Mid-late 70's movie showing scientists exiting a control room after completing their task into a desert/badlands area [duplicate]

Question

My father was a regular sci-fi genre movie viewer, and I have an unclosed thread in my past that has been haunting me over my years. I woke up as a child to see the following events unfolding on screen:

• scientists, who I believe were in white coats (and presumably about three of them), in a control room (which may have been in a room carved out of rock) utilizing their time or dimensional control machine.
• an exterior view window that looked out upon a desert or badlands panorama.
• same scientists, noting success that their journey/experiment had completed successfully, appear to show smiles of satisfaction.
• scientists exit the room and proceed into the badlands, viewable from the control room, and are visible walking into the environment as the credits begin to roll.

Answer 1

Could this be The Time Travelers, from 1964? Clips visible here. It was also featured in Mystery Science Theater's 11th season. The scientists travel through a portal to the future, which is a standard-issue atomic wasteland. They meet up with the remaining normal humans in their underground base (this may be the rocky control room you're remembering), where they are building a giant space ark to flee the planet.

Scientists open a portal to the future, which is a wasteland:

The scientists:

The wasteland, with mutants: