Following is a transcript of conversations in the Challenger crew cabin from two minutes and five seconds before liftoff to the explosion 73 seconds into flight. Times given are in minutes and seconds before launch (-) to minutes and seconds after launch (+).

The voices are of Francis R. Scobee, Michael J. Smith, Ellison S. Onizuka and Judith A. Resnik. The other three astronauts, Ronald E. McNair, Christa McAuliffe and Gregory B. Jarvis, could monitor all conversation but said nothing.

T-2:05 -- Resnik: "Would you give that back to me?"

T-2:03 -- Resnik: "Security blanket."

T-2:02 -- Resnik: "Hmm."

T-1:58 -- Scobee: "Two minutes downstairs; you got a watch running down there?"

T-1:47 -- Smith: "Okay, there goes the lox arm."

T-1:46 -- Scobee: "Goes the beanie cap."

T-1:44 -- Onizuka: "Doesn't it go the other way?"

T-1:42: Laughter.

T-1:39 -- Onizuka: "Now I see it; I see it."

T-1:39 -- Smith: "God I hope not, Ellison."

T-1:38 -- Onizuka: "I couldn't see it moving; it was behind the center screen."

T-1:33 -- Resnik: "Got your harnesses locked?"

T-1:29 -- Smith: "What for?"

T-1:28 -- Scobee: "I won't lock mine; I might have to reach something."

T-1:24 -- Smith: "Ohhkaaaay."

T-1:04 -- Onizuka: "Dick's thinking of somebody there."

T-1:03 -- Scobee: "Unhuh."

T-:59 -- Scobee: "One minute downstairs."

T-:52 -- Resnik: "Cabin pressure is probably going to give us an alarm."

T-:50 -- Scobee: "Okay."

T-:47 -- Scobee: "Okay there."

T-:43 -- Smith: "Alarm looks good."

T-:42 -- Scobee: "Okay."

T-:40 -- Smith: "Ullage pressures are up."

T-:34 -- Smith: "Right engine helium tank is just a little bit low."

T-:32 -- Scobee: "It was yesterday too."

T-:31 -- Smith: "Okay."

T-:30 -- Scobee: "Thirty seconds down there."

T-:25 -- Smith: "Remember the red button when you make a roll call."

T-:23 -- Scobee: "I won't do that. Thanks a lot."

T-:15 -- Scobee: "Fifteen."

T-:6 -- Scobee: "There they go, guys." Ignition.

T-:6 -- Resnik: "All right."

T-:6 -- Scobee: "Three at a hundred."

T:0 -- Resnik: "Allll riiight."

T+:1 -- Smith: "Here we go." Vehicle motion.

T+:7 -- Scobee: "Houston, Challenger roll program."

T+:11 -- Smith: "Go, you mother."

T+:14 -- Resnik: "LVLH." Reminder for cockpit switch change.

T+:15 -- Resnik: " Expletive hot."

T+:16 -- Scobee: "Ohhhhkaaay."

T+:19 -- Smith: "Looks like we've got a lotta wind here today."

T+:20 -- Scobee: "Yeah."

T+:22 -- Scobee: "It's a little hard to see out my window here."

T+:28 -- Smith: "There's 10,000 feet and Mach point five."

T+:30: Garble.

T+:35 -- Scobee: "Point nine."

T+:40 -- Smith: "There's Mach one."

T+:41 -- Scobee: "Going through 19,000."

T+:43 -- Scobee: "Okay, we're throttling down."

T+:57 -- Scobee: "Throttling up."

T+:58 -- Smith: "Throttle up."

T+:59 -- Scobee: "Roger."

T+:60 -- Smith: "Feel that mother go."

T+:60 -- Uncertain: "Woooohoooo."

T+1:02 -- Smith: "35,000 going through one point five."

T+1:05 -- Scobee: "Reading 486 on mine." Routine airspeed check.

T+1:07 -- Smith: "Yep, that's what I've got too."

T+1:10 -- Scobee: "Roger, go at throttle up."

T+1:13 -- Smith: "Uh-oh."

T+1:13: Loss of all data.