Those were other planes. They took them out into the desert and used a giant guillatine machine to cut their fusalage in two so the soviet spy satellites could take pictures of them, after that they were presumably scrapped.
These planes are theoretically still usable, but some of them have been out there for decades and have very old equipment, so they're pretty nearly useless. I don't know if they routenly scrap old planes out of there or not. I know many of them are used for parts for in-service planes, so quite a few are likely in various stages of decomposition. Also, to bring a plane back, it would have to undergo an intensive inspection and overhaul, so it's certanly not like they could just roll it off the desert and fly away.
There's appearently a big commercial airliner graveyard out there too, that's really big right now because of the decline of the airline industry, they mothball planes out there while waiting for a pickup in the industry.