Elon Musk has said SpaceX is shifting its near-term focus from Mars to building a self-sustaining city on the Moon, citing faster timelines and more frequent launch windows. The update came through a series of posts on X.
Musk responded to a user who questioned rumors that SpaceX was stepping back from Mars during the current Earth-Mars launch window.
“For those unaware, SpaceX has already shifted focus to building a self-growing city on the Moon, as we can potentially achieve that in less than 10 years, whereas Mars would take 20+ years,” said Elon Musk.
The main constraint, Musk said, is orbital mechanics. Travel to Mars is only practical when Earth and Mars align roughly every 26 months, with a journey time of about six months. In contrast, missions to the Moon can launch every 10 days and reach their destination in around two days. That difference allows SpaceX to test systems, fix failures, and scale operations far more quickly on the Moon.
Musk said SpaceX still plans to begin building a Mars city within five to seven years. However, he said the Moon is the faster path to securing humanity’s long-term survival beyond Earth. Frequent launches and shorter travel times make the Moon a more forgiving proving ground for life-support systems, habitats, and in-space logistics.

