What were the "7 minutes of terror" that the nasa scientists had to go through?

I’m not totally positive but I think that if this is in reference to early space travel, it may be referring to when they went around the backside of the moon because satellite communication wouldn’t work there. So the scientists would have been completely out of communication when the astronauts orbited the back side of the moon. For the first time especially, whether they had died or just lost communication may have been unknown

Cuz i said so. which gives it to b