SpaceX founder Elon Musk has suggested that his company could launch the next-generation Starship rockets -- which he hopes will eventually -- for much less than it costs NASA to send rockets aloft. Getting SpaceX's "fully reusable" system to orbit will take $900,000 worth of propellant, Musk said earlier this week, according to Space.com.
Factoring in operational expenses, the cost will be "like $2 million," he told US Air Force Lt. Gen. John Thompson, at the Air Force's Space Pitch Day, "much less than even a tiny rocket."
On Thursday, Musk offered more detail in a response to a Twitter follower.
"The economics have to be something like that to build a self-sustaining city on Mars," he wrote, before noting that "a thousand ships" will be needed to create such a settlement.
In September, Musk said SpaceX's Starship could make its first trip into orbit within six months -- an early version had some successful tests over the summer. He provided a tour of the rocket last month.
SpaceX didn't offer any further comment.
First published Nov. 7 at 5:33 a.m. PT.
Updated Nov. 8 at 6 a.m. PT: Adds Musk tweet.