thereby creating a fully reusable medium lift system capable of performing many important supporting mission roles. With a payload delivery capability to Mars of up to 25 tons, about twenty times as much as the landing system used to support the Curiosity and Perseverance missions, it could also deliver large scale robotic exploration missions to the Red Planet, as we shall discuss below.

Finally, and critically, the Starboat would endow the Mars base crew with global mobility. Mars is a planet with a surface area equal to all the continents of the Earth put together. It cannot be explored from a single base using slow moving ground vehicles with limited range. To explore Mars competently, we need worldwide access and the ability to travel rapidly across distances of continental scale. With 50, or better yet, 100 tons of propellant, the Starboat could give us this capability in spades. (See Endnote 4.)

Without Starboat, Mars base explorers would be limited to a region about the size of Brooklyn. With Starboat, they would have the freedom to roam over an expanse nearly double the size of the continental United States.

If additional Starships were landed to establish refueling bases scattered at long distances across the planet, more such explorable regions could be opened up. Nine such refueling stations would provide coverage of the entire world.

The Starboat would add enormously to both Artemis and Mars mission effectiveness, and make the two programs coherent with each other. It should therefore be developed as an essential program element. (See Endnote 5.)

Musk said when he first proposed Starship that it would be better to concentrate all development and research on Starship and its booster, because making a successful re-usable rocket would be so difficult.  But once SpaceX has made Starship work, there is no particular reason why "Starboat" can't be made. 

The last couple of months have however raised another issue.  Is Musk still capable of running any business?  He tweets all day; he's obsessed with spreading right-wing tropes and memes; he's obviously neglecting Tesla.  Gwynne Shotwell runs SpaceX, so it might be OK. 

One of the saddest things about Musk disappearing down his rabid-right rabbit-hole is that we may not get to Mars for another 30 years.  This would have been an extraordinary achievement for him.   Instead he will be remembered for the DODGY disaster.

DreamChaser, Sierra Nevada's re-usable "boat".

Settling Mars

 Another extract from Robert Zubrin's  article The Mars Dream is Back  (See the previous extract with my comments here)

Mars can and should be settled. But it is important to be clear about how and why this should be done.

Elon Musk has propounded the idea that thousands of Starship flights should rapidly land a million people on Mars to create a metropolis that will “preserve the light of consciousness” after the human race is destroyed on Earth. This idea, which Musk says is inspired by Isaac Asimov’s noteworthy Foundation science fiction trilogy, is seriously misconceived.

In Asimov’s novels, a group of scientists are sent to settle the planet Terminus (also the name Musk has suggested for his colony) on the edge of the galaxy, so that after the anticipated collapse of the galactic empire their descendants can emerge to reconstruct civilization. It’s a grand read. But it is not applicable to the task at hand.

A human Mars civilization cannot be created in the manner of the D-Day landings, delivering settlers to land on the hostile shore 100,000 people at a time. The troops on Normandy beach could be supported from England by Liberty ships capable of carrying 10,000 tons of cargo each across the channel in a matter of hours. In contrast, Starships will be able to carry only about 100 tons of cargo from Earth to Mars and will take 6 to 8 months to perform the transit. Consequently, a Mars settlement of any size cannot be supported from Earth. Before large numbers of people go to the Red Planet, the agricultural and industrial base that are needed to feed, clothe, and house them will have to be developed, built, and up and running. The settlement of Mars must therefore occur organically, as the settlement of America did, with small groups of pioneers creating the first farms and industries that provide the basis for supporting ever larger waves of settlers to follow.

Furthermore, Martian civilization is very unlikely to emerge in the form of a million-person metropolis, as any city of that size requires a well-developed system of long-distance transportation to provide it with necessary materials. That is why million-person cities on Earth were rare until the invention of railroads. Instead, the initial settlement of Mars is most likely to occur in the form of a multitude of smaller towns, with locations optimized to access different types of material resources, and populations of thousands to tens of thousands, with perhaps 50,000 (the size of Renaissance Florence) representative of a cultural capital.

