Crew:

James A. Lovell, Jr.

John L. Swigert, Jr.

Fred W. Haise, Jr.

Backup Crew:

Milestones:

06/13/69 - S-IVB ondock at KSC

06/29/69 - S-II Stage ondock at KSC

06/16/69 - S-1C Stage ondock at KSC

07/07/69 - S-IU ondock at KSC

04/11/70 - Launch

Payload:

Odyssey (CM-109) and Aquarius (LM-7)

Mission Objective:

Apollo 13 was supposed to land in the Fra Mauro area. An explosion on board forced Apollo 13 to circle the moon without landing. The Fra Mauro site was reassigned to Apollo 14.

Launched: 11 April 1970 UT 19:13:00 (02:13:00 p.m. EST)
Malfunction forced cancellation of lunar landing
Returned to Earth: 17 April 1970 UT 18:07:41 (01:07:41 p.m. EST)

"Houston, we have a problem..."

James A. Lovell, commander
John L. Swigert, Jr., command module pilot
Fred W. Haise, Jr., lunar module pilot

Apollo 13 Crew

Apollo 13 was intended to be the third mission to carry humans to the surface of the Moon, but an explosion of one of the oxygen tanks and resulting damage to other systems resulted in the mission being aborted before the planned lunar landing could take place. The crew, commander James A. Lovell, Jr., command module pilot John L. Swigert, Jr., and lunar module pilot Fred W. Haise Jr., were returned safely to Earth on 17 April 1970.

Mission Profile

Apollo 13 was launched on Saturn V SA-508 on 11 April 1970 at 19:13:00 UT (02:13:00 p.m. EST) from pad 39A at Kennedy Space Center. During second stage boost the center engine of the S-II stage cut off 132 seconds early, causing the remaining four engines to burn 34 seconds longer than normal. The velocity after S-II burn was still lower than planned by 68 m/sec, so the S-IVB orbital insertion burn at 19:25:40 was 9 seconds longer than planned. Translunar injection took place at 21:54:47 UT, CSM/S-IVB separation at 22:19:39 UT, and CSM-LM docking at 22:32:09 UT. The S-IVB auxilliary propulsive system burned at 01:13 UT on 12 April for 217 seconds to put the S-IVB into a lunar impact trajectory. (It impacted the lunar surface on 14 April at 01:09:41.0 at 2.75 S, 27.86 W with a velocity of 2.58 km/s at a 76 degrees angle from horizontal.) A 3.4 second mid-course correction was made at 01:27 UT on 13 April.

Apollo 13 Tanks

A television broadcast was made from Apollo 13 from 02:24 UT to 02:59 UT on 14 April and a few minutes later, at 03:06:18 UT Jack Swigert turned the fans on to stir oxygen tanks 1 and 2 in the service module. The Accident Review Board concluded that wires which had been damaged during pre-flight testing in oxygen tank no. 2 shorted and the teflon insulation caught fire. The fire spread within the tank, raising the pressure until at 3:07:53 UT on 14 April (10:07:53 EST 13 April; 55:54:53 mission elapsed time) oxygen tank no. 2 exploded, damaging oxygen tank no. 1 and the interior of the service module and blowing off the bay no. 4 cover. With the oxygen stores depleted, the command module was unusable, the mission had to be aborted, and the crew transferred to the lunar module and powered down the command module.

Apollo 13

Apollo 13 Damage

At 08:43 UT a mid-course maneuver (11.6 m/s delta V) was performed using the lunar module descent propulsion system (LMDPS) to place the spacecraft on a free-return trajectory which would take it around the Moon and return to Earth, targeted at the Indian Ocean at 03:13 UT 18 April. After rounding the Moon another LMDPS burn at 02:40:39 UT 15 April for 263.4 seconds produced a differential velocity of 262 m/s and shortened the estimated return time to 18:06 UT 17 April with splashdown in the mid-Pacific. To conserve power and other consumables the lunar module was powered down except for environmental control, communications, and telemetry, and passive thermal control was established. At 04:32 UT on 16 April a 15 second LMDPS burn at 10% throttle produced a 2.3 m/s velocity decrease and raised the entry flight path angle to -6.52 degrees. Following this the crew partially powered up the CSM. On 17 April at 12:53 UT a 22.4 second LMDPS burn put the flight path entry angle at -6.49 degrees.

