challenge crew, were pioneers. i want to say something to the schoolchildren of america, who were watching the live coverage of the shuttle's takeoff. i know it's hard to understand, but painful things like this happen. it's all part of the process of exploration and discovery. it's all part of taking a chance and expanding man's horizons. the future doesn't belong to the faint-hearted. it belongs to the brave. the challenger crew was pulling us into the future and we'll continue to follow. i've always had great faith in and respect for our space program. what happened today does nothing to diminish it. we don't hide our space program. we don't keep secrets and cover things up. we do it all up front and in public. that's the way freedom is, and we wouldn't change it for a minute. we'll continue our quest in space. there will be more shuttle flights and more shuttle crews, and yes, more volunteers, more

civilians, more teachers in space. nothing ends here. our hopes and our journeys continue. i want to add that i wish i could talk to every man and woman who works for nasa or who worked on this mission and tell them, your dedication and professionalism has moved and impressed us for decades and we know of your anguish. we share it. there's a coincidence today. on this day, 390 years ago, the great explorer sir francis drake died aboard a ship off the coast of panama. in his lifetime, the great frontiers were the oceans and the historians later said, he lived by the sea, died on it, and was buried in it. well, today, we can say of the challenger crew, their dedication was like drake's -- complete. the crew of the space shuttle challenger honored us in the manner in which they lived their

lives. we will never forget them, nor the last time we saw them, this morning, as they prepared for their journey and waved goodbye and slipped the surly bonds of earth, to touch the face of god. thank you. >> flight of the space shuttle challenger on mission 51-l, the 25th flight of the space shuttle program, began at 11:38 a.m. eastern standard time on january 28th, 1986. it ended 73 seconds later in the structural break-up of the external tank and orbiter, in which the seven crew members perished. the solid rocket boosters continued in flight and were destroyed by the range safety officer, 110 seconds after launch.

>> the delivery and assembly of 51-l launch vehicle components began months prior to launch. the solid rocket booster segments were transported by rail to the kennedy space center. the srbs were inspected and partially assembled at the rotation processing and storage facility. the segments were then moved to the vehicle assembly building or vab where they were stacked on the mobile launch platform. the external tank arrived by barge and was moved into the vab where it was checked out and

mated to the stacked solid rocket boosters. after orbiter checkout, challenger was rolled into the vab and mated with the external tank and srbs. the sts 51-l vehicle was transported from the vab to the launch pad on december 22, 1985. at a crawler speed of approximately one mile per hour, the journey takes about six hours. the launch was rescheduled several times, resulting in the final countdown on january 28, 1986. the weather was forecast to be clear and cold with temperatures dropping into the low 20s overnight. the fuelling of the external

tank began at 1:25 a.m. ice had accumulated on the launch pad during the night. several water systems were opened slightly and allowed to flow into drains. the drains froze and caused overflows. high wind gusts spread the water over large areas and ice formed. the air temperature at launch was 36 degrees fahrenheit. this was 15 degrees colder than any previous launch. at t minus seven minutes and 30 seconds, the ground launch began retracting the arm. it can be put back in place within 15 to 20 seconds if an emergency arises and the crew must evacuate the pad. at t minus three minutes and 15 seconds, checks of the main

engines were performed. all three engines move in a preprogrammed pattern to verify flight control. the sequence ends with the engines in the start positions. at t minus two minutes and 55 seconds, external tank liquid oxygen pressurization began and main engine purging was completed. at t minus two minutes and 50 seconds, retraction of the gas oxygen vent hood began. the ground launch sequence verified full retraction at t minus 37 seconds. sound suppression water was started at t minus 16 seconds. at t minus eight seconds, hydrogen igniters were turned on to burn off any free hydrogen. 6.6 seconds before launch,

challenger's liquid fuel main engines were ignited in sequence and run up to full thrust. thrust from the main engines bends the shuttle stack. when it returned to vertical, the solid rocket boosters ignited. at t zero the bolts were exmroe sufficiently released. after the initial prerelease motion, structural forces on the assembly are dissipated through vibration at a rate of three cycles per second during first few seconds of flight. rollover was initiated 7.24 seconds. it was completed at 21.124 seconds. >> 104%. throttle down to 65%.

>> the main engines were throttled back to 65% at 35.379 seconds for about 16 seconds in order to alleviate loads during maximum dynamic pressure. >> altitude 4.3 nautical miles. >> the engines were then throttled up. >> 104%. >> during the flight, data gave no indication of problems. >> one minute 15 seconds. altitude nine nautical miles. down range decision, seven nautical miles.

