NASA prepares for the first crewed flight of the Orion spacecraft with the goal of confirming that all of the spacecraft’s systems operate as designed in the actual deep space environment. (Photo : Joe Raedle/Getty Images)

NASA is gearing up for the first crewed flight of the Orion spacecraft, which marks a significant step forward on the "Journey to Mars."

The mission involves confirming whether all of the spacecraft's systems are working as designed in an actual deep space environment. According to NASA, this will be their first crewed mission in a series of missions in the proving ground, which is an area of space around the moon where crew can build and test systems needed to prepare for the challenge of missions to Mars.

"Like every test flight, we will have test objectives for this mission both before and after we commit to going to the moon," Bill Hill, deputy associate administrator for Exploration Systems Development at NASA's Headquarters in Washington, said in a statement.

"It's just like the Mercury, Gemini, and Apollo programs, which built up and demonstrated their capabilities over a series of missions. During this mission, we have a number of tests designed to demonstrate critical functions, including mission planning, system performance, crew interfaces, and navigation and guidance in deep space."

The test flight is built around a concept called multi-translunar injection (MTLI) or multiple departure burns, in which the Orion spacecraft and its Exploration Upper Stage (EUS) will be placed initially into an elliptical orbit around the Earth with an apogee of 35,000 kilometers. After spending a day in the orbit, the spacecraft will separate from the EUS and use its service module engine for a final burn that will fly the spacecraft to the moon, NASA said.

Orion will fly on a "free return" trajectory around the moon without going into orbit and without the need for another engine burn. The mission will return to Earth eight days after launch but could be extended to up to 21 days to complete additional flight test objectives.

According to Space News, the approach differs from the earlier concepts for Exploration Mission 2 (EM-2), which was initially planned to last 9 to 13 days. But the new mission plan takes consideration the risks associated with the flight.

"We've effectively designed this mission to be commensurate with the amount of risk we're taking with crew on the vehicle for the first time," Bill Gerstenmaier, NASA associate administrator for human exploration and operations, said in a report. "We've tailored the mission to be appropriate with the risk we're willing to take."

According to Gerstenmaier, one specific issue is that testing the spacecraft's life support system in Earth orbit first reduces the risks of problems if it does not work. The use of a free return trajectory will also minimize the risk, with Orion flying around the moon and back to Earth without the need to perform an engine burn.