Very close-up, slo-mo of the Columbia launch debris.

Florida Today ^ | 02/01/03

[ironman]

Orbital Maneuvering System (OMS)

[Prov1322]

Interesting point, Amerigomag.

Does anyone know 1) how the "escape" portion of the shuttle works and 2) under what conditions will it work successfully!?

[WoofDog123]

"But alas this same board will also conclude that not enough information is avaliable at that stage of the flight to warrant such an economically expensive decision and therefore the accident was unavoidable without a complete redesign of the mission vehicles."

My interest is in what the board will say about the decision to change to a non-freon based foam insulation, which from the beginning demonstrated a tendency to break off and hit the vehicle, and why this decision was not reversed. If the primary motives in not reversing the foam change were ideological/political/economic, hopefully it will become public.

[XBob]

54, 118

Very Good memory Mr. Marion, putty change. Yes indeed, the challenger crew was killed by leaking putty (non-asbestos sealing the o-rings)

And now the non-freon foam peeling off the external tank.

So now it comes out - the Greenies have killed 2 shuttles and crews so far.

And then the first group, of 3, Grissom, White and Chaffee, I just remembered, was killed by the Oxygen fire -

so I guess that makes all 3 crews killed by the greenies.

Wow - they are right - messing with the environment is really dangerous.

[ladyinred]

Wondering also, since at the time they checked it out and said it was no big deal. Had they thought it was, wouldn't they have done something?

[Jael]

AEDC Performs Shuttle Materials Test for NASA/Lockheed Martin

ARNOLD AFB, Tenn.
-Arnold Engineering Development Center is assisting the National Aeronautics Space Administration with improvements in existing Space Shuttle materials. 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.
The loss of external tank foam material and subsequent damage to reentry tiles is a concern because it causes tile replacement costs to significantly increase,,u. however, it is not a flight safety issue. As a result, NASA-Marshall Space Flight Center selected AEDC to perform flight hardware materials tests on the shuttle's external tank panels in the center's von Karman Facility Supersonic Tunnel A.

The purpose was to establish the cause of failure for the tank thermal protection materials at specified simulated flight conditions. "NASA chose AEDC due to its technical expertise and historical program successes," Steve Holmes, a NASA-MSFC technical coordinator, said

---

(These are two different articles)
A review of the records of the STS-86 records revealed that a change to the type of foam was used on the external tank.
This event is significant because the pattern of damage on this flight was similar to STS-87 but to a much lesser degree. The reason for the change in the type of foam is due to the desire of NASA to use "environmentally friendly" materials in the space program.
Freon was used in the production of the previous foam. This method was eliminated in favor of foam that did not require freon for its production. MSFC is investigating the consideration that some characteristics of the new foam may not be known for the ascent environment."

http://www.freerepublic.com/focus/news/834139/posts?page=54#54

[Jael]

Do you know anything about the formula of the insulation foam being changed?

[XBob]

I've now seen a clearer version of this video clip.

how about giving us a link, please.

[Balata]

Dan Rather just showed a still picture of this video on his news update. I'm betting he or his staff read FR.

[chimera]

I saw the engineer who made the final decision. Looking at him I won't be surprised if he kills himself soon.

That would be unfortunate. All this is speculation after the fact. Those films were reviewed long after the shuttle was on station in orbit. Unless someone was watching in detail in real time and had the authority to abort the ascent to orbit, once orbit was achieved they couldn't do much of anything except carry on and hope for the best. Even if they knew and determined that there was damage, they couldn't fix it. There aren't any heat shield tile replacement service stations in orbit. Columbia couldn't reach the ISS on this mission because of orbital mechanics and lack of fuel and engine power. Other than trying reentry with what they had, the only other option would have been to stay up there and hold out as long as they could while someone else went up there and tried to get them, kind of like a Hollywood movie. I get the sense that NASA doesn't like to think about these kinds of scenarios. Its too ghoulish, thinking maybe, well, seven people can't hold out until a "rescue" ship gets there, but maybe six could. Or five? Or three? Or one? Then, who is going to be thrown out of the hatch to save the others? Forget about it. They were going to make it back together, or not, but they would stay together as a team.

Similar speculation went on during and after Apollo 13. Electrical power there was the critical consuamble. The scenario would have been particularly ghoulish if the O2tank had gone up while the lunra module was on the surface at Fra Mauro. Then you'd have two healthy astronauts and space vehicle stranded on the lunar surface while the command module and its pilot died overhead. The NASA planners about went crazy thinking about that one. But, like in the present accident, there's not much you can do once the critical comittments have been made.

