Project: Apollo 13

Transcipt of key moments in the Apollo-XIII flight (NOT the movie). Contains actual CapCom Air-to-Ground and Flight Director (FD) Loop conversations that took place in the Mission Operations Control Room (MOCR) on April 11-17, 1970.

More than 30 years ago three brave American explorers started on a journey that would become know as a "successful failure" their story is told by first-hand accounts in the following books: (click on the title for additional information)

Apollo 13: Anniversary Edition by James Lovell & Jeffrey Kluger

Failure Is Not an Option by Gene Kranz

Apollo 13 Mission Report (The NASA Mission Reports) by Robert Godwin

The Unbroken Chain by Guenter Wendt "Padleader"

Flight: My Life in Mission Control by Chris Kraft

Moon Lander: How We Developed the Apollo Lunar Module by Thomas J. Kelly

...and the Ron Howard film Apollo 13...

Apollo 13 DVD Dolby Digital Audio

Apollo 13 DTS DVD DTS Audio

(PLEASE NOTE that this is a work in progress.)

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Additional APOLLO-13 images can be found on-line at The Project Apollo Image Gallery. The World-Wide Web's most extensive collection of high-quality Apollo images. Many photographs on this website are courtesy of the National Aeronautics and Space Administration, specifically the NASA History Office, Kennedy Space Center and Johnson Space Center.

This FAQ is maintained by Anthony W. Haukap

The current version of this FAQ document can always be found on my website at:

http://www.cyberspace.org/~awh/

While every attempt is made to present accurate data it should be noted that the author makes no guarantee as to the accuracy of any information provided in this document, and is not responsible for any consequences of its use.

John Kennedy speeches leading up to the Apollo program. For additional information see the JFK Library website.

[Typical Prelaunch Sequence, 170KB GIF]

T-28:00:00 Official countdown starts LM stowage and cabin closeout. (T-31:30:00 to T-18:00:00)

[The launch of Apollo 13 is from Kennedy Space Center (KSC), Launch Complex 39, Pad A. Apollo 10 is the only Apollo/Saturn-V to have been launched from Complex 39, Pad B. The stack (spacecraft and launch vehicle) is designated AS-508. The Apollo 13 spacecraft consists of, Command/Service Module CSM-109, callsign "Odyssey" and Lunar Module LM-7, callsign "Aquarius". 13's mission was originally slated as a "Type H" mission.]

T-22:30:00 Topoff of LM super critical helium. (to T-20:30:00)

T-19:00:00 CSM crew storage. (to T-12:30:00)

T-19:30:00 LM The thermal shield installation. (to T-15:30:00)

T-16:00:00 LV range safety checks. (to T-15:00:00)

T-15:00:00 Installation of ALSEP FCA. (to T-14:45:00)

T-11:30:00 Connect LV safe and arm devices. (to 10:05:00) CSM pre-ingress operations. (to T-08:45:00)

T-10:15:00 Start MSS move to parksite.

T-09:00:00 Built-in hold for 9 hours and 13 minutes. At end of hold, pad is cleared for LV propellant loading.

[By providing built-in holds in the countdown, technicians could use this hold time to evaluate and work any problems without causing delays in the planned lift-off time.]

[At T-7:32 the weather report included an area in the Atlantic with 28-knot winds and 8-10 foot seas. This represented abort times from 6 minutes, 30 seconds to 8 minutes, 10 seconds G.E.T. and was considered acceptable.]

[The back-up Command Module Pilot's (CMP) task on launch day is to verifiy that each switch in the Command Module (CM), is correctly set for the ingress of the prime crew.]

T-03:32:00 Breakfast.

[They had the traditional breakfast of steak and eggs; tenderloin steak, eggs, orange juice, coffee, jelly and toast.]

T-03:07:00 Depart Manned Spacecraft Operations Building for LC-39 via crew transfer van.

[After a brief mission briefing, they donned their space suits and took the 8 mile trip in the transfer van to the pad area.]

T-02:49:00 - MCC PAO: "All three men breathing on what we call portable oxygen ventilators at this time. They have been on these since they were put into their suits in the suit room and they will remain on the portable oxygen ventilators until they actually enter the spacecraft and hookup into the spacecraft system. Now at two-hours, forty-eight minutes, twenty-nine seconds, this is Kennedy launch control."

[About three hours before launch, the prime crew begins to enter the CM. The Commander (CDR), James (Jim) A. Lovell, Jr., takes the left couch. Command Module Pilot (CMP), John (Jack) L. Swigert, Jr., occupies the center couch, facing the caution and warning panel. Lunar Module Pilot (LMP), Fred W. Haise, Jr., takes the right couch. The CDR is the last person to perform an Inertial Measurement Unit (IMU) align before the computer takes control of the lift-off.]

[The prime or launch team of flight controllers will take up their positions at the MCC consoles at T- 2:30 hours and remain until relieved at a ground elapsed time of about seven hours. Thereafter, the shift change for the flight controller teams will normally be every eight hours, varying slightly as determined by the activities in the flight plan. The team will come on duty about one hour prior to the shift change and will be briefed by the team they relieve.]

[At T-2:00 Flight Director Milt Windler and his Maroon Team of Flight Controllers come on shift.]

[At T-1:55 an anomaly is reported, a procedural error in failing to console select the Booster Systems Engineer (BSE) for commanding the launch abort check sequence.]

T-00:53:00 - MCC PAO: "Just a few minutes ago, Ken Mattingly, who until a few days ago was the prime command module pilot for Apollo 13, arrived in Mission Control and Ken will be assisting at the CapCom console and he's joined astronaut John Young and astronaut Joe Kerwin on the capcom console. As he arrived in Mission Control, Flight Director Milton Windler greeted him and said, 'Sorry to see you here, Ken.'"

T-00:43:00 Retract Apollo access arm to stand-by position (12 degrees).

[The Apollo access arm ("white room"/swing arm number 9) provides access to the CM and covers the CM hatch until the crew is aboard and the hatch is sealed for launch. At 43 minutes before launch the Apollo access arm is swung away from the spacecraft by 12°, this allows the white room to be quickly repositioned over the hatch to allow the crew to egress should it become come necessary to do so during an abort event. At five minutes before launch, the Apollo access arm is moved to the 180° position on the opposite side of the Launch Umbilical Tower (LUT).]

T-00:40:00 Final launch vehicle range safety checks. (to 00:35:00)

T-00:30:00 Launch vehicle power transfer test LM switch over to internal power.

T-00:20:00 Shutdown LM operational instrumentation. (to T-00:10:00)

T-00:15:00 Spacecraft to internal power.

T-00:06:00 Space vehicle final status checks.

T-00:05:30 Arm destruct system.

[In the event of an abort during powered flight the Saturn-V launch vehicle has attached to its outer surface explosive devices that will rupture the fuel and oxidizer tanks, dispersing their contents into the atmosphere to be consumed before reaching the ground. The destruct actions of course would not be taken until the astronaut crew had been advised and were safely away from the vehicle.]

