Today, Elon Musk elaborated on his plans to make humanity a planet-faring species. We’ve known for a long time that Mars is SpaceX’s destination, but the fine details haven’t been revealed. In today’s talk at the International Astronautical Congress (IAC), Musk revealed a game-changer for travel to Mars, and beyond.
If anyone has ever guessed that Musk’s plans involved a refuelling ship, I’ve never heard them say it out loud. But that’s exactly what Musk revealed. SpaceX plans to launch a Mars-bound craft into orbit, then launch a refuelling craft to refill the interplanetary ship’s fuel tanks. Only then would the Interplanetary Transport System (ITS) depart for Mars.
SpaceX’s proposed system is all about lowering the cost of travel to Mars. Only when the cost is lowered, does a sustained presence there become realistic. And Musk’s ITS system will definitely lower the cost.
Traditional space travel would cost $10 billion to get one person to Mars. Musk said that they can get it down to the median cost of a house in the US, about $200,000 US. The idea is that anyone who really wanted to could save up enough money and go to Mars. Musk did acknowledge that it will be tricky to reduce the cost of the Earth to Mars trip by a whopping 5 million percent.
There are four keys to reducing the cost:
- full reusability
- refilling in orbit
- propellant production on Mars
- right propellant
The ITS would feature reusable boosters, reusable spaceships, and refuelling in orbit. The interplanetary ship would be launched into orbit around Earth and parked there. Fuel ships would make 3 to 5 trips to fill the tank of the interplanetary ship waiting in orbit. From there, Musk thinks that the trip to Mars could take as little as 80 days. In the more distant future, that could be cut to 30 days.
If this whole system isn’t shocking enough, and thrilling enough, for you, Musk has more than just one of these craft in mind. He imagines a fleet of them, perhaps 1,000, travelling en masse back and forth to Mars.
The driving force behind all this is, of course, making Mars possible. In his presentation, Musk said we have two paths. One is to stay on Earth and face extinction from some doomsday event. The other is to become an interplanetary species, and use Mars to back up Earth’s biosphere. The SpaceX system is designed to make the second path possible.
Musk talked about the need to create a self-sustaining city in its own right. That obviously won’t happen right away, but it’ll never happen unless transport to Mars, and back, becomes feasible. With the proposed SpaceX system, Mars will be an option. Musk thinks that the ITS could also get us to one of the Jovian moons, if we could create fuel production and depots. In fact, he said we can probably go all the way to Pluto and beyond.
There are a lot of challenges for this system. It’s far from a done deal. The system will require newer, more powerful engines. But SpaceX is already working on that. It’s called the Raptor, and testing has already begun.
Musk talked about the impressive exploration done on Mars by NASA and other agencies, but stressed that it’s time to take things further and aim for a sustained presence on Mars. To that end, SpaceX plans on sending a craft to Mars during every Earth-Mars opposition, which happens about every 2 years. Initially, that will be done with an unmanned Dragon capsule.
The mood at Musk’s presentation was one of excitement. The crowd was definitely there to see him. There was one humorous moment when Musk remarked “Timelines. I’m not the best at this sort of thing.” This is a nod to the difficulties with creating a timeline for something like the ITS. But really, what agency can adhere to strict schedules when doing something that’s never been done before? Especially in the realm of interplanetary travel?
The excitement surrounding Musk’s plans for travel to Mars is palpable. That’s understandable, considering the magnitude of what he’s talking about, and considering how long people have dreamed of going to Mars. The fact that someone with a track record like SpaceX’s is starting to lay the groundwork for travel to, and a presence on Mars, is exciting. There’s no way around it.
But there are lots of questions. Musk is the first to admit that he doesn’t have all the answers. He says up front that he sees his role as developing the transport system. Once that is moving ahead, others will address the challenges of establishing a presence on Mars.
One of the primary questions is around energy, and there are two sides to that. Fuel processing will have to be established quickly on Mars if the ships are to return to Earth.
Musk also talked about the three possible fuel types to be derived on Mars.
The ITS ships will be able to carry a large payload, so it’s possible that the parts and pieces for a fuel plant could be pre-built somehow, then sent to Mars. There is an enormous amount of detail missing when it comes right down to it, but human ingenuity being what it is, this may be solvable.
Assuming that a rocket fuel plant could be assembled on Mars, that begs the second energy question. Creating this fuel will in itself require lots of energy. Much more than solar can provide. Musk briefly mentioned the possibility of nuclear energy, but didn’t go into detail. That’s understandable, because he clearly sees his role as developing the transportation system.
Establishing nuclear energy on Mars would also require a lot of infrastructure. On Earth, uranium processing is an enormous task. How will that be done on Mars? Is there enough uranium in Mars’ crust? Conventional atomic reactors use water, lots of it, to produce energy. Where will that water come from on Mars? Will the same amount be needed?
Or will thorium reactors be used? If you’re not up on thorium reactors, they are different than uranium reactors and are worth reading about. They use thorium for fuel, not uranium, and are different in other ways. They’re safer and produce less waste, but is there sufficient thorium available on Mars? Thorium is much more plentiful in Earth’s crust than uranium.
Small Modular Reactors (SMRs) are being developed for use on Earth. They are built in one location, then moved to their operational location. They can be linked together and require less sophisticated operators. Perhaps SMRs using thorium will provide the energy required for the ITS to work.
These questions are all important of course, and they bear thinking about. But one thing that can’t be denied is Musk’s vision. Anyone that wants humanity to survive, or that grew up reading science fiction, will love what Musk is doing. For that matter, anyone with a sense of adventure will love Musk.
Musk’s overall vision of us as a planet-faring species is something that will be a long time coming, I think. Fleets of interplanetary cargo ships plying the solar system, with fuelling depots along the way. An established human presence on Mars, the Moon, and perhaps the moons of the gas giants, and all the way out to Pluto.
It seems like a fanciful dream, but remember what Musk said at the start of his presentation. There are really only two paths. The first is to restrict ourselves to Earth, and die at the hands of some sort of extinction event.
The second path is to head outward and expand throughout the solar system.
It’s not science fiction anymore. It’s simple survival.