Challenger Tragedy: Transcript

By Marty McDowell/NASA

Months of speculation about the fate of the Challenger astronauts immediately after the explosion were only partially put to rest with the July 28, 1986 transcript (see below). Rumors about on-board personal cassette recorders containing conversations from crew members after the explosion finally led NASA to release the following statement on the 10th anniversary of the tragedy.

10th Anniversary NASA Statement

This message in response to the continued interest in the Challenger transcripts, and in the hopes that a detailed listing of events will help quell a persistent myth. There are no "partial" Challenger transcripts, and there are no voice tapes recorded after the breakup of the vehicle.

The Challenger onboard intercom was recorded on one of two operational recorders (hereafter, "ops" recorders) aboard the orbiter.

Shuttle orbiters have several onboard components with memory-saving capacity: the General Purpose Computers (GPC), Ops recorders, a payload recorder, and a Modular Auxiliary Data System (MADS) recorder. Personal cassette recorders are available to crews for note taking, but it is thought that they were not in use during Challenger's launch.

The ops recorders store Shuttle ascent telemetry data and air-ground voice channels. Ops recorder 1 records the 60 kilobits/second (KBPS) data stream from the three main engines; Ops recorder 2 records at 128 KBPS the Shuttle downlink/downlist data and the two air-ground channels. Circa 1986, the Ops recorders were played back after reaching orbit to bridge gaps in real-time telemetry to ground stations or through Tracking and Data Relay Satellite coverage.

On March 19, 1986, NASA announced that four of five Challenger General Purpose Computers (GPC) had been recovered from the Atlantic and moved to the IBM Federal Systems Division facility in Owego, NY. The GPCs were cleaned under controlled conditions and submerged in deionized water at Kennedy Space Center prior to air shipment March 16, 1986, to Owego. The GPC ferrite core memories were examined for any possible residual data -- a process that at the time was expected to take several months. This information was in the form of data--not onboard voice--and this path was pursued to add any possible additional information to the accident investigation. Many weeks later, it was found that the additional data frames did not measurably add to the information already gathered during the investigation.

Both Ops recorders and the MADS recorder were recovered and were taken to the Marshall Space Flight Center, Huntsville, AL, for cleaning in clear, cold water and for subsequent drying in a thermal vacuum chamber. The cleaning/drying of recorder tapes took about two weeks, after which the tapes were taken to the Johnson Space Center for extraction of any usable data.

On April 30, 1986, JSC announced that it had so far been unable to extract data from the tapes. "Because the long exposure to salt water has deteriorated the tapes such that they cannot be unwound from the reels without total loss of the data, all attempts to date to recover information from then have been unsuccessful." JSC also reported that one of the personal cassette recorders available to crew members for note-taking had been recovered, but it was still in its stowage container, indicating it had not been used, and the recording tape was too severely damaged to be played back.

On July 16, 1986, JSC announced that additional efforts had been made to salvage the tapes from the Ops recorders. The tapes underwent treatment at IBM's facility in Tucson, Arizona, to remove magnesium oxide caused by seawater reaction with magnesium tape reels. The tapes were first treated with diluted nitric acid, and then rinsed in methanol. Earlier treatment immediately after recovery had included submersion in clear, chilled water until methods for salvaging the tape could be devised.

Through these types of intensive efforts, it ultimately was possible to listen to the tapes and provide a transcript of them to the media. The transcript was made available on July 28, 1986 at 4:30 p.m. EDT. Initially, NASA had concluded that the crew was unaware of the events preceding the breakup of the Challenger. But detailed analysis revealed a final comment, providing "the first potential indication of awareness on their part at the moment when all data was lost at 73 seconds into the flight," NASA announced. That comment was "Uh oh," attributed to Pilot Michael Smith.

There is no transcript after the 73-second point because once the Challenger began to break up, power was lost and the recorders stopped running.

Out of respect for the families of the crew, NASA felt strongly that the voice tape audio should not be released. A transcript was released and the contents were widely reported for several days. Later, the New York Times sued NASA for release of the tape audio itself, a case which ultimately went to the Supreme Court, with the court ruling in NASA's favor.

In the July 28 news release announcing the transcript and the release of a report from astronaut Dr. Joseph Kerwin on the cause of death of the crew members, Rear Admiral Richard Truly, then head of NASA's Office of Space Flight, thanked all of the people involved in the massive salvage effort. "Their work deserves the admiration and thanks of the American people, and I believe their efforts have now closed this chapter of the Challenger loss," he said. "We have now turned our full efforts to the future, but we will never forget our seven friends who gave their lives to America's space frontier."

Brian Welch
Chief, News & Information
NASA Headquarters
Washington, DC
January 29, 1996

Original 7/28/86 NASA Statement

NASA has completed its analysis of the Challenger operational recorder voice tape. The enclosed transcript reveals the comments of Commander Francis R.Scobee, Pilot Michael J. Smith, Mission Specialist 1 Ellison S. Onizuka, and Mission Specialist 2 Judith A. Resnik for the period of T-2:05 prior to launch through approximately T+73 seconds when loss of all data occurred. The operational recorder is automatically activated at T-2:05 and normally runs throughout the mission. During the period of the prelaunch and the launch phase covered by the voice tape, Mission Specialist 3 Ronald E. McNair, Payload Specialist 1 S. Christa McAuliffe, and Payload Specialist 2 Gregory B. Jarvis were seated in the middeck and could monitor all voice activity but did not make any voice reports or comments.

