NoD,
The tile system on all the shuttles is standard. However, each tile is unique, fitted to its particular location on the shuttle. The thermal protection offered by a tile also differs, depending on the temperature regime it is expected to encounter on re-entry. So one could not stock 50 or 100 tiles on the shuttle as spares and stick them wherever one wished, as the likelihood is that they would not fit.

Typically, about 50 tiles are replaced after each flight because of damage. The damage usually is caused by debris strikes during launch, or in-orbit strikes from micro-meteroids or space debris.

Airship, the orbital inclination for this last Columbia was 37 degrees. The ISS is at a 55 degree inclination or thereabouts. While George Lucas can easily maneuver his starships between such inclinations, real-world spacecraft would find it nearily impossible to shift inclinations to this extent.

Saturn V

Thanks for the update. Glad to hear it. That should help establish the sequence of failures no end.

CNN - Timeline:

A timeline of the final minutes of the shuttle flights and the hours following it (all times EST):

Additional data in italics from NASA press conference.

8:15 a.m.
Space shuttle Columbia fires its braking rockets and streaks toward touchdown.

8:53 a.m. (Over California)
Ground controllers lose data from four temperature indicators on the inboard and outboard hydraulic systems on the left side of the spacecraft. The shuttle is functioning normally otherwise, so the crew is not alerted.

08:53
20 to 30 degree rise in temperature in left wheel well over 5 minutes.

08:54 (Eastern California & Western Nevada)
Mid-fuselage bond line (bond between fuselage and top of wing on the port side) has a 60+ degree temperature rise over 5 minutes. Starboard side is nominal at 15+. Inside of fuselage wall the temperature is nominal.

8:56 a.m.
Sensors detect rise in temperature and pressure in tires on the shuttle's left-side landing gear.

8:58 a.m.
Data is lost from three temperature sensors embedded in the shuttle's left wing.

08:58 (New Mexico)
The FCS starts to add roll trim to the right. Implication is to counter increased drag on the port side.

8:59 a.m.
Data is lost from tire temperature and pressure sensors on the shuttle's left side. One of the sensors alerts the crew, which is acknowledging the alert when communication is lost.

08:59 (West Texas)
Wheel well temperatures lost. Roll trim continues to increase as the FCS continues to try to roll the shuttle to the right. Implication is that drag is continuing to increase on the port.

08:59 (East Texas)
Signal lost.

NASA have interviewed the astronomer in Owen's Valley (California) who reported debris coming from the shuttle. They have his statement and believe it is an important contribution.

Interesting overview, especially "abort options":

http://science.ksc.nasa.gov/shuttle/...n_profile.html

NoD

On TV here this morning an ex astronaut said that the idea of an escape pod had to be dropped because the weight penalty was too big.

Regarding EVA, even if they had been trained a NASA spokesman said there were no handles of any sort on the underside of the craft so no way could an astronaut have got there but if they could they had no facilites to conduct any repairs.

Thanks for that Blue Eagle. Perhaps this may change in future designs.

Also regarding EVA, Ron Dittemore said in the press conference today (Sunday) that even if the crew had been trained, it had long been policy not to consider tile repair. No 'kit' was available on board.

Apparently the risk of causing further damage during the EVA was too great, so the possibility was discounted

Airship

I don't agree with your proposals and will do all that I can to veto them.

I believe that mankind must take risks in order to advance our way of life. I believe that the crew of the shuttle was aware of these risks and accepted them.

I believe that we have the proper balance of risk assessment and engineering judgement available to make future decisions regarding continuation of missions. I will continue to support the teams now in place who will have access to the facts and be able to weigh the risks vs the benefits.

FYI this thread will will only deal with technical discussion/speculation. Anyone who can't be bothered to read the whole thread before posting and then ends up quoting or repeating something already discussed should not be surprised if their post is removed.

