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."

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.

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.

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.

How do you know that these tiles fell off over California?

I believe that astronomer who said that his telescope showed bright flares breaking off the shuttle over California. I don't believe that plasma trails would resemble "flares". I believe these "flares" were tiles.

Almost everything in life requires judgment. Some here do not want us guessing what happened. I believe that it's OK to guess as long as we're open-minded enough to change our mind if new evidence makes our guesses obsolete. If no one would ever takes guesses on anything, we would never accomplish anything. Just like it's our guess that supply-side economics is much better than government mandated wealth redistribution through the tax system. I believe speculative discussions also help to get to the truth. Sue me.

You're absolutely right Willie, everything is easily avoidable in retrospect.

Thank-you, Luis.
I think if all these folks demanding perfection would stop to think about it, they'd realize that engineers understand there is no such thing as perfection. It is totally impossible to design a failproof piece of technology as complicated as the shuttle. That is the whole reason for providing "redundant" and "backup" systems whenever possible. If the primary system fails, hopefully the backup can help avert a catastrophe.
I can't name what backup systems were on the shuttle, but everybody knows there are many of them. Same thing on our naval ships, airplanes, etc. etc. etc. It all boils down to: it's not a perfect world. If it was, there'd be no need for backup systems at all.

http://spaceflightnow.com/shuttle/sts107/status.html

Dittemore says of the external tank foam insulation striking Columbia's left wing during launch: "It was judged that event did not represent a safety concern."

The foam was seen breaking free from the bi-pod area of the tank where the orbiter nose attaches to the tank.

"As we now look at that in hindsight, that impact was with the left wing" and the signs of problems today are all on that wing. Dittemore says NASA "cannot discount there might be a connection" but there shouldn't be a "rush to judgement."

"Dittemore says foam was also lost from the same area of the external tank on STS-112 -- two flights ago in October -- as was noted January 16 during Columbia's launch. The last flight in November didn't appear to shed any chunks of foam. He said even prior to today, a review was being conducted to understand why two of the last three missions has suffered foam loss. That review would have determine what was causing the problem before clear the next shuttle for launch in March."

["As this investigation continues, I am very comfortable that the questions will be answered and the solutions applied." Dec. 1997 Greg Katnik is a mechanical systems engineer at the Kennedy Space Center for the group that is responsible for the shuttle's external tank, solid rocket boosters, main engine and thermal protection system.]

According to NASA, during several previous Space Shuttle flights, including the shuttle launched Nov. 29, 1998, the shuttle external tank experienced a significant loss of foam from the intertank.
The material lost caused damage to the thermal protection high-temperature tiles on the lower surface of the shuttle orbiter." http://www.arnold.af.mil/aedc/newsreleases/1999/99-041.htm

As soon as the orbiter was approached, light spots in the tiles were observed indicating that there had been significant damage to the tiles. The tiles do a fantastic job of repelling heat, however they are very fragile and susceptible to impact damage. 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 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. Foam cause damage to a ceramic tile?! That seems unlikly, however, when that foam is combined with a flight velocity between speeds of MACH two to MACH four, it becomes a projectile with incredible damage potential.

http://ltp.arc.nasa.gov/space/team/journals/katnik/sts87-12-23.html

The above link is where I found the original article from a fellow Freeper. THat link will not open any longer.

The page however was mirrored here.

http://www.geocities.com/Heartland/2121/used_news.htm

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