Sorry if this is slightly out of context but I have decided that this thread will deal with the technical discussion of the Columbia disaster. Please use the Shuttle Columbia breaks up during re-enry thread for emotional/condolence type posts. [edited]

I cannot understand why you guys are all so uncritical of the Shuttle
missions.

They are serve no scientific purpose at all.
The technology is old. The "experiments" conducted on board are
laughably trivial; mainly for high school teaching programs ("let's
see what happens to watercress when we grow it in microgravity").

Not a single piece of scientific research from a Shuttle mission has
ever appeared in a decent peer-reviewed scientific journal; it all
goes into mediocre NASA house journals. The whole thing is a
preposterous waste of money.

Unmanned vehicles are safer, cheaper and have produced stunning
scientific discoveries.

The real tragedy of yesterday's accident is that seven highly
talented and courageous individuals lost their lives for a
completely pointless trip into space; the international space station
is an adult equivalent of building a tree house.

Dear Luke,

The ISI web of science has about 2050 publications in the database involving the space shuittle. This is the latest.

Lancaster RS, Spinhirne JD, Manizade KF
Combined infrared stereo and laser ranging cloud measurements from shuttle mission STS-85
J ATMOS OCEAN TECH 20 (1): 67-78 JAN 2003

Of course the launch and repairs to the Hubble and the launch of Chandra (the X-ray observatory) were also key parts of major scientific accomplishments.

The recent flight had nothing to do with ISS, incidentally.

Beasusoleil
okay, I agree that the shuttle was helpful in repairing Hubble (which
has been productive scientifically). But relaunching a repaired
Hubble would have been safer and cost a lot less than the Shuttle
program.

In my post I did acknowledge that many papers have appeared from
the shuttle program. But they are generally trivial, in house
journals with little or no citation impact.

For example on Pubmed today there are 849 papers from the Shuttle
trips. None of these are in the big life science journals (such as
Nature, Science, Cell, New England Journal of Medicine, Lancet or
journals of similar caliber). Instead they are in obscure journals
with titles such as "the effects of microgravity on cell wall
metabolism" and "the effects of microgravity on the mouse immune
system". These are data-dredging exercises which do no address
fundamental questions. I just now trawled through the abstracts of
the most recent 100 of these papers, and the only feeling I am left
with is how pointless most of this "research" is. If the billions spent
on manned space programs had been invested in the NIH, the
scientific product would have been dramatically better.

I know I may get some hostile reaction to this (and I appreciate the
courteousness of your email). However I mean no disrespect to the
crew who died so tragically yesterday. But we don't serve them
well by suspending our critical faculties. If the shuttle program
ends now, there will be no effect at all on scientific progress (in fact
it would be be helpful, because earmarked funds could be
rediverted into real science).

Luke

Luke Davies

I'm not sure why you feel the need to criticise now, but this statement is complete rubbish. I used to work with data from SRTM (Shuttle Radar Topography Mission), and plenty of data from that and the SIR-C/X-SAR (Shuttle Imaging Radar/X-band Synthetic Aperture Radar) experiments were published in the Journal of Geophysical Research - which everybody (apart from you) would regard as a "decent peer-reviewed scientific journal".

:rolleyes: :mad:

Luke, what you say has been said many times before and it is a valid point when faced with the high cost of losing life. But the simple fact is that we are explorers, we are curious about everything that exists around us. What we know of our Universe comes from our need to find answers and that will never change. Unfortunately the pioneers of this "extension of knowledge" sometimes become victims of the quest, but that is known by all participants.

You must not forget that manned space exploration is in its infancy, but it will continue, and it will bring rewards, perhaps not immediately to us, but certaintly to our descendants. The road to knowldege and understanding is filled with danger but thankfully it has not stopped us. Remember, where there is a mountain there will be someone ready to climb it, no matter how dangerous or costly it is.

