Sunday Cinema: “Doomsday Machine” (1972)
Doomsday Machine is a 1972 SciFi film starring Denny Miller, Ruta Lee, Grant Williams, Mala Powers, Henry Wilcoxon and Bobby Van.
From the YouTube description:
Spies discover that the Red Chinese have built a “doomsday machine” capable of destroying the surface of the Earth, and that they plan to use it within a matter of days. Meanwhile, Project Astra, a manned U.S. space mission to Venus, is in its final hours before launch when it is taken over by the military and nearly half of its all-male crew is replaced by women.
https://www.youtube.com/watch?v=fIjKTXd1VZU
No dialog for the first 5m 50s. At 9m39s Mike Farrell asks the first question as a reporter. At 12m35s and often thereafter Casey Kasem appears as an Air Force lieutenant colonel. Without a doubt, the dumbest ending I have ever seen.