Regardless of how it is distributed, no Martian million-person civilization could possibly survive the collapse of human civilization on Earth. Technological civilization requires a vast division of labor. Given the multitude of the components and alloys in a good electric wristwatch, it is unlikely that a society of 1 million people could produce one, or even a wristwatch battery, let alone an iPhone.

So, the idea of sending people to Mars to survive the extermination of terrestrial humanity simply won’t work. Furthermore, it is so morally repulsive that its embrace would doom any program so foolish as to adopt it. Coated with ideological skunk essence, its protagonists would appear more like the selfish characters in Edgar Allan Poe’s “The Masque of the Red Death,” dancing in a castle while everyone outside dies in an epidemic, than the heroes of Asimov’s Foundation series.

We are not going to Mars to desert humanity. We are going to Mars to strengthen humanity — to vastly expand its power to meet all future challenges by establishing new highly-inventive branches of civilization. We are not going to Mars to “preserve the light of consciousness” in an off-world hideaway. We are going to Mars to liberate human minds by opening an unlimited frontier to human hands. We are not going to Mars to party while the Earth burns. We are going to Mars to prevent Earth from burning by showing that there is no need to kill each other fighting over provinces when by invoking our higher natures we can create planets.

Together to Mars, then together with Mars, human freedom will expand into the cosmos.

See my piece from July 2024 Will there ever be a viable colony on Mars, where I come to not dissimilar conclusions.  We might be able to get to Mars (that seems very likely), but the economics of settling on Mars is a different story.  There aren't going to be a thousand ships packed with settlers, because they have nowhere to settle.  There are no grasslands, no forests, no seas.  Just a forbiddingly cold world with a very, very thin and poisonous atmosphere.  Yes, technology will allow us to live in domes, and maybe survive.   But that will be costly, in dollars, and in terms of resources, especially energy.  We will need energy to transform regolith into food and shelter.  We will need time to transform regolith (toxic rubble and sand) into soil.  And even then, for hundreds of years, we will need to grow our plants under protective domes.  Mars is not the New World, with all nature's bounty.  It's a harsh, lethal, dangerous world where mankind will have to work hard to make ourselves a garden. 

Note that Zubrin does NOT see Mars as a bolthole for billionaires (which of course it isn't and won't be for centuries) and also regards the very idea as "morally repulsive" (which it is.)

Why go to Mars?

This is an extract from Robert Zubrin's article in New Atlantis, The Mars Dream Is Back — Here’s How to Make It Actually Happen. It's a long piece, and covers several topics, so I will post more extracts later.

There are three reasons to send humans to Mars: for the science, for the challenge, and for the future.

1. For the Science

The early Earth and the early Mars were twins. Both were warm, wet, rocky planets with atmospheres dominated by carbon dioxide. Earth evolved life. If the theory is correct that life emerges naturally from chemistry through a process of complexification that occurs whenever conditions are right, then life should have evolved on Mars too. We need to know if it did, and if so, what forms it took. We now know from observations made by the Kepler Space Telescope that, out of the stars that are like our Sun, an estimated one in five have roughly Earth-size planets orbiting in their habitable zones. This means there are perhaps as many as 80 billion such planets in our galaxy alone. If life evolves wherever there is a decent planet, it means life is everywhere. Furthermore, since the entire history of life on Earth is one of development into diverse forms, including those manifesting ever greater capacities for activity, intelligence, and accelerated evolution, if life is everywhere, intelligence is everywhere. If we find evidence of past or present life on Mars, it means we are not alone. This is something that thinking men and women have wondered about for thousands of years. It is worth risking life and treasure to find out.

Moreover, while there are forceful arguments that can be made why life must be based on complex hydrocarbon molecules and aqueous chemistry, there is no a priori reason why life must necessarily employ the same DNA–RNA information system utilized by all life on Earth. In trying to understand the phenomenon of life, biologists today are like untraveled people who, having encountered only the Latin alphabet in their homelands, think it is what alphabets are. But in fact, it is possible instead to achieve the same purpose using the Cyrillic or Arabic alphabets, or even Chinese characters, which not only look different, but operate according to an entirely different set of principles. What alphabet does life elsewhere use? The question is of more than academic importance. Biotechnology is going to be one of the main engineering sciences of the twenty-first century and many to follow. It is nanotech made real. A different bioinformation system could offer engineering possibilities as much greater in comparison to DNA–RNA as silicon computers are to ones based on vacuum tubes, electric relays, or mechanical Babbage machines.

