Posted on 02/02/2003 6:35:58 PM PST by TLBSHOW
Astronauts doomed from the start
THE seven astronauts on space shuttle Columbia may have been doomed in the first moments after they were shot into space 16 days ago.
NASA officials are investigating whether loose foam from an external tank that struck Columbia's left wing during takeoff contributed to its disintegration under the stress of re-entering the Earth's atmosphere – one of the most dangerous parts of any shuttle mission. The last words between mission control at Houston and shuttle commander Rick Husband gave no clue of impending disaster:
Mission control: "Columbia, Houston, we see your tyre pressure messages and we did not copy your last."
Cdr Husband: "Roger, but . . ." No more was heard.
The homeward-bound space shuttle broke up in flames and trails of smoke and vapour over Texas yesterday, killing all seven astronauts aboard.
The disaster struck 16 minutes before Columbia, the oldest in the shuttle fleet at 22 years, was due to land at Cape Canaveral in Florida. Echoing the tragedy of space shuttle Challenger, which stunned the world 17 years last week, Columbia exploded at an altitude of about 63km as it was travelling 18 times the speed of sound.
The explosion scattered debris and human remains across hundreds of square kilometres in Texas and Louisiana and shook houses in the area around Nacogdoches, Texas.
Police in Hemphill, eastern Texas, said human remains believed to be from the crew of Columbia had been recovered.
"I can confirm human remains from the space shuttle Columbia have been found in the debris," Hemphill police spokeswoman Karen Steele said, declining to elaborate.
A burnt torso and thigh bone were found on a Texan country road while elsewhere a scorched helmet and arm patch from one of the space suits were discovered.
In a televised address to the nation, an emotional President George W. Bush paid homage to the astronauts, saying, "The crew of the shuttle Columbia did not return safely to earth but we can pray that they are safely home".
The sparse information NASA had yesterday seemed to point to failures on the craft's left side.
Sensors on the shuttle's left wing and in the left wheel gear detected a sudden temperature increase or failure minutes before the vehicle exploded 63km over Texas as it flew at more than 20,000km/h.
NASA had concluded only two days ago there was no serious damage to the tiles, but was uncertain last night.
"As we look at that now in hindsight we cannot discount that there might be a connection," stunned shuttle manager Ron Dittemore said.
Investigators have all but ruled out terrorism as a cause because the shuttle's high altitude and extreme speed effectively put it out of range of an attack from the ground.
Officials are focusing on the extent of damage sustained during take-off.
Experts said many other malfunctions could have destroyed the shuttle during re-entry, when a cocoon of hot plasma envelops the spacecraft.
Columbia's underside and the leading edges of its wings would have been subjected to some of the highest temperatures during re-entry – up to 1650C – as friction from air rushing by heated its surface, experts said.
During this critical period, computers control the shuttle's angle of descent as it flies with its nose pointed about 40 degrees upward; the slightest deviation from the ideal orientation can expose underprotected parts of the vessel, causing it to burn up.
The shuttle's chief defences against an inferno are about 28,000 heat-resistant tiles attached to its vulnerable aluminium exterior. Experts have worried about the tiles' tendency to break off during flights since the earliest days of experimental test flights.
Relatives of the astronauts – six Americans and an Israeli – watched in horror while waiting at Cape Canaveral's VIP area to welcome their loved ones.
Residents in Texas, Louisiana and Alabama reported hearing the explosion as the shuttle fell apart at more than 18 times the speed of sound.
Bob Molter from Palestine, Texas, said he had seen the shuttle break up in the sky.
"There was a big boom that shook the house for more than a minute, and I went outside because I thought there had been a train accident," he said.
"I looked up and saw the trails of smoke zig-zagging, going across the sky."
Thousand of pieces of debris landed over vast areas of Texas and Louisiana which experts said may take years to find. People were warned not to touch any wreckage because it might be contaminated with toxic propellants.
President George W. Bush rushed to the White House from where he described the disaster in a televised address as a national tragedy.
"The Columbia is lost. There are no survivors," he said, before later ordering all flags be flown at half-mast.
The crew, six of whom were married and five of whom had children, were relatively inexperienced. Only three had flown in space before.
