President Biden picks former senator and one-time astronaut Bill Nelson to lead NASA

Nelson flew aboard the Space Shuttle Columbia in 1986.

Jeff J Mitchell via Getty Images

President Joe Biden has selected former Democratic senator Bill Nelson to lead NASA, the White House announced on Friday. If approved by the Senate, Nelson will succeed Jim Bridenstine, who vacated the post at the end of Donald Trump's term.

The three-term senator from Florida and Biden ally has long been an advocate of NASA's mandate. In 1986, he flew aboard the Space Shuttle Columbia, becoming the second sitting member of Congress to do so. He was also a vocal critic of Jim Bridenstine's appointment. "This committee has heard me say many times: NASA is not political. The leader of NASA should not be political," he said ahead of a vote that split among party lines.

Nelson will oversee the agency at a critical point in its history. Partway through February, NASA landed Perseverance, its most technically advanced rover to date, on the surface of Mars. Over the new few years, it will explore the planet, searching for signs of ancient life. He will also oversee NASA's attempt to return to the Moon under Project Artemis. The agency currently aims to take humans back to the lunar surface by 2024, an ambitious timeline that NASA may have trouble meeting.

If there's something that could derail Nelson's confirmation hearings, it's his history of support for the Space Launch System (SLS). The project to build a new heavy-lift rocket for NASA is years behind schedule and billions over budget.