The service module, which had been kept attached to the command module to protect the heat shield, was jettisoned on 17 April at 13:15:06 UT and the crew took photographs of the damage. The command module was powered up and lunar module was jettisoned at 16:43:02 UT. Any parts of the lunar module which survived atmospheric re-entry, including the SNAP-27 generator, planned to power the ALSEP apparatus on the lunar surface and containing 3.9 kg of plutonium, fell into the Pacific Ocean northeast of New Zealand. Apollo 13 splashed down in the Pacific Ocean on 17 April 1970 at 18:07:41 UT (1:07:41 p.m. EST) after a mission elapsed time of 142 hrs, 54 mins, 41 secs. The splashdown point was 21 deg 38 min S, 165 deg 22 min W, SE of American Samoa and 6.5 km (4 mi) from the recovery ship USS Iwo Jima.

The spacecraft was the second of the Apollo H-series. The purposes of the mission were (1) to explore the hilly upland Fra Mauro region of the moon, (2) to perform selenological inspection, survey, and sampling of material in the Fra Mauro formation, (3) to deploy and activate an Apollo lunar surface experiments package (ALSEP), (4) to further develop man's capability to work in the lunar environment, and (5) to obtain photographs of candidate lunar exploration sites. These goals were to be carried out from a near-circular lunar orbit and on the lunar surface at 3 deg S latitude, 17 deg W longitude. Although the planned mission objectives were not realized, a limited amount of photographic data was obtained. Lovell was a Navy captain on his fourth spaceflight (he'd flown previously on Gemini 7, Gemini 12, and Apollo 8), Haise and Swigert were both civilians on their first spaceflights. The backup crew was John Young, Charles Duke, and John Swigert (who replaced Thomas Mattingly on the prime crew after the crew was exposed to German measles). The Apollo 13 Command Module "Odyssey" is now at the Kansas Cosmosphere and Space Center, Hutchinson, Kansas. It was originally on display at the Musee de l'Air, Paris, France.

Detailed Chronology of Events Surrounding the Apollo 13 accident

Events from 2.5 minutes before the accident to about 5 minutes after

Times given are in Ground Elapsed Time (G.E.T.), that is, the time elapsed since liftoff of Apollo 13 on 11 April 1970 at 19:13 UT (2:13 PM EST).
55:52:00 G.E.T. is equal to 03:05:00 UT 14 April 1970 (10:05 PM April 13 EST).


55:52:31 - Master caution and warning triggered by low hydrogen 
    pressure in tank no. 1

55:52:58 - CapCom (Jack Lousma): "13, we've got one more item 
    for you, when you get a chance.  We'd like you to stir up 
    the cryo tanks.  In addition, I have shaft and trunnion .....

55:53:06 - Swigert: "Okay."

55:53:07 - Lousma: ".... for looking at Comet Bennett, if you 
    need it."

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

55:53:18 - Oxygen tank No. 1 fans on.

55:53:19 - Oxygen tank No. 2 pressure decreases 8 psi.

55:53:20 - Oxygen tank No. 2 fans turned on.

55:53:20 - Stabilization control system electrical disturbance 
    indicates a power transient.

55:53:21 - Oxygen tank No. 2 pressure decreases 4 psi.

55:53:22.718 - Stabilization control system electrical 
    disturbance indicates a power transient.

55:53:22.757 - 1.2 Volt decrease in ac bus 2 voltage.

55:53:22.772 - 11.1 amp rise in fuel cell 3 current for one 
    sample

55:53:26 - Oxygen tank No. 2 pressure begins rise lasting for 
    24 seconds.

55:53:38.057 - 11 volt decrease in ac bus 2 voltage for one 
    sample.

55:53:38.085 - Stabilization control system electrical 
    disturbance indicates a power transient.

55:53:41.172 - 22.9 amp rise in fuel cell 3 current for one 
    sample

55:53:41.192 - Stabilization control system electrical 
    disturbance indicates a power transient.

55:54:00 - Oxygen tank No. 2 pressure rise ends at a pressure 
    of 953.8 psia.

55:54:15 - Oxygen tank No. 2 pressure begins to rise.

55:54:30 - Oxygen tank No. 2 quantity drops from full scale for 
    2 seconds and then reads 75.3 percent.

55:54:31 - Oxygen tank No. 2 temperature begins to rise rapidly.

55:54:43 - Flow rate of oxygen to all three fuel cells begins 
    to decrease.

55:54:45 - Oxygen tank No. 2 pressure reaches maximum value of 
    1008.3 psia.

55:54:51 - Oxygen tank No. 2 quantity jumps to off-scale high 
    and then begins to drop until the time of telemetry loss, 
    indicating failed sensor.

55:54:52 - Oxygen tank No. 2 temperature sensor reads -151.3 F.