[chimera]

Wondering also, since at the time they checked it out and said it was no big deal. Had they thought it was, wouldn't they have done something?

What could they do once they were in orbit? They don't have in-flight tile repair capability. That is a specialized operation only done on the ground. They couldn't reach the ISS. Columbia doesn't have the engine power for that height of orbit and anyway the orbit was set up for this mission such that the ISS was not within reach. They had consuambles for a set time. Sending another ship up to rescue them in time probably wasn't possible. We don't have these things lined up on the launch pads ready to go whenever we want.

The only thing I have heard suggested was changing the re-entry profile to that that damaged areas of the heat shield didn't get as much of the heat load as they normally might. But there are limits to that. There's no way you can completely avoid heating in an area. In fact, the gain maximum heat rejection you generally want to distribute the heat load evenly. Shielding one area means other areas are likely getting hotter.

[HiTech RedNeck]

ok, good - you don't even need a pencil to put a hole in that, just stick your finger through it

If it punctures that readily, why doesn't the onrush of air during landing smash the tile?

[FReepaholic]

>>...how about giving us a link, please...<<

It was shown on TV. Sorry.

[One Sided Media]

This is the spouse of "One Sided Media" and I am relaying to you the information I passed on to NASA regarding what probably caused the destruction of Columbia.

In the news conference held about an hour ago, part of the discussion was about the "roll control" and the inertial control systems that attempt to minimize deviations in the pitch, yaw, and roll of the shuttle. We know that in the last couple of minutes of communication with the ship, the shuttle was rolling to its left, evident by the increase in surface temperature on the left hand side wing and fuselage. As of the last contact, excluding the 32 seconds of unformed date that the Director was mentioning, this battle for control was occurring. Within a few seconds of the telemetry failing, and it may have been what caused the communications failure, the shuttles' ability to self correct completely failed. My belief is that ultimately the roll control failed resulting in superheating of the tiles on top of the wing and fuselage as the shuttle rolled over, an area whose tiles were not designed for reentry temperatures. This superheating is what caused the explosion seen in the video that has been repeated through out the day.

The ultimate question will be as to why the roll control was lost.

[kanawa]

WASHINGTON (Reuters) -- President Bush wants to boost funding for NASA by almost a half-billion dollars to modernize the space agency's aging shuttle fleet and develop a new space plane, an administration official said Sunday.

[null and void]

You know that. I know that. He knows that.

But he's still a human being who feels like his failure caused the death of seven collegues, and the loss of 1/4 of the fleet.

He was really hurting...

[HardStarboard]

>>>Obviously fairly soft as it puffed into a cloud of frost(?) powder.<<<

That "cloud of frost(?)powder" may very well have been tiles themselves disintegrating. They are very fragile and porous ceramic (not like your kitchen tiles at all) and the insulation from the fuel tank hitting them could have very possibly damaged them.

[null and void]

Yup. Keep reading...

[chimera]

You know that. I know that. He knows that.

But he's still a human being who feels like his failure caused the death of seven collegues, and the loss of 1/4 of the fleet.

He was really hurting...

Well, I hope the guy gets some help because its obviously not a call made by a single individual acting alone. The recommendation probably gets passed on by any number of people higher up. Technical decisions in any kind of engineering endeavor are often made by consensus, not a single, isolated person.

The earlier discussion about damage by the piece of insulation mentioned high speeds of the material and/or wing surface. Sure, they're all travelling fast at that point of the launch, but is not damage inflicted by the impacting object a function of the relative velocities? The familiar example is the image of a piece of straw driven by tornadic winds impaling itself in a tree trunk. A normally flimsy and light object driven to high speeds penetrates and damages a relatively strong material. But there the target is stationary and the moving object hitting with a high relative speed. If the two objects are moving together or at close relative speeds, is not the energy imparted somewhat reduced? I'm thinking here of the classical mechanics problem of conservation of momentum in the center-of-mass frame of reference. Unless there was tremendous slowing down of that piece of foam as it left the external tank, I can't imagine the relative velocities being too terribly different.

[strela]

I seem to vaguely recall some discussion, years ago, of replacing the current crew cabin configuration on the orbiters with an integral, reentry-survivable pod. If an emergency arose during launch, it could be ejected under its own power and soft-land. It could also re-enter the atmosphere from orbit if the orbiter failed the re-entry burn.

Do you recall why that option was never utilized? Cost? Technical hurdles?