Could it be from the 1967 movie Countdown?
I have wanted, and never found, that movie ever since I could buy DVDs, so can't help. But can exclude the 1969 movie
Marooned with its bad acting and highly-variable special effects. The command module in
Marooned doesn't have a window frame that protrudes as far from the surface of the CM at the end of the clip on Nixon's TV.
The clip certainly looks cinematic, right down to the second astronaut who has a hint of flesh colour in his face and looks a bit like he's standing, courtesy of gravity, beyond the first one. Note also the rather small, white docking mechanism at the front of the CM.