27th September 2016 will go down in the hearts and minds of many as the day that the future of Humanity was unveiled. The day eagerly awaited since the first rumours of Elon Musk’s plans began to circulate 13 years ago. Hold on tight.
As usual, explanations for technical terms can be found in the Jargon Buster at the bottom of the article.
This is no exaggeration. Announced at the International Astronautical Congress in Mexico, the plans are the culmination of SpaceX’s developments spanning 14 years, 5 failed missions and 29 successful ones will be the expertise and funding required to land 100 people and 450 tonnes of useful cargo safely on Mars – not once, not twice, but hundreds of times. It will require the use of SpaceX’s newly designed Raptor rocket engine and the gargantuan Interplanetary Transport System (IPS), with an optimistic first journey taking place within the next ten years, leading to permanent and sustainable human colonisation of the Red Planet by the end of the century.
But who is Elon Musk? How could anyone believe that SpaceX wants to move one million people to Mars within the next century, let alone believe that they might pull it off?
Elon Musk made his fortune from co-founding and eventually selling PayPal to eBay for $1.5Bn, with Musk receiving $165 million. Unlike most Dotcom millionaires, Musk used the money to launch three revolutionary companies: SpaceX, Tesla Motors and SolarCity. SpaceX was founded in June 2002 with the aim of colonising Mars and making humans a “true spacefaring civilisation”. Since then, SpaceX has become the first ever private company to put a satellite into orbit (2008) and to supply the International Space Station (2012). For more of the back-story read my earlier article on this topic here.
The reason to colonise another planet is often described thus: Why would you make a backup of a hard drive that fails fairly regularly but not of our entire civilisation? Historically, mass extinction events have occurred many times, whether it be from asteroid impacts or changes in climate, and the number of possible ‘existential risks’ being created by our own technology is growing fast. Even without considering the Fermi Paradox (detailed in the Jargon Buster below), it is prudent that humanity should one day colonise another planet in order to dramatically increase the chances of our species’ survival. This is where the 1,000,000 people number comes from – it is an estimation of the number required to be completely self-sustaining such that if life on Earth ceased to be, our species could continue to exist.
Of all the planets in the Solar System, Mars is the most like our own. Indeed, many millions of years ago it probably hosted liquid water oceans and had temperatures not too dissimilar to our own. The next closest candidate, Venus, is a nebulous, high-pressure acid bath which makes Mars looks homely in comparison. On Mars we could grow plants just by compressing the atmosphere indoors and could eventually warm the planet up to once again have liquid water oceans. Even the length of the day is virtually the same as Earth’s, at twenty-four hours and forty minutes.
How could anyone afford it?
If you wanted to buy a ticket to Mars today, using conventional technology, it would cost you in the region of $10 billion. The goal of SpaceX is to enlarge the intersection of people who can afford a ticket and people who want to go, with the main method being – you guessed it – reducing the cost of a ticket. The method for this cost reduction is three-fold:
- Achieve full reuseability. Think of a jet airliner. If a Boeing 737 could only be used once, a ticket to fly from London to Nice would cost $500,000. Due to reusability, however, the cost is more like $50 per ticket. SpaceX has already made major strides in this area, with the existing Falcon 9 rocket able to land its first stage to be refuelled and launch another payload to space, massively reducing the cost. It’s already spectacular to watch, so imagine the same but with a rocket fifteen times larger.
- Refuelling in orbit. Without this capability, the rocket booster would have to be made up of three stages and total five to ten times the cost. Furthermore, this approach spreads the risk and cost across multiple launches, allowing for redundancy (an engineer’s best friend).
- Producing fuel on Mars. One of the biggest benefits both of Mars and of the methane fuel used by the Interplanetary Transporter is that more fuel can be easily created using the carbon dioxide-rich atmosphere of Mars. This would not be true of conventional rocket fuels, which are usually a complex hydrocarbon similar to Kerosene.
