TONIGHT'S MUST-SEE

"American Experience: Race to the Moon," 9 p.m., PBS. Approaching the Apollo 8 mission in 1968, astronauts and officials seemed calm and confident. In private, they were filled with doubts. Their space program had faced setbacks and delays. Trailing the Russians, they wanted to be first to have men orbit the moon. It was a gamble. Christopher Kraft, the flight director, told Susan Borman there was only a 50-50 chance her husband Frank would return alive. Even that was more optimistic than her guess. "I really didn't think they'd get him back," she says in this involving documentary. Then everything worked perfectly. Ten times, the three men orbited, staring out the window like kids at Disneyland. "We had our noses pressed against the glass," Jim Lovell says.

OF NOTE

"How I Met Your Mother," 7:30 p.m., CBS. Ratings are usually down a little on Halloween, so CBS (like NBC) is filling the night with reruns. This happens to be an exceptionally good one. It's the pilot film in which Ted warily tackles the dating scene.

"Prison Break," 8 p.m., Fox. In a new episode (preceded by a rerun), Abruzzi the mobster loses his power over other prisoners.

"Out of Practice," 8:30 p.m., CBS. Here's another terrific pilot film. A young man is bummed because he's the only nonphysician in the family — and because his wife has just left him.

"Medium," 9 p.m., NBC. Halloween seems like a logical time to air three straight reruns of this drama, which is both spooky and fairly well made. Patricia Arquette stars as someone who uses her ESP to stop crooks.