NASA administrator Jim Bridenstine has said he will step down from the position when Joe Biden becomes President of the United States.
Mr Bridenstine was appointed by President Donald Trump and has served as administrator for three years.
Prior to that he was a Republican congressman representing Oklahoma.
He said stepping aside would be in the best interest of NASA under a Joe Biden-led administration.
“What you need is somebody who has a close relationship with the president of the United States. You need somebody who is trusted by the administration … and I think that I would not be the right person for that in a new administration,” Mr Bridenstine told Aerospace Daily.
Under Mr Bridenstine’s leadership NASA has pushed ahead with plans to return people to the moon and potentially establish a base there.
He has also progressed the agency’s embrace of commercial partnerships, including the historic launch of two NASA astronauts to the International Space Station by a private company for the first time.
“We’ve had a lot of success, but it’s because of relationships,” Mr Bridenstine said.
“You have to have those relationships. Whoever the president is, they have to have somebody they know and trust and somebody the administration trusts. That person is not going to be me.”
While he doesn’t plan to stay on, he said there was “political agreement that America needs to do big things in space exploration” and said leading NASA had been “the greatest experience” of his life so far.
“But I am under no illusions,” he said.
“There are a lot of people that can do great work as the NASA administrator.”