- CHALLENGER (10)
- Pad 39-B (6)
- 25th Shuttle mission
- 10th liftoff OV-099
- 1st Shuttle from LC-39B
- Francis R. Scobee (2), Commander
- Michael J. Smith (1), Pilot
- Judith A. Resnik (2), Mission Specialist 1
- Ellison S. Onizuka (2), Mission Specialist 2
- Ronald E. McNair (2), Mission Specialist 3
- Gregory B. Jarvis (1), Payload Specialist 1
- Sharon Christa McAuliffe (1), Payload Specialist 2 (TISP)
- OPF - Nov. 11,1985
- VAB - Dec. 16,1985
- PAD - Dec. 22,1985
Click here for Additional Info on 51-L
- Planned objectives were deployment of Tracking Data Relay
Satellite-2 (TDRS-2) and flying of Shuttle-Pointed Tool for Astronomy
(SPARTAN-203)/Halley's Comet Experiment Deployable,
a free-flying module designed to observe tail and coma of Halleys
comet with two ultraviolet spectrometers and two cameras. Other
payloads were Fluid Dynamics Experiment (FDE); Comet Halley
Active Monitoring Program CHAMP); Phase Partitioning Experiment
(PPE); three Shuttle Student Involvement Program (SSIP)
experiments; and set of lessons for Teacher in Space Project
- January 28, 1986,11:38:00 a.m. EST. First Shuttle liftoff scheduled
from Pad B. Launch set for 3:43 p.m. EST, Jan. 22, slipped to
Jan. 23, then Jan. 24, due to delays in mission 61-C. Launch reset
for Jan. 25 because of bad weather at transoceanic abort landing
(TAL) site in Dakar, Senegal. To utilize Casablanca (not equipped
for night landings) as alternate TAL site, T-zero moved to morning
liftoff time. Launch postponed a day when launch processing
unable to meet new morning liftoff time. Prediction of unacceptable
weather at KSC led to launch rescheduled for 9:37 a.m. EST, Jan.
27. Launch delayed 24 hours again when ground servicing equipment
hatch closing fixture could not be removed from orbiter hatch.
Fixture sawed off and attaching bolt drilled out before closeout
completed. During delay, cross winds exceeded return-to-launch-site
limits at KSC's Shuttle Landing Facility. Launch Jan. 28 delayed
two hours when hardware interface module in launch processing
system, which monitors fire detection system, failed during liquid
hydrogen tanking procedures.
- Just after liftoff at .678 seconds into the flight, photographic
data show a strong puff of gray smoke was spurting from the vicinity
of the aft field joint on the right Solid Rocket Booster. Computer
graphic analysis of film from pad cameras indicated the initial
smoke came from the 270 to 310-degree sector of the circumference of
the aft field joint of the right Solid Rocket Booster. This area of
the solid booster faces the External Tank. The vaporized material
streaming from the joint indicated there was not complete sealing
action within the joint.
- Eight more distinctive puffs of increasingly blacker smoke were
recorded between .836 and 2.500 seconds. The smoke appeared to puff
upwards from the joint. While each smoke puff was being left behind
by the upward flight of the Shuttle, the next fresh puff could be seen
near the level of the joint. The multiple smoke puffs in this
sequence occurred at about four times per second, approximating the
frequency of the structural load dynamics and resultant joint flexing.
As the Shuttle increased its upward velocity, it flew past the
emerging and expanding smoke puffs. The last smoke was seen above the
field joint at 2.733 seconds.
- The black color and dense composition of the smoke puffs suggest
that the grease, joint insulation and rubber O-rings in the joint seal
were being burned and eroded by the hot propellant gases.
- At approximately 37 seconds, Challenger encountered the first of
several high-altitude wind shear conditions, which lasted until about
64 seconds. The wind shear created forces on the vehicle with
relatively large fluctuations. These were immediately sensed and
countered by the guidance, navigation and control system. The
steering system (thrust vector control) of the Solid Rocket Booster
responded to all commands and wind shear effects. The wind shear
caused the steering system to be more active than on any previous
- Both the Shuttle main engines and the solid rockets operated at
reduced thrust approaching and passing through the area of maximum
dynamic pressure of 720 pounds per square foot. Main engines had been
throttled up to 104 percent thrust and the Solid Rocket Boosters were
increasing their thrust when the first flickering flame appeared on
the right Solid Rocket Booster in the area of the aft field joint.
This first very small flame was detected on image enhanced film at
58.788 seconds into the flight. It appeared to originate at about 305
degrees around the booster circumference at or near the aft field
- One film frame later from the same camera, the flame was visible
without image enhancement. It grew into a continuous, well-defined
plume at 59.262 seconds. At about the same time (60 seconds),
telemetry showed a pressure differential between the chamber pressures
in the right and left boosters. The right booster chamber pressure
was lower, confirming the growing leak in the area of the field joint.
- As the flame plume increased in size, it was deflected rearward by
the aerodynamic slipstream and circumferentially by the protruding
structure of the upper ring attaching the booster to the External
Tank. These deflections directed the flame plume onto the surface of
the External Tank. This sequence of flame spreading is confirmed by
analysis of the recovered wreckage. The growing flame also impinged
on the strut attaching the Solid Rocket Booster to the External Tank.
