On the last night of his Olympic career, NBC announced today that it will broadcast Michael Phelps: America’s Golden Champion at 7 PM on Sunday. The one-hour special will be an “intimate look at 18-time gold medalist and 22-time overall Olympic medalist”. Tonight, NBC Olympics pointman Bob Costas interviewed Phelps who is the most decorated Olympian ever. The 27-year old announced his intention to retire from Olympic competition after this year’s games and had his last turn as an Olympian today on the American men’s 4×100 meter medley relay. NBC also will be airing Gymnastics, Beach Volleyball, Track and Field, and Diving during primetime Sunday as scheduled.