Fossil hunting to find evidence of past life on Mars will involve, as it does on Earth, hiking long distances through rough terrain, using intuition to search for subtle clues, doing heavy digging and pickaxe work, and performing delicate work to reveal traces of past life pasted between pages of hardened sediments now turned to rock. Finding current life will require wide-ranging field exploration followed by setting up drilling rigs to access liquid water a kilometer or more underground, bringing up samples, and analyzing them in a well-equipped lab on the Martian surface. These tasks are light years beyond the capabilities of robotic rovers. Only human explorers can achieve them. If we don’t go, we won’t know.

2. For the Challenge

Nations, like individuals and institutions, grow when they challenge themselves and stagnate when they do not. A humans-to-Mars program would pay us back with massive generation of intellectual capital by inspiring millions of young citizens to develop their talents with a bracing challenge: Learn your science and you can be an explorer of new worlds! In the 1960s, the Apollo program issued precisely that challenge. What followed was a doubling in the number of our science and engineering graduates, whose innovations have since repaid us the program cost many times over. With the scientific professions now open to young women and minorities in a way that was simply not the case in the Sixties, the social impact of a bold Mars exploration program would be even greater today.

Forcing NASA to engage in a brave Mars program is precisely what is needed to transform the agency into an effective instrument for supporting all of the nation’s goals in space. NASA today is like a peacetime military with plenty of talented and enthusiastic junior officers but whose upper ranks have become filled by dead wood. It must be thrown into the heat of battle in order to purge it of its McClellans and find its Grants.

Finally, it is by rising to the challenge of Mars that we can demonstrate both the courage and the excellence that we need to show if we are to maintain world leadership. Americans were the first to fly to and the first to reach the Moon. The world needs to know that it is still true that Americans are the ones who can do — and who dare to do — what others can only dream of. So we need to be the first to Mars.

3. For the Future

Philosophers who claim that we are living at the end of history could not be more wrong. We are living at the beginning of history. A thousand years from now there will be hundreds of new branches of human civilization thriving not only on Mars, but on scores of planets orbiting stars in this region of the galaxy. What language will they speak? What traditions and values will they hold dear?

Only people who choose to be parents get to have descendants. Only those nations that take part in the settlement of space will get to put their stamp upon the future.

Of all the worlds beyond Earth currently within our reach, Mars is by far the most viable candidate for human settlement, as I’ve shown in detail in The New World on Mars: What We Can Create on the Red Planet (2024) and elsewhere. On the Moon, outside of a few ultracold craters at its South Pole, water exists only in concentrations of a few parts per million diffused in its soil. In contrast, Mars has oceans of water, including vast amounts in liquid form deep underground, continent-sized regions of frozen mud ranging from five to sixty percent water by weight, and massive formations of pure water ice glaciers, containing perhaps as much water as the American Great Lakes or more, extending from the North Pole down to 38 degrees N, the latitude of San Franscico on Earth. The Moon is lacking in any meaningful supply of carbon or nitrogen, elements essential for life. Mars, with an atmosphere that is 95 percent carbon dioxide and 2.6 percent nitrogen, has plenty of both. Mars not only possesses all the elements needed for industry but has had a complex geological history including both vulcanism and water action that has allowed many rocks to be concentrated into useful mineral ore. In contrast, the waterless Moon lacks many essential industrial elements and those that it has are all mixed together in trash rock. As thin as it is, averaged across the dome of the sky, Mars’s atmosphere provides the equivalent of about two feet (65 cm) of water’s worth of radiation shielding to its surface. That is well above the thickness required for a solar flare storm shelter, and thus fully adequate to protect both astronaut explorers and thin-walled greenhouses taking advantage of Mars’s 24-hour day to grow crops using natural sunlight. In contrast, the Moon has a month-long cycle of day and night and no atmosphere at all, making greenhouse agriculture on its surface a non-starter. Instead, plants would have to grow underground using electrically generated artificial light to support photosynthesis. The power requirement to do this at scale would be enormous. (For radiation concerns, see Endnote 1.)

