Astronauts Will Only Make One Loop Around The Moon

NASA has scaled back its plans for the first crewed mission of its Orion spacecraft, Exploration Mission 2 (EM-2).

Speaking at a November 30 meeting of the NASA Advisory Council in Palmdale, CA, NASA Associate Administrator for human exploration and operations Bill Gerstenmaier said that the mission is now planned to last eight days with only a single loop around the moon, according to a report from Space News.

Under the revised plan, the Orion spacecraft will perform what is called a multi-translunar injection free minimum mission. It would place the Orion capsule and the Exploration Upper Stage (EUS) in an elliptical orbit around earth with an apogee of about 22,000 miles. Then the final burn of the service module will place the spacecraft on a trajectory to the moon.

After making one loop around the moon, Orion would return to Earth, with the mission lasting a total of eight days. But the agency said it still has the option of extending the mission to 21 days.

Gerstenmaier said that the new plan was developed after the agency gained a better understanding of 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,” he said. “We’ve tailored the mission to be appropriate with the risk we’re willing to take.”

He said a free return will be used because it does not require an engine burn in the vicinity of the moon, an approach that was supported by the committee. Former astronaut Ken Bowersox, interim chair of the NASA Advisory Council, said that revision the approach offered a "more vigorous" test of Orion and the upper stage, and provide an additional layer of safety. “Anywhere after you’ve established an orbit, if you have an EUS failure, the service module should be able to do the burn to get you home,” Bowersox said.

The new plan does not affect the mission profile for EM-1, the uncrewed first flight of Orion and the SLS booster. That mission, planned for 2018, will establish Orion in a distant retrograde orbit around the moon where it will stay for several days. The EM-1 mission is expected to last nearly a month.

(Images provided by NASA)

FMI: www.nasa.gov