please be as basic as possible. i read the wikipedia article about this event but i still am not quite sure what was the cause. thank you. :]
What caused the Space Shuttle Columbia Disaster?
Security was tight at launch and no indication of sabotage.
Initial speculation was the vertical tail fin broke apart.
The reason for the break up: it seems the left wing was hit by a piece of foam from the Space Shuttle External Tank (ET) during launch. At the time of the launch it was judged that event did not represent safety concern.
July 2nd, 2009 at 6:55 am
Ice
References :
July 2nd, 2009 at 7:37 am
What caused the Space Shuttle Columbia Disaster?
Security was tight at launch and no indication of sabotage.
Initial speculation was the vertical tail fin broke apart.
The reason for the break up: it seems the left wing was hit by a piece of foam from the Space Shuttle External Tank (ET) during launch. At the time of the launch it was judged that event did not represent safety concern.
References :
http://www.aerospaceguide.net/spaceshuttle/columbia_disaster.html
July 2nd, 2009 at 8:17 am
Hi. Unfortunately a piece of insulating foam broke off from the external tank and damaged the leading edge of the left wing. The heat of reentry got into the wing and melted enough of the wing’s structure so that it failed.
References :
July 2nd, 2009 at 8:57 am
The left wing was hit by a peice of foam during liftoff which made a little hole in the wind, so when the shuttle was entering the earth’s atmosphere, super hot air from the atmosphere entered the hole causing evrything to overheat
References :
July 2nd, 2009 at 9:47 am
A peice of foam broke off the shuttle during launch, and damaged the wing.
Upon re-entry, the inside structure of the wing, which was no longer protected, took in tremendous amounts of heat. The entire shuttle began to break up.
Of course, in my opinion, the causes were:
1. Beaurocracy’s nature to not communicate well.
2. Shedding foam concearns that many people kept ignoring, sort of like how you might continue to drive a car with a known engine problem, but since it appears to be working, you don’t take it to the mechanic.
References :
July 2nd, 2009 at 9:58 am
The failure of mission planners to recognize a basic problem with the large fuel tank is the main cause. It is very cold, and will collect ice from condensation of moisture out of the air. Some foam insulation, like what portable drink coolers are made from, was sprayed on the outer parts of the tank and its pipes. This insulation was seen coming off in past missions, but it was mistakenly assumed that small pieces would not affect the safety level.
On the Columbia mission, soon after blast-off a large piece of insulation was seen hitting the leading edge of one wing. The light weight foam was moving at hundreds of miles an hour when it hit. No one was sure that there was any damage. But later tests showed that as large as a two foot hole could have been made in the carbon-carbon fiber panel at the wing’s edge. This is a critical area. High speed air during reentry is heated to thousands of degrees from friction. This air entered the wing structure and caused sensors to fail, then beams of aluminum melted. The wing began to bend, and caused excessive drag on one side. The shuttle tumbled out of control and broke into many pieces. Everyone died. Parts were recovered along the flight path in a very large area in Texas.
References :
July 2nd, 2009 at 10:20 am
Well, it was caused because a piece of foam detached from the external tank during launch and hit it right on the nose of the wing.
At this place, the shuttle experiences strong heating during reentry, and needs special tiles, which are very heat resistant, but even more fragile as the other heat shield tiles. The small foam part accelerated to about 300 km/h by the airflow around the tank and create a small gap inside this tile.
A few days later, during reentry, hot air entered the gap and slowly welded through the internal structure of the wing. The Shuttle is made of aluminum, which melts already at about 280°C, the air which entered the Shuttle was already about 1500°C hot. The strong main wing spar and the many layers of insulation inside the shuttle withstood the hot air for a few minutes, but finally, the hot air reached deeper into the wing and damaged main landing gear and sensors, before weakening the structure even more.
At this point, the orbiter started loosing first a few tiles and the aerodynamics of the orbiter changed by the softer wing, which deformed. This got noticed by the autopilot and he attempted to correct this.
Seconds later, the whole wing collapsed and flew away, leaving the shuttle in a violent spin. The Shuttle needs to fly at a special angle to the incoming air, with the black side pointing forward - the white tiles can’t survive the full heat, just like the windows. The increased heating and the rapid accelerations without the wing quickly teared the shuttle into smaller parts.
References :
July 2nd, 2009 at 10:36 am
As was said the foam punched a hole in the left wing.
When Columbia came back into the atmosphere she was moving about 18,000 mph. (or Mach 30 or 13 Km per sec.). When she hits the end of the runway in Florida she was supposed to come to a complete stop. Obviously slowing down from that speed to a dead stop is difficult. The amount of energy (speed) that must be dissipated is very large. Stopping a one hundred tonne craft from a speed of 13 km per second in eighty minutes requires nearly two thousand megawatts of power.
The way NASA does that is for the shuttle to loose energy into the atmosphere as it comes in. Most of that energy takes the form of heat. As the orbiter comes into the atmosphere the friction of rubbing against the air slows it down. This friction generates heat, (that is where the energy goes…basicly the shuttle is converting speed into heat as it comes into the atmosphere). This is why spaceships have heat shields on them. The air outside the spaceship gets very very hot.
The hole in the wing meant there was a hole in the heat shield.
As Columbia was coming in, super-hot air got into the hole in the wing. This was pretty much the same thing as going in there with a huge blowtorch. It melted away the wing from the inside out.
This caused the wing to break apart.
At this point the astronauts were several miles up, going at several thousand miles an hour. Their space ship was inside an envelope of super hot air, and it was starting to come apart.
When the wing came off, Coumbia began to tumble.
Not all of the shuttle is covered with a heat shield. As the shuttle tumbled parts of it that wern’t designed to be heated got exposed to the heat. They melted as well. This, combined with stresses the shuttle was not desingned to take (the G forces would have been pretty rough) caused the ship itself to break up totally. I read that what actually killed the astronauts was being slammed around the cabin as the ship came apart, but if that hadn’t gotten them, the superhot air outside the cabin, or the lack of anything to breathe, or just the fall would have killed them.
http://www.cbsnews.com/stories/2008/12/30/national/main4691844.shtml?source=mostpop_story
References :