Chronologie de l'accident de la navette spatiale Challenger

La chronologie de la mission STS-51-L est la chronologie détaillée des événements depuis l'allumage des moteurs principaux de challengers jusqu'à la destruction des deux propulseurs d'appoint à poudre, et comprend une transcription des conversations de l'équipage à partir de l'enregistreur de voix (Cockpit Voice Recorder) à bord de l'Orbiteur.

STS-51-L était le vingt-cinquième vol du programme navette spatiale, marqué par le premier vol civil à bord de la navette spatiale. La mission utilisait la navette spatiale Challenger, qui a décollé de l'aire de lancement 39B du Centre spatial Kennedy, en Floride en 1986. La mission s'est terminée en catastrophe, par la destruction de Challenger 73 secondes après le décollage en raison de la défaillance d'un joint torique sur le propulseur d'appoint à poudre de droite de Challenger, ce qui a conduit à la désintégration rapide de la navette en raison de l'écrasante pression aérodynamique resultante. Les sept membres de l'équipage ont été tués peu de temps après l'éclatement du véhicule.

Légende

Voici la légende des acronymes utilisés :

• APU - Auxilixary Power Unit, générateur auxiliaire
• ET - External Tank, le réservoir externe
• GPC - General Purpose Computer, ordinateur principal
• HPFT - High Pressure Fuel Turbopump, pompe à carburant hautement pressurisée
• LH2 - Liquid Hydrogen, hydrogène liquide
• LO2 ou LOX - Liquid Oxygen, oxygène liquide
• MEC - Main Engine Controller, contrôleur du moteur principal
• PIC - Pyrotechnics Initiator Controller, contrôleur de la pyrotechnie
• psf - Pounds per square foot, pounds par pied au carré
• psi - Pounds per square inch, pounds par inch au carré
• RCS - Reaction Control System, système de contrôle
• CVR - Cockpit Voice Recorder, enregistreur de l'habitacle de la navette
• MET - Mission Elapsed Time, temps en secondes depuis le décollage