Also, please refrain from using this thread to make emotional or condolence type posts as they too will be removed. Feel free to make them on the other thread, Shuttle Columbia breaks up during re-enry

For those that say that nothing is accomplished by putting man in space, I would suggest that you think about how productive flying was after man had achieved its first 100 or so flights in powered aircraft! Lots of people were killed for something that didn't move a whole lot faster than a horse and carried a whole lot less!

The simple act of flying man in space is important in the natural progesssion of humanity. If we are ever to leave this planet ( and some day we must, it is our nature to expand ) it starts with baby steps, just like the wobbly short flight the Wright brothers took 100 years ago.

The astronauts knew the risks and took them willingly. They accept that 1 in 75 chance that comes with flying on the Shuttle because this is what they do! This is not a commercial airplane ride. This is research and developement, which is not always the safest thing in the world. While not safe, it is important. The Astronauts CHOSE to go.

I admire the courage, and am comforted in knowing that they died for something they loved, at the pinacle of their game. They won't be forgotten.

Cheers
Wino

Re-entry imagery prior to STS-107
 

I am wondering if anyone on the forum can speak to this....

I seem to recall ground based video of prior shuttle re-entries some years ago which showed the shuttle at very high altitude and Mach (overflying California, I believe) without any significanltly visible trailing plume. The amateur videos broadcast yesterday seemed to me to appear quite different, in that prior to the visible breakup of the orbiter, there was a significant trailing plume behind Columbia.

Now, I've never observed a shuttle re-entry first person, nor is my memory infallible (quite the opposite!), but I am curious to compare prior entry imagery with what was witnessed on Feb 1.

My purpose is not to speculate, but this has been kinda stuck in my mind all day....

Any thoughts?

S

slsman, did you try searching for that footage under the google archive or the nasatv archive?

Bubbette,

Yes, good idea. I have found some imagery, so far night images of STS-93 which does clearly show a following trail.....

S

At the risk of wandering a little of topic, what happened to OV101 Enterprise, the very first shuttle. How feasible would it be for this vehicle to be used as a replacement, like Endeavour was for Challanger?

I sense that there will inevitably be a growing conspiracy theory about whether NASA chose to ignore the damage to the left wing on launch in favour of a fingers-crossed "it'll be alright on the night" approach. I find this scarcely credible, given the customary attention to detail and precision in all of their activities, and can only conclude that any damage was deemed negligible, because this is what the evidence available indicated. Whether this evidence was sufficient is debatable in the light of subsequent events, but I find myself unable to buy into the "they knew it was doomed" school of "thought" that will doubtless find its ultimate voice in that august scientific journal The National Enquirer

Enterprise is not feasable at all.
That was discussed after the challenger explosion, but none of the stuff required for space is in Enterprise. It was cheaper to build a whole new orbiter after Challenger, and that is what they did...

Cheers
Wino

Could the plume have been some, hydrogen, water tanks or nasty hydrazine which was torched ( I hate to use this word, but suspect that the crew all passed away very quickly)?

Don't comets leave trails hundreds (thou.) of miles long through space, when hit by solar particles or due to the upper atmosphere friction on a comet's frozen (liquids: methane etc?) surface?

Tyre fire?
 

Excuse my engineering ignorance here, but is it possible that missing heat shields near the wheel bay could have caused heat build up in that area to a point where the tyre could have caught fire?

Just the sequence of the events below posted by "ORAC" has me intrigued.

08:53
20 to 30 degree rise in temperature in left wheel well over 5 minutes.

08:54 (Eastern California & Western Nevada)
Mid-fuselage bond line (bond between fuselage and top of wing on the port side) has a 60+ degree temperature rise over 5 minutes. Starboard side is nominal at 15+. Inside of fuselage wall the temperature is nominal.

8:56 a.m.
Sensors detect rise in temperature and pressure in tires on the shuttle's left-side landing gear.

8:58 a.m.
Data is lost from three temperature sensors embedded in the shuttle's left wing.

Tyre Fire??
 

