JonathanDunbar
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Seconds from Disaster – Space Shuttle Challenger (2007), National Geographic
Not sure if many of you have seen this episode; if not, you can view it on youtube.com.
I have been up all night fighting a bad cold/flu and have been watching the National Geographic channel.
This morning they just finished airing the above mentioned episode, and it was an eye opener for me.
First off, the ‘O’ ring failure isn’t the main reason the vehicle and crew were lost. There were many unrelated errors, miscalculations, and design flaws that all worked together to doom the mission.
We all know about Discovery that flew a year earlier at 53 Degrees Fahrenheit and how the lone Morton-Thiokol engineer, argued vehemently against flying challenger the night before citing the badly burned ‘O’ rings from Discovery’s flight in 1985.
Acclaimed quantum physicist, Richard Feynman also bought into the theory that ‘O’ rings doomed Challenger because they didn't seal do the cold weather. Well there was more and still is with shuttles…
Thiokol engineer, Roger Boisjoly, had literally screamed at his managers and NASA managers telling them that the temperature was too low, and that they would likely lose the vehicle on the pad. Thiokol management took a vote after being pressured by NASA management to give a ‘go’ for launch, they did, and then NASA saw this as a ‘blessing’ from the contractor that things were safe for launch.
OK, we all know this part… now comes the things that I didn’t know about from previous programs and articles:
Roger Boisjoly was right, and the ‘O’ Rings didn’t seal. Let me backup a bit before I continue on the ‘O’ Rings.
30 minutes prior to lift-off of Challenger, a commercial jet was passing over the launch area after being cleared by controllers at the cape. The airliner hit severe turbulence at 35k’ and had to take emergency action to get the plane down to 30k’; the plane had been hit by 150+ mph cross winds (Hurricane category 4).
NASA released weather balloons about 45 minutes prior to launch, but by the time the count was picked up again at T-9 minutes, the balloons were miles down range and could not see the air above Challenger.
Everything is going to plan. Main engine start at T-6 seconds... Roger Boisjoly is viewing the launch from atop the Vehicle Assemble Building (I know this from seeing him interviewed on other programs). Now the events that doom Challenger start: Main Engine Start. The shuttle’s main engine ignite and due to the geometry of the off center nature of the vehicles configuration, the entire assembly rocks back and forth; 3 – 4 feet deflection! It does this while the SRBs are bolted to the launch pad. This translates into a curving of the SRB stack (It still does, even with the newly designed SRBs). Any flaws in the seals between the segments are exacerbated due to this motion.
We have main engine start, 4 … 3… 2… 1… SRB ignition and LIFT-OFF lift of Space Shuttle Challenger!
At this point, the seal failed completely, and should have led to a rupturing of the casing, and the loss of vehicle, crew, and pad… but it didn’t happen that way… why?
Upon ignition of the SRBs, standing waves are set up inside the core of the motor; its natural frequency. At T+2.6 seconds, black puffs of smoke are seen coming from the lower segment of the SRB. 9 in total and they are being emitted at the SAME frequency of the natural frequency of the SRB! The ‘O’ Ring HAS failed and the black puffs are gases and propellant bypassing the seal. So why didn’t everything just stop there? Well the slag, the molten aluminum byproduct that is used to increase the ISP of the motor, filled the gap. You talk about angles watching over you. Ok, the puffs stop, the slag seals the gap, and Challenger is on her way to orbit.
Now we go back to the inaccurate weather data that NASA has about the air above the launch site. As Challenger is passing through, 30k feet, it encounters hurricane force crosswinds. This can be seen in the zigzag smoke trail that the vehicle is leaving while ascending. Challenger is FIGHTING to break free of the atmosphere. Even with the throttling down to 63% total thrust of Challenger’s main engines, the loads are severe on vehicle and the SRBs. The slag that saved Challenger 2.6 seconds after lift-off is now broken free and starts to burn through the casing, lower support strut and ET.
We know what happens after this point.
The thing that struck me while watching this program is that Roger Boisjoly was 100% correct and the vehicle should have been lost on the pad, but for a fluke bit of slag from the motor. The launch procedure of the shuttle is flawed in that the vehicle sways and this places stresses and strains on the SRB stack so that minor flaws are amplified. If NASA had real-time weather information, the launch would have been delayed.
Several things had to happen in order and I guess it was the fate of Challenger’s crew to perish no matter what.