T-00:05:00 Apollo access arm fully retracted. (180 degree position)

T-00:05:00 - KSC PAO: "Swing arm number nine, now is retracting to the full retract position, swing arm number nine coming back to the full retract position. And the director of launch operations (Walter J.) Walt Kapryan (Kennedy Space Center) has given Apollo 13 a go for launch. We're now approaching the four minute mark. At the T minus four minute mark we'll be standing by for Jack Baltar the launch vehicle test conductor to say that his launch vehicle team is ready to carry out the final phase here of the countdown. At the T minus three minute, seven second mark we will get the ignition sequence start, this will put us on an automatic sequencer and the remainder of the count from that time will be on automatic. The astronauts checkout literally hundreds of items in the space vehicle, at the same time the team here in launch control will be monitoring red line values these are such things as temperatures and pressures which we do not want to either go above or below. A final communication check now, the astronauts on the astro-comm circuit and launch operations manager Paul (C.) Donnelly during his final check said 'Good luck. Head for the hills.' He was refering to the Fra Mauro, hilly Fra Mauro region of the moon. As we come up on the T minus three minute mark. At three minutes the capsule communicator (CapCom) Paul J. Weitz will begin reading out the minus time to the crew. Looking up at our status board now we can see that the spacecraft, or the first stage preparations are now complete. The firing command has not been initialized, this is the automatic sequencer and we have confirmation on our status board that the launch sequence has started. We're now in our final three minutes of the countdown."

[Astronaut Paul Weitz, communicates with the crew in the spacecraft from the Launch Control Center (LCC), KSC. In the Mission Operations Control Room (MOCR), Houston, Texas, astronaut Joe Kerwin will be the Capsule Communicator (CapCom) for launch day. Once the Saturn-V vehicle has cleared the tower, control of the mission transfers from the LCC at the Cape to the MOCR in Houston. Flight Director Milt Windler and his Maroon Team of flight controllers are on station in the MOCR and ready to support a launch.]

[15k MP3 Audio file]

Flight: "Okay. All flight controllers coming up on auto sequence, Booster, how you?."
Booster: "We're go, Flight."
Flight: "EECom?"
EEcom: "Go, Flight."
Flight: "GNC?"
GNC: "Go, Flight."
Flight: "Telcom?"
Telcom: "Go, Flight."
Flight: "Control?"
Control: "Go."
Flight: "Network, got it there?"
Network: "That's affirmative, Flight."
Flight: "Okay."

(loop)

Booster: "Auto sequence initiated, Flight."
Flight: "Roger."
Booster: "Flight, Booster."
Flight: "Go."
Booster: "S-IVB prepress complete."
Flight: "Roger."

T-00:00:50 Launch vehicle transfer to internal power.

[60k MP3 Audio file]

(loop)

Booster: "Flight, Booster. S1C pre-press complete, and we're on internal power, and we're go."
Flight: "Roger. How's it look EECom? You got your spacecraft..." (interrupted by EECom)
EECom: "Looks good, Flight."
Flight: "Okay. MCC (Mission Control Center) recorders to flight speed."

[At T-17 seconds, the Saturn V's inertial guidance platform is released from the systems which have up to now been holding it in the correct orientation for the flight.]

T-00:00:08.9 Ignition sequence start.

T-00:00:08 - KSC PAO: "...eight, ignition sequence has started, six, five, four, three..."

(loop)

Booster: "Ignition, Flight."
Flight: "Roger."
Control: "Clock start, Flight."
Flight: "Roger."

T-00:00:02 - KSC PAO: " ...two, one..."

[The launch time is determined by "launch windows" - these are periods of time which are influenced by the rotation of the Earth vs. the moon/sun angle at the time of lunar surface landing. The first launch window for Apollo 13 opens 2:13 PM Eastern Standard Time, on April 11, and lasts 3 hours, 23 minutes. If the launch is delayed for any reason, they must wait for three consecutive launch opportunities in May. The first launch window in May opens on the 9th and extends to the 11th.]

[The first stage of the Saturn-V is produced by the Boeing Co.'s Launch Systems Branch, is 138 feet high and weighs close to five million pounds when fueled. The function of this stage is to lift the enormous weight (more than 6.2 million pounds) of the Apollo/Saturn V space vehicle (stack) off the pad and carry it to an altitude of about 38 miles and a speed of about 6000 miles per hour. The first stage uses the F-1, the most powerful engine ever produced. It is 19 feet long, weighs about 18,500 pounds and produces 1,500,000 pounds of thrust. The first stage has five F-1 engines for a total thrust of 7,500,000 pounds.]

Booster: "Roger, go all engines."
Flight: "Rog."

[At 1.35 seconds after liftoff, the launch vehicle is yawed 1.25 degrees from vertical away from the LUT to ensure clearance in case a swing arm fails to fully retract or a gust of wind pushes the vehicle towards the tower. At nine seconds into the flight the vehicle is brought back to a vertical position again. This yaw maneuver is accomplished by gimbaling the four outboard engines of the first stage, the center engine in the first stage cluster is fixed and can not be gimbaled.]

[60k MP3 Audio file]

[Once the vehicle has cleared the LUT, control of the mission is transferred to the MOCR in Houston, Texas.]

Flight: "Okay, Fido how's it look?"
Fido: "Look good here, Flight. Good agreement."
Flight: "Okay, Booster how do you look?"
Booster: "S1C, look good Flight."
Flight: "Okay, CapCom. We're go here on the ground."

00:00:30 - CapCom: "13, Houston. Go at thirty seconds."

00:00:34 - Lovell: "Roll complete and we're pitching."

[This maneuver places the spacecraft into a "heads down" attitude.]

00:00:42 - Lovell: "One-bravo."

[Abort Mode One-Bravo (Mode 1B): The pop-out canard fins at the top of the launch escape tower (LET) caused the CM to flip over and after a couple of oscillations, settles into a "heavy end forward" (Blunt-End-First attitude) mode that is ready for the LET to be jettisoned and for the safe deployment of the drogue and main parachutes. It took several seconds for the LES/CM to do the turnaround. Used until the air became too thin for the canards to work and the LET was jettisoned. Resulting landing point would be near the grgoundtrtact between the vicinity of the launch site and approximately 400 miles downrange.]

(loop)

Flight: "Okay, we're go at one (minute) CapCom."
EEcom: "Cabin relieving, Flight."
Flight: "Roger"

00:01:07 - Lovell: "13, roger."

[The Cabin Pressure Relief valve in the CM is set to its Boost/Entry position so that when the outside pressure drops below the cabin pressure, cabin air will be exhausted until the interior cabin pressure reaches 6.1 pounds.]

[The following exchange is what the flight controllers called "going around the horn."]

Flight: "Booster, how do you look?"
Booster: "Look good, Flight. We're go."
Flight: "Okay, Fido?"
Fido: "We're go, Flight. Looks good here."
Flight: "Guidance, how does it look?"
Guido: "Good, Flight."
Flight: "EECom, GNC?"
EECom: "Looks good, Flight."
GNC: "Looks good, Flight."
Flight: "Okay, Surgeon?"
Surgeon: "Looks fine."

(loop)

Booster: "Through max Q, and we're go, Flight."
Flight: "Roger, Booster."

[Booster sits at one of the consoles on the front row (known as the 'trench') of the MOCR. After the Saturn V's task is complete and Apollo 13 is on its way to the Moon, the three booster consoles are not used for the rest of the mission.]

00:01:58 - Lovell: "One-charlie."

[Abort Mode One-Charlie (Mode 1C): Command Module attitude control thrusters are used to turn the spacecraft into the Blunt-End-First attitude mode.]

Flight: "Go for staging, CapCom."

00:02:03 - Lovell: "Go for staging, roger. We're EDS MANUAL."

00:02:06 - JSC PAO: "Altitude now seventeen miles coming up on staging."

00:02:08 - CapCom: "Copy that."

00:02:15 - Lovell: "Inboard."

00:02:19 - JSC PAO: "Jim Lovell reports the inboard engine has shutdown as scheduled."

00:02:27 - CapCom: "We confirm inboard out, 13. You're looking good."

[To alleviate the severe pogo effect which plagued the early flights and the shock of all five engines of the first stage engines shutting down at once, the center engine of the cluster is shut down earlier than the outboard engines.]

