After two decades of doing public affairs for the US Army, Robert Mirelson knows how vital it is to be open and accessible. As Kimberly Krautter reports, he has taken those qualities to NASA.

His blue worsted wool suit is military crisp and telegraphs efficiency. His manner is quiet and circumspect. But his eyes evince the responsibilities he has shouldered. Retired US Army Colonel Robert N. "Doc" Mirelson spent the past three decades managing the public face of military affairs across ...