Mars is a trillion dollars away
Even if Musk’s mega-rocket can be fixed, fundamental obstacles make Mars travel preposterously expensive
Elon Musk’s giant rocket blew up. This happens in space-machine development. In 1957 America’s first attempt to launch a satellite resulted in an exploding rocket
With Musk’s rocket no one was harmed, no taxpayer money was wasted, and SpaceX Starship may someday work.
But Musk is not being honest with the public with his claim the giant rocket will take people to Mars. This is somewhere between high-tech snake oil and outright lie.
Distracting snake oil, too. Someday our descents will live on many worlds. For now, Mars is not a backup home in case we break Earth environmentally or politically. Mars travel is and will remain so expensive and impractical the Red Planet might as well be in another galaxy.
There are two practical barriers, cost and weight. Musk’s rocket will not overcome them even if someday it flies perfectly.
Cost. In 2017 Musk told an interviewer a ticket to Mars on his rocket would cost half a million dollars. Musk is a terrific actor (and comedian, as he showed on SNL) because he was able to say this without bursting out laughing.
(Comment at about 11 minutes.)
NASA’s Artemis rocket, which is similar in size and power to Musk’s Starship, has flown once, a successful mission that cost $4.1 billion. The price was for one launch, not including development and infrastructure. The Artemis flight was uncrewed; six seats were available. That’s $683 million per ticket, not $500,000.
Surely the cost of Starship will moderate, as costs do in the private sector (but never in government). If you’d told the Wright Brothers that someday people would fly from New York City to Paris in a few hours for $16 -- $500 in the money of 1903 -- they would have called you certifiable It happened; lower costs for rockets will happen too.
But even with economies of scale the price of going to Mars, using existing or reasonably-imaginable tech, will remain many multiples higher than Musk predicts.
In 2012, for Harvard Business Review, I estimated Mars is “a trillion dollars away,” assuming the most improved chemical rockets engineers could describe. Even if Musk’s improved big rocket is fixed, the basic price range won’t change.
Maybe – maybe – there’s a case for sending a few people on a scientific mission to Mars, though that alone might cost $1 trillion. Automated Mars probes are a thousand times more cost-effective.
There is not going to be a Mars settlement – not run by Musk, not run by Jeff Bezos, not run by NASA or the European Space Agency or by China – until such time as there may be a fundamental propulsion breakthrough.
Chemical rocket propulsion has changed little since moon-race days. Liquid hydrogen, the propellant for the space shuttle’s main engines and the Apollo rocket’s upper stage, already has the maximum energy value practical for a rocket. Other ideas are quite speculative and a generation or more away.
It may be a long time till a propulsion breakthrough occurs, if it ever does. And with current propulsion – the sort of engines and fuels Musk’s Starship uses – the weight requirement will overcome all possible plans involving people and Mars.
Weight. Let’s compare to weight numbers for a Mars mission to Apollo 17, the final Apollo mission. This flight was the longest (12 days) and carried the most weight, pound-for-pound the most efficient Apollo launch.
Mars travel and moon travel are not apple-to-apples, but they are oranges-to-tangerines. Both require a lot of fuel, water, air, food and equipment to use after landing. (Or else what’s the point?)
Apollo missions each were self-contained. Mars missions could go in tranches, with equipment being placed on Mars, and fuel tankers put in orbit there, before any people departed. The weight totals would work out about the same.
Mars travel would not burn as much fuel per day as Apollo missions did, because the transit would involve months of coasting. But Apollo never passed beyond Earth’s magnetic field, so radiation shielding was not required. A Mars flight would spend most of its time exposed to solar storms and cosmic rays. Shielding would be needed, and shielding is really heavy. (No Star Trek force fields, sorry to say.)
A Mars mission would require a fully equipped operating theater, since if four astronauts are in transit at least 400 days (smallest crew, fastest there-and-back) odds are someone will have a medical emergency. Apollo capsules only carried a first aid kit.
There’s that word capsule. Apollo capsules were so cramped you couldn’t stand up. A spaceship in transit 400 days will need room to move around in. Long stays have been possible on the International Space Station because there’s room to move and use exercise bikes; our Mars ship will require a lot more cubic volume than Apollo. (Sending the ISS to Mars is not practical and more likely impossible.)
Robert Goddard, inventor of the modern rocket.
The Red Planet has about five times the gravity of the moon, and some atmosphere; blasting off from Mars to return home will require a lot more propellant than blasting off from the moon did.
In all, while some aspects of a Mars-bound ship will weigh less than the Apollo spacecraft, some will weigh more.
Innovations – perhaps inflatable structures, perhaps sending an automated nuclear reactor station to Mars to produce water, air and fuel from Martian resources – would help. The underlying numbers won’t be altered; the automated nuclear refinery would weigh quite a bit.
Now the underlying numbers. Apollo 17, most efficient moon mission, consumed 1,500 pounds per astronaut per day. That was mostly fuel (always the biggest factor in rocketry), plus water, air, food, various supplies and weight of the spacecraft themselves.
At 1,500 pounds per astronaut per day our spartan four-person Mars voyage will need 2.4 million pounds at departure from low-Earth orbit. That’s 1,200 tons.
The entire Apollo program moved about 600 tons out of Earth’s gravity well. A single Mars mission would require at least twice that tonnage.
Musk’s rocket (assuming it works) is somewhat more powerful than the Saturn V, but not by an order of magnitude. It took 10 Saturn V flights to propel those 600 tons away from Earth. You’d need 20 to 30 launches of the Musk mega-rocket to send our spartan four-person travel party to Mars and bring them home.
Musk says his rocket can deliver 100 tons to the surface of Mars. That’s about 2 percent of its launch weight. Apollo 17 delivered one-fifth of one percent of its launch weight to the surface of the moon. Even if Musk is right and his rocket proves tenfold better than the Saturn V at moving weight to other worlds – that’s what his estimate works out to – the number of launches required doesn’t decline enough to alter the economics.
My trillion-dollar estimate seems right on the money. Plus, besides launch costs, there’s building the spacecraft!
All these numbers are for a proof-of-concept mission, which is what Apollo was – let’s prove we can go there and come back safely.
Musk has said people should “move to Mars.” If that means build apartment blocks, shops and schools – first power plants and oxygen generators – add trillions more, plus trillions for constant supply deliveries. The costs become completely ridiculous compared to improving our world at home. A single modest Mars community could expend the GDP of the entire world.
Consider: settling Antarctica would cost far, far less than settling Mars, and no one has the slightest interest in the absurd cost of building cities in Antarctica.
Among the Case for Mars crowd -- I’ve attended a couple of their conferences – the saying goes, “Is there life on Mars? No, but there will be.”
Surely that’s right. Surely our far descendants will live not just on Mars but across the Milky Way, exploring, discovering and protecting the human family against any local extinction.
But that’s too distant to contemplate except in the abstract, and absolutely not an excuse to mistreat the one place we know life to be possible.
Let’s hope Musk perfects his rocket – it would create a lot more value for society than Twitter. But let’s not entertain delusions about living on Mars. With existing or reasonably-imaginable tech, it is out of the question.
Bonus: Musk’s rocket was discussed in All Predictions Wrong just two days before the explosion! It’s at the bottom of a newsletter mainly about the NFL. Am I on the news or what?
