I found a way to kinda cheat the system. If you leave the planet at the last second before it completes the upcycle, even if the danger would be 99.99%, it won't explode and still count as an upcycled planet. With that you could go endlessly from planet to planet xD
What's done cannot be undone.
Humanity has sucked earth dry of all it's natural resources and funneled it all into the space exploring program. The only problem is how expensive space exploration is...