The Doolittle Raid

The first American air raid on the Japanese home islands during World War II was launched on April 18, 1942, four months after the opening Japanese attack on US forces in the Philippines, Guam, Wake Island, and Oahu. The raid was tactically insignificant, carried out by only 16 North American B-25 bombers, all of which were lost in the raid, but was a tremendous psychological victory for the United States in the Pacific theater. You can read more about it here:
The Doolittle Raid

Since the United States had no air bases within striking distance of Japan given the range of aircraft available at the time, the B-25's were moved into position and launched off the aircraft carrier USS Hornet 650 nautical miles from the island of Honshu. The bombers were just barely able to take off in the space of the Hornet's deck, and since they weren't equipped to land on the carrier, the plan was to fly on to airfields in unoccupied nationalist China, from which presumably the crews and aircraft would be returned to America. When a Japanese picket boat spotted the Hornet 10 hours before the scheduled launch time, the decision was made to fly immediately, and as a result none of the B-25s had sufficient fuel to reach their intended destinations. Only one airplane landed on a runway, in Vladivostok, where the crew was interred by the Soviet Union for a year and the airplane became a jungle gym for elementary school kids.

Remarkably, 73 of the 80 Doolittle raiders made it back to the United States, where Jimmy Doolittle, leader and chief planner of the raid, was convinced he would be court-martialed for the loss of a squadron of bombers with little to show for it. In the event, America went wild for Doolittle and his airmen, branded them heroes of the first order, and granted Doolittle a Medal of Honor and ultimately a promotion to General. Given the complexity and foolhardiness of the raid, this is about as well as things could have been expected to go.