Just thought I would share this with the forum as I thought it was very informative.
Jonathan
Not sure if many of you have seen this episode; if not, you can view it on youtube.com.
I have been up all night fighting a bad cold/flu and have been watching the National Geographic channel.
This morning they just finished airing the above mentioned episode, and it was an eye opener for me.
First off, the ‘O’ ring failure isn’t the main reason the vehicle and crew were lost. There were many unrelated errors, miscalculations, and design flaws that all worked together to doom the mission.
We all know about Discovery that flew a year earlier at 53 Degrees Fahrenheit and how the lone Morton-Thiokol engineer, argued vehemently against flying challenger the night before citing the badly burned ‘O’ rings from Discovery’s flight in 1985.
Acclaimed quantum physicist, Richard Feynman also bought into the theory that ‘O’ rings doomed Challenger because they didn't seal do the cold weather. Well there was more and still is with shuttles…
Thiokol engineer, Roger Boisjoly, had literally screamed at his managers and NASA managers telling them that the temperature was too low, and that they would likely lose the vehicle on the pad. Thiokol management took a vote after being pressured by NASA management to give a ‘go’ for launch, they did, and then NASA saw this as a ‘blessing’ from the contractor that things were safe for launch.
OK, we all know this part… now comes the things that I didn’t know about from previous programs and articles:
Roger Boisjoly was right, and the ‘O’ Rings didn’t seal. Let me backup a bit before I continue on the ‘O’ Rings.
30 minutes prior to lift-off of Challenger, a commercial jet was passing over the launch area after being cleared by controllers at the cape. The airliner hit severe turbulence at 35k’ and had to take emergency action to get the plane down to 30k’; the plane had been hit by 150+ mph cross winds (Hurricane category 4).
NASA released weather balloons about 45 minutes prior to launch, but by the time the count was picked up again at T-9 minutes, the balloons were miles down range and could not see the air above Challenger.
Everything is going to plan. Main engine start at T-6 seconds... Roger Boisjoly is viewing the launch from atop the Vehicle Assemble Building (I know this from seeing him interviewed on other programs). Now the events that doom Challenger start: Main Engine Start. The shuttle’s main engine ignite and due to the geometry of the off center nature of the vehicles configuration, the entire assembly rocks back and forth; 3 – 4 feet deflection! It does this while the SRBs are bolted to the launch pad. This translates into a curving of the SRB stack (It still does, even with the newly designed SRBs). Any flaws in the seals between the segments are exacerbated due to this motion.
We have main engine start, 4 … 3… 2… 1… SRB ignition and LIFT-OFF lift of Space Shuttle Challenger!
At this point, the seal failed completely, and should have led to a rupturing of the casing, and the loss of vehicle, crew, and pad… but it didn’t happen that way… why?
Upon ignition of the SRBs, standing waves are set up inside the core of the motor; its natural frequency. At T+2.6 seconds, black puffs of smoke are seen coming from the lower segment of the SRB. 9 in total and they are being emitted at the SAME frequency of the natural frequency of the SRB! The ‘O’ Ring HAS failed and the black puffs are gases and propellant bypassing the seal. So why didn’t everything just stop there? Well the slag, the molten aluminum byproduct that is used to increase the ISP of the motor, filled the gap. You talk about angles watching over you. Ok, the puffs stop, the slag seals the gap, and Challenger is on her way to orbit.
Now we go back to the inaccurate weather data that NASA has about the air above the launch site. As Challenger is passing through, 30k feet, it encounters hurricane force crosswinds. This can be seen in the zigzag smoke trail that the vehicle is leaving while ascending. Challenger is FIGHTING to break free of the atmosphere. Even with the throttling down to 63% total thrust of Challenger’s main engines, the loads are severe on vehicle and the SRBs. The slag that saved Challenger 2.6 seconds after lift-off is now broken free and starts to burn through the casing, lower support strut and ET.
We know what happens after this point.
The thing that struck me while watching this program is that Roger Boisjoly was 100% correct and the vehicle should have been lost on the pad, but for a fluke bit of slag from the motor. The launch procedure of the shuttle is flawed in that the vehicle sways and this places stresses and strains on the SRB stack so that minor flaws are amplified. If NASA had real-time weather information, the launch would have been delayed.
Several things had to happen in order and I guess it was the fate of Challenger’s crew to perish no matter what.
Just thought I would share this with the forum as I thought it was very informative.
Jonathan
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