NASA is losing four key senior officials close to its flagship moon program, according to people familiar with the changes, adding more uncertainty over the agency's space exploration trajectory as Elon Musk and President Donald Trump play up missions to Mars.

Should it continue the Artemis program and establish a lunar base, or shift its focus directly to Mars? While using the Moon as a stepping stone could be a more efficient approach, a direct Mars mission would be faster but far riskier.

Though Artemis was conceived in President Donald Trump's first term, he has openly mused about bypassing the Moon and heading straight to Mars -- a notion gaining traction as Elon Musk, the world's richest person and SpaceX's owner, becomes a key ally and advisor.

Four NASA senior officials working on the agency’s moon program, Artemis, will retire this week. These officials were part of the team that succeeded in launching Artemis I as “the first flight test of the integrated Orion spacecraft and the Space Launch System (SLS) rocket,

The US space agency is losing four senior officials, insiders say, including a key defender of the Artemis missions Nasa is losing four key senior officials close to its flagship moon programme, according to people familiar with the changes,