Shuttle landing in question

[Forrest]

Weren't some of the last words from the shuttle something to do with tire pressure? Raised heat because of a loss of insulation or damage around the tire area?

 

[Doc Tinker]

Early in the mission, NASA seemed to have discounted a missing tile or two as having much affect, because they've lost tiles before without complications. It doesn't take a rocket scientist to understand that the tiles, lost during re-entry, probably came off after they absorbed most of the heat and most likely came off during the cooling period, after the craft slowed down.



I agree with Mike that someone pulled a boner when they said everything was fine and dandy. What kind of backup support does NASA have for these missions anyway? Don't you think that the program is mature enough that they should be providing some kind of repair/rescue plan?



Doc

 

[HEMI®Dart]

I remember reading the Shuttle had back-up systems on top of back-up systems to prevent something like this.

 

[EMD Diesel Power]

Ice will form on the external fuel tank in any conditions..... the conditions will dictate how much ice is formed though.



remember... . the fuels are liquid oxygen and liquid hydrogen (for the main engines) These are in a container at room temp and ice will form on the outside. the insulation is there not only for protection from the booster heat... but to keep the fuels cold. The SRBs (boosters) are solid fuel propelled.



That is also why they have to empty the darn thing everytime there is a substantial delay in the lauch time. the fuels evaporate (I think??) if its left to sit too long.



More info on the fuels--- Cryogenic propellants are liquid oxygen (LOX), which serves as an oxidizer, and liquid hydrogen (LH2), which is a fuel. The word cryogenic is a derivative of the Greek kyros, meaning "ice cold. " LOX remains in a liquid state at temperatures of minus 298 degrees Fahrenheit (minus 183 degrees Celsius).



LH2 remains liquid at temperatures of minus 423 degrees Fahrenheit (minus 253 degrees Celsius). In gaseous form, oxygen and hydrogen have such low densities that extremely large tanks would be required to store them aboard a rocket. But cooling and compressing them into liquids vastly increases their density, making it possible to store them in large quantities in smaller tanks.



and a last tidbit. Why is the tank orange? instead of white as in the first shuttle missions? Its no longer painted..... saves 600 pounds!!





Jeff

 

[COBRAJET]

NASA explained that the reason they did not take pictures of the wing in space was due to the fact that they got poor results when they tried a couple of years ago to photograph a shuttle when the parachute panel blew off on takeoff. The photos were useless. They also said if something did happen they would not be able to repair it in space. This mission was not equipped to dock with the space station or perform space walks... which do not occur very far outside of the cargo bay



The domino effect seems to be getting a lot of attention. This theory says after a couple of tiles break off in one area than many more may peel off as well due to heat and speed leaving the aluminum hull exposed to the heat. This eventually leads to the melting of the craft. What caused the tiles to come off would be the question. Columbia was the oldest but had not flown the most missions. All of the Shuttles are maintained beyond are wildest dreams. They are basically new everytime they go back up



Ice routinely forms on the shuttle and the booster rockets as it does on many airplanes in what would be called a "clear" day. Many a pilot has died as he forgot to pull the carb heat out on a single engine Cessna as he decended from 6-8K feet in perfectly clear... . cold weather. When I was learning to fly the instructors beat that fact into your head every time you landed... . and this was in Texas any time of the year. Ice crystals can be routinely seen on the windows of all commercial flights..... CJ

 

[illflem]

What really surprised me listening to the NASA guys is that there is no plan in place for rescue if the shuttle should be damaged during take-off or orbit to the point that reentry is risky. What's the crew supposed to do, risk suicide trying to come back or starve to death in space?

Very fragile system, I have much respect for anyone who would risk taking the ride.

 

[Texas Diesel]

Here is some interesting reading, most of it applies to the Challenger but the Columbia (old) is mentioned, and it gives a peek at how decisions are made at NASA



http://www.tsgc.utexas.edu/archive/general/ethics/shuttle.html

 

[Jff24Gordn]

Columbia couldnt have docked to the space station. It didnt have the docking connector, Didnt have the orbit high enough to reach the station. it is up higher to get it out of the upper atmosphere. Where the shuttles usually orbit, there is still a very little atmosphere and it will slow it down, so its higher to keep it from slowing down as much. Also Columbia has never been to the space station. it was by far the heaviest shuttle and it would be harder to get it up the extra miles.

 

[TxDieselKid]

It's kinda crazy here in town, a chunk landed accross the street. Some are saying the air might be toxic because this is the debray zone. I doubt it, but oh well.



