I was showing my friend what Kerbal Space Program was all about, and I wanted to launch a quick mission to the Mun and land so I could EVA just to show him the massive scale of the game. When I got to the Mun, as soon as my rocket touched down, I got an error saying the game had crashed. I figured oh well, I never quick saved so not a big deal, but then I went back in to my save and for some reason it quick saved right before colliding with the Mun. Is there any way to revert this flight in the game files? I'm OK with losing the money spent on the rocket itself, but I don't really want to lose Bob due to this.
Well, I was not able to find a way to revert a flight in game files yet, but I will post this here in case it is able to help somebody while I keep this question open waiting for an answer.
In lieu of reverting the flight, I was able to edit the persistent game file to add fuel to my rocket, burn retrograde and return to Kerbin.
In order to do this, I went in to my Kerbal Space Program folder in my Steam files. Then, go to saves, and find your persistent game save file. Open it in a text editor, Notepad will do. Then, I find it easiest to CTRL+F and type in the name of the ship you are looking to edit. After finding your ship, scroll the parts list to find the fuel tank or booster you need to add fuel to, and edit the resource and save the file. Reload it in KSP and you will have the fuel.