Chronologie

Temps (UTC) (heure:minute:seconde)	Mission Elapsed Time (MET) (en secondes)	Évènement	Source
16:37:53.444	-6.566	Commande d'ignition du SSME-3.	GPC
16:37:53.564	-6.446	Commande d'ignition du SSME-2.	GPC
16:37:53.684	-6.326	Commande d'ignition du SSME-1.	GPC
16:37:54	-6	CDR: "There they go guys!" MS2: "All right!" CDR: "Three at a hundred."	CVR
16:38:00	0	MS2 "Aall riight!"	CVR
16:38:00.010	0.000	Commande d'ignition du SRB.	GPC
16:38:00.018	0.008	Holddown Post 2 PIC firing.	Appareil photographique E8
16:38:00.260	0.250	First continuous vertical motion.	Appareil photographique E9
The O-rings in the right-hand SRB field joint fail.
16:38:00.688	0.678	First confirmed puff of smoke appears above SRB/ET attachment ring field joint on right-hand SRB.	Appareil photographique E60
16:38:00.846	0.836	Eight puffs of smoke appear above field joint, lasting from t+0.836 to t+2.5 seconds MET.	Appareil photographique E63
16:38:01	1	PLT "Here we go."	CVR
16:38:02.743	2.733	Dernière preuve de fumée provenant du joint.	Appareil photographique CZR-1
A solid-fuel 'plug' seals the gap formed by the O-ring 'blow-by'.
16:38:03.385	3.375	Dernière preuve de fumée.	Appareil photographique E60
16:38:04.349	4.339	SSMEs throttled up to 104%	E41M2076D
16:38:05.684	5.674	Right-hand SRB pressure 11.8 psi above normal.	B47P2302C
16:38:07	7	CDR: "Houston, Challenger - Roll program."	CVR
16:38:07.734	7.724	Roll program initiated.	V90R5301C
16:38:11	11	PLT: "Go you Mother!"	CVR
16:38:14	14	MS1: "LVLH"	CVR
16:38:15	15	MS2: "(Expletive) hot!"	CVR
16:38:16	16	CDR: "Ooohh-kaaay."	CVR
16:38:19	19	PLT: "Looks like we've got a lotta wind here today."	CVR
16:38:19.869	19.859	SSMEs throttled back to 94%	E41M2076D
16:38:20	20	CDR: "Yeah."	CVR
16:38:21.134	21.124	Roll program completed.	VP0R5301C
16:38:22	22	CDR: "It's a little hard to see out my window here."	CVR
16:38:28	28	PLT: "There's ten thousand feet and Mach point five."	CVR
16:38:30	30	[Garble]	CVR
16:38:35	35	CDR: "Point nine."	CVR
16:38:35.389	35.379	SSMEs throttled back to 65%	E41M2076D
16:38:37.000	36.990	Roll and Yaw Attitude Response to wind shear (36.990 to 62.990 sec).	V95H352nC
The solid fuel 'plug' is dislodged.
16:38:40	40	PLT: "There's Mach one."	CVR
16:38:41	41	CDR: "Going through nineteen thousand."	CVR
16:38:43	43	CDR: "OK, we're throttling down."	CVR
16:38:51.870	51.860	SSMEs throttled up to 104%	E41M2076D
16:38:57	57	CDR: "Throttling up."	CVR
16:38:58	58	PLT: "Throttle up."	CVR
16:38:58.798	58.788	First evidence of flame on right-hand SRB.	Appareil photographique E207
16:38:59	59	CDR: "Roger."	CVR
16:38:59.010	59.000	Reconstructed Max Q (720 psf)	Best estimated trajectory
16:38:59.272	59.262	Continuous well defined plume of flame on right-hand SRB.	Appareil photographique E207
16:38:59.763	59.753	Flame from right-hand SRB in downwards direction (seen from south side of vehicle).	Appareil photographique E204
16:38:60	60	PLT: "Feel that mother go!" "Woooohoooo!"	CVR
16:39:00.014	60.238	Pressures in right- and left-hand SRBs begin to diverge.	B47P2302
16:39:00.248	60.238	First evidence of intermittent plume deflection.	Appareil photographique E207
16:39:00.258	60.248	First evidence of SRB plume attaching to ET ring frame.	Appareil photographique E203
16:39:00.998	60.988	First evidence of continuous plume deflection.	Appareil photographique E207
16:39:01.734	61.724	Peak roll rate in response to wind shear.	V90R5301C
16:39:02	62	PLT: "Thirty-five thousand going through one point five."	CVR
16:39:02.094	62.084	Peak TVC response to wind shear.	B58H1150C
16:39:02.414	62.404	Peak yaw response to wind shear.	V90R5341C
16:39:02.494	62.484	Right-hand outboard elevon actuator hinge moment spike.	V58P0966C
16:39:03.934	63.924	RH outboard elevon actuator delta pressure change.	V58P0966C
16:39:03.974	63.964	Start of planned pitch rate manoeuvre.	V90R5321C
The plume of flame burns through the LH2 tank in the ET.
16:39:04.670	64.660	Change in anomalous plume shape (LH2 tank leak near 2058 ring frame).	Appareil photographique E204
16:39:04.715	64.705	Bright sustained glow on sides of ET	Appareil photographique E204
16:39:04.947	64.937	Start SSME gimbal angle large pitch variations	V58H1100A