Surely there would not have been enough atmosphere at 200k feet to provide oxygen for a "conventional" fire involving the tires?

I would have thought more likely that the rising temperatures of the tire were more likely just a result of heat coming from friction of the craft (possibly less aerodynamic than it was designed, due to damage) as it passed through the thin air at Mach 18?

Few questions from a total non-specialist...

1. Just wondering if there is any kind of flexibility in the re-entry trajectory: I understand that there is a given amount of kinetic energy to dissipate (and this was the heaviest landing in the Shuttle history); I also understand that you can not dissipate it too quickly. But assuming you accept the fact that you will miss your initial landing objective is there a possibility to choose a less stressful approach ?
   
2. Is there any real-time computer follow-up of the re-entry phase ? I understand that the telemetry analysis is clearly showing that "something" was not normal a few minutes before the actual break-up. I don't believe it would be possible for an human operator to actually pick-up the trend in real-time but it I believe that a real-time computer model & tracking system (based on the considerable database the NASA should have after 100+ missions) could have raised an alert 3 to 5 minutes before the actual break-up.
   
3. Finally, how do you achieve attitude control at those altitudes / speeds ? Is it aerodynamical (aileron / elevator) or thrust ?

This is obviously pure speculation but it seems to me that they might have had a small window of opportunity not to actually abort the re-entry but to follow a different trajectory that would significantly reduce constraints to the airframe. They would have obviously missed their intended landing point by quite a big margin, they would have probably needed to hand fly a very heavy glider but the whole point is that there *might* be a plan B after all...

An interesting article on Shuttle Safety deficiencies from the UK Observer newspaper.

http://www.observer.co.uk/internatio...887236,00.html

nasaboy, I entirely agree with your statement and might I suggest a re-read of my post will dispell your assertion

My initial thought is that thrust would be used, but in thinking about it, control surfaces may be used at those heights because of the speed and some atmosphere. Certainly, the roll-trim was being added by the on-board computer to react to the drag of the left wing, so one would assume control surfaces were sufficient to attain and execute the roll routines to lose speed (which occur at 56 degrees nose up.

(edited for spelling)

atacaks:

The re-entry profile is already the least stressful. This question was asked during last night's press conference and answered by Mr Dittemore

ISS or NOT
 

Just wondering: would anyone more skilled than myself do the actual calculation and come up with the ammount of fuel necessary for an ISS rendevous vs. the on board ammount (including the desorbintg reserve) ?
Thanks - I missed that one.

Would anyone care to expand on that one ? What would be the problems of doing a less agressive entry ?

Just totally off-topic............does anyone else find it slightly peculiar that Challenger, Endeavour and Discovery were all named after British ships?

Atlantis, Challenger and Columbia were named after American ships. The Endeavour and Discovery were named after Captain Cook's ships. And the Enterprise was named after a certain starship........
Shuttle names

A link to a very good close up video showing the "foam" debris hiting the orbiter at launch.

http://www.floridatoday.com/columbia/debrisvideo.htm

There is no possible "less aggressive entry." Nasa already determined the entry profile that would cause the least stress on the shuttle and that's the one they're using. Any other profile would result in more stress on the shuttle, not less. If there was a less risky, lower stress profile, they'd already be using it.

Ok, for once I'm on par with the rest of you on an aeronautical subject: I also know sod all about it.

For years now I've been tracking the Shuttle and ISS on the web. It has long seemed to me that the Space Shuttle as a concept has been oversold to the American public, probably in order to secure NASA the immense budgets needed to develop it, and then to keep it running.

i. It is not reusable. (Recycleable, more like, or, perhaps, semi-expendable).

ii. It is not routine.

iii. It is not safe. (i.e. Even the post-Challenger target of 1:1,000 failure ratio is not 'safe').

iv. It is not casual. (i.e. ad-hoc EVAs).

v. Once in orbit, it is not really a 'space ship', in the popular sense. (More like a sophisticated projectile, with the ability to perform minor adjustments to its orientation and orbit).


