In KSP, the respawn time is based on real life time, not in-game time. The default time is 2 hours, though you can change it in the game settings down to 1 hour. If you have experience in tampering with the save and settings files, you could change it to 0 hours or something else via this method:
- Make sure KSP is not running, and go to the
...\Kerbal Space Program\saves\NAME directory, where
NAME is the name of the savegame.
- Next, go to the
GAME/PARAMETERS/DIFFICULTY/RespawnTimer parameter. The unit here is in seconds.
- Change the number (default
7200) in any time amount you want! NB: If you try to change this in-game afterwards, it will reset, and you will have to do the process again.
I hope this helps in the revival of Bob!