A lot can go wrong in the meantime: electrical or communication systems could fail, orbital insertion burns could fail (either due to messed up timing, communic

A lot can go wrong in the meantime: electrical or communication systems could fail, orbital insertion burns could fail (either due to messed up timing, communication, propulsion, or any number of other things), etc etc. But that said, barring any huge design flaws, if you make it out of atmo you're probably going to be just fine. (Usually. Probably.) So it's mainly just a waiting game now.