Even a brand new Shuttle system is not going to meet all of the above criteria, and unlikely to meet even two of them.

The reality is that technology has yet to catch up to the space travel expectations of the public imagination. The Shuttle was, and is, a magnificent demonstration of American technology. But even that's not enough, yet.

TW

So which is right?

http://science.ksc.nasa.gov/shuttle/...hallenger.html

Atakacs, you say "(and this was the heaviest landing in the Shuttle history)"

This interests me. Do we know what the Main Mission was on this particular launch.

I assume from your point, that some kind of recovery operation must have been at least, part of the Mission.

The weight was due to the science modules in the cargo bay, no recovery operation was carried out.

On another note in 1979 NASA said it intended 560 shuttle flights in the first 12 years. Peaking at 65 flights in 1988. the anticipated turn around times were 2 weeks for routine ops and "a matter of hours for rescue missions" Designs were started in the early 80's for 74 seat pax modules (to ferry crews to orbiting production facilities) and liquid fuel boosters to replace the srb's allowing 50,000kg payload. Its a pity those dreams have not been recognised.

The cost for development in 1980 dollars was $3bn over 10 years.

I reiterate, does anyone know what the Main Mission was on this particular launch.

BahrainLad,

The British one, someone at NASA playing a blinder...
I thought it might have been possible they acquired later, but not so.

"On 21 December 1872 the 2306 ton steam assisted corvette HMS Challenger sailed from Portsmouth on a 3-year voyage of marine exploration which laid the foundations of almost every branch of oceanography as we know it today."

"After her three years of glory, her fate was even more ignominious. Commissioned as a Coast Guard and Drill ship of Naval Reserves at Harwich in July 1876, she was finally paid off at Chatham in 1878. She remained in reserve until 1883, when she was converted into a receiving hulk in the River Medway, where she stayed until she was finally broken up for her copper bottom in 1921."

El Grifo, research. See the Mission Preview.

El Grifo, the "Main Mission" was a host of scientific experiments - a Space Laboratory, if you like. A wealth of info is avaiable on the STS-107 site at NASA. This is on the Missions site which has details of previous & future flights. Further exploration of the NASA site will answer most of the other foregoing questions (or FAQs!) on the subject.

Due to the fact that there has suddenly been an uncharacteristic surge in space-interest from the press and public, no doubt some sites are a bit slow right now.

There is also an excelent and very up-to-date site at Space.com, and many others. Hope this helps.

From the Jerusalem Post: According to news reports, a team of NASA engineers sent a report two days before Columbia's break-up on reentry stating that the damage caused to the shuttle's left wing during takeoff was greater than originally thought and could seriously affect its reentry and landing.

http://www.jpost.com/servlet/Satelli...=1044246922125

Flash presentation: http://lb.wnd.com/columbia.html

What happenbed?
 

I entered a post on the other shuttle thread indicating that the Reliability of the shuttle degrades with every launch. NASA may make welding repairs to engine plumbing but they do nothing to determine if there is structural degradation. The Columbia accident investigation is more open and transparent than the Challenger accident and if it is proven that the thermal tiles were damaged during transition to orbit then NASA will have to accept full responsibility which they did not on Challenger.

I personally believe that NASA was not completely forthcoming relative to the cause for the Challenger accident. If anyone wishes to question me regarding this statement I will gladly post my reasoning. It can be done on this thread or on a new thread.

:suspect:

There is much talk about "foam" hitting the left wing on launch. Could one of you better informed technical types elaborate on what this "foam" is. Was it ice? (Heard something like that on the news). For the layman foam is what you find in your couch/mattress, so all this makes no sense to me, really.

Thank you.

And ORAC,
as you are no doubt aware, another of Cook's ships was the Resolution, which heroically sailed Antarctic waters, among others.

Let the next Shuttle constructed, or derivative spacecraft evolved, be so named.