He was the son of teacher Bredo Henriksen (1888–1974) and Edna Lucy Brahde Davidsen (1891–1967).
He fought in the Norwegian Campaign in 1940, and during the subsequent German occupation of Norway he was a member of the clandestine resistance group XU.
In this position, he was responsible for the construction of Harestua Solar Observatory north of Oslo.
He lectured in celestial mechanics and spherical astronomy, and also researched optics related to astronomical instruments as well as calculating the tidal force and the lunar eclipse.
He also published popular science books and articles, he was a common guest in radio and television programmes and provided commentary for the Norwegian Broadcasting Corporation during the television coverage of the Apollo 11 Moon landing.