00:02:36 - JSC PAO: "Coming up on thirty miles altitude."

00:02:44 First stage cutoff.

[The crew experiences a maximum of 4g just prior to first stage cutoff. This is the higest g load they will reach during the boost phase.]

00:02:50 Second stage ignition.

00:02:50 - Lovell: "S-II ignition."

00:02:51 - CapCom: "Roger."

[The second stage of the Saturn-V, built by North American Rockwell's Space Division, is the largest and most powerful hydrogen-fueled stage ever produced. It is 81.5 ft. tall and weighs more than 1 million pounds fueled. It takes over from the first stage and boosts its payload of the third stage and Apollo spacecraft into space (an altitude of about 118 miles) and to a speed of more than 14,000 miles per hour. The second stage uses the J-2 engine, the largest hydrogen-fueled engine ever built. The J-2 engine produces up to 225,000 pounds of thrust; the second stage uses five J-2 engines producing a maximum of 1,125,000 pounds of thrust.]

00:03:04 - Lovell: "Roger."

00:03:06 - JSC PAO: "CapCom Joe Kerwin confirming to the crew that the second stage looks good at this point. We're now forty-six miles high, seventy miles, (correcting himself) seventy-eight miles downrange."

00:03:18 - Lovell: "Skirt sep, tower jett."

[The LET consists of the tower, with its solid rocket motors, instrumentation and canards; and the Boost Protective Cover (BPC), which is a cover over the entire CM which protects the spacecraft from the heat generated by friction and from the exhaust of the LET rocket motors four nozzles should it be used for an abort. Only when the LET is jettisoned are all the windows in the CM uncovered. The forward heat shield contains four recessed fittings into which the legs of the launch escape tower are attached. The tower legs are connected to the CM structure by frangible nuts which contain small explosive charges. When the launch escape system is jettisoned, these charges are fired, breaking the nuts and separating the tower from the module.]

00:03:22 - Lovell: "Mode two."

[Abort Mode Two (Mode 2): This abort could be performed from the time the LET is jettisoned until the full-lift CM landing point reached 2,800 nautical miles downrange. Service Module RCS thrusters are used to separate the CSM from the launch vehicle. The CM would then separate from the SM and freefall for re-entry and splashdown. Landing on the groundtrack would be between 320 and 2,800 nautical miles downrange.]

00:03:40 - JSC PAO: "And Lovell reports that the guidance system is correcting the small errors."

00:03:44 - CapCom: "13, Houston. The guidance is good and the CMC (Command Module Computer) is go."

00:03:46 - Swigert: "Okay, Thank you, Joe."

00:03:47 - Lovell: "13, roger."

00:03:56 - JSC PAO: "Coming up on four minutes we're now at an altitude of sixty-three miles."

00:04:15 - JSC PAO: "At four minutes, fifteen seconds the trajectory...(interrupted by CapCom)"

00:04:18 - CapCom: "13, Houston. You're go at four minutes. The little red lines are right on the little white lines down here."

00:04:23 - Lovell: "Sounds good."

00:04:33 - JSC PAO: "They're currently about up to eleven-thousand feet per second. That's about thirty-six percent of the amount needed for a minimum orbit. We're now seventy-five miles in altitude, (pause) two-hundred twenty-two miles downrange now. The EECOM reports... (interrupted by CapCom)."

00:04:55 - CapCom: "13, Houston. Coming up on five minutes. You're looking perfect. Over."

00:04:59 - Lovell: "13, roger."

00:05:03 - JSC PAO: "And the EECOM reports that the cabin pressure is sealed at six point one pounds, which is normal. We're now two-hundred fifty miles downrange, altitude eighty-one nautical miles."

00:05:27 Center engine cutoff (occurred about 2 minutes, 12 seconds early, planned for S-II ignition +4min. 47sec.)

[During powered flight, five launch vehicle indicator lights are arranged to resemble the pattern of the engine cluster on the S-IC and the S-II stages, these lights will provide the crew with a status of each engine in that stage. When the inboard engine of the S-II stage shuts down prematurely the center light changes from off to on (illuminated).]

00:05:32 - Lovell: "Inboard."

00:05:37 - CapCom: "Roger. We confirm inboard out."

(loop)

Booster: "Comfirm inboard out, Flight."
Flight: "Roger."
Booster: "Staging, Flight."
Flight: "Roger."
Fido: "Flight, Fido. Trajectory confirms staging."
Flight: "Roger."

[Contingency Orbit Insertion (COI) - This is another way of saying "Mode 3".]

00:05:54 - CapCom: "Roger. You got it now, Jim."

00:05:56 - Lovell: "We've got S-IVB to C.O.I."

(loop)

Booster: "Flight, Booster. That inboard out was way early."
Flight: "Okay."
CapCom: "Flight, confirm number 5 engine down."
Flight: "Rog. Booster, you don't see any problem with that though, do you?"
Booster: "Negative, not right now Flight. All the other engines are go."

[The early shutdown of the center engine caused considerable deviations from the planned trajectory. The altitude at shutdown was 10.7 nautical miles lower and the velocity was 5,685.3 feet per second slower than expected.]

00:06:08 - Lovell: "Go at six."

00:06:13 - Lovell: "And Houston what's the story on engine five?"

00:06:16 - CapCom: "Jim, Houston. we don't have a story on why the inboard out was early, but the other engines are go, and you're go."

00:06:24 - Lovell: "Roger."

[The center engine of the S-II stage of the Saturn V launch vehicle prematurely shut down at 132 seconds due to large 16 hertz oscillations in thrust chamber pressure.]

00:06:43 - CapCom: "(Lost under the Public Affairs Commentator)...you're still looking good, your gimbals are good, trim is good."

00:06:46 - Lovell: "Roger."

00:06:57 - CapCom: "13, Houston. Level sense arm time eight plus three, eight, nominal, S-II cutoff time ninerer, plus four, eight, over."

00:07:04 - Lovell: "Roger, nominal on the sense arm, ninerer, four, eight on the S-II cutoff"

[Each propellant tank in the S-II stage has five sensors near the bottom which signal when they are uncovered by the draining liquid fuel. When two sensors are uncovered in the same tank, the IU computer begins the engine cut-off sequence. This signal is the "level sense arm" and the CapCom is telling the crew when Mission Control expects it to occur based on current consumption, and when it will lead to engine cutoff.]

00:07:13 - Lovell: "Roger. We have S-IVB to orbit."

[Should the S-II cut out early, the S-IVB now has the ability to place the spacecraft into a safe orbit. However, there would not be sufficient propellant remaining to preform the TLI burn. The crew would then switch to an alternate Earth orbit mission plan.]

00:07:45 - JSC PAO: "At seven minutes, forty-five seconds, Booster reports we are go. All four engines remaining looking good."

00:07:59 - JSC PAO: "The early shutdown of the center engine will cause no problem, we will burn a little longer than normally schedule... (interrupted by CapCom)"

00:08:05 - CapCom: "13, Houston. Looking good at eight minutes."

00:08:10 - Lovell: "13, roger."

00:08:18 - JSC PAO: "And at eight minutes seventeen seconds we show a velocity of eighteen-thousand feet per second that's about seventy-one percent of the amount needed for a minimal orbit."

00:08:38 - JSC PAO: "At eight minutes thirty-five seconds continuing to burn on the second stage all four remaining engines looking good at this point."

00:08:49 - CapCom: "Apollo 13, Houston. Mark. Level sense arm."

00:08:52 - Lovell: "Mark. Level sense arm. Roger."

00:09:01 - CapCom: "Apollo 13, Houston. At nine minutes you're go, the CMC is go."

