Challenger Explosion

May 15, 2013 in 1986, Am, In the Public Domain, Pictures, United States



Picture Taken On:
Jan 28, 1986


Place:
Kennedy Space Center, Florida

Behind the Camera:
NASA Tracking Camera

Picture Summary:
Space Shuttle Challenger breaking up soon after takeoff.
This image is in the public domain because it was taken by a federal employee
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The Challenger crew on that Jan 28, 1986 morning was a PC dream team. Two white women (Sharon Christa McAuliffe and Judy Resnik), an Asian American (Ellison S. Onizuka), an African American (Ron McNair), and three white men (Greg Jarvis, Michael J. Smith, and Dick Scobee). McAuliffe was the first citizen astronaut, a teacher, who won a place on board Challenger by beating out a group of 11,000 other entrants. During the mission she was going to broadcast live a lesson to millions of school children across the country. When the seven boarded that morning they had to step carefully as they entered the shuttle, as the boarding platform was covered in ice from an unusual Florida deep freeze. It was this same cold weather that would ultimately doom their launch.

Canadian Cold Front


Ice formed on the Challenger

Icicles on the day of the launch


The odd cold front had come down from Canada putting much of Florida well below freezing. Ice covered the shuttle while it was waiting for take-off at the Kennedy Space Center. These cold temperatures, which dropped to –5 C (20 Fahrenheit), raised concerns in the control room and after the astronauts had entered the shuttle, launch was delayed to allow the temp to increase. Some of the concerns were about the two booster rockets, more specifically the two booster rocket’s O-rings that helped seal together the different segments that made up each rocket. Engineers had come to the conclusion that the O-rings’ design was flawed in extreme cold conditions like those reached on Jan 28. When the temperature dropped the O-rings became brittle and they would not expand to prevent ignited rocket fuel from bursting out through the seals.

Previous launches had come dangerously close to Challenger’s fate with much higher take-off temperatures, the lowest up to that point was 12 C (53 Fahrenheit). Roger Boisjoly, an engineer at, Morton Thiokol the contractor who built the booster rockets, became so concerned that he and his co-workers tried to stop the, cold weather, Challenger launch. NASA managers listened to their concerns and told the group they had 45min to prove the launch would fail, “We had 45 minutes to prepare for the most important meeting of our lives,” Boisjoly said. After the presentation NASA still refused to delay the launch, putting the O-ring issue in the acceptable flight risk category. Morton Thiokol company managers also backed down. Perhaps fearing that any delays might damage their upcoming contract renewal they made a “management decision” overriding their engineers and refused to take the issue any farther.
Oblivious to all this, the seven astronauts patiently waited for the go ahead. After a 2 hour wait the green light was given. The following are excerpts from the timeline that started at 11:38 a.m. EST, Jan. 28, 1986 when the solid rocket ignition command was sent.

