For payloads that are too heavy for a single Falcon 9, or that need a lot of energy to leave Earth orbit, SpaceX offers the Falcon Heavy. NASA has used it for several of its most demanding science missions. This article explains how the rocket is built and which heavy payloads it has launched.
How Falcon Heavy is built
According to NASA, the Falcon Heavy first stage consists of three Falcon 9 boosters strapped together: two side boosters and a central booster. An upper second stage on top of the central booster carries the payload. Together, the first stage's 27 Merlin engines produce more than five million pounds of thrust at lift off.
Falcon Heavy payload capacity
According to SpaceX, Falcon Heavy can carry up to 63,800 kg to low Earth orbit, 26,700 kg to geostationary transfer orbit and 16,800 kg to Mars. The rocket is 70 metres tall, and its payload fairing is 13.1 metres high with a diameter of 5.2 metres. See our comparison of launch vehicles for GEO missions.
How a Falcon Heavy flight works
NASA's coverage of the Nancy Grace Roman Space Telescope launch on 30 August 2026 describes the sequence. The two side boosters shut down their engines about 2 minutes and 24 seconds after launch, separate from the centre core and perform a flip manoeuvre and boost back burn to return and land near the launch site. The centre core keeps firing until main engine cutoff, after which the second stage ignites its Merlin Vacuum engine to continue to orbit.
Heavy payloads and deep space missions
- Psyche: launched on 13 October 2023 from Launch Complex 39A at Kennedy Space Center towards a metal rich asteroid, as shown on the cover image.
- Europa Clipper: launched on 14 October 2024 towards Jupiter's moon Europa.
- Nancy Grace Roman Space Telescope: launched on 30 August 2026. Read our article on the Roman launch.
When a heavy launcher makes sense
Heavy launchers are needed when a payload is very massive, when it must be sent directly towards the Moon or other planets, or when it must be placed in high energy orbits. For most small and medium satellites, a Falcon 9 or a rideshare mission is sufficient and much cheaper per mission.
Sources
- NASA: Liftoff of NASA's Psyche and DSOC Experiment
- NASA: Liftoff of NASA's Europa Clipper
- NASA: Roman Space Telescope, Falcon Heavy Side Boosters Begin Return
- SpaceX: Falcon Heavy
Cover image: A Falcon Heavy launches NASA's Psyche spacecraft from Launch Complex 39A, 13 October 2023. Credit: NASA/Aubrey Gemignani (NHQ202310130017), public domain.