Evo, what you say is correct however the point trying to be made is that the same research and results could have been attained on an unmanned spaceflight . As a pilot this does not sit well with me as I am sure many others who read such but I am afraid from a purely research/results/cost orientated standpoint it is difficult to argue against the merits of an unmanned program.

firewall - I completely agree. But that's not the point.

The statements were that "They are serve no scientific purpose at all" and "Not a single piece of scientific research from a Shuttle mission has ever appeared in a decent peer-reviewed scientific journal". That's just wrong. The shuttle has flown some very high quality experiments that have produced very high quality data. Could it have been done cheaper? Yes, in almost every case it could have been - but only a fool, NASA-basher or troll would claim it has done nothing of scientific value.

But that's enough from me. Not the time or place for the old manned/unmanned argument.

Although I haven't worked in astronautics for about 10 years since I discovered the joys of flight test, I still routinely come across many papers on work done in the Orbiter - albeit on the technology level.

The political point made by Luke isn't a new one. The fact is NASA decided to go in a particular way which isn't particularly cost-efficient in terms of pure science done. However it has allowed huge flexibility and statistically a good level of safety and success given the complexity of the technology. It has also forced the development of technologies that as mankind expands outwards, will be essential. You could argue that they should be working more on STS' successor, but you can't deny the huge effect the programme has had on world science.

Incidentally he's also wrong; probably the most prestigious basic science journal in the world is "Nature" and a quick search on their website found a huge number of papers where shuttle work is mentioned. I can't say I understand many of the titles, but I'm an Engineer not a biologist so this is unsurprising - I can certainly see the significance of papers like "Effect of microgravity on the crystallization of a self-assembling layered material" which is big stuff in semiconductor technology.

I suppose it's inevitable that the accident will cause a lot of open discussion, and some political points will be aired. So I'll make one of my own. I am British, and for my entire adult life I have lived under governments that have never seen any benefit in participating in manned spaceflight. That upsets me.

G

LUKE: The Shuttle's missions are not all scientific. Earlier "secret payload" missions assuredly included military/defense objectives; most probably they included the retrieval of several former Soviet spy satellites. :eek:

A good link...

Most interesting part to me:
____________________________________
---------
8:59am ET
---------

A message from Mission Control about low tire pressure:
?Columbia, Houston. We see your tire pressure messages and
we did not copy your last.?

Commander Husband:
?Roger, uh ...?

The transmission goes silent for several seconds, followed by
static. This would be the last communication with Columbia or
its crew.

---------
9:00am ET
---------

The shuttle is 39 miles over central Texas at this time.

NASA PAO:
?Columbia out of communications at present with Mission
Control as it continues its course towards Florida.?

Agonizing moments go by while mission controllers frantically
try to restore communication with the shuttle.

---------
9:06am ET
---------

Mission Control:
?Columbia, Houston. Comm check??

Columbia breaks apart over Dallas, ......
__________________________________________

6-7 minutes from Loss of Communication to Break Up? I don't know how accurate this is, but I would have thought that once things start going wrong at 210,000' / M18 they go wrong very quickly, and until I saw the above, I presumed this process took a few seconds at most.

Maybe by 9:06 they mean the first reports, or confirmation? However, I am sure it will be cleared up - some of the film footage probably has a time stamp....

NoD

STS-107, Chronicle Of A Disaster Foretold?
 

I thought that a separate thread to discuss the probable causes of the loss of Columbia was called for, as a mark of respect to those expressing their sentiments over the loss of life in the first.

My concern is that an initial incident, possibly resulting in the eventual loss 15 days 22 hours and 22 seconds into the mission, namely that of the impact of foam insulation debris at launch on the shuttle's left wing was never considered dangerous enough to warrant further action.

NASA's announcements so far regarding this event include statements that any damage from the incident was assessed as not representing a danger, that there were no on-board capabilities to visually examine the area of the wing in question, nor any capability by the crew for repairing any damage sustained to the tiles.

