The Orion Multi-Purpose Crew Vehicle (MPCV) is a partially reusable crewed spacecraft used by NASA for the Artemis lunar exploration program. It consists of a crew module (CM), a space capsule built by Lockheed Martin, and is paired with a European Service Module (ESM) provided by the European Space Agency (ESA) and manufactured by Airbus Defence and Space. Orion supports a crew of four beyond low Earth orbit for up to 21 days undocked or up to six months when docked. It is equipped with a NASA Docking System port and glass cockpit displays. It is intended to be launched atop the Space Launch System (SLS) rocket with a tower-mounted launch escape system. Orion was conceived in the early 2000s by Lockheed Martin as a proposal for the Crew Exploration Vehicle (CEV) to be used in NASA's Constellation program and was selected by NASA in 2006. After the cancellation of the Constellation program in 2010, Orion was extensively redesigned for use in NASA's Journey to Mars initiative; later named Moon to Mars. The SLS became Orion's primary launch vehicle, and the service module was replaced with a design based on ESA's Automated Transfer Vehicle. As of 2026, three flight-worthy vehicles had been built along with several boilerplates and test articles. Three additional flight-worthy vehicles are under construction. In May 2025, the second Trump administration proposed terminating the Orion spacecraft program after Artemis III. The One Big Beautiful Bill Act signed in July 2025 included a provision to fund procurement of Orion for Artemis IV and reuse in future missions.
Design
Orion is based on the configuration of the Apollo command and service module (CSM), with a larger diameter, updated thermal protection system, and modern avionics. It is designed for deep space missions supporting up to 21 days of active crew operations and up to six months of quiescent spacecraft operation. The Orion crew module launches with the European Service Module, a spacecraft adapter, and a launch abort system. The Orion crew module (OCM) is a reusable capsule providing habitable volume, storage for consumables and research equipment, and an International Docking System Standard (IDSS) port for crew transfers. It is the only major spacecraft element that returns to Earth after each mission and is designed for refurbishment and reuse, with modular systems intended to support incremental upgrades over time.
Structure and manufacture The OCM is built of aluminum-lithium alloy and has a 57.5° frustum shape with a blunt spherical aft end, 5.02 meters (16 ft 6 in) in diameter and 3.3 meters (10 ft 10 in) in length, with a mass of about 8.5 metric tons (19,000 lb). The module provides approximately 50% more internal volume than the Apollo command module and is designed to carry four astronauts on Artemis missions. It is manufactured by Lockheed Martin, with the pressure vessel built at the Michoud Assembly Facility in New Orleans, Louisiana, and final assembly conducted at the Operations and Checkout Building at Kennedy Space Center in Florida.
Thermal protection After evaluation of thermal protection materials, NASA selected AVCOAT for the ablative heat shield. AVCOAT consists of silica fibers embedded in a resin within a honeycomb structure of fiberglass and phenolic resin. It was previously used on the Apollo missions and the Space Shuttle orbiter.
Crew systems and accommodations The OCM uses a glass cockpit with digital control systems derived in part from those used in the Boeing 787 Dreamliner. The commander and pilot are seated facing three main display screens and seven switch panels within arm's reach, which provide spacecraft status information and allow control of onboard systems. A cursor control device enables interaction with the display screens under high g-forces, when the crew can not easily reach out. The interface supports both routine operations and anomaly response through integrated electronic procedures and warning systems. Rotational and translational hand controllers enable the crew to manually adjust the spacecraft's orientation and movement. The four crew seats are designed to accommodate a wide range of astronaut body sizes, from approximately the 1st to the 99th percentile, and are adjustable. For launch and re-entry, astronauts are positioned on their backs with knees bent at a 90-degree angle and feet secured in foot pans. Each seat incorporates a five-point harness, headrests, and shoulder and hip bolsters, with foot restraints that interface with crew footwear to limit movement. The seats include an impact attenuation system, which reduces loads during splashdown by allowing controlled motion along guide rails. Once in orbit, the foot pans on the commander and pilot seats are removed and stowed to increase cabin space, and a cargo net over the mission specialist seats provides storage for equipment and suit components. The spacecraft operates with a mixed nitrogen/oxygen (N2/O2) atmosphere at either sea-level pressure (101.3 kPa or 14.69 psi) or a reduced pressure (55.2 to 70.3 kPa or 8.01 to 10.20 psi). As of 2019, the Spacecraft Atmosphere Monitor was planned to be used in the OCM.
The OCM includes the compact Orion flywheel exercise device, which allows astronauts to perform aerobic and resistance exercises during flight using a cable-driven flywheel mechanism. The system was designed to meet the spacecraft's mass and volume constraints while also allowing for a wide-range of exercises. Mounted below the side hatch, it also functions as a step for crew members entering or exiting the spacecraft. The OCM includes a space toilet called the Universal Waste Management System (UWMS) inside a fully enclosed 5-square-foot (0.46 m2) compartment for privacy that uses airflow to manage liquid and solid waste. Solid waste is stored in sealed containers, while treated liquid waste is vented overboard. The potable water dispenser supplies water for rehydrating food, preparing drinks, and supporting medical needs in Orion. It connects to four pressurized tanks in the service module. A briefcase-style food warmer plugs into Orion's power utility panel for operation and allows the crew to heat food and beverages. It can be secured to cabin surfaces using Velcro when needed and stowed when not in use.
Launch and recovery
… excerpt ends here. Continue reading the full article.