Actual Transcript

CDR.....Scobee
PLT.....Smith
MS 1....Onizuka
MS 2....Resnik

The references to "NASA" indicate explanatory references NASA provided to the
Presidential Commission.)

Time              Crew            Crew
(Min:Sec).........Position        Comment


T-2:05............MS 2   Would you give that back to me?

T-2:03............MS 2   Security blanket.

T-2:02............MS 2    Hmm.

T-1:58............CDR    Two minutes downstairs; you gotta watch
                         running down there?
(NASA:   Two minutes till launch.)

T-1:47............PLT     OK there goes the lox arm.
(NASA:   Liquid oxygen supply arm to ET.)

T-1:46............CDR     Goes the beanie cap.
(NASA:   Liquid oxygen vent cap.)

T-1:44............MS 1     Doesn't it go the other way?

T-1:42............          Laughter.

T-1:39............MS 1     Now I see it; I see it.

T-1:39............PLT      God I hope not Ellison.

T-1:38............MS 1     I couldn't see it moving; it was behind the center
screen.
(NASA:   Obstructed view of liquid oxygen supply arm.)

T-1:33.  .........MS 2     Got your harnesses locked?
(NASA:   Seat restraints.)

T-1:29............PLT      What for?

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

T-1:24............PLT       Ooh kaaaay.

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

T-1:03............CDR       Unhuh.

T-59..............CDR      One minute downstairs.
(NASA:   One minute till launch.)

T-52..............MS 2     Cabin Pressure is probably going to give us 
                           an alarm.
(NASA:   Caution and warning alarm.  Routine occurrence during prelaunch).

T-50..............CDR      OK.

T-47..............CDR      OK there.

T-43..............PLT      Alarm looks good.
(NASA:   Cabin pressure is acceptable.)

T-42..............CDR      OK.

T-40..............PLT      Ullage pressures are up.
(NASA:   External tank ullage pressure.)

T-34..............PLT      Right engine helium tank is just a little bit low.
(NASA:   SSME supply helium pressure.)

T-32..............CDR      It was yesterday, too.

T-31..............PLT      OK.

T-30..............CDR      Thirty seconds down there.
(NASA:   30 seconds till launch.)

T-25............PLT        Remember the red button when you make a roll call.
(NASA:   Precautionary reminder for communications configuration.)

T-23............CDR         I won't do that; thanks a lot.

T-15..............CDR        Fifteen.
(NASA:   15 seconds till launch.)

T-6...............CDR        There they go guys.
(NASA:   SSME Ignition.)
                  MS 2       All right.
                  CDR        Three at a hundred.
(NASA:   SSME thrust level at 100% for all 3 engines.)

T+O...............MS 2       Aaall riiight.

T+1...............PLT        Here we go.
(NASA:   Vehicle motion.)

T+7...............CDR........Houston, Challenger roll program.
(NASA:   Initiation of vehicle roll program.)

T+11..............PLT        Go you Mother.

T+14..............MS         LVLH.
(NASA: Reminder for cockpit switch configuration change.
       Local vertical/local horizontal).

T+15..............MS 2       (Expletive) hot.

T+16..............CDR        Ooohh-kaaay.

T+19..............PLT        Looks like we've got a lotta wind here today.

T+20..............CDR        Yeah.

T+22..............CDR        It's a little hard to see out my window here.

T+28..............PLT        There's ten thousand feet and Mach
                             point five.
(NASA:   Altitude and velocity report.)

T+30............             Garble.

T+35..............CDR        Point nine.
(NASA:   Velocity report, 0.9 Mach).

T+40..............PLT        There's Mach one.
(NASA:   Velocity report, 1.0 Mach).

T+41..............CDR        Going through nineteen thousand.
(NASA:   Altitude report, 19,000 ft.)

T+43..............CDR        OK we're throttling down.
(NASA:   Normal SSME thrust reduction during maximum dynamic pressure region.

T+57..............CDR        Throttling up.
(NASA:   Throttle up to 104% after maximum dynamic pressure.

T+58..............PLT        Throttle up.

T+59..............CDR        Roger.

T+60..............PLT        Feel that mother go.

T+60............             Woooohoooo.

T+1:02............PLT        Thirty-five thousand going through one point five
(NASA:   Altitude and velocity report, 35,000 ft., 1.5 Mach).

T+1:05............CDR        Reading four eighty six on mine.
(NASA:   Routine airspeed indicator check.)

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

T+1:10............CDR        Roger, go at throttle up.
(NASA:   SSME at 104 percent.

T+1:13............PLT        Uh oh.


T+1:13.......................LOSS OF ALL DATA.

Source: NASA.

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"I was aboard the Coast Guard Cutter Dallas (WHEC 716). We were just south of Nassau Island in the Bahamas in an area known as the tounge of the Ocean conducting anti sumbarine exercises. We got a message to proceed at maximum speed to Cape Canaveral about 1/2 hour after the shuttle exploded. We did not have television reception in that area so we did not know exactly what happend for several hours. We arrived on seen sometime before midnight and became the on seen command for the recovery operation. I think that we spent about 10 days there recovering parts of the shuttle. It was a very humbling experience. We were grateful that we were able to help in some very small way." --Anonymous

Space References (Videos):
Cosmos. PBS, 2000.
Stephen Hawking's Universe. PBS, 1997.
Hyperspace. BBC, 2002.
Life Beyond Earth PBS, 1999.
The Planets. BBC, 1999.
Understanding The Universe. A&E, 1996.