STS-41-D was the 12th flight of NASA's Space Shuttle program, and the first mission of Space Shuttle Discovery. It was launched from Kennedy Space Center, Florida, on August 30, 1984, and landed at Edwards Air Force Base, California, on September 5. Three commercial communications satellites were deployed into orbit during the six-day mission, and a number of scientific experiments were conducted.

The mission was delayed by more than two months from its original planned launch date, having experienced the Space Shuttle program's first launch abort at T-6 seconds on June 26, 1984.