What is it?: A spacecraft design currently under development by NASA. Each Orion spacecraft will carry a crew of four (for ISS missions) to six astronauts (for Lunar missions), and will be launched by the Ares I (see previous Space Tech of the Week). Both Orion and Ares I are elements of NASA's Project Constellation, which plans to send human explorers back to the Moon by 2020, and then onward to Mars and other destinations in the Solar System.
"Orion will launch from Launch Complex 39 at Kennedy Space Center, the same launch complex that currently launches the Space Shuttle." The first Orion flight to the ISS is currently scheduled for 2015, but delays are expected. If commercial orbital transportation services (by Space X with its Dragon capsule) are unavailable, Orion will handle logistic flights to the Station.
"The Orion Crew and Service Module (CSM) stack consists of two main parts: a conical Crew Module (CM), and a cylindrical Service Module (SM) holding the spacecraft's propulsion system and expendable supplies. Both are based substantially on the Apollo Command and Service Modules (Apollo CSM) flown between 1967 and 1975, but include advances derived from the Space Shuttle program."
During the early phases of its development Orion was going to have the capability land on land (like the Soyuz) as well as on water (like Apollo, Gemini, and Mercury). Since then, due to weight issues, water landings have become the only method of recovery for this spacecraft.
"Another feature will be the partial reusability of the Orion CM. NASA aims to reuse each craft for up to ten flights." "Both the CM and SM will be constructed of the aluminium lithium (Al/Li) alloy currently used on the Shuttle's External Tank, and the Delta IV and Atlas V rockets. This alloy is as strong as the Shuttle Orbiter's aircraft aluminium skin, but will make the spacecraft lighter than both its Apollo and Shuttle predecessors."
"Like its Apollo predecessor, the Orion Service Module (SM) has a rough cylindrical shape, but unlike its Apollo predecessor, the new Orion SM will be larger in diameter, shorter, and lighter. It too will be constructed from the same Al-Li alloy as the Orion CM, and will feature a pair of deployable circular solar panels, similar in design to the solar panels on the Mars Phoenix lander, eliminating the need to carry fuel cells and the associated hardware—mainly tanks containing liquid hydrogen [LH2]—needed for their operation. The spacecraft's main propulsion system is an Aerojet AJ-10 rocket engine, derived from the second stage of the Delta II rocket, powered by hypergolic fuels, that are kept in helium pressured fuel cells. "
Official NASA site
Official Lockheed Martin site