>> the solid rocket boosters continued in flight and were destroyed 110 seconds after launch. data from nearly 200 cameras were analyzed during the investigation. the following sequence of events is based on the evaluation of film, video and telemetry data. this graphic indicates viewing angles for three cameras in the vicinity of the launch sight. the first is from camera e-63 at the lower right of the chart. at .678 seconds ah strong puff of gray smoke can be seen spurting from the joint on the right solid booster. the material indicates there was not complete sealing action within the joint. this second view is from camera

e-60. the smoke can be seen between the right srb and the external tank and moves in the upward direction. the angle between this view and e-63 is approximately 100 degrees. with e-60 and e-63 side by side, it's clear when smoke is first visible to e-60, it is not visible to e-63. .2 seconds later it becomes visible and is seen in puffs reaching maximum visibility at about 1.9 seconds. a third higher resolution camera d-67 was located east of the launch pad. d-67 recorded this view of the smoke at approximately the same time of maximum development. smoke appears to the right side of the srb only.

while normal water condensation vapors appear to the left. this plan shows that none of the cameras directly view the surface of the right srb in the shaded region of the graphic. analysis of film from several pad cameras indicated that the smoke came from between 270 and 310 degrees on the circumference of the joint. as indicated on these pre-flight photos, the smoke emerged from just above the strut between the srb and et at a point along the longitudinal axis near the aft field joint. the multiple smoke puffs occurred at a rate of four times per second, approximating the frequency of the structural load dynamic and joint flexing. this greatly exaggerated computer animation depicts the flexing of the srb joint.

this flexing increased the gap at the location of two rubber o ring seals. last evidence of smoke above the aft detach ring is at 7.23 seconds. the last appearance is 3.75 seconds. film records of the assembly of the solid rocket booster were reviewed to determine any evidence of cause for the smoke. photographs taken just prior to mating of the booster saysme ee show a subtle variation but through computer enhancement was a shadow caused by irregularities in the grease. no evidence of o ring defects was observed in any of the photography. the facility hydrogen vent arm was not captured after retraction at launch. film analysis however showed that it did not rebound and

contact the vehicle or contribute to the accident. post launch inspection of the hold down posts revealed that the kick spring assembles on four of the posts were missing. doe tailed analysis determined that the assemblies could not have been detached prior to t plus 850 milliseconds and were not a contributing factor to the smoke observed at liftoff. the next significant event was the development of the srb burn through plume. camera e-207 located about six miles north of the launch pad shows the growth of this plume. the first evidence of flame appeared on the right solid rocket booster at 58.788 seconds. this occurred as the main

engines had been throttled up and the srbs were increasing thrust. camera e-203 was located west of the launch site and gives an aft view. the exposure was set for the booster nozzle plumes. this graphic illustrates the location of the flare. the flare was located near the aft field join approximately 300 degrees circumferential which is consistent with the smoke emissions at liftoff. within half a second, the flame had grown into a continuous and well defined plume. at the same time, telemetry showed a divergence in pressure between the right and left srb. pressure in the right was lower as a result of the growing leak. the plume is seen here on the surface of the external tank and

lower aft strut. at 62 seconds, the control system elements began to respond to the forces caused by the plume. as recorded on e-207 and e-204, the first visual indication that the plume penetrated the external tank was seen at 64.66 seconds as an abrupt change in the shape and color of the plume. this is an indication of hydrogen leaking from the external tank. at 64.705 seconds, a bright sustained glow developed between the orbiter and the external tank. slight changes in the hydrogen tank pressure data confirmed the leak 2.2 seconds later at 66.8 seconds when the lh-2 tank pref

pressurization could no longer maintain its rate. the pressure could no longer be maintained indicating leak path was growing rapidly. at 72.2 seconds, the guidance system showed that right srb motion diverged from the orbiter and left srb indicating the strut was severed or pulled loose. during this time frame, exaggerated staring command and control system responses registered in data. at approximately 73 seconds, both liquid hydrogen and liquid oxygen pressure to the main engines showed a significant drop. this was followed at 73.124 seconds by the appearance of a white pattern around the et aft region suggests tank structural failure. 13 milliseconds later, at 73.137 seconds, vapor was observed

indicative of the lick witness oxygen tank failing thchlt can be attributed to abnormal loads induced by the right srb rotation at the forward attach point or the propulsive forces. probably both. within milliseconds, liquid oxygen was observed streaming along the external tank. at 73.191 seconds, a flash was observed between the et and orbiter that was followed by the start of the total vehicle breakup at 73.213 seconds. during the next 100 milliseconds, additional flashes occur in the srb forward attach area. as the et broke up, the released fluids vaporized rapidly producing a cloud of gases, vapors and fluid with imbedded debris and localized combustion of mixed gases.

