Controlling the ship can be tricky thanks to the physics used in the game. I’ve crashed into the asteroids on mission 2 a lot!
In fact, mission 2 is too hard in my opinion now that I’ve played it a few times after the jam; it needs more difficulty balancing but would have ran out of time in the jam to do so anyway.
I haven’t looked in the code yet (that’s something I’ll do if I get around to doing any post-jam work on the game) but I’d guess from the info you’ve provided that the error has probably occurred in the code responsible for updating the HUD’s displayed values (since division was used there to get the proportion of a value against it’s maximum to know how much to fill the value’s meter on the HUD).
Thanks for the reporting the bug, I’ve added a line to the game’s description on itch.io advising that since Solar Guard is still in development, there’s a fair chance that issues/bugs will be encountered.