For the coming age of space settlement, Mars compares to the Moon as North America compared to Greenland during the age of European maritime exploration. Greenland was closer to Europe, so Europeans reached it first. But it was too impoverished an environment to host more than a few outposts. In contrast, America was a place that could be not only settled but become the home for a huge vibrant new branch of Western civilization.

For our generation and those that will follow us in this century, Mars is the New World.

I would add two more.

4.   Mars will be a powerful technological forcing function  

Technological need drives technological advances, and these benefit not just the industry where they were developed, but spread out from there to benefit the whole economy.  Space has already led to or encouraged many technological leaps, such as these, and these, and of course, solar panels.  From before the first rocket leaves for Mars, and on Mars itself, we will need to develop technologies which are cheap and energy-efficient, such as:-

• Air purification systems
• Water purification
• Machines to extract CO2 from the atmosphere
• Vat meat, fish and milk.  There are no great grasslands on Mars, no seas to fish.
• Materials to build domes and habitats
• Genetically modified fast-growing plants to provide fresh food
• Medical advances to treat the illnesses caused by radiation on Mars
• Safe and workable nuclear reactors, fusion or fission.
• Rocket propulsion systems.

Each of these technological breakthroughs will be immensely useful on Earth too.

5.     Mars will change the way we think about ourselves and our place in the universe

Just as the first picture of the Earth, taken on the first Moon landing, and showing Earthrise over the horizon on the Moon, changed our perspective of what we are, so will the televised images of our first trio to Mars and our first colony there widen our horizons. We will never be the same again.

Living on Mars -- VI

Exploration of Valles Marineris by Sean Brady (2009)
Via HumanMars

These excerpts are from a fascinating piece by Robert Zubrin in National Review.

He who follows Freedom, let him leave his homeland, and risk his life.— Adam Mickiewicz, Polish poet, 1832

I have known Musk for some two decades now. In 2001, I was among those who helped convince him to make Mars his calling. His plan is based to a significant degree on my own work, which is generally known as the Mars Direct plan. Published in 1990 and elaborated in detail in 1996 in my book The Case for Mars, Mars Direct was a radical break with previous NASA thinking on how human Mars missions might be accomplished. But Musk’s Starship plan is far more radical still.

With the exception of a period in the 1990s when NASA, under the guidance of Mike Griffin, the associate administrator for exploration, did embrace an expanded version of Mars Direct, the space agency has stuck with a paradigm set forth by Wernher von Braun in a number of variations between 1948 and 1969. According to those ideas, orbital stations should first be built, providing platforms for on-orbit construction of giant interplanetary spaceships using advanced propulsion systems, which would travel from Earth orbit (or currently, rather more absurdly, lunar orbit) to Mars orbit. Departing from these orbital motherships, small landing craft could take crews down to the Martian surface to plant the flag, make a few footprints, and then return to orbit after a short stay.

In contrast, both Mars Direct and the Starship plan use direct flights from Earth orbit to the surface of Mars, with direct return from the surface to Earth using methane/oxygen propellant made on the Red Planet from local materials. Both plans shun any need for orbital infrastructure, orbital construction, interplanetary motherships, specialized small landing craft, or advanced propulsion. Both involve long duration stays on Mars from the very first mission. For both, the central purpose of the mission is not to fly to Mars but to accomplish something serious there.

Musk’s plan offers more mission capability than Mars Direct does, but that capability comes with a price. Specifically, if the crew is to come back, you need to refuel a Starship, which needs about 1,000 tons of propellant. In the Mars Direct plan, the much more modest earth-return vehicle sent to the Red Planet in advance of the crew requires only 100 tons. The Mars surface-power and other base requirements needed to support Starship operations are a factor of ten higher than those needed to implement Mars Direct.

So a large base needs to be built in advance, with several Starships sent one-way to Mars and loaded with lots of base equipment, ten football fields’ worth of solar panels, and robots to set it all up. Not until all that is in place can the first crew carrying Starship arrive. That makes the system suboptimal for exploration. But exploration is not what Musk has in mind.