My observation is that the tiles, and any questions relating to them are of prime importance for obvious reasons. The questions I have include:

1) Why did NASA discount the incident at launch?

2) What, if any measures did NASA take to inspect the left wing during the mission (eg) by land or space-based telescopes etc. ?

3) Had the incident at launch time been taken seriously, what options would have been available to NASA in order to save the crew (eg) launch of another shuttle, diversion of the shuttle to the ISS etc. ?

As in "normal flight" incidents, while the "primary" cause may have been an equipment failure, the reason for the eventual disaster may well lie in "human error".

All your points are answered on the other thread.

<<1) Why did NASA discount the incident at launch? >>
They did not by any means...

<<As in "normal flight" incidents, while the "primary" cause may have been an equipment failure, the reason for the eventual disaster may well lie in "human error".>>
May be true, but not along the lines of the baloney you wrote above...

In short, they considered it, were unable to do anything to inspect it, and if they found a problem, what do they do? There was no means of repairing any damage even had they discovered it.

We're not talking civil aviation safety standards here. There are plenty of "critical aspects" where a single point failure = death to all. The astronauts knew that better than anyone...

Maybe before starting this link, you should have read the other thread, particularly the recent post with a link to a site with an FAQ section that repeatedly and comprehensively answers your questions.

NoD

Luke, the NIH budget for 2003 is $27 billion. In 2003, NASA intended to spend $113 million on bioastronautics, and $56 million on fundamental space biology. There have been numerous complaints, from organizations such as the National Academy of Sciences, that the NIH cannot demonstrate what scientific and medical results it is getting from spending these large sums of money. Certainly, there is not $27 billion worth of science annually being published in the peer review journals, both great and minor.

Regarding your suggestion that Hubble should have been returned to earth, repaired, and relaunched, it is impossible without the shuttle to do that. Very very few unmanned spacecraft are designed to withstand atmospheric re-entry, and none of these are intended to be re-used.

Airship, regarding the first question on your new thread, which NOD rightfully suggested that you first look at the google group FAQ link listed in a post above:

NASA did not discount it. NASA did an assessment based on the estimated size, weight, and velocity of the foam insulation that struck the left wing, and concluded that it was unlikely to have caused significant damage. In October 2002, a piece of insulation from the same general area of the external fuel tank pulled away and struck a cowling on one of the solid rocket motors (SRMs). NASA recovers and reuses the SRMs, and thus was presumably able to examine the amount of damage from that strike. The damage to the cowling was considered superficial.

That said, having a sizeable piece of insulation tear away from the external tank and strike either the shuttle or an SRM in two of the last three launches suggests there was:
1.) a recent change in the composition of the insulation or how the insulation was manufactured; or,
2.) a recent change in the process for bonding the insulation to the tank; or,
3.) a quality control problem in the manufacturing or installation of the insulation.

As the previous strike was in October, temperatures during pre-launch checkout and launch would not seem to be a factor.

NoD,

I think it's a great shame that you feel the need to bring out the insult handbook like that. Would a "Hi, I think most of your points are covered, hope you find them" not have sufficed? You know that you wouldn't have the balls to talk to strangers like that face to face, so the fact that you do so behind the shield of a Username is only going to serve as a sign of your cowardice. Feel free to be a grump but there's no place for your rudeness here.

AMR

NoD

I believe that all Shuttle re-entries involve several minutes of 'routine ' comms black out thanks to a plasma field round the craft at the period of max temps.

It appears the breakup happened during this period

Airship - in answer to Q3, I think the only option would have been an abort launch command which would have brought the shuttle down on an emergency strip. That decision would have to have been taken early, perhaps within seconds of seeing the bit fall off, with very little data instantly to hand and would have taken a (!)VERY BRAVE PERSON(!) to make it.

Imagine facing the NASA bosses that afternoon when the damage had been assessed as 'negligible' and YOU aborted the launch.

As it happens, it would appear to have not been negligible, and lives would probably have been saved, but ...................

