Well at that point all humans were living to be about 300. And we know that he was already researching the vex so it would have likely been towards the end of the golden age anyway. Plus the awoken used to be human right? So he could have fled and become one of them, then gone back... Yah know what? As I'm writing this I am realising how far I am stretching probability. But an awoken being in the cosmodrome in the first place is already a pretty darn big stretch. So I'll leave it at that.