Rendering of Dragon approaching the International Space Station. Image credit: SpaceX.
Dragon is a reusable spacecraft being developed by SpaceX as a successor to the Space Shuttle with funding from NASA's Commercial Orbital Transportation Services (COTS) and Commercial Crew Development (CCDev) programs. In December 2008, NASA announced the selection of SpaceX's Falcon 9 launch vehicle and Dragon spacecraft to resupply the International Space Station (ISS) following the retirement of the Shuttle. The $1.6 billion contract represents a minimum of 12 flights, which are scheduled to start in late 2010.
Dragon consists of a pressurized capsule and an unpressurized "trunk" used for Earth to low Earth orbit (LEO) transportation of pressurized cargo, unpressurized cargo, and/or up to 7 crew members. It has three main elements: the nose cone, which protects the vessel and the docking adaptor during ascent; the spacecraft, which houses the crew and/or pressurized cargo as well as the service section containing avionics, the RCS system, parachutes, and other support infrastructure; and the trunk, which houses unpressurized cargo and supports Dragon's solar arrays and thermal radiators. Although current operation calls for a water landing, SpaceX intends to develop a thruster system that would eventually allow Dragon to make a soft touch-down on land.
Landmarks in the development of Dragon
In 2010, SpaceX placed an unmanned Dragon capsule in orbit thus achieving a first for a commercial enterprise. In May 2012, the company achieved another first in private spaceflight when a Dragon capsule docked with the ISS before returning to Earth with safe splashdown. It took half a ton of food and supplies up to the ISS astronauts, and brought down about two-thirds of a ton of completed experiments and redundant equipment.
In August 2012, SpaceX learned that it was to get a further $400 million of funding from NASA to develop a life-support system to enable crewed missions and also a means of escape so that if a serious problem developed with the Falcon launch vehicle, the Dragon capsule could separate early and return safely to Earth.
In October 2012, a SpaceX Dragon returned to Earth, ending the first commercially contracted re-supply mission to the ISS. The robotic ship was launched on October 7, with 400kg of food, clothing, experiments, and spares for the orbiting platform's six astronauts, and docked three days later. On its return, the capsule carried broken machinery and medical samples gathered by the astronauts aboard the ISS over the course of the past year.