America's New Manned Spacecraft
America's new manned spacecraft—the Shuttle's replacement—is not a NASA designed and built craft. It is a commercial craft provided by a private firm. It made its initial unmanned flight Dec. 8, 2010, completing two orbits, reentering, and splashing down in the Atlantic on target.
Developed and built by Space Exploration Technologies Corporation, known as SpaceX, the Dragon is a multipurpose craft that will function as both a cargo carrier to supply the ISS, and a manned spacecraft to ferry up to seven astronauts to the space station after the Space Shuttle is retired. Its successful orbital flight, reentry and recovery last year brought its entry into service closer than ever, possibly as early as this year to transport cargo to the ISS.
The spacecraft, like NASA’s pre-shuttle spacecraft such as Gemini and Apollo, consists of three sections. First is the spacecraft itself, which will house the crew, or cargo, depending on configuration. Then there is the service section. This contains the avionics and reaction control system (RCS) that provides both attitude control and orbital maneuvering as well as the parachutes for landing. In the drawings below, each section is clearly visible.
The third section is a departure for Dragon. It is called the ‘trunk’ and houses the spacecraft’s unique solar panels. Dragon uses solar panels for its electrical power rather than fuel cells.
Even in manned configurations, the Dragon can carry some unpressurized cargo in the trunk. With a four person crew, pressurized cargo can be carried in the crew module.
Dragon’s capabilities are not limited to just a hop to the ISS. In what SpaceX terms its DragonLab configuration, the spacecraft can fly in space on its own, performing many of the experiments and functions done with the Space Shuttle. The extent of these will have to be tested when flights actually take place.
Dragon reenters the atmosphere like pre-Shuttle craft did. An ablative heat shield protects it from reentry heat. But Dragon’s heat shield is configured as a lifting surface so G-forces can be limited and landing points can be more precise. It is reusable, like the Shuttle, and so less expensive to operate than previous similar spacecraft.