Designer and space enthusiast Josh Sherrington has just released a great short video explaining the basic concepts, challenges, and possible future of the Interplanetary Transport System.
Josh created all of animations in this video. If you like his style, check out his Earth Flag design at www.earthflag.co.uk.
The full transcript is below, used with the author’s permission.
Entrepreneur and SpaceX owner Elon Musk unveiled the Interplanetary Transport System, a method by which SpaceX eventually hopes to transport 100 people to Mars per flight.
Using traditional methods of spaceflight, this would have been prohibitively expensive, but SpaceX intends to make use of economies of scale and revolutionary new materials to create a self-sustaining human colony on Mars, and make it possible to relocate for anyone who wants to.
Musk’s plan is untested and currently in need of funding on the order of about 10 billion dollars, but the engineering behind it is good.
By reusing hardware several times and refuelling in orbit, SpaceX has engineered an elegant and feasible solution to the problem of transporting large amounts of cargo and passengers on a realistic time frame and for an achievable budget.
What happens when people actually get on Mars is not really a question SpaceX is looking to answer – but if you want to make a civilization on Mars possible, the most important problem to solve first is the problem of getting there in the first place.
The Interplanetary Transport System is made up of two parts, the “Booster” and the “Spaceship.”
At the bottom of the booster are 42 Raptor engines, powerful and efficient Methane-burning engines, outputting 3 times as much thrust as the Saturn V moon rocket.
With this many engines, the booster will be able to lose several engines at a time and still successfully fly to orbit.
By mass-producing these engines and using newly-developed, advanced production methods, SpaceX hopes to be able to significantly lower the cost per unit, lowering the cost of the whole system.
Once the system reaches a certain velocity, the spaceship separates from the booster and lifts itself to a stable parking orbit.
At the same time, the booster decelerates and propulsively lands itself back on the Launchpad, where a tanker vehicle is loaded onto it, and launched.
The tanker docks with and refuels the spaceship, lands and refuels the spaceship up to five times.
Once it has been fully fuelled, the spaceship sets itself on a course to Mars, enters the Martian atmosphere and lands on the surface around two months later.
Once on the surface, the system makes use of a chemical reaction: the Sabatier reaction.
By reacting Carbon Dioxide, which makes up almost 96% of Mars’ thin atmosphere, together with Hydrogen, which is abundant in the form of water in the Martian soil, Methane is produced, along with water and energy.
The methane produced is used to refuel the spaceship, which can launch itself to orbit and back to Earth due to Mars’ low gravity and thin atmosphere.
SpaceX is intending to send mostly cargo and only about a dozen people on the first missions, but once this system has been tried and tested, SpaceX will send larger and larger fleets of vehicles every two years – when Mars and Earth’s orbits are in the optimal positions.
By sending multiple ships at the same time, the fleet becomes much safer, as if there is a serious problem on one vehicle, passengers can be transferred to other ships.
The first flights of the ITS will carry about a dozen passengers and mostly cargo, but eventually, Elon Musk wants a ticket to Mars to cost as
little as 1 or 2 hundred thousand dollars, the median house price in the United States,
with the goal of creating a self-sustaining city on Mars.
If this infrastructure was extended with refuelling stations, the ships could travel to and land anywhere in the solar system, including the Moon and even the moons of Jupiter and Saturn!
The Interplanetary Transport System is unique among orbital spacecraft in that it extensively incorporates carbon fibre into its structure.
This makes the entire structure of the ship much lighter – about 30% lighter compared to using more traditional Aluminium-lithium.
With the ship’s structure weighing much less, the effective efficiency of the system is vastly improved.
Until recently, carbon fibre tanks could not store liquid-cooled densified methane propellant without cracking or leaking, but SpaceX have successfully constructed a prototype fuel tank which has so far already passed preliminary testing, which means that SpaceX is already well under way in solving this crucial engineering problem.
The Raptor engine is the second key part to the system. Operating under an extremely high chamber pressure, the engine performs with a high
thrust to weight ratio, burning dense and
cold methane fuel.
The engine is even more efficient when operating in a vacuum, as it will on the spaceship.
Previously, the business model to make flights to Mars available to the average person simply did not exist, mainly because space travel has, until recently, been restricted to government agencies, using expensive single-purpose spacecraft for very particular goals.
But this is a problem for which the solution can be engineered – as long as resources are spent on trying to do so.
The first obstacle to developing the Interplanetary Transport System is money.
During his presentation, Musk was pretty vague about how the ITS would be funded, citing an approximate development cost of 10 Billion Dollars, and saying that a public-private partnership would be the best way to raise the money.
10 Billion dollars is a lot of money, but it’s definitely achievable – if the price estimate is accurate, that’s just over half of NASA’s yearly budget in total.
Spread that cost over 10 years, and the price becomes much more feasible.
People flying through space are subjected to radiation which can increase the risk of cancer and other illnesses.
However, as the trip to Mars only lasts about 2 months, the radiation experienced by the crew is within safety limits.
In the event of a solar flare, the passengers can gather behind the ship’s water tank, which makes an effective shield.
Scientists at NASA have been creating more efficient radiation-resistant materials, like hydrogenated boron nitride nanotubes.
This material could be used to upholster spaceships and habitats to make them more radiation-resistant without taking up valuable mass.
Also, on Mars, habitats and living spaces can be built underground, or be surrounded by artificial magnetic fields or radiation-resistant materials.
However, this isn’t really SpaceX’s problem! SpaceX specialises in launch vehicles and spacecraft – other companies, like Bigelow Aerospace are in the business of creating habitats.
Radiation aside, Mars is a surprisingly habitable, but extreme place. Its day lasts 24 hours and 39 minutes, temperature on the surface ranges between a high of 20 degrees Celsius and -153 degrees Celsius, (cold but much more temperate than places like the Moon), a surface area roughly equal to all the land on Earth, and the gravity is about 40% that of Earth’s, which humans should be able to adapt to with little effort.
SpaceX has been the subject of some scepticism following a recent launch pad explosion, but SpaceX’s track record is actually 93%, just 2% lower than the industry average.
There is inherent risk in Space Travel – SpaceX will continue to have setbacks, as will NASA, as will the Russians, the Europeans, the Chinese,
it’s a part of the job.
A big emphasis of SpaceX’s Dragon 2 Capsule is its Launch Escape System, which will fly the capsule and its passengers to safety in
the event of an accident.
We should not wait until all the problems on Earth have been solved before we go to Mars.
There will always be problems on Earth, and there will be problems on Mars as well.
The skills and knowledge we gain solving the considerable technical challenge of settling the most inhospitable environment will be essential to solving problems on Earth in the future.
Progress happens and society benefits when we push the limits of what is possible.
Finally, even though the Interplanetary Transport System has little funding behind it as of yet, its most fundamental design issues are well on their way to being solved.
What’s amazing is that SpaceX says it can develop a heavy lift rocket that can be mass-produced, is reusable and is relatively lightweight – even if no one wanted to go to the existence of such a rocket is a major game changer in the space industry.
By creating the means to lift large payloads into orbit, SpaceX intends to encourage innovation and development in the Space industry by creating
a higher demand for space equipment, as well as strong competitors, transforming a previously restrictive, expensive and small market to one that is expansive, relatively inexpensive and open.
In the 2020s and 30s, the space industry might become mass market in the same way computers did in the 1980s and 90s.
And if SpaceX goes bankrupt and this system never gets off the ground, there’s nothing stopping anyone giving some engineers ten
billion dollars, some blueprints and saying “make me one like this.”