NASA’s Artemis I Mission to Moon Nears Completion With Return of Orion Spacecraft

The agency has said it would begin live coverage of the maneuver through its NASA TV site at 11 a.m.

On Saturday afternoon, Orion conducted a propulsion maneuver to ensure the vehicle was on the correct landing course, according to NASA. A final propulsion burn was expected early Sunday morning before Orion entered the Earth’s atmosphere.

As of 7:57 a.m. Sunday, Orion was 38,292 miles from Earth, speeding back to the planet at nearly 7,000 miles per hour, NASA said in a tweet.

The Orion crew module—a gumdrop-shaped vehicle that astronauts are expected to travel in during future Artemis missions—faces a significant test before splashdown. That is because a heat shield on the spacecraft will encounter temperatures of up to 5,000 degrees as it re-enters the Earth’s atmosphere on its journey back from the moon.

Assuming the re-entry goes as planned, a team from NASA and the U.S. Navy will recover the Orion capsule from the ocean.

NASA officials have said gathering data about the heat shield is a major objective for Artemis I, as the current uncrewed test flight is called. The component is designed to protect a vehicle that will carry astronauts in the future.

Testing the heat shield and reaching other goals are “critical things we need to do before we can talk about going to Artemis II,” Jim Free, associate administrator of NASA division focused on developing exploration systems, said during a briefing in August.

“If we don’t get all those, we’ll have a discussion about the risk that remains before we would put crew on Artemis II.”

Artemis is NASA’s program to return astronauts to the surface of the moon and achieve other space-exploration goals. The agency has tapped

Lockheed Martin Corp.

, which developed the Orion spacecraft, SpaceX,

Northrop Grumman Corp.

and other companies to develop vehicles and components for the multiyear effort.

Those contractors continue to work with NASA to start planning future Artemis missions.

On Friday, the space agency said it awarded

Boeing Co.

a contract worth about $3.2 billion to keep manufacturing the main parts of future Space Launch System rockets the agency would use for two future Artemis flights and handle other work for rockets set to be used on missions further down the line.

At least two teams, including one led by

Jeff Bezos

‘ space company, recently submitted bids to NASA to build a second vehicle to transport people to the surface of the moon from lunar orbit and bring them back up on future Artemis missions.

NASA initially struggled to blast off the first SLS rocket used for the current flight, facing repeated fuel leaks before its teams launched the vehicle on Nov. 16 from the Kennedy Space Center in Florida.

Since then, officials at the agency have said the mission has proceeded well, highlighting robust performance of the SLS rocket and Orion’s relatively smooth journey out to orbit the moon and its return so far.

If NASA is able to keep to its current schedule, it will use another SLS rocket in 2024 to blast an Orion spacecraft with astronauts on board to an orbit the moon. The following year, the agency would send astronauts to lunar orbit, where two of them would exit an Orion ship and board a Starship lander developed by SpaceX.

That vehicle from the

Elon Musk

-led company would then take them to the surface of the moon. Space Exploration Technologies Corp., as SpaceX is called formally, hasn’t yet tried to conduct an orbital test flight for Starship. NASA last transported astronauts to the surface of the moon in 1972.

Write to Micah Maidenberg at micah.maidenberg@wsj.com