That's the fun part. You don't! Though I think things aren't necessarily hit at the same times, plus if you get there in time but it's close there is a way to control the damage before it happens. Honestly there's enough going on at Astrape that even if you can't get there before it's fried this time, there should be something else to do, and making it there makes it faster the next time, which could get you there before things get bad.