You should not lose progress when crashing during a Mission. Just go to your Main Menu and tap on the Fight tab, select the feature that you were in the process of completing, and your previous Mission should be loaded.
You can also see the Bots you have assigned to a Mission by going to your BOTS tab and tapping on the bots with the Mission symbol. Please note that if you crash during a battle, your bot may take additional damage due to inactivity.