NASA has ruled out human error.
That's a real possibility, although I think they would have heard or felt the impact. An explanation might be that it might not require that large an object to severely damage the tile. I believe that the orbiter normally flies with cargo bay doors open to radiate heat to outer space and wouldn't present much of a silhouette to debris in earth orbits. NASA should have good probability data for such an occurrence and it would be interesting to see how it stacks up for the 107 and some flights. I don't remember what the overall probabilities are for Shuttle Missions but I think we are pretty close with the two losses. Bottom line however may really be are we lucky or unlucky.
My theory was that there may have been a failure in the left landing gear door seal that would have the effect of a hot gas jet penetrating the interior wing structure and would result in it's failure. In today's conference, they said data on the tires just dropped out and then said later that the wheelwell compartment DID NOT see an increase in temperature, so that could rule out a seal failure. I'm eager to see if any of the new "unreliable" data they expect to recover may still hold this possibility open, if there was in fact a temperature increase.
But someone had to guess it was correct before it was proven.
But then, You seemed to be the rocket scientist......
It doesn't take a rocket scientist to watch a piece of ice strike a wing and speculate that it damaged some tiles (if it was ice).
An Australian Newspaper *knows* this already? I can pass off anyone who already claims to know anything as a fool I don't even have to read from.
You're awfully cavalier about other people's lives.
Let me know where you do your engineering.
These sensors detected problems over California. They went out over Texas at burn-through. Problems were detected at 8:53 I believe. Columbia was over California at 8:53.
And if it wasn't ice, what would a rocket scientist say?
BTW, can you point me to ANY places in California where they are searching for debris?
It sprayed on impact with the wing. I wouldn't think foam would spray. It looked like ice to me.
This is from Mr. Dittemore's most recent remarks. Maybe as time passes we are getting more information.
At 8:53 a.m. EST, he said, as Columbia was sailing high above California on its way to landing at the Kennedy Space Center, "four left-hand elevon (wing flap) hydraulic return line temperature measurements dropped off scale. The left brake line, (landing gear) strut actuator and uplock actuator temperature measurements rose significantly, 20 to 30 degrees in five minutes. This is significant in that these measurements were located in the left wheel well. This was the first occurance of a significant thermal event.
"It's also important to us that we understand and have found out that the elevon temperature measurements that I talked about (Saturday) that dropped off scale low are routed adjacent to the wheel well area.
"At 8:54, we were over eastern California and western Nevada. At this time, the mid fuselage left bondline temperature sensor showed an unusual temperature rise," Dittemore said. "We're talking about a temperature on the left side of the vehicle above the wing. The temperature rose 60 degrees over five minutes whereas on the right-hand side of the vehicle, in the same location but opposite on the right-hand side, showed a nominal 15-degree rise over five minutes.
"Another interesting piece of information, that even though the mid fuselage bondline temp showed a 60-degree rise in five minutes, just inside that wall, in the payload bay, our cryo tanks were nominal. So it didn't look like there was any increase in temperature in the payload bay as far as we are able to discern today. "At 8:58 a.m. over New Mexico, the roll trim in the elevons started to increase, indicating we had an increase in drag on the left side of the vehicle," Dittemore said. "Does this mean something to us? We're not sure. It could be indicative of rough tile, it could be indicative perhaps of missing tile. We're not sure. We do know it's indicative there was an increase in drag on the left side of the vehicle. "At this time, we also lost the left main landing gear tire pressure and wheel temperature measurements. We're fairly confident that this loss of information was measurement related and not loss of the tires themselves because the measurements were staggered in their loss. If we'd have lost a tire, we believe we would have lost all the measurements at the same time. That didn't occur.
"At 8:59 a.m. we were over west Texas. Again we see an increase in the roll trim as indicated by elevon motion, indicating the vehicle was reacting to an increased drag on the left-hand side. The flight control system was countering that drag by trying to command the vehicle to roll to the right-hand side. ... Soon after, we had loss of signal."
Not being "cavalier" about other peoples lives at all.
Simply recognizing objectively that there is no such thing as perfection.
There is always a need to improve upon safety and reliability, but perfection will never exist.
If you don't understand that, then you are simply foolish.
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