55:54:52.703 - Oxygen tank No. 2 temperature suddenly goes  
    off-scale low, indicating failed sensor.

55:54:52.763 - Last telemetered pressure from oxygen tank 
    No. 2 before telemetry loss is 995.7 psia.

55:54:53.182 - Sudden accelerometer activity on X, Y, Z axes.

55:54:53.220 - Stabilization control system rate changes begin.

55:54:53.323 - Oxygen tank No. 1 pressure drops 4.2 psi.

55:54:53.500 - 2.8 amp rise in total fuel cell current.

55:54:53.542 - X, Y, and Z accelerations in CM indicate 1.17g, 
    0.65g, and 0.65g.

55:54:53.555 - Master caution and warning triggered by DC main 
    bus B undervoltage.  Alarm is turned off in 6 seconds.  All 
    indications are that the cryogenic oxygen tank No. 2 lost 
    pressure in this time period and the panel separated.

55:54:54.741 - Nitrogen pressure in fuel cell 1 is off-scale 
    low indicating failed sensor.

55:54:55.350 - Telemetry recovered.

55:54:56 - Service propulsion system engine valve body 
    temperature begins a rise of 1.65 F in 7 seconds.  DC main 
    bus A decreases 0.9 volts to 28.5 volts and DC main bus B 
    0.9 volts to 29.0 volts.  Total fuel cell current is 15 
    amps higher than the final value before telemetry loss.  
    High current continues for 19 seconds.  Oxygen tank No. 2 
    temperature reads off-scale high after telemetry recovery, 
    probably indicating failed sensors.  Oxygen tank No. 2 
    pressure reads off-scale low following telemetry recovery, 
    indicating a broken supply line, a tank pressure below 
    19 psi, or a failed sensor.  Oxygen tank No. 1 pressure 
    reads 781.9 psia and begins to drop.

55:54:57 - Oxygen tank No. 2 quantity reads off-scale high 
    following telemetry recovery indicating failed sensor.

55:55:01 - Oxygen flow rates to fuel cells 1 and 3 approached  
    zero after decreasing for 7 seconds.

55:55:02 - The surface temperature of the service module 
    oxidizer tank in bay 3 begins a 3.8 F increase in a 15 
    second period.  The service propulsion system helium tank 
    temperature begins a 3.8 F increase in a 32 second period.

55:55:09 - DC main bus A voltage recovers to 29.0 volts, DC 
    main bus B recovers to 28.8.

55:55:20 - Swigert: "Okay, Houston, we've had a problem here."

55:55:28 - Lousma: "This is Houston.  Say again please."

55:55:35 - Lovell: "Houston, we've had a problem.  We've had a 
    main B bus undervolt."

55:55:42 - Lousma: "Roger. Main B undervolt"

55:55:49 - Oxygen tank No. 2 temperature begins steady drop 
    lasting 59 seconds indicating a failed sensor.

55:56:10 - Haise: "Okay. Right now, Houston, the voltage is -- 
    is looking good.  And we had a pretty large bang associated 
    with the caution and warning there.  And as I recall, main B 
    was the one that had an amp spike on it once before.

55:56:30 - Lousma: "Roger, Fred"

55:56:38 - Oxygen tank No. 2 quantity becomes erratic for 69 
    seconds before assuming an off-scale low state, indicating a 
    failed sensor.

55:56:54 - Haise: "In the interim here, we're starting to go 
    ahead and button up the tunnel again."

55:57:04 - Haise: "That jolt must have rocked the sensor on - 
    see now - oxygen quantity 2.  It was oscillating down 
    around 20 to 60 percent.   Now it's full-scale high."

55:57:39 - Master caution and warning triggered by DC main 
    bus B undervoltage.  Alarm is turned off in 6 seconds.

55:57:40 - DC main bus B drops below 26.25 volts and continues 
    to fall rapidly.

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."  
    AC bus fails within 2 seconds.

55:57:45 - Fuel cell 3 fails.

55:57:59 - Fuel cell current begins to decrease.

55:58:02 - Master caution and warning caused by AC bus 2 being 
    reset.

55:58:06 - Master caution and warning triggered by DC main bus 
    undervoltage.

55:58:07 - DC main bus A drops below 26.25 volts and in the 
    next few seconds levels off at 25.5 volts.

55:58:07 - Haise: "AC 2 is showing zip."

55:58:25 - Haise: "Yes, we got a main bus A undervolt now, 
    too, showing.  It's reading about 25 and a half.  Main B is 
    reading zip right now."

56:00:06 - Master caution and warning triggered by high 
    hydrogen flow rate to fuel cell 2.

Credit NASA