Reporting from the scene in Nacogdoches,

Andrew



P. S. You should see all the news vans, there's about 25 of them.

 

[Sled Puller]

You would think every mission would have space walk capabilitys, to go patch a tile or two up just to be safe.



About a terrorist attack- they did not have a thing to do with it. Yet, they have a small victory, with us thinking about it being a remote possibility.

Just another reason to keep thumping them.



Can't believe paint would weigh that much, but I guess that tank is pretty big.

 

[Mike Ellis]

I was still in college when Challenger was lost, was walking through the student center looking at the news feed when it blew. It was really harsh, I remember vividly the camera panning over to the VIP stand and the looks of confusion and fear on the faces of the astronauts' families.

What I found remarkable after the facts were all put on the table, was how much effort was put into CYA by the folks at NASA and within the government. There was scads of info on the Thiokol engineers recommendations against a mission "Go" with the SRBs that cold, yet the fact that NASA had spent much time debating that very subject prior to launch didn't come to light until Richard Feynman (Nobel prize winner in physics) demonstrated the problem with the famous "O-ring in ice water" in front of the committee. With a simple and irrefutable display of a major weakness in the design, and the obvious implication of management stupidity in going ahead with a launch under such conditions, there was no way NASA could dodge the bullet any longer.

 

[Sled Puller]

That had to be hard for the engineers that said don't launch that day.

Surpise me if somebdoy didn't get a busted nose over that deal or worse.

 

[TxDieselKid]

Originally posted by Sled Puller

That had to be hard for the engineers that said don't launch that day.

Surpise me if somebdoy didn't get a busted nose over that deal or worse.

Doubtful in that blue collar world.

 

[Scot]

Originally posted by Mike Ellis

There was scads of info on the Thiokol engineers recommendations against a mission "Go" with the SRBs that cold, yet the fact that NASA had spent much time debating that very subject prior to launch didn't come to light until Richard Feynman (Nobel prize winner in physics) demonstrated the problem with the famous "O-ring in ice water" in front of the committee. With a simple and irrefutable display of a major weakness in the design, and the obvious implication of management stupidity in going ahead with a launch under such conditions, there was no way NASA could dodge the bullet any longer.

My father is one of the guys who taught geology to the astronauts that walked on the moon. He went on to fly some experiments on NASA's U2C and some of the early Shuttle missions, among other jobs. He was not even remotely involved in the propulsion end of the missions. He came home and mentioned (several times) the o-ring burn through problem long before the Challanger explosion. My father is not one to share a lot of personal/work information without prying. That was not the first time they had a problem. It is just the first time it bit them. Previous missions had o-rings burn nearly through. The system already had undergone one major redesign.



He left NASA about two years prior to the Challanger explosion.



It is interesting that the Columbia diasaster occured 17 years and about a week after the Challanger.



As for looking at the problem, rumor has it that one of the early spy satilites (KX series?) was turned around to look at Apollo 13 very quickly after the explosion. They were what, 2/3 of the way to the moon? And that was '60's technology!

 

[baby.driver]

Correct me if I'm wrong.....

But I had always assumed the pilot of the shuttle could blow the bolts that connect the shuttle to the external tanks and glide on down in case of a problem prior to reaching space. AKA abort the mission. They don't have that capability?

 

[COBRAJET]

I believe it is more of an escape type pod with the nose being blown off and the crew being brought down in the pod with parachutes attached to it... CJ

 

[John]

Originally posted by Sled Puller

You would think every mission would have space walk capabilitys, to go patch a tile or two up just to be safe.

I believe they do on EVERY Space Shuttle mission.



The silica tiles fall off ALL THE TIME. I had originally read of this in a magazine years ago. More recently, the had a documentary on this on one of the DirecTV satellite channels... very informative show. Cobrajet is correct, there does seem to be somewhat of a domino effect as the tiles are lost. Also, after each orbiter has been through post flight maintenance, it is virtually a new ship!



BTW, I thought absolute zero was -368 degrees F. If so, how do you arrive at -423 degrees F. EMD Diesel Power? (just wondering)

 

[illflem]

NASA had no luck with tests on repairing tiles in space. Since there is nothing exposed on the bottom of the shuttle to hang onto because it would burn up on reentry pushing on a tile to glue it on in zero gravity doesn't work, the person's body just pushes away. In fact they found that attempting repairs in space caused more damage to undamaged tiles due to astronaut collisions, those tiles are about as strong as chalk. If the robot arm was redesigned so that it could reach over and around to the bottom there could be a stabile platform to perform repairs from. A repair platform could also be added to the space station.