BBC article on the rarely-mentioned Operation Freshman, the first Allied attack on the heavy water plant the Nazis used in occupied Norway https://www.bbc.co.uk/news/articles/cn03e7rzrj4o
Most of those lost on the mission probably had no idea this was to foil attempts to build an atomic weapon, they just knew it was something the Nazis couldn't have, and they risked their lives to try and stop it.
