Enlarge / Then Rep. Bill Nelson (D-Fla., at bottom) undergoing zero-gravity training onboard a KC-135 along with other astronaut trainees in 1985. On his right is schoolteacher Christa McAuliffe, who died along with six other crew members in the Challenger disaster. (credit: Bettman | Getty Images) On Monday, a rumor that has simmered in Washington for several weeks boiled to the surface—that former US Senator Bill Nelson, a Democrat from Florida, is a leading contender to become the next NASA administrator. The publication Breaking Defense publicly shared the rumor on Twitter, noting that Nelson has a "strong" relationship with President Biden and understands how Congress works.