According to the NASA spokesman on telly this morning the crew did inspect the wing whilst in space (during a spacewalk I think) and could not find any damage.

I was under the impression they knew pretty much to the second when communications were to be lost

If this was the case, surely they wouldnt have been surprised to be cut off mid-conversation?

I have read the FAQ, while useful, it does not offer any satisfactory answers. Some notable points it contains and I quote are:

1) "...one of the tasks assigned to the STS-107 crew was to take photographs of the
External Tank immediately after tank separation to see just what broke off, where it broke loose, and how big it really was. Those photos were taken, but sadly they will probably not be recoverable."
2) "Even if there had been some suspicions, there was simply no way for the crew to perform any sort of check of the underside of the shuttle."
3) "...an EVA was simply not possible as there was no EVA airlock."
4) "...the Shuttle program manager specifically stated that the crew had no capabilities to to tile repairs." (original typographic errors)
5) "...in this flight, the shuttle did not have the docking system to dock to the station." (the station being the ISS)

What one is forced to conclude is that even if the cause of the disaster was damage sustained to the heat-shield in the incident at launch, there was no way of verifying its' condition in-flight. Even if the damage could have been verified soon after, there was no way for repairs to be effected. Even if there had been a way to launch another shuttle in a resue attempt, or to divert the shuttle to the ISS, there would still have been no rescue due to the lack of the EVA airlock and docking system because of the original mission constraints.

It sounds like the builders and operators of the Titanic not only believed their vessel was unsinkable but that even when the vessel was struck, decided not to launch any lifeboats at all, and sending an SOS would have been an entire waste of effort.

John Farley,

I believe blackouts of shuttle communications during re-entry no longer happen. The shuttle communicates and transmits data in the UHF, S, and Ku bands. The Ku (and I think the S band as well) band space-ground data is sent using geostationary TDRS (Tracking and Data Relay) satellites. Using the TDRS avoids the blackout that was the constant feature of all Mercury through early shuttle missions.

Downlink data rate on the Ku Band is 50 Mbps. So NASA should have all the telemtry data to the moment of breakup and complete loss of signal.

This is indeed correct.

NASA has real time data for the complete reentry phase.

Not that could *do* much

--alex

airship

I apologize for the tone I used ...

<<It sounds like the builders and operators of the Titanic not only believed their vessel was unsinkable but that even when the vessel was struck, decided not to launch any lifeboats at all, and sending an SOS would have been an entire waste of effort>>
I disagree. Any book you read on something such as the shuttle will tell you there are a number of "critical" failures that are fatal - full stop.

1. The designers never considered the shuttle "unsinkable"
2. They are not able to incorporate or launch "lifeboats"
3. "and sending an SOS would have been an entire waste of effort" - frankly yes.

I think you have to remove traditional safety concepts of civil / public transportation from a vehicle such as the shuttle. If you applied these standards (lifeboats etc.) it would never fly.

You are also jumping to the conclusion that the break up had something to do with the loss of the foam on launch. I agree it is the only other "event" of note with this flight so far, but that does not mean it was the cause. Most accidents tend to have a multitude of causes, and rarely the ones that appeared obvious on day 1. I think we'll have to wait sometime longer...

If it was a tile loss / damage leading to overheating then break up I would have thought some temperature sensors would have given more warning of this? There was talk of temperature sensiors built into the body (wing underside?). Any experts out there know the point of maximum heating in the recovery?

NoD

BOAC (I loved that airline!),

I would have to agree with your point. While allowing that an "abort" would have been very hard, if not impossible to "call", I also think that the obvious is being ignored. This is that manned-missions close to earth should be envisaged with the view that rescue is possible.

<<NASA has real time data for the complete reentry phase.

Not that could *do* much >>

Not to save the crew of vehicle - however, hopefully does mean the full telemetry is recorded and able to be analysed for the investigation. Had there been a "black out" phase (as I initially thought) and the break up occurred then, the investigation would have had almost nothing.

