I don't believe that. I'm sure there were some other scientific minds capable of rigging a foil to prevent detection.
9 seconds sound clip from the Robot Monster (1953) movie soundboard.
You can hear this line at 00:19:14.612 in the Blu-ray version of the movie.
Quote context
[...]
- Maybe we could kill him, huh, Pop?
- No, Johnny. The armies of the entire world tried and failed.
- We have thrown everything we had at him, but he's impervious.
- Unless we can find his weak spot.
- Could I have just a little water, Mom?
- If we only could find a way, only one way of communication with each other.
- Do you think we still have a garrison on the space platform? Ro-Man hasn't destroyed that yet.
- Well... It could be. If we only could get through to them.
- But why should we succeed where others failed?
[...]