Orion - Crew Exploration Vehicle

Orion will be capable of carrying crew and cargo to the International Space Station. It will be able to rendezvous with a lunar landing module and an Earth departure stage in low-Earth orbit to carry crews to the moon and, one day, to Mars-bound vehicles. Orion will also serve as the Earth entry vehicle for lunar and Mars returns. The vehicle borrows its shape from capsules of the past; however, it takes advantage of 21st century technology in computers, electronics, life support, propulsion and heat protection systems.

Orion will be similar in shape to the Apollo spacecraft, but significantly larger. The Apollo-style heat shield is the best understood shape for re-entering Earth's atmosphere, especially when returning directly from the moon. Orion will be 5 meters (16.5 feet) in diameter and have a mass of about 22.7 metric tons (25 tons). Inside, it will have more than two-and-a-half times the volume of an Apollo capsule. This larger size will allow Orion to accomodate four crew members on missions to the moon, and six crew members on missions to the International Space Station or Mars-bound spacecraft. It is scheduled to fly its first missions to the space station by 2014 and carry out its first mission to the moon by 2020.

A launch abort system atop the Orion capsule will be capable of pulling the spacecraft and ints crew to safety in the event of an emergency on the launch pad or at any time during ascent. Orion's power and propulsion systems will be housed in a service module that will be mounted directly below the capsule, covering the entry heat shield during launch and in-space activities. A spacecraft adapter will connect the Orion capsule and service module to the launch systems.

Orion will be launched into low-Earth orbit by the Ares I crew launch vehicle. To maximize the crew’s safety, Orion and its abort system will be placed at the top of the Ares I rocket. The rest of the two-stage Ares I will be stacked vertically, below the crew vehicle. This design will virtually eliminate the possibility of debris from the booster striking Orion during ascent.

The vehicle will be able to remain docked to the space station for up to six months, providing a means for the crew to return to Earth at any time. The spacecraft will have the ability to stay in lunar orbit untended for the duration of a lunar surface visit that could be up to six months. Orion will be capable of carrying pressurized cargo to the space station on unpiloted missions.

Orion and its crew will reenter Earth’s atmosphere using a newly developed thermal protection system. Parachutes will further slow Orion’s descent through the atmosphere.