NoD

The last comms exchange prior to total comms/telemetry loss between Houston and Columbia was Houston acknowledging receipt of data on tire pressures. If this data indicates a pressure increase this could be due to the extreme temps on re-entry actually penetrating the heat-resistant "system" as a consequence of the integrity of the heat-resistant "system" being impaired on launch.

All total speculation at this stage.

NASA does, however, appear to be keeping the public informed this time round, after the semi-secrecy following Challenger. Let's all hope that once the data/telemetry that were subject to the contingency is married with the outcome of the NTSB/NASA investigation a cause can be established and new measures adopted for future manned missions.

There have been suggestions that an EVA was not possible, that the underside of Columbia was not able to be viewed and that there was no possibility of a dock with ISS. Let's hope future missions can incorporate some flexibility on such issues.

:cool:

Some viewpoints:

"Aborting" the launch.
Once the "button" is pressed to launch, the Shuttle is committed to continue until the SRBs are jettisoned. Once these have gone, there are various "options" - however, all are hazardous. There is RTLS (Return to Launch Site) - however, I believe this has a significant chance of ending up in the sea. There is "abort to Africa" - I think this happens with 2 engines lost - again, hazardous. Then there are the safer ATO - Abort to Orbit e.g. for 1 orbit - however, this will involve a reentry. There has, I believe, been 1 abort to date for an engine failure - however, it was the mildest option, and left the shuttle in a lower than desired orbit.

I think you will find that very rarely are the Crew / Mission Control going to "call" an Abort - in practice they will be "forced" into one of the above options by onboard engine failure(s).

<<There have been suggestions that an EVA was not possible>>
Yes - the kit was not on board, nor had the training been carried out for this crew's mission.

<< that the underside of Columbia was not able to be viewed>>
Exactly - there is no mechanism, except EVA. Even the arm, when carried (it was not here) cannot "see under". I have to ask the question - if they saw damage what were they going to do?

<< and that there was no possibility of a dock with ISS.>>
A massive loss of flexibility if this is to be required. It takes a hell of a lot of energy to get into orbit. To now decide you want a different orbit is not like changing lanes on a motorway - it is like needing most of the energy supply you had at launch at your disposal again. Note when they have problems how tight the launch windows are if some rendevous if required.

<< Let's hope future missions can incorporate some flexibility on such issues.>>
I doubt it - the loss of flexibility and increase in costs would make an already dubious machine financially absolutely useless.

If you want to go down this route, I think the only way to do so is to seriously look at whether the work done by the shuttle needs to manned spacecraft. It comes down to one's moral judgements - all viewpoints of which have to be respected.

Personally, looking at the slim margins and design fundamentals of the shuttle, 2 losses in over 100 missions is probably par for the course, if not better than expected. There have been a number of VERY close shaves, and all of these are still Criticality 1 items - if they happen = total loss.

NoD

NoD,

No problem, but thanks for your message!

It is true that I am guilty of jumping to conclusions. There could not be a discussion if we were to wait for the official declarations...

Regarding the sensors, I understood from the NASA press conference that there were 12 or more temperature sensors in the left wing area, all of which operated normally until moments before the accident. There was also some mention that simultaneous "failure" of sensors can also be due to malfunction of the signal processor or multiplexer unit through which their signals are processed. However, I understand that not all of these sensor's signals went through the same "avionics box". Needless to say, it was probably by far too late to abort re-entry by the time these anomalies occurred? If there had been significant damage to the heat-shield after launch, would these same sensors have not registered anomalies during the shuttle's orbits, when the underside would have been (repeatedly) exposed to wide fluctuations in temperature from exposure to the sun?

Your comments concerning:

1. The designers never considered the shuttle "unsinkable" - granted.
2. They are not able to incorporate or launch "lifeboats" - just as the lunar module on one of the Apollo missions provided relief (or was that just a film?!), an EVA airlock and docking system are both valid and pre-requisite for would-be rescues of near-Earth missions.
3. "and sending an SOS would have been an entire waste of effort" - frankly yes. - in this case there was no "Houston, we have a problem" message because Houston didn't think it had a problem. In space, nobody cries "Wolf"!

