First Man Into Space (1959)

Starring Marshall Thompson, Marla Landi, Bill Edwards, Robert Ayres, Bill Nagy
Directed by Robert Day
(actor & director credits courtesy IMDB.com)

Test flights probing the edges of the boundary between the Earth and outer space are led by a Navy commander and piloted by his brother, but the pilot's risky decisions lead to tragedy and horror.

As my friend Dan Day, Jr. pointed out, the plot here is more of a variation on The Quatermass Xperiment than an original story, but it's nevertheless well-acted and directed, although elements of the clash between the brothers seem torn from the pages of a soap opera.  Director of photography Geoffrey Faithfull was a fine cinematographer and the scenes where Edwards excitedly views an exquisitely framed star field from his cockpit are breathtaking for the audience as well.  Although this was a British film, and was per IMDB largely filmed at MGM's British studios, it was set at a Navy base in New Mexico, and the filmmakers do an exceptional job of passing their product off as an American film, from changing the names of writers John Croydon and Charles F. Vetter in the credits, to populating the cast with non-Brits including leading man Marshall Thompson and Italian-born leading lady Marla Landi.  The film's greatest similarities to Quatermass come in its second half, where a monster transformed by cosmic radiation preys on human blood, and its climax is nowhere near as well-written or staged as the 1955 Hammer classic, but the performances are still genuine and engaging.  This isn't a great movie but it is an entertaining piece that delivers a monster and a warning about the perils of the unknowns in outer space.