But with the start of World War II, she joined the U. S. Navy WAVES (Women Accepted for Volunteer Emergency Service) in 1942.
She received training in atmospheric science and meteorology and then served as aerological officer at a military facility, the Naval Air Station in Klamath Falls, Oregon, and then in Seattle.
[1] After the war, Hedeman was awarded Goucher's Dean Van Meter Fellowship to pursue graduate studies in astronomy and earn a second master's degree (M.S.)
Working with her colleague Helen Dodson Prince, the pair of astronomers co-authored many papers, some of which are still "considered important in the field of solar research.
"[4] Apparently that trip did not include an exploration of the Panama Canal, which she regretted, until, "at age 86 and accompanied by a niece and nephew, she made that passage as well".