Transcript

Shuttle Challenger Liftoff


0.000 – Solid rocket ignition command is sent.
Astronaut Judy Resnik, intercom: “Aaall Riight!”
1.000 – Shuttle pilot Michael Smith, intercom: “Here we go.”
3.375 – Launch commentator Hugh Harris, NASA-SELECT television: “… Liftoff of the 25th space shuttle mission, and it has cleared the tower.”
11.000 – Smith, intercom: “Go you mother.”
15.000 – Resnik, intercom: “Shit hot!”
19.000 – Smith, intercom: “Looks like we’ve got a lot of wind here today.” Shuttle commander Dick Scobee: “Yeah.”
22.000 – Scobee, intercom: “It’s a little hard to see out my window here.”
28.000 – Smith, intercom: “There’s 10,000 feet and Mach point five.” The shuttle is 10,000 feet high traveling at half the speed of sound.
40.000 – Smith, intercom: “There’s Mach 1.”
59.000 – Challenger passes through the region of maximum aerodynamic pressure, experiencing 720 pounds per square foot.
59.262 – A continuous “well defined intense plume” of exhaust is seen on the side of the suspect booster by tracking cameras. This is clear evidence of an O-ring joint burn through.
59.753 – First visual evidence of flame on the right-side booster. 70 mm tracking camera closeup: A flickering tongue of flame appears on the side of the right-side booster away from the shuttle and quickly becomes continuous.
60.000 – Smith, intercom: “Feel that mother go!” Unknown, intercom: “Wooooo Hooooo!”
64.660 – The plume from the burn through changes shape suddenly, indicating a leak has started in the shuttle’s liquid hydrogen tank to fuel the fire.
64.705 – A bright, sustained glow is photographed on the side of the external fuel tank.
65.000 – Scobee, intercom: “Reading four eighty six on mine.” This is a routine airspeed indicator check. Smith: “Yep, that’s what I’ve got, too.”
66.764 – The pressure in the shuttle’s external liquid hydrogen tank begins to drop, indicating a massive leak. Smith had real-time readings of pressure in the liquid hydrogen tank, but it is doubtful he noticed anything unusual because of the rapidity of the failure. It made no difference, ultimately, because even if Challenger’s pilots had suspected an SRB problem there was nothing they could have done about it. While the shuttle separates from its external fuel tank shortly before reaching orbit, it does so with no engines firing and in a benign aerodynamic environment. As Scobee and Smith well knew, separating from the tank while the SRBs were firing would drive the shuttle into the bottom of the fuel tank.
68.000 – Mission Control spokesman Steve Nesbitt in Houston: “Engines are throttling up. Three engines now at 104 percent.”
Dick Covey, mission control: “Challenger, go at throttle up.”
70.000 – Scobee calmly responds, air-to-ground: “Roger, go at throttle up.”
73.000 (approximate) – Smith, intercom: “Uh oh…” This is the last comment captured by the crew cabin intercom recorder. Smith may have been responding to indications on main engine performance or falling pressures in the external fuel tank.

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O-rings


The booster Orings


On the ground, onlookers who had braved the cold watched in horror as the O-rings failed and super heated ignited fuel from inside the booster rocket acted as a blowtorch and igniting the huge external fuel tank. A fireball exploded across the sky as metal flew everywhere and the two booster rockets free of the shuttle spiraled off into the sky. In the stands the children of pilot Mike Smith at first stared in shocked silence and then started screaming, “I want my father! I want my father! He told us it was safe!” AP reporter Howard Benedict dictated the breaking news over the phone to the New York office, “There was no immediate indication on the fate of the crew, but it appeared that nobody could have survived that fireball in the sky.”
Yet, Howard Benedict was wrong. Years after the crash, officials acknowledged that the crew cabin of the shuttle survived the shuttle break-up, intact. There was no real explosion, no detonation of the huge amounts of fuel carried by the shuttle. As the shuttle structure was broken down from the leaking flaming booster rocket it was torn apart by incredible aerodynamic forces outside the super sonic shuttle. At 48,000 ft., the shuttle ripped apart freeing the crew section, which still under great momentum flew to a peek altitude of 65,000 ft before returning back to earth. As the crew compartment flew higher, released fuel from the External Tank (ET) and shuttle burned in seconds creating the huge fireball seen below. The force that tore apart the rest of the shuttle wasn’t great enough to destroy the crew compartment, in part because air density at that height is much lower. Recovered flight recorder data revealed that Shuttle computers still functioned after break-up, even shutting down the engines when sensors showed there was no fuel.

Did the crew survive the explosion?

