Acting NASA Administrator Robert Lightfoot’s announcement today that he will retire on April 30 raises obvious questions about who will lead the agency thereafter. President Trump’s nominee, Rep. Jim Bridenstine (R-Oklahoma), has not been confirmed by the Senate and it is not clear when or if it will go to the Senate floor for a vote. With other top positions at NASA vacant and the first test flights of new commercial crew systems coming up in a few months, the agency seems particularly in need of strong leadership, but the impasse between the White House and the Senate remains.

Lightfoot has been pulling double duty the past 14 months, serving both in his “day job” as Associate Administrator (AA), the third ranking official and top civil servant at the agency, as well as Acting Administrator, the top political position. Today, he announced that he will retire from NASA at the end of next month.

President Trump nominated Bridenstine to be the new NASA Administrator in September 2017 and he was approved by the Senate Commerce, Science, and Transportation Committee in November 2017 and again in January 2018 (the nomination had to be resubmitted when the second session of the 115th Congress began). The votes were 14-13 along party lines, however, and the opposition of at least one Republican Senator, Marco Rubio (Florida), has held up a floor vote. One or two other Republicans also reportedly would vote against the nomination, though they have not spoken about it publicly.

Rubio and his Democratic Florida counterpart Sen. Bill Nelson are leading the opposition primarily on the grounds that Bridenstine is not technically qualified to run the agency at a time when two new human spaceflight systems — SpaceX’s Crew Dragon/Falcon 9 and Boeing’s CST-100 Starliner/Atlas V — are about to begin flight tests this year, and NASA’s own Orion/Space Launch System will do so in 2020. Democrats also object to Bridenstine’s views on climate change and LGBTQ rights.

In a tweet this evening, Vice President Mike Pence, who chairs the White House National Space Council, called for the Senate to confirm Bridenstine after thanking Lightfoot for his service.

Capping nearly 30 years in government, we thank Robert Lightfoot for his service to @NASA & our Nation. @RepJBridenstine would continue @NASA’s important work & the Senate should swiftly confirm him as Administrator to carry on NASA’s proud tradition. — Vice President Mike Pence (@VP) March 13, 2018

Nelson earlier today reiterated his opposition to Bridenstine, however. In a press statement he said the country owes Lightfoot “a debt of gratitude” for his years of “outstanding service and leadership at NASA,” but the President needs to nominate a “space professional,” not a politician, to succeed him.

“[Lightfoot will] surely be missed but I’m confident that there are a number of highly qualified individuals at the agency who can assume his role in the interim and continue the great work being done there to get us to Mars.” “Longer term, the White House needs to nominate a space professional for NASA administrator who will actually garner strong bipartisan support. The current nominee doesn’t have the votes.” — Sen. Bill Nelson

Rep. Lamar Smith (R-Texas), chairman of the House Science, Space, and Technology Committee, also praised Lightfoot’s service in a press release, but did not comment on succession plans.

If no one is confirmed as NASA Administrator before April 30, the White House will need to appoint someone to be Acting Administrator, but there are limitations.

As explained in a Congressional Research Service (CRS) report, pursuant to the Vacancies Act the President cannot, for example, appoint Bridenstine because he has been already nominated for the position. The President may appoint someone who has already been confirmed by the Senate for another position or is a “senior officer or employee” of the agency if that person has served in that position for at least 90 days preceding the vacancy and is at least a GS-15 on the federal pay scale.

The only Senate-confirmed positions at NASA are Administrator, Deputy Administrator and Chief Financial Officer (CFO). All three of those are vacant at the moment, with Lightfoot serving as Acting Administrator and Andrew Hunter as Acting CFO. Jeffrey DeWit has been nominated to be CFO, but he is not confirmed yet.

There are many people in senior positions at NASA at a GS-15 level and above, however. According to NASA Policy Directive 1000.3E, section 1.3.1., the order of precedence when the Administrator slot is vacant is Deputy Administrator, Associate Administrator, Chief of Staff, Center Director of Johnson Space Center, Center Director for Kennedy Space Center, and Center Director of Marshall Space Flight Center.

The Deputy Administrator and Chief of Staff positions are vacant. Steve Jurczyk was just appointed as Acting AA. The Directors of the three centers listed are Ellen Ochoa, Bob Cabana, and Todd May. That does not mean one of them would be appointed, but they are among the options.

The key is that NASA needs strong leadership at this critical time. John Logsdon, Professor Emeritus at George Washington University and founder of its Space Policy Institute, cogently underscored the importance of resolving the impasse in an emailed statement to SpacePolicyOnline.com today: