What is SpaceX's Falcon 9?

Falcon 9 takes its name from the Millennium Falcon in Star Wars and from the number of engines on its first stage: nine Merlin 1D engines burning RP-1 kerosene and liquid oxygen, producing about 7,600 kN of thrust at liftoff. The second stage carries a single vacuum-optimized Merlin. At 70 m tall and 3.7 m in diameter, it can place about 22.8 t into low Earth orbit if the first stage is expended, and somewhat less if it returns to land. A 5.2 m payload fairing protects the cargo, which can be a satellite, a batch of Starlink satellites, or the Dragon capsule.

The first Falcon 9 launched on June 4, 2010 from Cape Canaveral. The design has grown since then: the 1.1 version in 2013 stretched the tanks and engines, the Full Thrust version in 2015 subchilled the propellants to gain density, and Block 5 in 2018 locked in the current configuration, designed for ten flights without deep refurbishment and many more with inspections. On December 21, 2015, a first stage landed on the ground for the first time; in March 2017, a previously flown stage launched again with a commercial payload.

Reusability changed the economics of the industry. First stages are recovered on land or on barges, and some have flown more than twenty missions; fairings are also recovered from the sea. This pace let SpaceX deploy the Starlink constellation, carry astronauts to the International Space Station since 2020 with the Crew Dragon capsule, and perform more than a hundred launches a year, unprecedented figures for a single rocket model (as of September 2026). Three first stages joined together form the Falcon Heavy.