• President-elect Donald Trump on Wednesday nominated Jared Isaacman, a private astronaut and the billionaire CEO of Shift4, to be the next NASA administrator.
• Isaacman has led two private spaceflights through SpaceX, including the company's first spacewalk in September.
• "It is the honor of a lifetime to serve in this role and to work alongside NASA's extraordinary team to realize our shared dreams of exploration and discovery," Isaacman wrote in a statement.

President-elect Donald Trump on Wednesday nominated Jared Isaacman, the billionaire CEO of Shift4 who has led two private spaceflights, to be the next head of NASA.

"Jared will drive NASA's mission of discovery and inspiration, paving the way for groundbreaking achievements in Space science, technology, and exploration," Trump wrote in a post on social media.

Isaacman accepted Trump's nomination to be NASA administrator in a statement: "Having been fortunate to see our amazing planet from space, I am passionate about America leading the most incredible adventure in human history."

"It is the honor of a lifetime to serve in this role and to work alongside NASA's extraordinary team to realize our shared dreams of exploration and discovery," Isaacman said.

Isaacman said he plans to leave Shift4 once he's confirmed as NASA administrator. In a letter to Shift4 employees, Isaacman wrote he intends "to remain CEO until my confirmation" and "retain the majority of my equity interest," but will reduce his shareholder voting power.

The National Aeronautics and Space Administration is currently led by Administrator Bill Nelson, nominated in 2021 by President Joe Biden. Nelson did not immediately respond to CNBC's request for comment.

Nelson, a former U.S. Senator, currently oversees NASA's nearly $25 billion budget. During his tenure, the space agency launched the first uncrewed mission under its top priority, the multi-billion dollar Artemis moon program. But subsequent planned crewed missions, ultimately aiming to return U.S. astronauts to the lunar surface, have been heavily delayed and over budget.

Isaacman has led two private spaceflights through SpaceX, in 2021 and 2024, commanding a pair of crews on multiday trips around the Earth.

His spaceflight ambitions have fostered an increasingly close relationship with SpaceX CEO Elon Musk, who has become an influential figure in Trump's administration planning.

Isaacman has previously criticized NASA's Artemis architecture, particularly the program's heavy spending on its expendable SLS rockets and the agency's decision to award a second crewed lunar lander contract to Jeff Bezos' Blue Origin.

"Spend billions on lunar lander redundancy that you don't have with SLS at the expense of dozens of scientific programs. I don't like it," Isaacman wrote in a post earlier this year.

In addition to running payments company Shift4, Isaacman has been leading an effort called the Polaris Program — a trio of missions with increasingly ambitious goals.

The first mission in that program, Polaris Dawn, launched earlier this year and saw Isaacman conduct a brief spacewalk from SpaceX's Dragon capsule — the company's first such extravehicular activity, or EVA, in space.

"Back at home we all have a lot of work to do, but from here, Earth sure looks like a perfect world," Isaacman said during the spacewalk after emerging from the capsule.