The newly elected US President Donald Trump has appointed billionaire Jared Isaacman (41), who was the first civilian to go into space as part of the Space X project, as the head of the space agency NASA.

He is a close associate of Elon Musk, whose company SpaceX led the two all-civilian manned missions in which Isaacman participated, the AP reported.

As part of another such mission called Polaris Dawn, Isaacman exited the capsule and performed a spacewalk.

Isaacman, who made his fortune running his electronic payments company, will replace NASA Administrator Bill Nelson, 82, a former Democratic senator from Florida who was appointed by President Joseph Biden.

Isaacman said he was honored by Trump's election and grateful to be able to hold such a position.

He said on the X platform that "having had the good fortune to see our fantastic planet from space, he looks passionately at the leading role of the United States in the most amazing adventure to conquer the cosmos."

During Nelson's tenure, NASA has stepped up efforts to return astronauts to the moon, and the US space agency is counting on Moscow-based SpaceX to land them on the moon's surface with its Starship mega rocket.

NASA has already entrusted Musk's company with transporting astronauts to and from the International Space Station, AP reminded.

Musk congratulated Isakman on the selection via the X social network, describing him as a man of "great ability and integrity," reports Tanjug.