00:09:06 - Swigert: "Okay, Joe."

00:09:07 - Lovell: "13, roger."

(loop)

Flight: "Booster, Flight. How you?"
Booster: "Go, Flight."
Flight: "Guidance?"
Guidance: "Go, Flight."
Flight: "GNC?."
GNC: "Go, Flight."
Flight: "EECOM?"
EECOM: "Go, Flight."

00:09:22 - CapCom: "13, Houston. You are go for staging."

00:09:26 - Lovell: "13, roger. Go for staging."

00:09:44 - CapCom: "Apollo 13, Houston. Standby for mode four capability. (pause) Mark. You have mode four, Jim."

00:09:47 - Lovell: "Mode four, roger."

[Abort Mode 4: Abort-to-Orbit - the CSM will separate from the Saturn and use the SPS (Service Propulsion System) to continue into Earth orbit.]

00:09:49 - Lovell: "Staging."

00:09:50 - CapCom: "Roger. Staging."

00:09:50 - JSC PAO: "And Lovell reports staging."

00:09:51 Third stage ignition. (S-II separation +03sec.)

00:09:51 - Lovell: "And S-IV ignition."

00:10:10 - CapCom: "Roger that Jim. Thrust looks good."

00:10:11 - Lovell: "Roger."

[The third stage is essentially the same as the second stage of the Saturn IB. On the Saturn V it serves in a double capacity. After the second stage burns out and is jettisoned, the third stage's engine burns briefly, just long enough to increase its velocity to about 17,400 miles per hour and put it and the Apollo spacecraft into earth orbit. It stays connected to the spacecraft from one to three orbits, then its engine is reignited at the proper moment to power itself and the spacecraft toward the moon. The third stage uses the J-2 engine, just like the second stage. The third stage uses one J-2 engine.]

00:10:26 - Lovell: "Thank you, Joe."

00:10:32 - JSC PAO: "At ten minutes thirty seconds we are now one-hundred two in altitude, one-thousand eighty miles downrange."

00:11:13 - CapCom: "13, Houston. At eleven minutes you are go. Predicted cutoff on the S-IVB is twelve plus three, four. Over."(no response)

00:11:39 - CapCom: "Apollo 13, Houston. You are go at eleven and a half and predicted cutoff time is twelve plus three, four. Over."

00:11:47 - Lovell: "Understand twelve plus three, four predicted cutoff time."

00:11:51 - CapCom: "That's affirm."

00:11:55 Earth orbit insertion.

00:11:59 - JSC PAO: "Coming up on twelve minutes still looking good."

00:12:25 - JSC PAO: "We're standing by for crew report of third stage shutdown."

00:12:34 Third stage cutoff.

00:12:32 - Lovell: "SECO"

00:12:33 - CapCom: "Confirm SECO, Jim. We're looking at the DSKY."

00:12:37 - Lovell: "Roger."

[The only significant launch phase anomaly was premature shutdown of the center engine of the S-II second stage. As a result, the remaining four S-II engines burned 34 seconds longer and velocity after S-II boost was 223 feet per second (fps) lower than planned. The S-IVB third stage orbital insertion burn was approximately 9 seconds longer than predicted with cutoff velocity within 1.2 feet per second of the planned velocity. Moreover, an adequate propellant margin was maintained in the S-IVB for the translunar injection burn (TLI).]

00:13:08 - CapCom: "Apollo thirteen, Houston. You have a go orbit, all sources and the booster is safe. Over."

00:13:12 - Lovell: "Go orbit and the booster is safe. Thank you, Joe."

00:12:16 - CapCom: "Don't mention it."

00:13:35 - CapCom: "13, Houston. We copy your noun 44."

00:13:40 - Lovell: "Okay, Joe."

00:14:00 - JSC PAO: "And the Booster Engineer reports at this time that the S-IVB third stage looks good, and being configured now for orbital operations. We're standing by for confirmation from the Flight Dynamics Officer (FIDO) of our preliminary orbit."

00:15:05 - CapCom: "Apollo 13, Houston. You're preliminary orbit down here is one-hundred two point five times one-hundred point three and everything is looking good."

00:15:14 - Lovell: "Roger, Houston. And it looks good to be up here again."

00:15:17 - CapCom: "Roger."

00:15:43 - CapCom: "Apollo 13, Houston. I have your Z torque angle when you're ready to copy."

00:15:51 - Lovell: "Roger that. We're ready to copy, Joe."

00:15:53 - CapCom: "Okay. It's plus decimal two, six. Over."

00:15:55 - Lovell: "Okay, Joe. Plus point two, six."

00:16:03 - CapCom: "That's roger."

00:17:00 - JSC PAO: "This is Mission Control at seventeen minutes. We have had loss of signal with the spacecraft. We’ll be reacquiring shortly through the Canary Island tracking station. The total burn duration on the third stage was about 45 seconds longer than planned, we would not expect at this point that this would have any serious effect on the translunar injection. The fact that we did consume a bit more propellant out of the third stage than was originally planned. We are standing by now for acquisition of signal through the Canary Island station. We should be reacquiring radio contact with the spacecraft shortly."

JSC PAO: "This is Apollo Control, we are still standing by for any conversation with the spacecraft over Canary Islands. The booster systems engineer reports that at this point he has no explanation for the early shutdown of the S2; Saturn second stage, center engine."

[Typical TLI Sequence, 165KB GIF]

[45k MP3 Audio file]

[The initial one and one-half earth orbits before translunar injection (TLI) were spent in spacecraft systems checkout and included television transmissions as Apollo 13 passed over the Merritt Island Launch Area, Florida, tracking station.]

02:25:49 - CapCom: "Okay. We're just starting to get data and everything still looks good to us."

02:25:53 - Swigert: "Hey, Joe. At two hours and twelve minutes, the O₂ flow high light came on, and it's been pegged high ever since, so it's been on about fourteen minutes now."

02:26:04 - CapCom: "Roger, 13. We're looking at it."

02:26:09 - Lovell: "Time base six."

02:26:12 - CapCom: "Copy. Time base six."

02:26:52 - CapCom: "Okay. Apollo 13, Houston. You have a go for all systems and the O₂ flow high check is nominal with the waste tank vent open at this time, and it's no sweat."

02:27:05 - Swigert: "Okay. just wanted you all to check it for me."

02:31:22 - CapCom: "Apollo 13, Houston. We will be losing data from Carnarvon in about 1 minute. We'll probably have voice through ARIA. Everything is honkey-dory and we will be listening for you to tell us how the burn goes."

[This trajectory is nominally one that provides a "free return" to earth; that is, if for any reason the spacecraft is not inserted into an orbit around the moon, the spacecraft will return to earth.]

02:35:47 - CapCom: "Copy that Jim. Good deal."

02:35:56 - JSC PAO: "Jim Lovell reports we have ignition. (long pause) Lovell’s report would indicate that we had a very close to on-time ignition. The total burn duration should be about five minutes, forty-seven seconds."

02:36:30 - Lovell: "Everything’s okay so far."

02:36:34 - CapCom: "Houston, roger."

02:36:40 - JSC PAO: "Jim Lovell just reported that everything looks good with that burn. We’re still about 7 minutes away from reacquiring the spacecraft through the station in Hawaii at which time we’ll get our first good look at the trajectory as a result of this burn."

02:38:27 - Lovell: "They’re off at 38." (unintentional transmission)

02:39:15 - JSC PAO: "We’re now three and a half minutes into the translunar injection burn. Some 2 minutes, 17 seconds remaining in the maneuver which will start Apollo 13 in route to the moon."

