Future of NASA: Who Will Take Over After Acting Administrator Robert Lightfoot Retires?

NASA's acting administrator Robert Lightfoot announced Monday that he will retire from the agency on April 30. Lightfoot has held the position of acting director since January 20, 2017, when the former administrator, Charles F. Bolden, resigned.

Under President Donald Trump, NASA has been given aggressive directives to return humans to the moon and find ways to explore deep space and Mars. Trump reinstated the National Space Council with Vice President Mike Pence as the chairman and gave the agency the task of returning to the moon.

In the letter sent to NASA employees by email, Lightfoot wrote that he would work with the White House to help transition the agency to the new administrator. He did not say who that person would be.

Trump's pick for administrator, former Congressman Jim Bridenstine, has been stalled for months. During a Senate confirmation hearing in November, Bridenstine was grilled about his views on climate change, NASA's research and whether he would treat everyone at the agency fairly, based on his past support of bills that discriminated against the LGBT community, The Washington Post reported.

The Senate committee confirmed Bridenstine in January but the full Senate vote is still on the Senate executive calendar.

Lightfoot thanked everyone at NASA for their support, hard work and determination. "NASA's history has many chapters with each of us having a part. I've written my part and now the pen is in your hands—each one of you," he wrote.

NASA currently has several vacant top administrative positions, according to the agency's organization structure. The second highest position at NASA, the position of deputy administrator, is vacant, as is the position of chief of staff. Additionally, the position of associate administrator is being temporarily filled by Steve Jurczyk.