Musk Unveils SpaceX’s Mars Architecture
published during a waning crescent moon.
09/27/2016

Mars architecture

First development tank for Mars ship. Credit: SpaceX

“Will you be the first man on Mars?” was one of the last questions Elon Musk took from the press after unveiling SpaceX’s Mars architecture this afternoon at the International Astronautical Congress in Guadalajara, Mexico.

Musk tilted his head as the packed room waited for a reply. The subtext was clear: it’s up to you if you want to be the first person on Mars.

“Maybe,” he said. “I would need to have a very good succession plan [for SpaceX] because the probability of death is very high on the first mission. And I’d like to see my kids grow up.”

Musk spent much of the Q&A discussing his personal investment in the mission to get to Mars. Regarding his succession plan in case of death, Musk said he wanted to be absolutely sure that SpaceX would not be turned over to the hands of those who just want to make money.

The hardware, presented with slides and video, delivered the feels promised for months. In one sequence, Musk displayed a silhouetted human for scale and then panned out to show the booster section of the Interplanetary Transport System, powered by 42 Raptor engines. As the simulated camera panned up the stem of the mammoth rocket, the audience gasped, and the human outline was reduced to a handful of pixels.

The spaceship was presented in unexpected detail, including a rendered fly-through of the crew compartment, a video of the first Raptor engine test, which SpaceX conducted early this week, and the surprise reveal of an already-built test article of the upper-stage spaceship liquid oxygen tank. The carbon fiber shell of this tank, Must said, was one of the toughest engineering challenges on the rocket itself, due to the tendency for carbon fiber to crack when exposed to supercooled propellants.

Musk also walked through the mission architecture, giving the first public comments on when the new rocket would fly. He was uncharacteristically vague on a first launch date but repeated his commitment that SpaceX would be flying missions to Mars every two years beginning in 2018, first with Red Dragon missions on Falcon Heavy, followed by spaceship missions. That first spaceship mission might even be in the 10-year time frame “if things go super well,” Musk said. At present, he said “less than five percent” of SpaceX company resources are being directed to the project.

The Interplanetary Transport System is fully reusable, with two stages: a booster and a spaceship. In a typical mission profile, the booster would launch and deploy a spaceship to orbit. Subsequent visits, with the ship functioning as a tanker, would provide on-orbit refueling. Musk said as many as three to five flights might be needed for this phase of each mission.

The spaceship would depart for Mars. Once landed, it would rely on propellant production on Mars to fuel itself for the return trip, a mission parameter included in many recent Mars mission architectures, including the fictional mission in Andy Weir’s The Martian.

Reusability, on-orbit refueling, and propellant production on Mars were three of four keys to success, Musk said. The fourth: “choosing the right propellant.” Here Musk labored over the many advantages of a liquid methane/liquid oxygen mixture. He specifically noted that a hydrogen-oxygen mixture, which powers a number of competitor engines (notably Blue Origin’s BE-3) was problematic because making and handling liquid hydrogen is a particular challenge on Mars. Blue Origin’s next engine, BE-4, is to be powered by a methane-oxygen mixture.

With the pieces in place, (“you’d want about one thousand ships”) Musk believes humanity can place a self-sustaining city of about one million people on the surface of Mars.

Given his earliest attempts to develop a Mars mission, the unveiling was a triumph for Musk, and he was not shy about his own personal investment. Although Musk noted many funding options were available, including Kickstarter and “stealing underpants”—to chuckles from the audience—he said that ultimately it may fall to the investment of SpaceX’s profits to execute the early missions.

“I should mention that the reason I am personally accumulating assets is to fund this.”

Seemingly aware of the irony, Musk suggested that the name of the first spaceship may be “The Heart of Gold,” an homage to Douglas Adam’s Hitchhiker’s Guide the Galaxy.


Joe Mascaro is Program Manager for Impact Initiatives at Planet, a satellite Earth imaging corporation headquartered in San Francisco, CA. The views expressed in this article are the author’s own, and do not reflect the views of Planet.