In the 1950s they thought that Nevada was very big and that the waste wouldn't even be noticeable.
They also thought the Pacific Ocean was very big and that the waste wouldn't even be noticeable.
Car drivers still think this way with their toxic emissions. It is very human to think 'out of sight out of mind' rather than 'take only photos, leave only footprints', so maybe it is actually fine to trash space with waste.
This... isn't really relevant for space. The amount of emptiness so massively outweighs the quantity of matter and energy it would be literally impossible to utilize a nontrivial portion of the volume available.
The only case in which releasing waste into space is problematic is when it's within a highly-utilized area, for example LEO. In the future, we may potentially use various transfer orbits and/or the Interplanetary Transport Network [1], so we should presumably avoid dumping there, but even within the solar system, the sheer volume of vacuum dwarfs any possible use.
They also thought the Pacific Ocean was very big and that the waste wouldn't even be noticeable.
Car drivers still think this way with their toxic emissions. It is very human to think 'out of sight out of mind' rather than 'take only photos, leave only footprints', so maybe it is actually fine to trash space with waste.