02:40:26 - Lovell: "We’re getting a little vibration during this time."

02:40:28 - CapCom: "Houston, roger."

02:41:20 - JSC PAO: "Now about 20 seconds away from the scheduled shut down time. Jim Lovell reported few seconds ago that they’re experiencing a bit of vibration on the S-IVB. Previous crews reported similar experience toward the end of the burn."

02:41:40 - Lovell: "It's off. Engine off."

02:41:42 - CapCom: "Houston, copy. Engine off."

02:42:00 - JSC PAO: "Lovell’s report of engine off came about five or six seconds after the pre-planned time."

[The flight was normal through TLI although some instrumentation was inoperative on the Saturn SIVB.]

02:42:30 - Lovell: "Roger. Through Hawaii on three minutes."

02:42:30 - JSC PAO: "Our communications continuing to come to us as relayed through the ARIA aircraft."

[After this Hawaii pass following TLI, there is continuous acquisition among the Goldstone (GDS), Madrid (MAD), and Honeysuckle (HSK) MSFN Stations.]

03:19:21 - CapCom: "Roger, understand hard dock. Good deal. Fred one more thing on the TV, if you could come down to F:22 again."

03:19:32 - Haise: "Okay. You got F:22 again."

[The probe is the CM's docking mechanism (male), the drogue (funnel-like shape) is part of the LM docking mechanism (female), the nose of the probe was inserted into the conical shaped drogue on the LM, the drogue has a small hole at its base, the probe's tip (capture latch assembly) would be pushed into this hole, and 3 latches would clamp shut on the inside of the hole - this was a "soft dock" condition, they would then retract the probe, which would bring the two spacecraft together and 12 clamps around the docking ring would snap shut for "hard dock".]

03:20:26 - CapCom: "Okay, Jim. Real good."

03:20:30 - JSC PAO: "A view of the Saturn third stage and the lunar module is coming to us from about 5,000 miles beyond earth. The spacecraft and S-VIB traveling at a speed of about 22,900 feet per second at this time."

03:21:38 - Haise: "Okay, Joe I'm pointing over towards Jack and it's pretty bright with the Earth out that window is that sort of washing out the picture here?"

03:21:49 - CapCom: "No Fred it's not, we've got a bright spot where the window is, but the rest of you are semi-silhouetted. It's a pretty impressive picture."

[The CM has five windows: two side, two rendezvous, and a hatch window. The side windows, about 13 inches square, are positioned at the side of the left and right couches and are used for observation and photography. The triangular rendezvous windows, about 8 by 13 inches, face the left and right couches and permit a view forward (toward the apex of the module). They are used to aid in the rendezvous and docking maneuvers as well as for observation. The hatch window is over the center couch. The windows each consist of inner and outer panes. The inner windows are made of tempered silica glass with 1/4-inch thick double panes, separated by a tenth of an inch. The outer windows are made of amorphous-fused silicon with a single pane of seven-tenths of an inch thick. Each pane has an anti-reflective coating on the external surface and a blue-red reflective coating on the inner surface to filter out most infrared and all ultraviolet rays. The outer window glass has a softening temperature of 2800 degrees F and a melting point of 3110 degrees F. The inner window glass has a softening temperature of 2000 degrees F. Each window has a shade which can be installed to cut off all outside light, The shades are made of aluminum sheet, have a non-reflective inner surface, and are held in place by wing levers.]

03:xx:xx - Haise: "And we're just about there... about 10 more feet now."

03:xx:xx - JSC PAO: "Rog."

03:xx:xx - Haise: "Everything looks pretty good down in the S-VIb too. The shroud still looks intact down there."

03:xx:xx - JSC PAO: "Good deal. There's really quite a bit of detail in this picture."

03:xx:xx - Swigert: "Okay. We've got 2-barber poles."

03:57:58 - CapCom: "Okay 13, Houston. You're go for LM sep whenever you're ready."

03:58:06 - Swigert: "Roger."

03:58:18 - CapCom: "Okay 13, Houston. Correction on that. You're go for LM sep at the nominal time and, or later. We don't want it early."

04:00:54 - Swigert: "Okay, we're about ready to pull the LM out, Joe."

04:00:59 - CapCom: "Okay, 13."

04:01:03 - Swigert: "Here she comes. (pause) Okay, it looks like we're clear, Joe."

04:01:19 - CapCom: "Okay, looks good. It's weird, cause we get the TV about 10 seconds after you call it."

[After the CSM and LM have docked, the pressure between the CM and the LM is equalized and the CM forward hatch is removed. A check is made to determine that all docking latches are engaged, the CSM-LM electrical umbilicals are connected, and the CM forward hatch is reinstalled. The LM's four connections to the SLA are severed by small explosive charges, and the spacecraft is separated from the SLA and third stage by spring thrusters.]

04:08:26 - Swigert: "Okay, Houston. We have the S-IVB in sight. You're go to maneuver the S-IVB."

04:08:31 - CapCom: "Houston, roger that."

04:09:04 - Swigert: "Try to give you a - Houston, we're going to try to give you a shot of the S-IVB with the TV out window number three."

04:10:05 - Swigert: "Okay, I can see the S-IVB now out the hatch window."

04:17:41 - CapCom: "And 13, Houston. We'll be commanding the evasive maneuver in about seventeen seconds."

04:18:40 - Swigert: "Okay, Joe. We can see it start to move, however there doesn't seem to be a lot of debris or vapor coming out of it."

04:18:48 - CapCom: "Roger that Jack. Booster says that great, he says the booster is doing its thing normally. Concur, we don't see much on the television at all."

[A change of shift takes place in the MOCR at approximately 06:00 G.E.T. Flight Director Gerry Griffin and his Gold Team of flight controllers takes over from Milton Windler's team. At approximately 07:00 G.E.T. astronaut Vance Brand takes over Capsule Communicators duties from Joe Kerwin.]

24:16:12 - Lovell: "Gosh, we had forgotten, but we'd like to hear what the news is."

24:16:15 - CapCom (Joe Kerwin): "Okay. There's not a whole lot to it... The Beatles have announced they will no longer perform as a group. The quartet is reported to have made in excess of a half billion dollars during their short musical career. However, rumors that they will use this money to start their own space program are false."

24:17:24 - Lovell: "Maybe we could borrow some?"

24:17:30 - CapCom (Joe Kerwin): "(laughter) Okay... Many air traffic controllers are still out, but reports indicate that they are slowly returning to work, and you'll be happy to know the controllers here in the MOCR are still on the job."

24:18:03 - Lovell: "(garbled)"

24:18:05 - CapCom (Joe Kerwin): "Go ahead."

24:18:09 - Lovell: "I said thank goodness for that."

24:18:10 - CapCom (Joe Kerwin): "Okay. Some truck lines are being struck in the Midwest and some school teachers have walked off the job in Minneapolis. Today's favorite pastime across the US, (dramatic pause and with mock urgency in his voice) oh, oh, have you guys completed your income tax?"

24:18:28 - Lovell: "How do I apply for an (income tax) extension?"

24:18:31 - CapCom (Joe Kerwin): "(laughter)"

24:18:32 - Swigert: "Yea, Joe. I got to - hey, listen; it ain't too funny. Things kinda happened real fast down there and I, I do need an extension."

32:18:43 - CapCom (Joe Kerwin): "(laughing)"

24:18:44 - Swigert: "I didn't get mine filed, I'm really serious, would you..."

24:18:47 - CapCom (Joe Kerwin): "You're breaking up the room down here."

24:18:52 - Swigert: "I may be spending time in a...I may be spending time in another quarantine besides the one they were planning for me."