These measures serve in part to decrease the mass of fuel taken into space, which is one of the costliest factors of the equation. Once these goals are achieved, the cost for a ticket to permanently move to Mars would be in the region of $140,000 – the median house price in the USA, and about 1/20,000th of the current cost. This is a price at which nearly anyone, should they save up the money and have the desire to go, could move to Mars. Combined with the offer of a free return trip should they not like living there, this price should see the number of people willing and able to go grow massively. This is not to say that early colonisation will be easy – it won’t. However, Musk believes that those with the right attitude will love the opportunities Mars offers: “You can go anywhere on Earth in 24 hours. There’s no physical frontier on Earth anymore. Now, space is that frontier, so it’ll appeal to anyone with that exploratory spirit.”
The Interplanetary Transport System (ITS)
Previously named the Mars Colonial Transporter, this giant, 130 metre tall spaceship will be able to carry one hundred or more people, with 450 tonnes of cargo to Mars. Commenting on the size of the spacecraft, Musk said “It’s quite big.” Launching on top of the skyscraper-sized ITS Booster from the launch pad at Cape Canaveral, Florida, the ITS would park in orbit before being refuelled four or five times by separate “tanker” ships, ready for its departure to Mars. By the tail-end of the century there could be a fleet of more than one thousand, all in orbit, waiting for Mars to reach its closest distance to Earth before setting off in unison in a scene reminiscent of science fiction movies.
The length of the trip would be between eighty and one hundred and fifty days, depending on the position of Mars with respect to the Earth. Musk also remarked that the trip would be “really fun and exciting”, with spaces dedicated to playing games in zero gravity, watching films at a cinema and eating at a restaurant, like a space cruise ship. All in all, the trip shouldn’t be uncomfortable in the slightest, and the zero gravity antics could certainly be the experience of a lifetime.
The rocket itself is in the region of one million times more capable than current launch systems (if you multiply the distance it is capable of flying with the payload), three times heavier and three times larger than the largest rocket ever made, the Saturn V, and will be the largest flying object ever. The scale can be quite hard to appreciate, so this may help:
Based on an entirely new type of fuel (methane), a new engine cycle and the highest engine pressure ever, the Raptor engine powering the ITS is a beast of an engine. Each of the current SpaceX Merlin engines produce enough thrust to lift forty cars, making the Falcon Heavy – with 27 – one of the most powerful rockets ever made. Each of the forty-two Raptor engines on the ITS, however, could lift a whole jumbo jet, or 172 cars. If you’re wondering why the ITS uses 42 “smaller” engines and not fewer larger engines, the main reason is redundancy. In fact, even if a handful of engines failed the mission could still continue.
Because the Earth is much closer to the Sun than Mars, it orbits faster, meaning that once every twenty-six months the Earth overtakes Mars. It is at this point that they are closest together and is also when we would send missions to Mars. The next Mars “opposition” will be in July 2018, a month which will be particularly significant because from there on out SpaceX will be sending a payload to Mars during every single opposition, beginning with the Red Dragon spacecraft which launches on a Falcon Heavy. After another few Red Dragons in 2020, Musk wants the maiden voyage of the ITS to take place in December 2022, carrying only cargo, with the first populated voyage taking place in early 2025.
2025. Nine years away.
No one is talking about it now, but when the time comes you can expect the hype to be substantial. Over the course of the next 15 years we will hopefully see a Mars village begin to grow, with the harsh realities of starting up brand new mines, schools and farms facing the adventurous new residents of the planet. By 2035, with more and more ships filled with passengers flying to and from Mars, the nascent city will start to seem normal. By 2050 there will be over a hundred thousand people there, with most living there permanently and many visiting or working there for, say, the twenty-six months before until the next opposition.
2065 could see the technology developed sufficiently that the journey only takes thirty days and costs only $60,000, paid for largely by the higher wages on Mars – a result of the high demand for labour. The economic forcing factor of the new colony will have driven the technology forwards to an enormous extent, and the ITS system (and others, perhaps from Amazon’s Jeff Bezos’ Blue Origin) will be used for a wide range of uses, from travelling to distant moons like Europa to asteroid mining.
