Douglas Loverro

NASA Associate Administrator for the Human Exploration and Operations Mission Directorate Douglas Loverro is seen during a NASA town hall event on Dec. 3, 2019, at NASA Headquarters in Washington

CAPE CANAVERAL, Fla. (AP) — NASA’s chief of human exploration has resigned just days before the first astronaut launch in nearly a decade from Kennedy Space Center.

The space agency notified employees of the news Tuesday.

Douglas Loverro, whose resignation took effect Monday, joined NASA last October. He is a former Defense Department and National Reconnaissance Office manager, specializing in space security matters for three decades.

NASA spokesman Bob Jacobs would only say Loverro decided to resign and, beyond that, the agency cannot discuss personnel issues.

The announcement comes just eight days before SpaceX attempts to launch its first astronauts under NASA’s commercial crew program. Liftoff is scheduled for May 27.

Besides overseeing SpaceX and Boeing's effort to ferry NASA astronauts to the International Space Station, Loverro was in charge of NASA's Artemis moon-landing program. Just 2 1/2 weeks ago, NASA announced the three winning corporate teams that will develop lunar landers for astronauts.

Former space shuttle commander Ken Bowersox, Loverro's deputy, will resume his role as acting associate administrator of human exploration and operations.