24:18:59 - CapCom: "We'll see what we can do, Jack. We'll get with recovery and see if we can get the agent out there in the Pacific when you come back. By golly, let's see... In professional basketball, the Nicks beat the Milwaukee Bucks 110 to 109, and Billy Casper is leading the Masters after 54 holes with a 208, and spring football practice is in full swing. And that's about all the news we got. The updated plan of the day for you guys; the uniform will be service dress inflight coverall garments with swords and medals; and tonight's movie, shown in the lower equipment bay, will be John Wayne, Lou Costello, and Shirley Temple in 'The Flight of Apollo 13'. Over."

24:19:50 - Lovell: "Outstanding! (pause) Houston, this is 13. Is it true that Jack's income tax return was going to be used to buy the ascent fuel for the LM?"

24:20:50 - CapCom: "And Jim McDivitt says, 'yes, now that you mentioned it, he forget to fill the ascent stage.' (pause) Should give you very good performance on descent."

24:21:00 - Lovell: "Suspicions confirmed."

24:21:11 - Haise: "We should have a lot more hover time, huh?"

24:21:13 - CapCom: "That's right! (pause) Okay, crew. About the only other thing I've got for you right now is an update to your P37 pad for lift-off plus 35. This is a change to the pad we gave you yesterday. The reason for the update is for weather avoidance in the mid-Pacific landing area at 70-hours, which is the return time for this pad, and in case the question arises in your mind, we don't expect any problem there for the end of the mission. The weather area is 20 degrees south of your end-of-mission landing point, and it appears to be moving to the south."

25:26:50 - CapCom: "I'd like to read to you the booster people's preliminary analysis on the S-II cutoff. Over."

25:26:58 - Lovell: "That would be very interesting. Go ahead."

25:27:00 - CapCom: "Okay, preliminary analysis of the data indicates that the center S-II engine vibrated at a somewhat higher amplitude than we've seen on previous flight, and it started at about 160 seconds into the S-II burn. As a result of these vibrations, the engine chamber pressure decreased to the level where the two low-level thrust sensors, the thrust... okay, sensors, initiated center engine cutoff. Early evaluation of the data indicates that no damage occured to the engine, and the cause of the increased vibration amplitude is still under investigation."

[The spacecraft will reach the midpoint in distance, where it's equally far from the earth to the spacecraft to the moon, at 27 hours, 20 minutes, 49 seconds G.E.T. At that time it will be 112,070 nautical miles from the earth and to the moon.]

29:30:54 - Swigert: "That's good news. I guess I qualify."

29:31:00 - CapCom: "Yes, we were just looking at the map, and you're south of Flordia so you're not in the country now."

--:--:-- - CapCom (FD Glynn Lunney): "American citizens out of the country get a 60 day extension on filing, I assume this applies to you."

[At 30:40:49 GET, a midcourse correction maneuver (23.2 fps MCC-2) was made using the service module propulsion systemand all burn parameters were normal. The crew preparations for the burn and the burn itself were monitored by the Mission Control Center (MCC) at MSC by telemetered data and by television from the spacecraft. This midcourse correction maneuver was a 23.2 feet per second hybrid transfer burn which took Apollo 13 off a free-return trajectory and placed it on a non-free-return trajectory (hybrid trajectory). A similar trajectory had been flown on Apollo 12. The objective of leaving a free-return trajectory is to control the arrival time at the Moon to insure the proper lighting conditions at the landing site. Apollo 8, 10, and 11 flew a pure free-return trajectory until lunar orbit insertion in which the spacecraft would swing around the moon (had L.O.I. not occured) and return intersecting the Earth. In comparision Apollo 13, by leaving the free-return trajectory, would return to the vicinity of the Earth, the closest approach would be around 40,000 miles. The Apollo 13 hybrid transfer maneuver lowered the predicted closest approach, or pericynthion, altitude at the Moon from 210 to 64 nautical miles.]

30:46:15 - CapCom: "What was that one again?."

30:46:18 - Lovell: "I say you know that new... the new fad with long hair."

30:46:21 - CapCom: "Right."

30:46:22 - Lovell: "It doesn't work too well up in space, you can't comb your hair up here."

30:46:27 - CapCom: "Well, I guess you have to give up something. (pause) At least it, it helps to try, we can see you trying to comb your hair there, Jim. It looks like your beards haven't come along to the point where you have to use the razor though."

30:46:51 - Lovell: "Well we've been debating that, we thought we'd take care of our beards tomorrow and make that one of our duties. (pause) And Vance, I thought we'd get a picture of Jack just so that all the girls know that he's still here. (pause) Say hello Jack."

30:47:34 - CapCom: "Yea, we, we appreciate that. There he is, big Jack."

[At approximately 31+00 Flight Director Milt Windler and his Maroon Team of Flight Controls come on duty.]

46:43:38 - CapCom (Joe Kerwin): "Ah, roger. Spacecraft is in real good shape as far as we're concerned, Jim. We're bored to tears down here. We do have a few little items for you like a P37 update and a couple of flight plan updates, but there's no rush about them. Over."

46:44:36 - Lovell: "It might be interesting that just after we went to sleep last night we had a MASTER ALARM and it really scared us... and we were all over the cockpit like a wet noodle."

46:44:45 - CapCom: "Sorry it wasn't something more significant. I've also got a procedure for you on that H₂ tank, simple thing after you get done stirring up the cryos."

[At wake-up (47+00) the crew was requested to cycle the cryo fans per the normal procedure. When the crew cycled the fans in O2 tank #2 the gauging system in that tank failed off scale high. A readout of the onboard gauge confirmed an off scale high reading. Loss of this gauge was of no great concern at this time since the tank status could be followed by monitoring pressure, temperature and the status of O2 tank #1.]

47:40:29 - Lovell: "Okay. Standy by. (pause) Joe, we confirm. Our gage reading is, on the number 2 O₂ tank is reading off-scale high now, but Jack just tells me that it was okay when we first looked at it this morning."

47:41:00 - CapCom: "We verifiy that. At 46:45 we had 82 percent and apparently when he stirred the, the cryos, the sensor broke."

47:41:17 - Lovell: "Okay."

47:45:20 - CapCom: "... and since we're not going to do a midcourse 3, we'd like LM entry at 55 hours. Is that okay with you?"

[The MCC-3 maneuver scheduled for 55+25 was deleted since the MCC-4 was only 4 fps. This figure was later revised to 3.6 fps when a new trajectory update was made.]

[LM familiarization, had a midcourse-3 burn been necessary, would have occured at 58 hours GET.]

51:07:44 - Lovell: "Okay. We'll start it (pause) now."

51:07:46 - CapCom: "Thank you. (pause) and 13, Houston. For your information, a normal 1-minute or so stir will be fine."

[A review of the analog playback of the O2 tank #2 gauging problem with the EECOM showed that the quantity went through 4-cycles, averaging about +/- 2% about 80% quantity, then went to 100% quantity, and subsequently remained there. It was assumed that the transducer failed.]

52:07:48 - Lovell: "Go ahead, Houston."

52:07:50 - CapCom: "Jim, just an advisory; expect a CAUTION AND WARNING on H₂ tank 1 pretty quick. No problems; just warning you about it."

52:08:05 - Lovell: "Okay. A zero pressure light on H₂ tank 1 coming on shortly, hun?"

[At 53+27 the crew was cleared to ingress the LM about 1-1/2 hours early, and LM press began at 53+34.]

