Who played Professor Hastings?

Over the past few years, IMDb has gradually added many of the unbilled character actors who appeared in Destination Moon, after initially listing only the five named cast members and one or two others. But there's one crucial actor still unnamed and unlisted on their "full cast and crew" page: the man who played Professor Hastings.

We see Hastings a couple of times in the pre-launch sequences -- telling Cargraves that if he can increase the engine thrust a little, they can make the trip in two days instead of four, and later seeing the men off as they jump on the gantry to escape the officer trying to serve the warrant to halt the take-off ("I wish you had room for me on the trip"). But he's heard a lot after the crew gets to the moon -- he's the man they communicate with about their efforts to lighten the ship's weight. And earlier, when Barnes decides to plunge ahead and take off right away, and Cargraves says that they're stuck because working out the ballistics for the trip is a week's work, Barnes asks him, "You think Professor Hastings is pretty good, don't you?" Barnes brightens and replies, "Best in the world." So obviously this is a very important character, and we see or hear him more than most of the other supporting players.

But -- he remains unlisted. The actor looks slightly familiar but I think I'm confusing him with other performers. He also sounds vaguely familiar. But in any case, it's odd that no one has stated who he is.

Anybody know?