In what year did Commodore Byron McCandless's grandson make the first ever untethered free flight in space?
Byron McCandless:  He was the father of Bruce McCandless, also a naval officer, and the grandfather of NASA astronaut Bruce McCandless II. Bruce McCandless II:  During the first of his two Space Shuttle missions he made the first ever untethered free flight using the Manned Maneuvering Unit in 1984.
1984