View Full Forums : I am no rocket scientist...


FyyrLuStorm
07-08-2003, 12:55 PM
"Shuttle investigator: 'We have found the smoking gun'"

<a href="http://www.cnn.com/2003/TECH/space/07/07/sprj.colu.shuttle.investigation/index.html" target="top">CNN</a>

<a href="http://www.google.com/url?sa=X&oi=news&start=0&num=1&q=http://www.washingtonpost.com/wp-dyn/articles/A23721-2003Jul7.html" target="top">Washington Post</a>[screw you too old grey whale]



They fired a 1.37 pound piece of foam at the wing of the orbiter with a cannon.
At 530 miles an hour.
Burst a 16 inch dia. hole in the wing.

Now my questions are:

1) Were not the foam and the shuttle traveling at just about the same speed?
2) Is there really that much acceleration during the 50-100 or so feet that the foam traveled to account for 530 miles an hour? How much would drag account for it.
3) Is the shuttle really that fragile?
4) What would happen if the orbiter hit a seagull, heron(Florida, you know), or a goose or something?

Zyphyr
07-08-2003, 01:28 PM
That test was utterly pointless in terms of helping to determine what actually brought down the shuttle.

Their test has the piece of foam blowing a hole <em>through</em> the test surface.

The piece of foam in the actual incident <strong>bounced off</strong>.

The only purpose for conducting that farcical test is to asuage public opinion.

Panamah
07-08-2003, 02:20 PM
SOE has done a lot of studies of high speed nerf bat whacking. I believe they were called in to assist with these experiments.

;)

BriennaMonk
07-08-2003, 02:54 PM
I think they were trying to prove that the foam could possibly have damaged the wing.

They can't really recreate the exact situation in the shuttle launch, but they've proven that the foam was strong enough to damage the wing.

Given the high stress of re-entry and the high temperatures, even a small chip or crack would be enough to be catastrophic.

FyyrLuStorm
07-08-2003, 03:21 PM
Every headline I have read today on this has been "Smoking Gun"...

The cynic in me thinks "Steaming Pile".

gamilenka
07-08-2003, 08:09 PM
If you throw a straw just right, you can pierce an apple with it.

They can focus water in to a stream powerful enough to cut through things, and not just push it around.

Diamonds are/are one of the strongest things on Earth. If you hit one just right, supposedly it will shatter.

What's so hard to believe that anything travelling at 500+ mph could potentially cause enough damage for what they said happened, to have happened?

Stormhaven
07-08-2003, 09:01 PM
If you're ever bored, look up "Interplanetary Dust Experiment" on Google. You can find out how much scientists are worried about how something as small as a micrometer sized dust particle will impact permanent orbital platforms and other space missions.

Get anything moving fast enough and it'll do a big amount of damage. After the nuclear blast at Hiroshima, usually benign items such as pages from a newspaper were reported to be lodged within concrete columns and walls.

Was the test in San Antonio an accurate representation of what happened on board the Columbia? Probably not. If it were, that would mean that the safety systems on board NASA's space shuttles were less sensitive than those aboard passenger class airplanes. If a 15" hole were punched through any part of an aircraft's body, you can bet that there would be 101 alarms buzzing in the cockpit and probably in a few traffic control towers.

Why?

Because of a neat little part of physics they call friction.

Friction is what allows a small crack in a wing to become a huge gaping hole when it's subjected to something as etheral as air particles at high speeds.

The 15" hole in the wing they demonstrated at San Antonio was for the slackjaws yokels willing to accept anything that CNN tells them as gospel. It was probably also to justify their 3.5 million dollar fee for essentially shooting a potato gun at a backyard fence and saying, "Well I'll be damned, it did make a big hole!"

The "Worlds Best Car Crashes Caught on Tape!" generation (ie: the "Fox Generation") is not going to accept that something as small as a microscopic crack in the wing could have possibly caused the shuttle to explode. The public requires a big explosion, a big hole, or some other type of extravagant explanation.

Science be damned. This is entertainment.

If the "Smoking gun" experiment proved anything, it was only that it is possible that a piece of foam from the external tank casing impacting the wing at high velocity could cause that amount of damage. There is no proof that there was anywhere near that extent of damage on the shuttle itself.

