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.
Sinister? Well, I suppose you might use that word since the report is more subjective and speculative than it is quantitative and analytically objective. Not that there's anything inherently "evil" about subjective and speculative analysis when 1 data point (the wear and tear experience on 1 flight) is all you have to go on.
As stated previously, there was a passing comparison to the previous flight that the damage was "greater". But that really doesn't supply any quantitative comparison as to the degree it was greater, or to what quantitative level it may or may not have impinged upon the level of acceptable wear and tear.
Naturally, "zero" wear and tear is desirable, but that doesn't happen in a complex and imperfect world. Some level of wear and tear must be expected, and maximum acceptable limits established. We, out here on the Internet, simply don't have the information to know whether or not the damage exceeded the maximum limit for acceptable wear and tear.
It is certainly worth knowing that a change to freon-less foam occurred for the data collected on flights STS-86 & 87, but that doesn't supply answers. It only raises additional questions for analysis. What type of foam was used in the subsequent flights and what quantifiable damage levels where experience then? Where there any other changes, trends, etc. etc.???
Heck, I can think of several ways I'd like to see some quantitative data accumulated and analytically presented that may be helpful. Not that the info in the report that Jael has posted isn't of interest. It is. It just isn't sufficient information upon which to draw any conclusions.
"Damage numbering up to forty tiles is considered normal on each mission due to ice dropping off of the external tank (ET) and plume re-circulation causing this debris to impact with the tiles. But the extent of damage at the conclusion of this mission was not "normal."
The pattern of hits did not follow aerodynamic expectations, and the number, size and severity of hits were abnormal. Three hundred and eight (308) hits were counted during the inspection, one hundred and thirty two (132) were greater than one inch. Some of the hits measured fifteen (15) inches long with depths measuring up to one and one-half (1 1/2) inches. Considering that the depth of the tile is two (2) inches, a 75% penetration depth had been reached. Over one hundred (100) tiles have been removed from the Columbia because they were irreparable. The inspection revealed the damage, now the "detective process" began.
During the STS-87 mission, there was a change made on the external tank. Because of NASA's goal to use environmentally friendly products, a new method of "foaming" the external tank had been used for this mission and the STS-86 mission. It is suspected that large amounts of foam separated from the external tank and impacted the orbiter. This caused significant damage to the protective tiles of the orbiter."
Keep in mind that NASA had this article posted as part of a Kid's Quest Science project. It's not written with a lot of highly technical information, but it does illuminate some startling facts for us.
I did not get to see the NASA news briefing yesterday which supposedly addressed the issues I brought up so forgive me for trying to clarify.
Did they say how MUCH farther out the ISS orbit is than what the current ability of the Shuttle is? Could they upgrade the engines for future missions or would larger engines weigh too much?
Obviously, it is a moot issue for the Columbia, but I seem to remember that when the Space Shuttle was first being "sold" to us, astronauts were going to be able to be just "shuttled" back and forth, e.g. with the "Shuttle" planes. If not these "Shuttles," which ones were they talking about? I don't recall what vehicles got the current astronauts to the ISS. Do you know?
KOZAK WROTE: "Repairing the tiles? Each tile is a custom fit. Do they carry spares for the entire heat shield?"
I understand that each tile is a different shape, prohibiting them from taking enough individual tiles for complete replacement.
My thought, however, is that since they typically only lose a "few" tiles, and since they are made of EASILY-CUT, light-weight STYROFOAM which has a heat-shield coating, they could take a sheet or two or three of it with them (e.g. 3-2x4 foot sheets) to CUSTOM CUT them down as specifically needed.
With an ABILITY to EXAMINE and REPLACE the heat-shields via an EMERGENCY SPACE WALK, they could look up the size they needed (or make templates) and cut and glue them on as needed. As easily as the styrofoam heat-shields come off, having that EMERGENCY SPACE WALK ABILITY IS CRITICAL.
KOZAK WROTE: "A Soyuz rescue mission would actually take at LEAST 4 missions as the Soyuz carries 3 passengers at a time. Thats 1 pilot and 2 shuttle crew at a time. Since there were 7 shuttle crew do the math. Do you think the Russians have them on the pad in six packs?"
It is my understanding that the Soyuz is bringing up supplies to the ISS wihin a day or two---UNMANNED. If so, it seems that it could have brought back three at a time (and might have EMERGENCY SPACE for more). Maybe we should have a BACKUP Shuttle (capable of reaching the ISS, e.g. the Shuttle "sold" to us as mentioned above), ready to go in an EMERGENCY (or one which could could be QUICKLY CONVERTED from a scheduled future mission).
KOZAK WROTE: "Space is a dangerous place. Just like military aviation there are situations which you cannot recover from. NASA has done an amazing job considering the complexity and danger involved in this area of exploration."
I understand and agree, EXCEPT that, who would have ever thought Apollo 13 could have recovered from so MANY problems---all with "SPARE PARTS" engineered out of ordinary and unrelated items?
EXACTLY!
Also, does anyone know if GPS would work in space? I would think it would, but I don't know that much about it. I understand it works via getting satellite positioning readings. It SEEMS like it would work in space as well, EXCEPT that it might need a FORTH satellite reading since the element of height above the earth's surface is introduced. Anybody know enough about GPS to answer?
Oh, that's a relief.
I guess we can forget about being worried that anyone from the CIA might sell out the country for a princely sum, as well.
Right?
Yes, I read all that before in your previous posts.
It really doesn't matter how frequently you repost the same information over and over again. It STILL doesn't tell us how the damage relates to maximum acceptable limits, as deviant from "normal" as it may have been. Remember, despite the damage, flight STS-87 landed SAFELY, and inspection occurred AFTER the additional wear and tear incurred during reentry.
Thanks and thanks. I'm hoping she (we) will get out of the hosital soon. She has been sick with respiratory problems for about 10 days and in the hospital since last Monday.
Unfortuantely, since she is severely mentally and physically disabled, she can't tell us what/how she feels when she is starting to get sick. Thanks again!
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