Dragon 2 is a class of partially reusable spacecraft developed, manufactured, and operated by American space company SpaceX, primarily for flights to the International Space Station (ISS). SpaceX also launches private missions, such as Inspiration4 and Axiom Space Missions. There are two variants of the Dragon spacecraft: Crew Dragon, a spacecraft capable of ferrying four crewmembers, and Cargo Dragon, a replacement for the original Dragon 1 used to carry freight to and from space. The spacecraft consists of a reusable space capsule and an expendable trunk module. The spacecraft launches atop a Falcon 9 Block 5 rocket and the capsule returns to Earth through splashdown. It has proven to be the most cost effective spacecraft in history to be used by NASA.