Meperidine
07-08-2003, 09:16 PM
Right..a car travelling at 503 mph only dings the car ahead of it it hits that was going at 500 mph. Its called kinetic energy.

edit: actually as soon as the foam broke off it lost its acceleration..so its more like throwing a shuttle wing at it.
And anyway since the 1980's we've been told that simply touching these ceramic tiles with an ungloved hand would ruin them. AND the potential catastrophitc failure rate on shuttles (which could have been made up during the media frenzy) was 2 percent...and I don't see why anyone is amazed we lost 2 of 117.

kineada
07-10-2003, 12:32 PM
<em>1) Were not the foam and the shuttle traveling at just about the same speed?</em>

When the foam was attached to the space shuttle, yes indeed they were going at the same speed.

<em>2) Is there really that much acceleration during the 50-100 or so feet that the foam traveled to account for 530 miles an hour? How much would drag account for it.</em>

Rockets would need to travel at approximately 7miles/sec (25,000 miles per hour) to reach escape velocity. 530 miles per hour isn't all that much considering the scale.

<em>3) Is the shuttle really that fragile?</em>

In a word ... Yes. Please note that anything that needs to reach 25,000 miles per hour needs to be as light as possible. Tradeoffs are run to balance stuctural integrity vs wieght. When resisting forces that it was designed to resist (vibration, drag, etc), the shuttle is very sturdy. When resisting forces that it wasn't designed to resist (chunks of foam), the shuttle is a wet paper towel.

<em>4) What would happen if the orbiter hit a seagull, heron(Florida, you know), or a goose or something?</em>

The space shuttle's velocity is relatively slow in the areas where birds might be flying.

P.S.
This is where I work:

www.ssloral.com/ (http://www.ssloral.com/)

We keep tabs on the shuttle :)

FyyrLuStorm
07-10-2003, 01:11 PM
"The space shuttle's velocity is relatively slow"

The piece of foam they shot at the wing looked rather large in size. A couple feet by a couple feet. Weighed only 1.37 lbs.

A seagull weighs more than a pound. And much more dense than a piece of foam.

I would not think that gaining 530 miles per hour at lift off, and certainly not all that far out of regular seagull territory, either ecosystem or altitude.


While I have no problems whatsoever about a crack received during take off being fatigued to the point of disintergration during descent.

I really am put off by the term "Smoking Gun". The experiment just looks flawed(still speculative at best) to me.



Main Entry: smoking gun
Function: noun
Date: 1974
: something that serves as conclusive evidence or proof especially of a crime

BriennaMonk
07-10-2003, 06:25 PM
Since the accident they have had no other theory. They know a piece of foam came off during liftoff - they have a video of it hitting the wing. They know that this particular area of the wing is where the problems began during re-entry (from heat sensors, etc.).

What they were attempting to prove was that this piece of foam could have conceivably done damage to the wing as they suspected. I'd say they proved it.

Now they need to figure out how to prevent it in the future. Or to figure out a way for the crew to fix a damaged tile before reentry.

Just because they called it a 'smoking gun' seems to be putting a lot of people off. I don't understand why. They had a theory - they proved it. The test they conducted was a 'smoking gun' for the theory they were attempting to prove.

Aquila Swiftspirit
07-11-2003, 04:48 AM
Those tiles are amazing. They shed heat like mad. When the shuttle was first built, I remember them showing on TV hitting the tile with a blow torch for a little bit (holding it with tongs), setting it down, and then picking it up with their fingers immediately, and saying it was room temperature.

They're also made to fit a specific place on the shuttle. Each is numbered, and goes in it's place. They can't be interchanged. That would make a repair scenario pretty difficult... the shuttle would be pretty full up just carrying a set of tiles.

Trevize
07-16-2003, 10:48 AM
The shuttles are old.

I keep thinking that perhaps NASA should get a few more pennies to build something for the year 2000 and beyond. Oh wait! We're already at 2003 flying 25 year old shuttles.

2 of 117 with a 2% predicted and government approoved rating. Well what are people bitching about exactly.

Granted lose of life and for them I moarn. But, the US is trying to play the blame game here and it is doing no good whatsoever.