The G-Forces from the breakup and decent back to earth may have rendered the crew unconscious but it was revealed that on the trip down at least some of the crew where awake. Of the four emergency oxygen tanks, called Personal Egress Air Packs or PEAPs, that were recovered from the ocean, three had been turned on. One of the PEAPs was identified as Smith’s and because the switch was located on the back of his seat investigators believe either Resnik or Onizuka, who sat behind Smith, had the presence of mind after the shuttle break up, to turn it on. It wasn’t until what was left of the shuttle smashed into the ocean at 200 mph some 2 minutes and 45 seconds after the disaster that the compartment was crushed and all inside killed instantly.
The fact that the crew wasn’t killed when the shuttle came apart wasn’t revealed until years after the crash. NASA officials still don’t like to talk about the fate of the crew after the 73 sec mark when the space craft broke up. Their resistance to making public such things as photos of the wreckage, autopsy reports, and other data recording sparked a number of conspiracy theories on the internet. One such viral email included a faked transcript of the final minutes and rumors that some of Challenger crew even survived the ocean crash but died at the bottom of the sea while waiting for a rescue.

Wreckage


Challenger wreckage still washes up


Efforts to find the wreckage in the waters off Florida were at first hampered by falling debris. Soon Navy and coast guard ships where helping in the search for shuttle remains. It took months to get all the wreckage that was recovered but efforts were complicated by the huge search area 1165 square kilometers (450 square miles), water depths of 15 to 365 meters (50 to 1,200 feet), currents of four to six knots, and the sheer number of shuttle pieces. In all 15 tons of debris was pulled from the ocean. 55% of Challenger, 5% of the cabin crew and 65% of the satellite cargo still lies on the ocean floor; occasionally some of it washes up on Florida beaches. The US government still owns the wreckage and under Title 18, United States Code, Section 641 charges anyone who is in possession of Challenger Debris. After the investigation all recovered pieces of the space shuttle where moved to two abandoned Minuteman Missile Silos at Complex 31 at the Cape Canaveral Air Force Station.

Whitehouse Pressure?

Ronald Reagan was supposed to give his State of the Union address the night of launch. After the crash a number of rumors surfaced that the Whitehouse pressured the shuttle to launch over NASA concerns because Reagan wanted to incorporate the astronauts in his speech. The rumors were taken seriously enough to be investigated by commissions into the cause of Challenger crash but no evidence of Whitehouse pressure was found. That evening instead of the State of the Union address Reagan gave a national address on the Challenger disaster. At the end of the speech he quoted a poem that was a favorite of aviators and astronauts, “High Flight” by John Gillespie Magee, Jr.: “We will never forget them, nor the last time we saw them, this morning, as they prepared for their journey and waved good-bye and “slipped the surly bonds of earth” to “touch the face of God.” Weeks after the crash all seven bodies where recovered from the water. Remains that could be identified were returned to their respective families on April 29, 1986. Dick Scobee and Michael Smith’s families chose to bury their bodies in Arlington National Cemetery. Body parts not able to be identified were buried together at a Space Shuttle Challenger Memorial in Arlington on May 20, 1986.

Why?

The Challenger crash was not the result of design flaws in the booster rockets. The crash also had nothing to do with the replacement of the original asbestos-bearing putty in the booster seals. The O-ring seals performed better than the asbestos putty and they would have functioned safely IF the weather conditions that cold Jan day were warmer. NASA operated under the idea of acceptable risk, and problems that weren’t deemed urgent were put aside to be dealt with in the future. Management forgot the, “principles of safely operating on the edge of extreme hazards.” After the shuttle tragedy, problems that had concerned NASA engineers in the past were brought forward. Among the 400 changes made before the next launch of the space shuttle Discovery, 32 months later, on September 29, 1988 was the addition of electric heaters installed in the O-rings to keep them at maximum performance.
Challenger crashed because management at NASA concerned with Challenger’s many launch delays and the effect of the delays on congress’s funding chose to suppress pre-launch valid safety concerns. Post-Challenger NASA had safety personal and representatives from the major contractors included in the mission management team, the group that gives the green light to shuttle launches and shuttle flight operations. Some tried to spin the Challenger tragedy by saying that the loss of human life was the price for expanding into space but this is only true of disasters that are unpreventable. The loss of the space shuttle Challenger and its seven crew was due to incompetent management not unpreventable events. The disaster was unnecessary.

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