There was such an episode in the '60s, the only other episode in that series with Dr. Tenma in it. Astro meets Tobio (who didn't die in that alternate universe, so there WASN'T and Astro in it either).
Mystery of the Metal Men . . . hmmm is being blown into an alternate universe the same as time travel? It really was an "alternate" universe, because Tobio was whiny and wimpy . . . so he was too scared to be driving recklessly in a robot car to get killed off and turned into a robot!!
I wonder what happened after Atom inspired him to be more "gutsy."
That was a very cool episode. 
