The correct way to make Groundmission, is not to safe at all.
If something really really goes bad, allowing your self to load the last geoscape safe, before attempting to fight the mission.
So you get something new each time. =)
If you allow Autosaving, the game will automatically create a Autosave, at the beginning of each groundmission and directly after it.
In Battlescape, you can also select enabling Autosave, which will create a automatic save for your new turn, depending on set intervalls.
If you really wanna play not ironman, just savy manually or use the quicksave slots.
If you step around the corner and get shot, then you approached this situation obviously wrong (your soldier dies) - thats x-com