55:15:04 - Lovell: (doing the camera work) "Roger, Houston. What we plan to do for you today is start out in the spaceship Odyssey, and take you on through Odyssey into the tunnel and into Aquarius, and show you a little bit of the landing vehicle, and your TV operator is now resting on the center couch looking at Fred Haise whose head is now just about at the tunnel, and his back is against the lower equipment bay optical area, and Fred will now transport himself into the tunnel and into the spaceship Aquarius."

55:15:48 - Haise: "Yea one thing I noted, Jack when we first came across here that starting upright in the command module and heading down into Aquarius there's a little bit of an orientation change that I been through it once in the water tank is still pretty unusual. I find myself now standing with my head on the floor when I get down inside the LM."

55:16:25 - CapCom: "That's a great picture, Jim. You got the light just right."

55:16:40 - Haise: "One of the nice things, Jack, particularly for a novice like myself is the ease of moving around in here, of course as you know from working in the command module simulator it's really quite a boon to have zero-gravity as an aide, you're confined really at one-g to move around very much in there and it's really quite easy. The LM as you can see looks pretty clean I found a couple of loose washers that's about it and the little plastic cap of the sequence camera had come loose and I found it lodge over by the ED (Explosive Devices) panel. Okay. Right under Jim now, he's actually standing on what looks to be a can here, and for the sake of all the people back there, housed inside this can is the LM accent engine, hopefully you can see my hand resting on top of right now. The engine that we use to get off of the Moon. Immediately adjacent to the engine cover here I have my hand on a white box now, which has been shown before, this happens to be Jim's PLSS or the backpack which will supply oxygen and water for cooling while on the Lunar surface. This device we hope to make use of for a planned 4 hours possibly up to as much as 5 hours."

55:22:37 - Lovell: "I might tell you that we're looking at right now, that round bag that's just behind Fred holds our vacuum hose that when we get back inside the LM, we'll hook our vacuum hose to our suits and it's resting, or it's attached to the hatch which we will open to go onto the lunar surface, and of course to come back in."

55:35:04 - Lovell: "And now Fred's engaged in his favorite past time, I found out on this flight so far."

55:35:47 - CapCom: "He's not in the food locker is he?"

55:35:52 - Lovell: "That's his second favorite past time, he's, he's rigging his hammock for sleep on the lunar surface now to try it out to see what it's going to be like."

55:36:03 - CapCom: "Roger, sleeping then eating."

55:36:29 - Haise: "It's kind of difficult here, Jack; getting into a hammock in zero g. I'm not sure if I keep floating away from it or if it keeps moving away from me."

55:38:56 - Lovell: "Okay, Houston. For the benefit of the television viewers, we've just about complete our little inspection of Aquarius and now we're proceeding throught the hatch again and through the tunnel and going back on the Odyssey."

(loop)

EECom: "Flight, EECom."
Flight: "Go ahead EECom."
EECom: "Okay. Let's terminate the battery B charge at 55 plus 5, 0."
Flight: "Okay."
EECom: "And at the same time, I'd sure like to have a cryo stir in O₂ tanks."
Flight: "Well, let's wait until they get settled down a bit more."
EECom: "Roger."

[125K MP3 Audio file]

55:45:08 - CapCom: "Okay, Jim. We're seeing the tape recorder now, and just by the way, just how long do you expect to keep the TV on this evening?"

55:45:18 - Lovell: "Well when ever you ...."

[LOUD POP can be heard on air-to-ground.]

55:45:25 - Haise: "Yea, I got them with the cabin repress valve again there, Jack."

55:45:29 - Lovell: "Every time he does that our hearts jump in our mouths. And Jack, anytime you want to terminate TV we're all set to go."

55:46:01 - CapCom: "Okay, Jim. it's been a real good TV show, we think we ought to conclude it, from here now, what do you think?"

(loop)

EECom: "Flight, EECom."
Flight: "Go EECom."
EECom: "We've got 40 amp-hours back in battery B now."
Flight: "Okay."

55:46:30 - CapCom: "Thank you 13."

55:48:40 - CapCom: "Apollo 13, Houston. The next thing we'd like you to do is to..."

55:48:45 - Swigert: "Go ahead."

55:48:46 - CapCom: "...we'd like you to roll right to 060 and null your rates for photography of the Comet Bennett. To do that, we would like you to enable quads C and D. For the maneuver, use all your quads. And in precisely 1 minute, we'd like to to terminate the battery charge on battery B. (pause) One other request, we'd like to have you verify..."

55:49:12 - Swigert: "Okay, we'll do it." (over CapCom)

55:49:14 - CapCom: "One other request, we'd like you to verify your high gain configuration. We'd like to know what track mode, what SERVO, and what beam width."

55:49:25 - Swigert "Okay, Jack. During the TV, we were AUTO TRACK, NARROW BEAM WIDTH, and the PRIMARY ELECTRONICS. And we had a good lockup. Just after we started the maneuver, I was able to lock you up and get real good signal strength, and it just seemed that right there at about 239 degrees in yaw, that the signal strength would just drop off and yaw would go to zero and pitch would go to 90."

55:50:05 - CapCom: "Roger. We copy, and the TV show was great."

55:50:12 - Swigert "Okay, real fine. Okay, I'm going to maneuver to 060, 090, and 0."

55:50:31 - CapCom: "And 13, we'd like you to check your C4 thrusters."

55:51:33 - Swigert "Okay, Jack. The battery charge has been terminated on the battery B."

55:51:38 - CapCom: "Roger. we see it, Jack. And we got a reading of minus 2 degrees on the docking index. We'd like to know it that's 2.0 precise or if it's 2.1 or 1.9."

55:51:54 - Swigert "No. It's a minus 2.0 precisely."

55:51:56 - CapCom: "Thank you."

[485K MP3 Audio file]

[The cryogenic hydrogen tanks are stirred by internal fans to homogenise their density. The cryogen, when in the tank, has been described as a very 'dense fog' rather than a liquid; in zero G it tended to separate into layers of different densities around the quantity gaging system's capacitive probe creating a false quantity reading. The two small fans were used to periodically (once/day) stir up the cryogen (H2 or O2) to make it homogeonous and allow the capacitive probe to produce an accurate signal/reading.]

55:53:07 - CapCom: "...for looking at comet (J. C.) Bennett (19691), if you need it."

55:53:12 - Swigert: "Okay. Stand by."

(loop)

Flight: "Now we haven't stabilized that attitude yet, but I don't think they're going to have any problems."
Guido: "Flight, I don't think there's any problem. They haven't opened up that vent."
Flight: "Yea, that's just what I'm saying. The time to do it is now Guidance."
Guido: "Flight, Guidance."
Flight: "Go Guidance."
Guido: "As long as he's in P00 and don't reselect it, we can downlink it... (garbled) ...enter it... (garbled)"
Flight: "Fido you got an update on the crew checklist anyway onboard don't ya..."
Fido: (over Flight) "Rog."
Flight: "...don't you got a page update, well why don't we read it up to them and that'll serve both purposes."
Fido: "Alright."
Flight: "The bulkhead matter as well as why don't you tell them what page you want of the checklist."
Fido: "Okay."
Telmu: "Flight, Telmu."

[Screen captures of the ECS console that show the CSM CRYO tanks taken at 55:53:47 GET (nominal pressure, 906 psi ), 55:54:47 GET (increased pressure, 1008.3 psi), and 55:54:53 GET (just after rupture, 19 psi). Note the bottom line that reads 'CRYO SUPPLY', the column under the heading '02-2' is the O₂ cryo tank number 2.]

Flight: "Go, Telmu."
Telmu: "We show the overhead hatch closed and the heater current looks normal."
Flight: "Okay."

