Answer: Mercury-Atlas 9
May 16, 1963, NASA astronaut L. Gordon Cooper, Jr. was in a pretty tight place. Cooper was the only crew member on board Faith 7 an orbital spacecraft moved up as part of the Mercury-Atlas 9-space mission with an Atlas LV-3B rocket ̵1; the first and only day-long mission in the Mercury program.
For the majority of Cooper's time in space, the earth paved nearly two dozen times in one and a half days, the mission was smooth. However, when the time for re-entry approached, the problems began to cut. In the 20th run, Cooper lost altitude readings and in the 21st orbit a short circuit left the automatic stabilization and control system without power. In addition to the electromechanical failures, the carbon dioxide level in the cab and in his space color increased.
Cooper kept his wits about him and used his wristwatch to get his manual control over the retrorockets, his knowledge of astronomy using the stars as reference points and a fat pen for drawing lines on the canister window to keep in line with the constellations when he flew, he performed a beautiful textbook landing. Under Cooper's expert touch, Faith 7 sprayed into the ocean 4 miles from the primary recovery vessel, the USS Kearsarge . This landing was so far and despite the lack of automatic controls, the most accurate canister landing in NASA history.
Cooper's cool-headed flight marked the last of the Mercury missions and the last manned mission until the launch of Gemini 3 in the spring of 1965.