If Mars Direct may be likened to an evolvable version of the Apollo program, Musk’s plan is like D-Day. He needs a fleet. So he’s creating a shipyard to build a fleet. But why build a fleet before testing even one ship? There are several reasons. The first is that Musk wants to be prepared to take losses. By the time the first Starship is ready for its maiden test flight, he’ll have three or four more already built and on deck, ready to be modified to fix whatever caused the first to fail. Launch, crash, fix, and repeat, until it works, and then keep launching, improving payload and cutting turnaround time, advancing performance, flight by flight, ferociously. [This is one of the best summaries of Musk's process, and it is one of the reasons why I (NPT) am not worried about the three partially-built Starships which have been turned to scrap during the testing so far.]

But there is another reason to build a fleet. It’s to make Starships cheap. NASA built five space shuttles over a twelve-year period, each one costing several billion dollars. Musk is creating a shipyard designed to ultimately mass-produce Starships at a rate of 50 or more per year. That may sound crazy, but it is not impossible. In 1944, the United States produced escort aircraft carriers at a rate of one per week. Scores of separate teams worked simultaneously, each on its own part of the ship for a few days before passing the job on to the next team. If Musk set up a similar line with a workforce of 3,000, that would mean labor costs on the order of $6 million per ship, or between $15 to $20 million each, with materials and avionics included. [Musk himself has stated that he could build each Starship for $5 million]

If he can get costs that low, then once the base on Mars is operational, with a growing industrial and greenhouse agricultural capacity, Starships carrying 100 passengers each could fly to Mars and stay there if necessary to provide housing, at a hardware cost per passenger of less than $200,000. So make the ticket price $300,000 — the net worth of a typical homeowner, or about seven years’ pay for an average American. In colonial times, working stiffs booked passage to America in exchange for seven years’ work. It’s a price many people can pay — and have paid — when they really want to make a move. All that is needed besides is Liberty to welcome the immigrants — if she is there, they will come, and prosper through their creativity.

On this latter point, Musk and I agree. An extraterrestrial settlement is unlikely to be able to produce a profit by export of any material commodity to Earth. The transport costs are simply too great, and so the numbers in business plans based on such concepts just don’t add up.  But intellectual property is another matter altogether, as it can be transmitted across interplanetary distances nearly cost-free. Bit for bit, the highest value any data can have is that contained in a patent. A Mars colony will be composed of a very technically adept population in a frontier environment where they will be free to innovate and forced to innovate.  It will be like 19th-century America, only much more so, a pressure cooker for invention. As historian Frederick Jackson Turner pointed out in his famous essay “The Significance of the Frontier in American History” (1893), an analogous situation made youthful America the most inventive culture ever, with Yankee Ingenuity bringing the world the blessings of electricity, steamboats, telegraphs, labor-saving machinery, recorded sound, light bulbs, telephones, centrally generated electric power — and shortly after he wrote, airplanes and mass-produced automobiles. So, to meet its needs, hard-driven and bureaucracy-free Martian Ingenuity can be expected to produce revolutionary advances in robotics, artificial intelligence, genetically modified organisms, synthetic biology, and many other fields. These inventions, created to meet the necessities of Mars, could be licensed as patents on Earth, bringing in the income needed to fund those imports of complex systems, which unlike bulk materials like food, fabric, fuel, steel, aluminum, glass, and plastic, may be too difficult to make on Mars for some time to come.

[Read more here]

You might also like:

Living on Mars -- I

Living on Mars -- II

Living on Mars -- III

Living on Mars - IV

Living on Mars - V

Zubrin talks Starship with Musk

From an interesting YouTube video from What about it?, covering a conversation between Dr Robert Zubrin, president and founder of the Mars society, and Elon Musk, founder of SpaceX, which took place at the recent SpaceX employment fair in Boca Chica.

