Dragon is a free-flying spacecraft designed to deliver both cargo and people to orbiting destinations. It is the only spacecraft currently flying that is capable of returning significant amounts of cargo to Earth. Currently Dragon carries cargo to space, but it was designed from the beginning to carry humans. The first demonstration flight under NASA's Commercial Crew Program launched on March 2, 2019 at 2:49 a.m. ET. The Dragon spacecraft successfully docked with the space station ahead of schedule at 6:02 a.m. ET on March 3, 2019, becoming the first American spacecraft in history to autonomously dock with the International Space Station.

The Dragon spacecraft is capable of carrying up to 7 passengers to and from Earth orbit, and beyond. The pressurized section of the capsule is designed to carry both people and environmentally sensitive cargo. Towards the base of the capsule and contained within the nose cone are the Draco thrusters, which allow for orbital maneuvering.

Dragon’s trunk not only carries unpressurized cargo but also supports the spacecraft during ascent. The trunk remains attached to Dragon until shortly before reentry into Earth’s atmosphere.

Falcon Heavy draws upon Falcon 9’s proven design, which minimizes stage separation events and maximizes reliability. The second-stage Merlin engine, identical to its counterpart on Falcon 9, delivers the rocket’s payload to orbit after the main engines cut off and the first-stage cores separate. The engine can be restarted multiple times to place payloads into a variety of orbits including low Earth, geosynchronous transfer orbit (GTO) and geosynchronous orbit (GSO).

Three cores make up the first stage of Falcon Heavy. The side cores, or boosters, are connected at the base and at the top of the center core’s liquid oxygen tank. The three cores, with a total of 27 Merlin engines, generate 22,819 kilonewtons (5.13 million pounds) of thrust at liftoff. Shortly after liftoff the center core engines are throttled down. After the side cores separate, the center core engines throttle back up to full thrust.