The “Orion” Multi-Purpose Crew Vehicle (MPCV) is a planned beyond-low-earth-orbit manned spacecraft that is being built by Lockheed Martin for NASA based on designs and tests already completed as part of the now-cancelled Constellation program, development for which began in 2005 as the Crew Exploration Vehicle.

Orion was developed to serve continuous (up to 6 months) space missions. At the beginning his purpose was to explore the moon, after that he was supposed to observe asteroids, and finally it is expected to carry humans to Mars. The spacecraft will be launched to space by the Space Launch System, which is, shortly said, multi-level carrier rocket. Both systems are developed by Lockheed-Martin for NASA and is expected to replace the outdated space shuttles.

As a type of vehicle Orion is Multi-Purpose Crew Vehicle (MPCV) and consists of 3 modules. The crew module houses crew of 4 to 6 members. This module is supplied with auto-docking system, unlike its predecessors which required manual piloted docking. The crew has an atmosphere close to the Earth – mixture of nitrogen and oxygen in balanced proportion. The space for the crew is nearly 9 cubic m. and ensures 21 day long flight, which could be prolonged by adding more service modules. This module will be reusable and could be used for up to 10 launches.

The service module will be the place that provides electric energy and propulsion of the whole complex. It is supposed to be made of aluminum-lithium alloy in order to reduce its weight and after every mission will be discarded. The presence of folding solar panels actually rejects the need for frequently malfunctioning fuel cells. The rocket engine has thrust of 3400kg and is upgraded version of the space shuttle engines.

The Launch Abort System should be used in unexpected cases of emergency. This system will separate the crew module from the launching device in case of breakdown.

via:[wikipedia]