so they are turned off or exploded then... have you made enemies with the visitors by chance?
Viewing post in My Omega Kerfur went missing instantly
check the rivers and low areas, most parts are round enough to have rolled to the lowest points possible
worst comes to worst, you can make another, but it will require either fetching a core from another save, or going into the cave...
If you choose the legitimate way, bring supplies, and you can wear more than one backpack, but I don't recommend trying to stay awake or leaving to sleep, better to rest when you can in there, it's a journey.