How does the Falcon 9 land?

It's worth clarifying what actually lands: the first stage, the large roughly 41 m cylinder with nine Merlin engines. The second stage, which carries the payload to orbit, remains expendable. The first stage separates at about two and a half minutes into flight, at roughly 70 km altitude and a speed of between 6,000 and 8,000 km/h depending on the mission. From that point it flies on its own, with propellant held in reserve for the return.

Right after separation, cold nitrogen thrusters flip the stage to point its engines in the direction of travel. If the target is a landing zone on land, three engines perform the boostback burn that reverses the trajectory; if the mission demands more performance, this is skipped and the stage continues on a ballistic path toward a drone ship stationed hundreds of kilometers out at sea. Before entering the dense atmosphere, a reentry burn slows the stage down and protects the structure from heat. Four grid fins deployed at the top of the stage steer it during descent, correcting its course with meter-level precision.

A few kilometers from the ground, the landing burn begins, almost always using the center engine. The stage can't hover: even with a single engine at minimum throttle, the thrust exceeds its weight, so the flight computer calculates a maneuver in which the speed reaches zero right as it touches the surface. The four legs, made of carbon fiber and aluminum, deploy in the final seconds. The first time it worked was on December 21, 2015, at Cape Canaveral; the first drone ship landing came on April 8, 2016. Since then the procedure has been repeated hundreds of times, and some stages have flown more than twenty missions (as of September 2026).