Interesting synopsis of possible cause is to be found

here at this link.

Takes a different perspective and looks at some of the critical factors that can affect re-entry.....or cause catastrophe.

airship...

<<Regarding the sensors, I understood from the NASA press conference that there were 12 or more temperature sensors in the left wing area, all of which operated normally until moments before the accident>>
This is an area that is interesting. NASA have commented in detail on how numerous temp (and other) in the left wing were progressively lost, and small mention of how some showed temp rises - this from Sky's site:
_________________________________________
1356: Temperatures in the housing of the left main landing gear rise. At this point the shuttle is 207,135ft or 39 miles up and travelling at 12,500mph - 18 times the speed of sound.

1358: Temperature sensors in the left wing, embedded in the structure of the vehicle, stop working.

1359: Pressure and temperature sensors for both tyres on the left main landing gear go offline
_________________________________________

What I'd really like to know is what the << Temperature sensors in the left wing, embedded in the structure of the vehicle>> showed prior to stopping working. Presumably these sensors are there to monitor the renetry, if only "after" the event.

<<Needless to say, it was probably by far too late to abort re-entry by the time these anomalies occurred?>>
They start 1 (of 3) APUs (1 needed to power flight controls and landing gear) in orbit prior to "deorbit" (a long burn to slow the shuttle down). Once deorbit starts, its coming to earth whatever! It has no fuel to regain all that energy - in fact, what little fuel it has remaining is "dumped" after the deorbit burn. But again, even if any anomolies had been seen, what to do? All one can really do is recover to earth and "hope for the best".

<<there had been significant damage to the heat-shield after launch, would these same sensors have not registered anomalies during the shuttle's orbits, when the underside would have been (repeatedly) exposed to wide fluctuations in temperature from exposure to the sun?>>
Interesting - but doubt it. The Heat Shield / Tiles protect against a short / sharp rise during renetry. In orbit things take longer, so probably expect to see fluctuations?

<<just as the lunar module on one of the Apollo missions provided relief (or was that just a film?!), >>
The Apollo missions had an escape rocket attached to the manned capsule. From Prior Launch to not too long after (it was then jettisoned) it could be used to drag the capsule away, and let them come down be parachute. Not suitable for the shuttle because its (only) way of landing is using the whole thing as a glider. They put some pole in with parachutes after Challenger, but I think the circumstances it can be used are very limited!

<<an EVA airlock and docking system are both valid and pre-requisite for would-be rescues of near-Earth missions. >>
It has a dead standard airlock into the cargo bay. However, any EVA system needs something to EVA into. What?

<<3. "and sending an SOS would have been an entire waste of effort" - frankly yes. - in this case there was no "Houston, we have a problem" message because Houston didn't think it had a problem. In space, nobody cries "Wolf"!>>
Some Prof on Sky making possible suggestion Mission Contorl knew all along recovery would be / may be fatal:
_______________________________________
Pressed by Jeremy Thompson, Prof Balogh said he was satisfied that NASA had been fully aware of the problem and had, in all probability, known all along it was potentially fatal
_______________________________________

I note from the NASA brief yesterday they only became aware of the bit falling off the day after launch - so no possibility of any decisions to be taken during the launch phase.

NoD

.
 

Divert to the ISS was never possible, changing plane of orbit takes *a lot* of fuel, far more than Columbia had.

TheShadow

Some interesting stuff in that link, but a lot of speculation - particularly about pilots and autopilot.

I think in yesterday's brief, NASA said 3 launches ago a similar section of tank detached. The next launch it did not, and then this launch it did. An investigation was ongoing which was to report prior to the next launch. Maybe some material change in the tank construction recently?

