Glenn’s Marine Corps nickname was “Magnet Ass.”
John Glenn was the first American in history to orbit the earth, and he later became a senator, but he was also a skilled fighter pilot. During World War II, he flew F4U Corsairs in the Pacific Theater before returning to battle over Korea in Grumman F9F Panthers. He earned the wacky but awesomely appropriate moniker "Old Magnet Ass" during his 63 missions with VMF-311 "Tomcats" over Korea. Although the moniker might seem mocking, it's not.
Glenn would aggressively pursue ground targets in his Panther, earning him the nickname "Old Magnet Ass." Sometimes, even after the element of surprise had been lost, he would fearlessly plunge in for attack runs. He would draw so much anti-aircraft artillery fire in the process that his jet would return with numerous holes in it. On 63 combat flights, he piloted an F9F Panther jet interceptor, twice returning with more than 250 holes in his ship. His air crew believed he caught flak in some way.