Humanity will be a true spacefaring civilisation, with a colony of one million people on Mars by the end of the century and with scientists and pioneers travelling the vast distances to the outer Solar System, advancing our species to ever-greater heights. And this is not science-fiction: As if to signal just how serious these plans are, SpaceX also released images of the ITS in various exotic locations around the Solar System.
Every single part of this announcement has been enough to cause me, an engineer, to need to remind myself that, yes:
This is real.
This is happening.
And it all begins in nine short years’ time.
If you want to know more, head to spacex.com/mars.
Jargon Buster & “Fun” Facts
- A rocket operates on a similar principle to that of a jet-engine: Expand a lot of gas through a nozzle to create a jet of gas which propels the craft forwards. A conventional rocket engine combusts on-board liquid oxygen and a fuel, stored in tanks. Credit: Seb Steele, “Would you live in a city on Mars?”
- Conventional rockets are often split into multiple different sections or “stages”, each composed of a fuel tank and a rocket. As the fuel drains the stage is released and dropped back to Earth, saving weight. Each stage’s rocket may also be designed to be most efficient in certain conditions, for instance at low-altitude or in space.
Credit: Seb Steele, “Would you live in a city on Mars?”
- A global catastrophic risk is a hypothetical future even that could damage human well-being on a global scale. Any event that could cause total human extinction is also known as existential risk. Such events may include nuclear war, climate change, asteroids or hostile artificial intelligence.
On a lighter note, I found this line on Wikipedia entertaining:
‘Researchers experience difficulty in studying near human extinction directly, since humanity has never been destroyed before.’
Credit: Seb Steele, “Would you live in a city on Mars?”
- The Fermi Paradox, named after physicist Enrico Fermi poses the question that, despite the huge number of potentially life-supporting planets in the universe, we have not found any evidence of alien civilisation. Given a rough number of ~10^23 stars in the universe (that’s 1 with 23 zeros after it. In other words, there are 10,000 stars for every grain of sand on Earth), and given perhaps 5% of them could support life, 22% of which may be Earth-like, there should be roughly 100 billion billion Earth-like planets in the universe. That is, there’s 100 Earth-like planets for every grain of sand on Earth. Keep going with the numbers and there could be 100,000 intelligent civilisations in our galaxy. So why haven’t we heard from them?
There are broadly two groups of explanations for the Fermi Paradox. Group 1 is the “Great Filter” I mentioned. It suggests that there could be a significant wall that most or all attempts at life hit. It could be in our past, for instance life beginning at all or the jump from single-celled to multi-cellular life – suggesting that we are exceptionally rare – or it could be in our future, for instance a regularly occurring explosive interstellar event like a gamma ray burst or a supernova destroying us, or a man-made technology (like AI) wiping us out. These could either prevent a civilisation from progressing because they were too slow to expand from their host planet or system, or it could be that nearly all civilisations who tried to make a certain technology were killed by it.
Group 2 suggests that there are logical reasons for not having seen evidence of alien life. There are several possibilities, such as aliens visiting before the 50,000 years for which we have existed; our technology being too primitive to listen to any activity that is going on; higher civilisations being aware of us and observing us (the “Zoo Hypothesis”); or that we are not advanced enough to even perceive their activities, just as an ant cannot understand what a skyscraper is.
In any case, Elon Musk, like many others, believes that the sooner we back-up humanity the more likely we are to survive any potential “Great Filter” events.
Credit: Seb Steele, “Would you live in a city on Mars?”
- The Interplanetary Transporter and Booster contains 8650 tonnes of propellant, which, assuming a stoichiometric mixture, would explode with a yield equivalent to 16 kilotons of TNT. This is a theoretical explosive force (so not including radioactive effects) equivalent to the atomic bomb dropped on Hiroshima (which by all accounts is a small atomic bomb by modern standards).
- Both during the journey to Mars and when there, solar radiation is not problematic. The worst part would be during the journey, but radiation from the sun would largely be shielded by the spaceship. In the worst scenario, the only effect would be a risk of cancer only marginally increased from that of a person remaining on Earth.