Invincibility:- Press V to become invincible to enemy fire or damage.
Note: This cannot be enabled in campaign mode.
Edit mission scripts:- The default mission scripts can be declassified.
Enter the mission editor and try to access the pull-down menu. Leave the
password prompt blank to declassify a mission. Once this is done, it may
be edited to allow invincibility (under the "Skills" setting), hard
landings, recovery, and more.