- The first visual indication that swirling flame from the right Solid
Rocket Booster breached the External Tank was at 64.660 seconds when
there was an abrupt change in the shape and color of the plume. This
indicated that it was mixing with leaking hydrogen from the External
Tank. Telemetered changes in the hydrogen tank pressurization
confirmed the leak. Within 45 milliseconds of the breach of the
External Tank, a bright sustained glow developed on the black-tiled
underside of the Challenger between it and the External Tank.
- Beginning at about 72 seconds, a series of events occurred extremely
rapidly that terminated the flight. Telemetered data indicate a wide
variety of flight system actions that support the visual evidence of
the photos as the Shuttle struggled futilely against the forces that
were destroying it.
- At about 72.20 seconds the lower strut linking the Solid Rocket
Booster and the External Tank was severed or pulled away from the
weakened hydrogen tank permitting the right Solid Rocket Booster to
rotate around the upper attachment strut. This rotation is indicated
by divergent yaw and pitch rates between the left and right Solid
- At 73.124 seconds,. a circumferential white vapor pattern was
observed blooming from the side of the External Tank bottom dome.
This was the beginning of the structural failure of hydrogen tank that
culminated in the entire aft dome dropping away. This released
massive amounts of liquid hydrogen from the tank and created a sudden
forward thrust of about 2.8 million pounds, pushing the hydrogen tank
upward into the intertank structure. At about the same time, the
rotating right Solid Rocket Booster impacted the intertank structure
and the lower part of the liquid oxygen tank. These structures failed
at 73.137 seconds as evidenced by the white vapors appearing in the
- Within milliseconds there was massive, almost explosive, burning of
the hydrogen streaming from the failed tank bottom and liquid oxygen
breach in the area of the intertank.
- At this point in its trajectory, while traveling at a Mach number of
1.92 at an altitude of 46,000 feet, the Challenger was totally
enveloped in the explosive burn. The Challenger's reaction control
system ruptured and a hypergolic burn of its propellants occurred as
it exited the oxygen-hydrogen flames. The reddish brown colors of the
hypergolic fuel burn are visible on the edge of the main fireball.
The Orbiter, under severe aerodynamic loads, broke into several large
sections which emerged from the fireball. Separate sections that can
be identified on film include the main engine/tail section with the
engines still burning, one wing of the Orbiter, and the forward
fuselage trailing a mass of umbilical lines pulled loose from the
- The Explosion 73 seconds after liftoff claimed crew and vehicle.
Cause of explosion was determined to be an O-ring failure in right SRB.
Cold weather was a contributing factor. Launch Weight: 268,829 lbs.
- Altitude: 150nm (planned)
- Inclination: 28.5 degrees (planned)
- Orbits: 0
- Duration: 01 min 13 seconds
- Distance: 18 miles
- SRB: BI-026
- SRM: L025(HPM)
- ET : 26/LWT-19
- MLP : 2
- SSME-1: SN-2023
- SSME-2: SN-2020
- SSME-3: SN-2021
- None. KSC Landing planned after a 6 day, 34 minute mission.
KSC Home Mission Index
Last Mission 61-C
Next Mission STS-26
- The planned orbital activities of the Challenger 51-L mission were as
- On Flight Day 1, after arriving into orbit, the crew was to have
two periods of scheduled high activity. First they were to check the
readiness of the TDRS-B satellite prior to planned deployment. After
lunch they were to deploy the satellite and its Inertial Upper Stage
(IUS) booster and to perform a series of separation maneuvers. The
first sleep period was scheduled to be eight hours long starting about
18 hours after crew wakeup the morning of launch.
- On Flight Day 2, the Comet Halley Active Monitoring Program (CHAMP)
experiment was scheduled to begin. Also scheduled were the initial "teacher
in space" (TISP) video taping and a firing of the orbital maneuvering engines
(OMS) to place Challenger at the 152-mile orbital altitude from which the
Spartan would be deployed.
- On Flight Day 3, the crew was to begin pre-deployment preparations
on the Spartan and then the satellite was to be deployed using the
remote manipulator system (RMS) robot arm. Then the flight crew was
to slowly separate from Spartan by 90 miles.
- On Flight Day 4, the Challenger was to begin closing on Spartan while
Gregory B. Jarvis continued fluid dynamics experiments started on day two
and day 3. Live telecasts were also planned to be conducted by
- On Flight Day 5, the crew was to rendezvous with Spartan and use the robot
arm to capture the satellite and re-stow it in the payload bay.
- On Flight Day 6, re-entry preparations were scheduled. This included
flight control checks, test firing of maneuvering jets needed for reentry,
and cabin stowage. A crew news conferences was also scheduled following
the lunch period.
- On Flight Day 7, the day would have been spent preparing the Space Shuttle
for deorbit and entry into the admosphere. The Challenger was scheduled to
land at the Kennedy Space Center.144 hours and 34 minutes after launch.
Last Updated Friday June 29 11:21:02 EDT 2001
Jim Dumoulin (firstname.lastname@example.org)