1.  There are currently 300 employees at SpaceX's Boca Chica operations.  This will be rapidly increased to 3000.
2. The new (again) LA facility will be used to build raptor engines, while Boca Chica will be where the rest of Starship and Super Heavy are assembled.  Musk plans to build 2 Starships a week.
3. Each Starship will cost—wait for it—just $5 million.  (The Super Heavy will be extra.) My earlier guesses were 10-15 times as high.  This is extraordinarily cheap.  It confirms that SpaceX will be running an  assembly line for Starship/Super Heavy.  Musk's earlier estimate of $2 million per launch (i.e., both Starship and Super Heavy) seems very plausible.  9 launches will be enough  to get a Starship to orbit and to refuel it for the trip to Mars, which means (at 100 passengers) a Mars ticket cost of just $180K.  Just a reminder: SLS will cost $1.5 to $2.5 BILLION per launch.  For the same cost, NASA could send 8000 astronauts to Mars.  Just saying.  Meanwhile, the whole fleet of 1000 Starships would cost just $5 billion.  You'll need fewer Super Heavys because they'll be re-usable several times a day, whereas Starships will have a more limited re-use because they'll be en route to Mars, or on the red planet itself, but on the other hand, the Super Heavys will cost at least twice the cost of the Starship itself.  So $10-$15 billion for the whole fleet?
4. The first 5 Starships will stay on Mars, which makes sense as they will be so cheap.  These will be the cargo versions of Starship, but there is no doubt they could be used as temporary habitats while permanent habitats are built.
5. No nuclear reactors (he means, presumably, NASA's KRUSTY kilopower reactors).  Zubrin pointed out that 6 to 10 football fields of panels would be needed to refuel a single Starship, and Musk replied "Fine!  That's what we'll do."   I still think that will require more Starships than SpaceX has been talking about so far, just to carry the solar panels.  But if Starships are so cheap ....  On the other hand, the next settlers may well be happy to have a diversified mix of nuclear, wind and solar, given the reality of planet-wide dust storms lasting months at a time.
6. The first crew ships will carry just 20-50 people, instead of the 100 each ship is capable of carrying.  Most prob'ly because  of the need for cargo space.
7. Musk also dismissed the whole "mini Starship" idea that Zubrin has been promoting.  Starships will be so cheap and production so rapid that leaving a Starship on Mars for 2 years (the Mars-Earth orbits only "sync" every 26 months) will only add a small amount to total costs.   
8. SpaceX will go for a 100 km high launch immediately after the 20 km launch.  Though he didn't say whether this would be SN1 (Serial number 1) or SN2 (both under construction at Boca Chica right now) which will attempt these landmark milestones.  100 kms (suborbital) will allow Starship to do point-to-point flights, and to circumnavigate the globe.  
9. Zubrin thinks that it is very likely that SpaceX will put boots on Mars before NASA gets to the Moon.  Looks very likely, doesn't it?
10. Progress constructing the first two test models of Starship, SN1 and SN2, has been extraordinarily rapid.  Subject to bureaucracy, the first test flights could happen as soon as April.

Living on Mars -- III

Mars with and without a dust storm

I talked here about the problems of living on Mars (temperature, air pressure, UV radiation, cosmic rays, toxic "soil") and about a solution to some of those problems (silicon aerogel, to raise temperatures and reduce UV radiation).  Now we come to the next big issue: energy.

With an glass/silicon aerogel/perspex dome cover, domes on Mars (at least between latitudes 40 N and S)  would be passively heated.  But it is very likely that heating will be required in winter, especially in the southern winter, when Mars is at its furthest from the sun (Mars has a more eccentric orbit than Earth).

That won't be the only need for energy by the first settlers, though.  A big need will be to manufacture fuel for return trips to Earth.   This will involve splitting water mined on Mars into hydrogen and oxygen, then harvesting CO₂ from the atmosphere.  A mixture of the CO₂ and H₂ is then passed at pressure and high temperature over a catalyst and this process (called the Sabatier process or reaction) produces methane.  More competent mathematicians than I have calculated that this will need 17MWh of electricity per tonne of fuel.  [But see below for an update—Robert Zubrin, the scientist who originally suggested propellant manufacture on Mars, has calculated it at 12 MWh/tonne.  About 70% my original information] Let's say each Starship requires 1100 tonnes or so of fuel (the Mars Colonial Transporter, the bigger first version of Starship, needed that), and there are 600 days between landing and relaunch.  That will require 31 MWh [22 on Zubrin's figures] of electricity per day, just to refuel a single Starship.

