https://techcrunch.com/2020/05/19/nasas-chief-of-human-spaceflight-doug-loverro-resigns-days-before-historic-crewed-mission/

Doug Loverro, NASA’s Associate Administrator for Human Exploration and Operations, has abruptly and unexpectedly resigned from his post, just days before a historic launch. Commercial Crew Demo-2 will take astronauts to the ISS aboard an American spacecraft for the first time since the Space Shuttle was retired, and Loverro was deeply involved.

The reasons for Loverro’s departure are not clear, but they must be very compelling for him to leave at this crucial moment when a program he oversaw is entering its final stages. Loverro came in as head of HEO in October, following the reassignment last summer of Bill Gersteinmaier, who led it for many years and reportedly left after clashing with NASA Administrator Jim Bridenstine.