(loop)

Guido: "Flight, Guidance."
Flight: "Go, Guidance."
Guido: "We've had a (Comand Module Computer - CMC) hardware restart. I don't know what it was."
Flight: "GNC you want to look at it?":
GNC: "(garbled)":
Flight: "Roger. See a hardware restart?":

[Summary of events leading to the failure of O₂ tank 2.]

Flight: "You see a AC bus undervolt there Guidance, (correcting himself) er, EECom?"
EECom: "Negative, Flight."
Flight: "I believe the crew reported it."
CapCom: "We got a main B undervolt."
EECom: "Okay, Flight we've got some instrumentation flags. Let me add them up."
Flight: "Rog."
EECom: "We've may have had an instrumentation problem, Flight."
Flight: "Rog."

(loop)

Inco: "Flight, Inco."
Flight: "Go, Inco."
Inco: "We switched to widebeam width about the time he had that problem."
Flight: "Okay, you say you went to widebeam there?"
Inco: "Yes."
Flight: "See if you can correlate the times, get the time you went to wide beam, Inco."

55:56:30 - CapCom: "Roger, Fred."

[Gene Kranz stated in the Apollo 13 Mission Operations Report that "At this time, I felt we had had a major short circuit that knocked much of the instrumentation offline, and that it might be related to the HGA (High-Gain Antenna) anomaly that occurred earlier."]

55:56:57 - CapCom: "Roger."

[The forward (docking ) hatch is a combined pressure and ablative hatch mounted at the top of the docking tunnel. It is about 30 inches in diameter and weighs about 80 pounds. The exterior or upper side of the hatch is covered with a half-inch of insulation and a layer of aluminum foil. The forward hatch has a six-point latching arrangement operated by a pump handle similar to that on the side hatch except that only one stroke is needed to open the latches. The handle is offset so that it can be reached easily by a crewman standing in the tunnel. This hatch also can be opened from the outside. It has a pressure equalization valve so that the pressure in the tunnel and that in the LM can be equalized before the hatch is removed. The valve is similar to the vent valve in the side hatch. There are no provisions for opening the latches manually if the handle gear mechanism should fail. Jim Lovell notes in his book "Lost Moon: The Perilous Voyage of Apollo 13" that Jack Swigert tried to seal the hatch to the tunnel leading into the LM several times and could not get the hatch to seat or lock, then he (Jim Lovell) tried and couldn't get it to seat. By this time he realized that if the LM had been it by a meteor and the hull compromised the spacecrafts would have depressurized by now. Its interesting to note that later in the mission just before jettisoning the LM the hatch seated and sealed without any problem.]

55:57:22 - CapCom: "Roger."

55:57:30 - Lovell: "And Houston, we had a restart on our computer. We had a PNGS ("pings") light and restart, reset."

55:57:37 - CapCom: "Roger, restart and a PNGS light... (correcting himself) restart on the PNGS, and reset on the computer."

55:57:44 - Lovell: "Okay. And we're looking at our service module RCS helium 1. We have, B is barber poled and D is barber poled, helium 2, D is barber pole, and secondary propellants, I have A and C barber pole."

[In both the LM & CM there are indicators (talkback) for important functions that are either "gray" (functioning properly) or "barber pole" (red & white stripes - problem or needs attention), they tell at a glance what state the monitored system is in.]

55:58:13 - CapCom: "Roger."

55:58:25 - Haise: "Yes, we got a main bus A undervolt now too showing."

55:58:29 - CapCom: "Main A undervolt."

55:58:29 - Haise: "It's reading about 25 and a half. Main B is reading zip right now."

(loop)

Flight: "Well lets get some recommendation here, Sy, if you got any better ideas."
Flight: "Okay Sy, what do you want to do? Hold your own and... (long pause) Sy, have you got a sick sensor type problem there or what?"
EECom: "Well we've lost AC. It does appear we've lost AC bus 2, voltage. Main B is reading 4 volts and that effectively takes AC 2 away from us."
Flight: "Okay."

55:59:38 - CapCom: "Standby one, Jim. (pause) 13, Houston. We'd like you to attempt to reconnect fuel cell 1 to Main A and fuel cell 3 to Main B. Verify that quad delta is open."

[Controllers asked the crew to connect fuel cell 3 to dc main bus B in order to be sure that the configuration was known.]

(loop)

EECom: "I copy, Flight."

(loop)

EECom: "We got Main A volts, no Main B volts. "

56:03:20 - CapCom: "That's affirmative, We're reading you. We're trying to come up with some good ideas here for you."

(loop)

CapCom: "Is there any kind of leads we can give them? are we looking at instrumentation, or we got a real problem, or what?"

56:03:37 - CapCom: "Say again, Fred."

56:03:42 - Haise: "In the interim, to help out MAIN A voltage, I've got MAIN BUS TIE BAT AC on. Or would you rather accept the 25 volts we are seeing on MAIN A?"

56:03:52 - Capcom: "Okay. BUS TIE AC on."

56:04:09 - Capcom: "13, Houston. We need OMNI Charlie, please."

56:04:19 - Haise: "You got it."

[Throughout all of the above, the spacecraft was relatively stable in attitude due to the crew exercising corrective attitude control, but now it was starting to drift which necessitated started omni switching. The ground was able to obtain good High Bit Rate data from the 210-foot (diameter satellite dish) MSFN site at Goldstone.]

56:05:46 - Haise: "Okay. Nitrogen on 1 and oxygen on 2 - is that correct?"

56:05:50 - CapCom: "Negative. Oxygen on 3."

56:05:54 - Haise: "Okay. (pause) Okay. Systems test 1-A says zip, and 2 baker which is 3 oxygen says point 6."

[Gene Kranz states in the Apollo 13 Mission Operations (April 28, 1970) Report that "Somewhere along here, I requested Glynn Lunney to advise center management that we had a major systems problem."]

56:06:57 - Haise: "Fuel cell 1 nitrogen reads zero."

56:07:01 - CapCom: "Roger, zero."

(loop)

Flight: "You don't want to get fuel cell pumps off do you?"
EECom: "We can do that on fuel cell number 1, Flight."
Flight: "Okay, well let's make sure we don't blow the whole mission. Can we review our status here Sy, and see what we got from a stand point of status. What do you think we got in the spacecraft that's good?"
EECom: "We're reading zero O₂ pressure in fuel cell 1 and 13 psi on fuel cell 3 O₂ pressure."
Flight: "Okay Barret what do you want to do? Open circuit fuel cell 1 and 3?"
EECom: "That's affirm, Flight."

Haise: "Okay. I’ll get to work on that."

Lovell: "And ah, Jack our O₂ quanity number 2 tank is reading zero, did you get that?"

(loop)

[65k MP3 Audio file]

EECom: "That's roger, Flight. That's the AC problem."
Flight: "Rog."

56:09:07 - Lovell: "That's AC? Okay. Yea, that appears to be what we're seeing. Okay. (pause) And it looks to me, looking out the hatch that we are venting something."

56:09:10 - CapCom: (over Lovell) "Roger."

(loop)

Flight: "Crew thinks they're venting."
EECom: "I got that, Flight."

(loop)

EECom: "Fido, EECom."
Fido: "Go ahead, EEcom."
EECom: "Let me know when it shows up."
Fido: "Roger that. Well we've already seen some of it."
EECom: "Okay."

(loop)

Flight: "Okay let's everybody think of the kind of things we'd be venting. G.N.C., you got anything that looks abnormal in your system?"
GNC: "Negative, Flight."
Flight: "How about you EECom see anything that, with the instrumentation you got that could be venting?"
EECom: "That's affirm, Flight. (pause) Let me look at the system, Flight, as far as venting is concerned."

[Since the problem was reported at 55:55 GET, the EECom and his backr