Average electricity demand in the US is around 12,000 kWh/person/year.  Assuming usage on Mars will be the same, for a colony of 100, that would mean 3.3 MWh of electricity per day.  Only, usage is likely to be higher on Mars than Earth.  If we use the higher consumption data for cold places on Earth (50,000 kWh/person/year for Iceland, 35,000 for Lichtenstein, 24,000 for Norway, 15,000 for Canada and Finland) then we're talking perhaps 10 MWh/day for the whole colony.   We will need electricity to heat domes, to control the air inside the domes (removing CO2 for example), to run rovers, to grow food, to light domes, etc.  So we'll need total output of 44 MWh [32 on Zubrin's calcs] per day—three-quarters of that for fuel production.

So where is this electricity going to come from?

Let's start with nuclear.   It's out of the question to build a large-scale nuclear reactor on Mars.  But NASA has been working on a smaller, simpler, safer reactor, designed specifically for use on spacecraft and on Mars and the Moon.  It's called KRUSTY (Kilopower Reactor Using Stirling Technology), and here's a video which gives a brief explanation of it.  A reactor 10 times larger is planned.  This will produce 10kW of electricity,  will weigh 1500 kg and will contain 44 kg of  U-235.  So each day, one of these reactors would produce 245 kWh of output.  We'd need 180 [130 on Zubrin's data] of the 10 kW kilopower reactors to produce enough electricity for the colony as well as refuelling one Starship.  They'd weigh 270 tonnes [195 tonnes Zubrin].  Just delivering them to Mars would require 3 Starships [2, Zubrin], assuming on current plans 100 tonnes of cargo per ship.

OK, what about wind?  You'd think that with the air pressure on Mars, just 0.6% of Earth's, wind turbines would be useless.  This informative video from Scott Manley shows how wind turbines on Mars could actually work quite well, despite the low atmospheric pressure.  For a start, don't confuse air pressure with air density.  Now on Earth, these two are related.  However, the air on Mars is denser than on Earth at the same pressure because it's 95% CO₂ and because it's much much colder.  This boosts the impact of air density on the output of a wind turbine by about 100% relative to Earth.

Also, average wind speeds on Mars at the Viking 2 lander site were 15 mph (just under 7 metres/second).  In the US, average wind speeds are between 6 and 12 mph, but of course, wind turbines tend to be sited where winds are stronger.  So, back-of the-envelope, 50% of Earth's wind capacity.   Small wind turbines will weigh something like 300kg, but more productive wind turbines are proportionately less heavy, because the power produced is proportional to the square of the blade radius. Let's assume one with a 10 m rotor diameter, twice the size of the rotors discussed in the link.  This will increase the electricity output four fold, but will weigh, say, 600 kgs.   Such a wind  turbine would produce half (on average) of a 10 kW Kilopower reactor at 1/3rd the weight, so we'd need two Starships to provide all the wind turbines you'd need for your  colony on Mars plus fuel production for the return home.  But—and this is key—it will be easy to manufacture small wind turbines on Mars, unlike (at least for the first decade) nuclear and solar generators.

Just as on Earth, the wind won't blow all the time, so you'll need complementary power source—solar.  Thin-film solar is less efficient than conventional solar cells, but they're 100 times lighter, and can be rolled up for transport.  Because Mars is further from the sun than Earth, solar panels there will be 40% less productive than on Earth.  At the equator on Earth (Singapore) 10 kW of solar panels will produce 12,600 kWh per year, or 34.5 kWh/day.  Reduce that by 60% at the Martian equator, and output of 10 kW of conventional solar panels would be 14 kWh/day per 10 kW of panels.  You'd need 32000 kW [23000, Zubrin] of panels.  One kW of solar panels would cover 2.75 metres.  So you'd need 12,000 square metres of panels on Mars to power the colony.  And if you use thin-film solar, some 25% more.  15,000 square metres.  Imagine a metre-wide strip of thin-film panel.  You'd need 15,000 metres in rolls.  15 kms!  It might be much the lightest generation source, but it will surely take up a lot of space inside a  Starship.  Solar output would be almost completely reduced to zero during Mars's periodic dust storms.  The good news is that wind speeds treble during the dust storms, so just as on Earth, wind is highly complementary to solar.