no shock wave or other evidence of a violent explosion was detected in the imagery. illumination from a combination of srb plume, reflected sun and burning of gases gives the cloud the appearance of a fireball. by 73.6 seconds, the main engines were in automatic shutdown mode as a result of pressure. the last telemetry was received 73.618 seconds after launch. the actual vehicle brokeup was essentially obscured by the vapor cloud which enveloped the vehicle. hundreds of fragments were noted exiting the cloud. those identified included the shuttle main engines, left wing, crew cabin and both srbs. approximately one second after initial breakup, film showed the front segment of the orbiter emerging from the cloud.

the nose, crew cabin and a portion of the cargo bay make it up in this view. oxidizer from the reaction control system provided an orange brown color to the cloud. by 74.578 seconds s a flash wa visible. this is believed to be caused by burning gas from the forward rcs. the flash reaction from the rcs abated revealing separation of the nose from the crew cabin. less than a quarter of a second later, the crew cabin was noted to be severed from the cargo bay. igniting a discharge continued to be observed from the forward rcs. a camera south of the launch pad

recorded a wider array of debris existing the vapor cloud. the initial emergence of the crew cabin from this perspective was at 75.237 seconds. the initial path of the crew cabin from the vapor cloud carried it across the path of an adjacent trail revealing its form and attitude. the left wing became visible at 78.531 seconds. the main engines and crew cabin are also identifiable. after ten seconds, the crew cabin was seen again with the front end and top of the cabin visible. as the subject moved further away and dropped lower on the horizon, the quality of the image for visual analysis deteriorated rapidly.

long range tracking cameras followed the srbs through safety destruct. at approximately 75.8 seconds, the right srb was seen exiting the cloud. camera e-207 shows the right srb after the breakup and the joints are clearly visible except for the aft field joint. this confirmed the location of the plume along the longitudinal axis of the srb. the separated nose cap and deployed parachute are identified at approximately 76.4 seconds. the shock wave from the detonation of the charge on the right srb can be seen clearly. sigh mul tan our multaneou

simultaneously, the left srb was destroyed. at approximately 37 seconds, challenger had encounter the first of several expected high altitude wind sheer conditions which lasted until about 64 seconds. these wind sheers are best illustrated by the effect on the booster exhaust trails. the effect of wind sheer was immediately sensed and count erd by the guidance navigation and control system. wind reconstructions were aided by comparing predicted exhaust trail shapes with photography. it was used to verify the loads were within limits. several flashes in the ssme plumes were observed during the flight. as similar flashes have been seen on several previous flights, they are considered not to have contributed to the accident.

the visible condensation that appears in this frame is created by shock waves which develop as the vehicle passes through the speed of sound. a large scale search effort was initiated to recover the space shuttle debris. 22 ships, 6 underwater search vesle vessels and 33 aircraft participated in the operation. the pieces recovered initially were those found floating on the surface. the submarine fleet was used to locate and inspect underwater debris. objects identified as being important to the investigation were retrieved.

50% of the entire vehicle was recovered in the effort. the ocean search area was located at edge of the gulf stream at depths up to 1200 feet. approximately 93,000 square miles of ocean were searched. the recovered hardware was brought to the logistics facility where reconstruction efforts helped to verify the investigation team's finding s s well as analyze the breakup of the et and srbs and orbiter. inside the facility, parts were arranged on the floor according to their location on the vehicle. 45% of the orbiter itself was recovered. the debris confirmed it did not contribute to the cause of the accident and that the orbiter break just was a result of

aerodynamic affects rather than explosive affects. shown here are parts of the orbiter forward fuselage structure which surrounds the crew cabin. extensive heating and erosion was detected on the right aft section of the orbiter. the paint was scorched and blackened on the right side of the aft fuselage. thermal distress was apparent on the right rudder speed brake while the left showed little effect. thermal effects were also seen on the elevan. the aft left side of the orbiter showed no apparent sign of heat damage.

the remaining recovered parts of the orbiter showed no evidence of fire or explosion from within the vehicle. all three main engines were recovered and helped to verify that they did not contribute to the cause of the accident. the external tank was similarly reconstructed. 25% of the liquid hydrogen tank, 80% of the inner tank and 5% of the liquid oxygen tank was recovered. most of the external hardware was also recovered. the nose cap sustained very little damage. in general, the recovered pieces

were quite large. the spray on on foam insulation exhibited varying degrees of thundersto thermal effects from extreme charring to practically no effect. the external tank range safety charges were recovered undetonated, eliminating them as a possible factor in external tank breakup. the inner tank region showed signs of buckling in the fore and aft direction. this would be consistent with the impulsive thrust that resulted from the sudden liquid oxygen from the aft section of the tank. this shearing failure of the forward attachment fitting with the right srb was caused by the booster's rotation after the aft strut area failed. the stiffener stringers on the right-hand side of the inner tank show evidence of contact

which matched marks on the forward assembly of the right srb. a section of the ring frame and a section of the aft dome from the lower strut attachment area was recovered in one piece. the lower strut attachment fitting had been pulled away. the effects of the anom louse srb plume can be seen on the external tank excluding an area which was shielded by the strut and attachment fitting. approximately 50% of solid rocket booster hardware was recovered. an ordnance storage facility was used to house the pieces as some contained unburned propellant. marks seen on the right srb matched the contact area shown previously on the e.t. inner tank stringers.

