Similar in shape to the Apollo spacecraft, Orion is designed to carry up to six astronauts to destinations such as the moon or Mars. Orion is a significant upgrade from Apollo — the spacecraft is newer and much larger than Apollo, and sports electronics decades more advanced than what Apollo's astronauts used to fly to the moon.
When it carries crews, Orion will fly in tandem with NASA's planned Space Launch System, a next-generation booster designed to bring astronauts out of low-Earth orbit again. Orion's first test flight, however, used a United Launch Alliance Delta 4 Heavy rocket.
Lockheed Martin is the prime contractor for the spacecraft. The company began work on the spacecraft in 2004 during a competition for the contract, which was valued at up to $8.15 billion when Lockheed Martin won it in August 2006.
Orion was originally built for NASA's Constellation program that was intended to bring humans to the International Space Station, the moon and, ultimately, Mars. The program was canceled in 2010 after President Barack Obama's administration requested that NASA focus on other goals.
At that point, NASA had already spent $5 billion on developing Orion and Lockheed had been working on the spacecraft for about six years. In early 2011, NASA hinted that the Orion spacecraft could be repurposed for their new directive. The agency followed up with a plan for the Multi-Purpose Crew Vehicle — one that was relatively close to the previous Orion spacecraft design, but instead could be used for the new mandate.
"We made this choice based on the progress that's been made to date," Doug Cooke, associate administrator for NASA's Exploration Systems Mission Directorate in Washington, D.C., said to reporters on May 24, 2011. "It made the most sense to stick with [the Orion design]." [The Orion Capsule: NASA's Next Spaceship (Photos)]
The Orion spacecraft consists of a gumdrop-shaped capsule and service module, which together are about 26 feet (8 meters) long with a diameter of 16.5 feet (5 m). The spacecraft's habitable volume is 316 cubic feet (8.95 cubic meters), which is about 1.5 times larger than the Apollo spacecraft.
Orion's crew module is just one of several components of the spacecraft. Orion also contains a launch- abort system to pull astronauts away from the spacecraft with escape rockets should something go wrong during launch.
The service module, built by the European Space Agency, contains solar panels for electricity, oxygen for breathing and rocket engines to propel the spacecraft. Orion also includes a spacecraft adapter (which shields the service module during launch) and an instrument unit that includes the guidance and control system for the booster. [Infographic: Orion Explained: NASA's Multi-Purpose Crew Vehicle]
First test flight and beyond
Orion's first uncrewed test flight, known as Exploration Flight Test-1, or EFT-1, launched on Dec. 5, 2014. This test flight marked the first time a spacecraft built for humans has flown outside low-Earth orbit in more than 40 years — since the last mission of the Apollo program in 1972.
The space capsule seemed to perform almost flawlessly during its 4.5-hour test flight, NASA officials said. Orion soared 3,600 miles (5,800 kilometers) above Earth before turning around for a high-speed re-entry. The parachutes and huge heat shield on Orion worked well during flight. The spacecraft beamed back some amazing images of the limb of the planet from its window during the test before it splashed down in the Pacific Ocean. [See photos from Orion's first test flight]
NASA originally planned the next Orion flight in 2017, aboard the Space Launch System rocket, but as of late 2018 the schedule has slipped to at least 2020 — with talk that it could be delayed even further.
NASA's Office of the Inspector General published a report in 2018 that said the SLS is behind schedule and over budget. The report cited numerous issues behind the SLS development, including overoptimistic development schedules, weather problems and technical snags.
Meanwhile, testing and development on the Orion spacecraft is ongoing, with some of the major milestones in 2018 including a successful last parachute test, the installation ofthe heat shield and completion of the pressure vessel.
Eventually, one of Orion's destinations could be NASA's Lunar Orbital Platform-Gateway, a lunar space station under development for deployment in the mid-2020s.