The transportation ship itself is probably the most controversial part of Musk’s plan. He wants the vehicle to be reusable 1,000 times, with up to 100 people on board. And he doesn’t want just one. Oh no.
“You would ultimately have upwards of 1,000 or more spaceships waiting in orbit,” he said. “Hence, the Mars Colonial fleet would depart en masse.”
The ships will need to be big, he says, to get enough people and cargo to Mars: “[T]o build everything from iron foundries to pizza joints to you name it – we need to carry a lot of cargo.”
And getting a million people on Mars eventually would be no mean feat. Assuming you go every two years, when Mars and Earth align for easy transit between them (Musk envisions travel time as short as 80 days with his system), you’d need 10,000 trips with 100 people on each ship. That’s quite a lot – although he notes that could be upped to 200.
“[I]t would take 40–100 years to achieve a fully self-sustaining civilization on Mars,” he says.
The giant rocket itself would be made of an advanced carbon fiber, presumably to keep weight down while still remaining kind of strong. It would ultimately be capable of lifting about 500 metric tonnes (550 US tons) in expendable mode (where the rocket is not recovered), and 270 tonnes (300 tons) in reusable mode. The Saturn V for comparison, the biggest rocket launched to date, could lift 140 tonnes (155 tons).
There are plenty more interesting tidbits in the paper, so it’s worth a read if you felt Musk’s talk was a bit light on some of the science involved in this endeavor.
He admits that they were “intentionally fuzzy” on when this might all happen. In four years, he plans to complete the first “development spaceship”. In 10 years, if things go “super-well”, the first Mars colonization missions could begin.
“There is a good chance we will not succeed, but we are going to do our best and try to make as much progress as possible,” says Musk. And it might not just be Mars – he has grander plans for sending people to Jupiter’s moons Europa and Enceladus, or Saturn’s moon Titan, or even Pluto.
“[Y]ou could travel out to the Kuiper Belt, to the Oort cloud,” he writes. “I would not recommend this for interstellar journeys, but this basic system – provided we have filling stations along the way – means full access to the entire greater solar system.”
Maybe let's take a few baby steps first though, eh?