NoD

NB NASA news conference 2130Z tonight I think. Given the detail they gave last night - I don't think anything significant has come out since - should be interesting.

Were NASA (or certain elements within) aware that STS-107 Columbia was doomed shortly after launch?

I have the following proposals:

1) We drink a toast to SOYUZ. Those on the ISS will be grateful that there is an alternative space program.

2) That a shuttle be permanently positioned at the ISS in order to perform SAR missions in near-Earth orbit.

3) That all future missions incorporate "crew" escape modules allowing for evacuation to another shuttle in space or re-entry under their own means.

4) That future missions rigourously incorporate the ability to "proceed by their own means to the ISS".

If future space missions are to be pursued, then it is high time that these cease to be regarded as a "dice with death".

airship...

<<That a shuttle be permanently positioned at the ISS in order to perform SAR missions in near-Earth orbit>>
<<That future missions rigourously incorporate the ability to "proceed by their own means to the ISS". >>

I think you are not understanding the problems of "orbit". It is massively difficult to rendevous when it is the aim of the mission. To do so on an ad hoc basis, particularly when something has gone wrong = degraded capability is just impractical.

If you persue this line, the best place for the "lifeboat" is on earth. At that point it has the potential to be launched into the desired orbit - i.e. match that of the "stricken" craft. If you go this route, then a criteria for launch is that this lifeboat is "ready to go".

<<If future space missions are to be pursued, then it is high time that these cease to be regarded as a "dice with death".>>
IMHO you've summed it up here. What value do you place on human life, particularly when those whose lives are at risk know far better than you and I the risks, and accept them.

Interesting website:
http://nasaproblems.com

In the 2 shuttle accidents to date, I do not think an escape capsule would have been of any value...

NoD

Airship, the photography requested was apparently done because of foam insulation coming off the external tank and striking the SRM cowling during the Atlantis launch in October, 2002. It was likely done to see whether the Atlantis problem was a one-of or something recurring.

Any Shuttle Experts out there...

Was the "tiling system" used in Columbia standard across all shuttles? I seem to recall something about later shuttles using a better matting system?

I note from C4 news that the original tile repair kits used on Columbia have been discontinued due "cost cutting". Just the sort of thing airship has been suggesting, although even if tile loss caused this after being hit by the tank section, no guarantees such a kit would have coped with whatever damage might have occurred....

NoD

Finding the debris
 

One news report mentions an observer in Owen Valley, California who noted flashes as the shuttle passed overhead which raises the possibility that pieces/tiles could have started coming off at that point.

Any such early pieces that came off would be important to the investigation, but what are the odds of finding them when they could have landed in snow, forest, desert, mountain or water after the winds have blown them off course?

The apparent intense fragmentation over a wide area makes it unlikely that all the pieces in the main debris field will be recovered, which will add to the difficulty of identifying by elimination which pieces came off first.

If a substantial span of the the left wing failed, the right wing would end up acting almost as a rudder and the left fuselage side would be exposed to beyond design aerodynamic forces at M18:(

Sally Ride said on the news this am that even if they had gone outside to inspect, they wouldn't have been able to see the area where the tiles would have been missing, and there would have been no way to replace them.

Lots of talk in the press about escape pods and how people like Buzz Aldrin have been pressing NASA for years to integrate one into the shuttles. It would be some escape pod which could work in all phases of shuttle launch and re-entry, including at Mach 18 at 200,000 feet. That has to be fantasy, doesn't it?

QDM

Crikey Firewall - no scientific benefit/publications from shuttle based missions !!.

Three letters, HST !

I may be biased as I work
at NASA GSFC but I think anyone would agree that the scientific value to mankind of Hubble (Entirely dependent on STS launch and servicing) has been considerable.

NASABOY

Endevour, the shuttle that replaced Challenger uses a different system. Not too sure of the exact details but I think the white low (lower!) temperature tiles were replaced with matting but the black high temp. tiles and the ceramic leading edge on the wing are the same.