Acting NASA Administrator Robert Lightfoot has named the Science Mission Directorate’s Planetary Science Division Director Jim Green as the agency's new chief scientist, effective May 1. He succeeds Gale Allen, who has served in an acting capacity since 2016 and will retire after more than 30 years of government service. "I want to thank Gale for all Acting NASA Administrator Robert Lightfoot has named the Science Mission Directorate’s Planetary Science Division Director Jim Green as the agency's new chief scientist, effective May 1. He succeeds Gale Allen, who has served in an acting capacity since 2016 and will retire after more than 30 years of government service. "I want to thank Gale for all