Space is not a hedge against these things. At best it's our final tomb.

There is no backup plan.

to be fair, in the pharoahs quest for immortality after death, if they could have put their pyramid burial tombs in space to avoid decay/ruin for longer they would have. I wouldn't be shocked to see the oligarchs paying for their own space burials inside very lavish satellites whose orbit won't decay for thousands of years so they can "live forever".