Late Thursday night — Friday in Adelaide, Australia, where the speech will take place — Elon Musk will give a presentation at the International Astronautical Congress (IAC) meeting about his “updated” plans for a rocket system that will take humans to Mars. On TwitterMusk has promised to discuss the “design of the planetary colonizer” in detail.
This speech follows a similar talk at last year’s IAC meeting, where Musk unveiled the “Interplanetary Transport System” design, featuring a massive 42-motor rocket capable of carrying a whopping 550 tons to low orbit. Earth – or about four times as much of NASA’s lunar rocket, the Saturn V launch vehicle. This reusable launch system, he said, could take humans to Mars by the mid-2020s.
It was a bold claim. The proposed spacecraft would be 50 meters high, on top of its rocket, with a maximum diameter of 17 meters. Instead of leaving Earth orbit at 4.5 km/s, the six Raptor engines, optimized for the vacuum of space, would accelerate it to 6 km/s, making the journey to Mars much easier. be reduced from six months to about three months. After launching and refueling in orbit, the ITS was able to deliver 100 tons to the surface of Mars. The largest payload NASA — or anyone else — has ever safely landed on the surface of Mars is the Curiosity rover, which weighs less than a ton.
While the 2016 speech presented an ambitious and bold vision of sending humans to the Red Planet, it was almost too fantastical. The missile was too massive to be credible. There was no roadmap to raising the funds to build it (just some jokes, like “sell underpants”). It all seemed a bit angry.
For this year we can expect more realism. Musk has already suggested that the large rocket will be scaled down to a diameter of 30 feet, which would fit SpaceX’s existing rocket factory. By scaling back to 30 feet, Musk likely plans to remove the outer ring from 21 Raptor engines, leaving a vehicle with 21 engines instead of the original 42. While still complicated to manage during the launch and flight, 21 engines seem more reasonable. Such a vehicle would also have about 50 percent less mass.
Not much more is known about any other changes Musk will announce, other than that he believes the design “feels right”. We may see an architecture that starts with a rocket powered by about 10 Raptor engines that scales up to a Mars rocket with 21 engines. This smaller version would be commercially viable with other heavy rockets coming online in the next five years, including Blue Origin’s New Glenn booster.
What to watch
For me, the interesting parts won’t be the design of the rocket. I’d rather see how Musk and SpaceX get to Mars from here. It’s easy to show eye-popping graphics, videos of huge rockets taking off and smiling people on Mars. It’s quite another to design the rocket, get the funding to build it, and negotiate the regulatory hurdles for launching cargo and people to another world. (It’s important to remember that no commercial company has ever sent people into orbit, or cargo, beyond low Earth orbit).
So how is Musk going to pay for Mars rocket development? I suspect SpaceX will follow its tried and true path. There will be some private investment – SpaceX continues to rise in private market valuations thanks to its growing dominance in the commercial satellite launch market – but we can expect the company to continue to leverage government contracts as well.
NASA is building its own heavy-lift vehicle, the Space Launch System, to power human missions to the Moon and Mars. How does Musk’s vehicle fit into that equation? Perhaps most importantly, the US Air Force is looking to develop a new generation of boosters in the mid-2020s and has awarded hundreds of millions of dollars in Rocket Propulsion System grants. Will Musk’s hardware meet the military’s need for a powerful rocket to deliver heavy satellites to geostationary space?
These are the questions we hope to see answered by Musk on Thursday evening. We plan to publish a full report Friday morning, so check back later.