16:39:05	65	CDR: "Reading four eighty six on mine."	CVR
16:39:05.174	65.164	Beginning of transient motion due to changes in aero forces due to plume.	V90R5321C
16:39:06.774	66.764	Start ET LH2 ullage pressure deviations.	T41P1700C
16:39:07	67	PLT: "Yep, that's what I've got, too."	CVR
16:39:10	70	CDR: "Roger, go at throttle up." (Last transmission on air-to-ground voice loop).	CVR
The flame burns through the lower attachment strut on the right-hand SRB, causing the SRB to move away from the ET.
16:39:12.214	72.204	Left- and right-hand SRB yaw rates begin to diverge.	V90R2528C
16:39:12.294	72.284	Left- and right-hand SRB pitch rates begin to diverge.	V90R2525C
16:39:12.488	72.478	SRB major high-rate actuator command.	V79H2111A
16:39:12.507	72.497	SSME roll gimball rates 5 deg/sec.	V58H1100A
16:39:12.535	72.525	Vehicle max +Y lateral acceleration (+.227 g).	V98A1581C
16:39:12.574	72.564	SRB major high-rate actuator motion.	B58H1151C
16:39:12.574	72.564	Start of H2 tank pressure decrease with 2 flow control valves open.	T41P1700C
16:39:12.634	72.624	Last state vector downlinked.	Data reduction
16:39:12.974	72.964	Start of sharp MPS LOX inlet pressure drop.	V41P1330C
16:39:13	73	PLT: "Uh-oh..."	CVR
16:39:13.020	73.010	Last full computer frame of TDRS data.	Data reduction
16:39:13.054	73.044	Start of sharp MPS LH2 inlet pressure drop.	V41P1100C
16:39:13.055	73.045	Vehicle max -Y lateral accelerarion (-.254 g).	V98A1581C
Challenger begins to disintegrate.
16:39:13.134	73.124	Circumferential white pattern on ET aft dome (LH2 tank failure). The bottom of the ET is open and liquid hydrogen spills.	Appareil photographique E204
16:39:13.134	73.124	Right-hand SRB pressure 19 psi lower than left-hand SRB	B47P2302C
16:39:13.147	73.137	First hint of vapour at intertank.	Appareil photographique E207
16:39:13.153	73.143	All engine systems start responding to loss of fuel and LOX inlet pressure.	SSME team
16:39:13.172	73.162	Sudden cloud along ET between intertank and aft dome. The right booster slams into the ET just as the LH2 tank is thrust into the oxygen tank.	Appareil photographique E207
16:39:13.201	73.191	Flash between Orbiter & LH2 tank.	Appareil photographique E204
16:39:13.221	73.211	SSME telemetry data interference from 73.211 to 73.303.	Data reduction
16:39:13.223	73.213	Flash near SRB forward attachment strut and brightening of flash between Orbiter and ET	Appareil photographique E204
16:39:13.292	73.282	First indication intense white flash at SRB fwd attach point.	Appareil photographique E204
16:39:13.337	73.327	Greatly increased intensity of white flash.	Appareil photographique E204
16:39:13.387	73.377	Start of RCS jet chamber pressure fluctuations.	V42P1552A
16:39:13.393	73.383	All engines approaching HPFT discharge temp redline limits.	E41Tn010D
16:39:13.492	73.482	ME-2 HPFT discharge temperature. Channel A votes for shutdown; 2 strikes on Channel B.	MEC data
16:39:13.492	73.482	SSME-2 controller last time word update.	MEC data
16:39:13.513	73.503	SSME-3 in shutdown due to HPFT discharge temperature redline exceedance.	MEC data
16:39:13.513	73.503	SSME-3 controller last time word update.	MEC data
16:39:13.533	73.523	SSME-1 in shutdown due to HPFT discharge temperature redline exceedance.	Calculation
16:39:13.553	73.543	SSME-1 last telemetered data point.	Calculation
16:39:13.628	73.618	Last validated Orbiter telemetry measurement.	V46P0120A
16:39:13.641	73.631	End of last reconstructured data frame with valid synchronization and frame count.	Data reduction
16:39:14.140	74.130	Last radio frequency signal from Orbiter	Data reduction
Loss of downlink - Challenger is lost.
16:39:14.597	74.587	Bright flash in vicinity of Orbiter nose.	Appareil photographique E204
16:39:16.447	76.437	Right-hand SRB nose cap separation & parachute deployment.	Appareil photographique E207
16:39:50.260	110.250	Destruction of right-hand SRB via Range Safety System.	E202 Camera.
16:39:50.262	110.252	Destruction of left-hand SRB via Range Safety System.	Appareil photographique E230

Notes et références

• (en) Cet article est partiellement ou en totalité issu de l’article de Wikipédia en anglais intitulé « STS-51-L Mission timeline » (voir la liste des auteurs)