How long starship to mars?

Earth and Mars line up for an efficient transfer only about every two years, and the crossing itself takes months on any practical trajectory: the spacecraft coasts along an ellipse that leaves Earth's orbit and meets Mars where the planet will be on arrival. A typical robotic cruise runs about seven months — Perseverance left Earth on 30 July 2020 and landed on 18 February 2021. Depending on the geometry of a given window and how much energy the launcher can spend, the flight ranges from roughly six to nine months. Missing a window does not cost weeks; it costs the better part of two years.

Starship is designed to change the mass delivered, not the clock. Its architecture rests on refuelling in low Earth orbit from tanker flights, so that a fully loaded ship departs with enough propellant to land tens of tonnes on the surface and, eventually, to return using propellant manufactured there from local water and carbon dioxide. Orbital propellant transfer is the pivot of the whole plan: without it the payload to Mars collapses. Arrival relies on aerobraking through the thin Martian atmosphere followed by a propulsive landing.

No Starship has yet flown to Mars, and the sequence that would make it possible — a reliable orbital flight profile, then ship-to-ship propellant transfer, then an uncrewed landing — had not been completed as of early 2026. SpaceX has repeatedly aimed at the nearest available window and those targets have repeatedly moved. A crewed flight would add a further constraint that no propulsion system removes: the crew must wait on the surface for the return window, turning a seven-month journey into a mission measured in years.