the size and location of the burn-through as indicated by the recovered srb debris were illustrated on an assembled booster. the aft center section of the joint shows a large hole. the irregular hole is roughly rectangular and is about 27 by 15 inches. the steel case material showed evidence of hot gas erosion caused by combustion products flowing through the opening. the aft section of the right srb showed a hole approximately 33 by 21 inches. the burned surface extended into the aft attached strut region. the exterior surface of the aft case featured a large heat-affected area. the shape and location of this

heat spot indicates an impingement from the escaping gases. there was a small burn-through in the case wall which appeared to have penetrated from the outside in. this was due to the impingement of hot gases from the anomolous plume. the hole in the solid rocket booster segments was the result of the joint leakage on the right hand srb which was determined to be the cause of the accident. the presidential commission concluded that the cause of the "challenger" accident was the failure of the pressure seal in the aft field joint of the right solid rocket motor. the failure was due to a faulty design, rendering the seal unacceptably sensitive to a number of factors. those factors include the effects of temperature, physical dimensions, the character of materials, the effects of reuse and processing and the reaction

of the joint to dynamic loading. more detailed analyses are contained in volume three of the report of the presidential commission on the space shuttle "challenger" accident. as the director of military and veteran affairs at the university of toledo in ohio, many veterans have come into my office talking about who they wants to vote for. regardless if they want to vote democratic or republican, it's your civic duty to get out and vote. many things are at stake with this election so i encourage you to get out, do your research and vote for the candidate that best supports your causes and the future of this nation. >> my name is todd. i'm here in toledo, ohio. i'm here supporting bernie sanders. i feel as though he's one of the most important candidates in this field right now. he's the most viable alternative

to mainstream politicians and he has the most progressive ideas that are most important for the country and i would encourage everyone to go out and support bernie if possible. >> the most important issue that the university of toledo college democrats feel is important in this election is going to be college tuition as well as jobs. when college kids go to school they need to know how to pay for it and afford it as well as when they're leaving college whashgs their future's going to look like, what the job market's going to look like, who's trying to bring jobs back into the u.s. and things like that. so as president of the college democrats i feel those are the two biggest issues for an election cycle. >> i was originally going to vote for bernie sanders. however, since i'm not that politically inclined i ended up voting for hillary because she seems more knowledgeable and has been in the political environment for more. she's my country's leader. she has been secretary of state and has already seen the inner workings of the white house and how the game goes.

our road to the white house coverage continues tuesday evening as voters in arizona, idaho, utah and american samoa head to the polls. our coverage with results and speeches will begin after polling places close live on c-span. 30 years ago, on january 28th, 1986, the space shuttle "challenger" exploded 73 seconds after lift-off. taking the lives of the seven crew members pictured here on their way to the launch pad. the crew included school teacher christa mcauliffe, selected from more than 11,000 am quantipplic be the first teacher in space. next on history tv's real america, a ten-minutes nasa video of mcauliffe, on the right in this photo, with backup teacher barbara morgan are shown

meeting the "challenger" crew, testing food and being fitted for space clothing. >> there we go. okay. >> oh, gee, thanks. >> that's all right. you missed the world's greatest picture. >> okay. y'all can relax. as soon as charles [ inaudible ]. he's trying to get one. >> we haven't really done that. you know, when it happened with

me, i'm sure it happened to barbara, we had a lot of people who wanted to know exactly what time we were stepping one foot off so they could interview us for eight hours. we talked briefly this morning and said -- >> okay. that's good. >> people take one of everything. >> we will just finish up the spinach. >> does that seem normal? >> no. it really seems strange.

>> this, when you drink it, keeps the liquid from coming out. >> you have to open that up before you can drink. like that. >> okay. then you just click it? >> yeah. you leave it sitting in zero gravity, it may have a tendency to fall out. >> okay. >> you can take it out. you don't have to -- you don't want to leave it sitting around. >> okay. >> [ inaudible ].

>> okay. why don't we do it this way. barbara, if you sit down here. christa, you sit back here. >> this is the stuff you'll be wearing in the launch. >> okay. put it around, wrap it around your leg there. okay. have a seat. just want to make sure these cut-outs come where your knees are.