A couple of conclusions:

• It would make sense for all three generation sources to be used.  The nuclear would provide "baseload", i.e., for all the demand for electricity excluding fuel manufacture.  The first priority is maintaining life.   So the first colony would need 60 10 kW Kilopower reactors, enough to heat, grow food, light, air and water purification, rovers, etc.
• 120 10-metre diameter wind turbines, which would on average provide about the same power.  Any surplus energy would be used to make methane and oxygen.
• 15,000 kw of thin-film solar panels.  Again, the electricity they generate will go towards making methane.
• The cargo demands for all these generators, space and weight suggest to me that more than the planned 4 cargo ships will be needed to start colonisation.  Just for electricity generators, five Starships will be needed, one for nuclear, two each for wind and solar.  [Possibly just 3 using Zubrin's estimate]  It won't be a problem once the Mars-Earth trade route is established, because the cost of sending cargoes to Mars will fall precipitously.  As I guess here, the cost of delivering 1 tonne from Earth to Mars will prolly fall to $20K  by the third or fourth expedition, since re-usability is key.  It's only a serious problem for the first expedition. At each subsequent expedition, more wind turbines/solar panels/kilopower reactors will be brought.
• Reducing the number of people doesn't make much difference, since three-quarters of the electricity is needed for propellant manufacture.   The only way to cut the energy needs is to remove the option to return after 2 years, and stretch it out to 4 or 6 years.  Hmmm.  Or, more plausibly, we send ten Starships on the first crewed expedition, two crewed and eight cargo.  But only one will return to Earth (based on my calculations above), so re-usability is in effect reduced, raising costs.  It'll be different after the second expedition, because then there'll be enough electricity generation capacity to make fuel to send two Starships back, and the number will increase with each expedition to Mars.  
• On these numbers, it will take 10 expeditions of 10 Starships at a time for enough fuel to be available to send them all home.   That's 20 years.  
• Even if some of the Starships are in effect not re-usable (because there isn't enough propellant to fly them back to Earth), the cost will still be far below NASA's estimate of $150 billion for a crew of 5.  At $100 million per Starship**, 10 Starships to get the colony started would cost $1 billion, even if they were never used again—and they'd provide shelter to the first colonists while ground-based shelter was built.  Thus the cost will be $1 billion initially, then $500 million per year (Mars is in opposition to Earth only every 2 years)
• If Starship works, NASA will surely ditch SLS and use the $1.5-$2 billion per launch, never mind the $10 billion plus development cost, to send 200 people every 2 years for a permanent Mars base.

As usual, anyone who knows more about this than me, or who spots flaws in my calculations or analyses, is invited to comment below.

See also:

Living on Mars -- I

Living on Mars -- II

Update:

Robert Zubrin (the guy who first suggested we manufacture methane on Mars to reduce the crippling fuel burden involved in bringing it from the Earth) has estimated the energy cost of producing methane in this tweet:

In other words, my calculations are too pessimistic.  Reduce them by 30% to get a more accurate measure.  Just so y'all know.

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**  [Update 27/04/2020] Musk has stated that he's aiming for a total capital cost per Starship of under $5 million, and a cost per launch below $2 million (including the cost of Super Heavy), with a payload of 150 tonnes.  Each launch will use $800 K of fuel.   To get Starship from LEO  to Mars will mean it has to be refuelled in orbit, and that will require 6 launches per flight to Mars, costing say $16 million per Starship to Mars, or $21 million if we add in the capital cost, since the first ships won't be returning.  That means the initial expedition of 10 ships will cost $210 million.  64 cents per inhabitant of the USA.  And a berth on a flight could cost as little as  $210K per ticket.  One tonne to Mars would cost $140 K.  Subsequent flights will be cheaper, because Starship will rapidly get more efficient as SpaceX learns while doing, just as Falcon 9 got better, and because some Starships will return.  Costs per passenger or per tonne are likely to halve over the first 10 years.   SLS, meanwhile, will cost $1.5-$2.5 BILLION per launch.