A cutaway drawing that imagines the inside of Elon Musk’s Big Falcon Spaceship. SpaceX plans to build and use the vehicle for the first crewed Mars missions. Copyright of Nick Oberg

Elon Musk, the founder of the rocket company SpaceX, has “aspirational” plans to launch people to Mars in 2024 and ultimately colonize the red planet.

To make the roughly six-month one-way journey, Musk and his engineers have dreamed up a 347-foot-tall launch system called the Big Falcon Rocket, or BFR. The spacecraft is designed to have two fully reusable stages: a 19-story booster and a 16-story spaceship, which would fly on top of the booster and into into space.

SpaceX employees are now building a prototype of the Big Falcon Spaceship at the Port of Los Angeles. Gwynne Shotwell, the company’s president and COO, reportedly said Thursday that the spaceship may start small test-launches in late 2019.

Several official graphics of the spaceship’s internal structure exist, but none show exactly how the ship would be equipped for Mars. So spaceflight-loving artist Nick Oberg created his own illustration of how the vehicle might look and function on the inside.

Oberg is a 29-year-old scientist at the University of Groningen in the Netherlands, where he’s working toward a PhD in astrophysics. But he used some spare time to make what he calls an “imaginative” cutaway drawing of the BFR spaceship. It includes detailed sketches of hydroponic greenhouses, messy crew cabins, and even a person pooping on a zero-gravity toilet.