Observation on TPS damage on Orbiter

NASA photos | 2-3-03 | BoneMccoy

[Budge]

Correct me if I'm in error, but the Columbia is the smaller dot (left), and the debris is the much larger flash (right side).

In each video showing re-entry, the flashes are rather large, much larger than the Columbia, yet no trouble was reported at the time. However, could crew reaction and/or mission control reaction be long enough to only report what we have heard?

[Cold Heat]

I would think a spectro-analysis of the color would require better film than we have here.

A destructive spectrometer is hard enough to get a accurate reading from a sample.

[Budge]

Bones, did you get my FReep-mail this morning?

[Cold Heat]

No, the big one is the shuttle . The smaller is the shedded material.

[bonesmccoy]

I can not ascertain the answer without more specific flight data. I am not privy to such information.

However, generally, the more massive payloads create higher heating loads. These heating loads can be dissipated across time by flying a trajectory with lower profiles. However, the profile OV-102 STS-107 was flying was apparently the lowest profile they could identify.

There was no other approach profile to fly.

The vehicle structure can experience maximum heat loads later than when it experiences maximum energy. The reason is that the TPS dissipates some thermal energy and other amounts slowly migrate into the structure by conduction.

In this case it appears from the Covault article posted in the last 24 hours that FR scooped the major media again.

FR consistent shows the superiority of having on-line expertise from various fields of experience. Although we are not involved with the space program, we have enough experience in various fields to identify the issues and apply standard analytical techniques.

I want to congratulate NASA on their successes and share in their loss. This is an international loss. Each crew reflects our hopes and dreams for a better planet.

Understanding how those dreams were lost in this accident can help us prevent similar incidents in the future.

At this point, I believe that the ET insulation had ice build up. That ice build up became substantial due to the changes in the ET insulation formula. ET contractors were probably aware of ice build up, but may not have been aware of the extent of the build up. Ice impact analysis is nothing new to Boeing. Ice impact analysis was done prior to the launch of STS-51 L per report in the Rogers Commission findings. That ice impact analysis was necessitated due to the realization that ice from the gantry could impact part of the orbiter.

The threat of ice impacting the orbiter has been known for many years. Changes to formulation in ET insulation made to support Clinton-Gore environmental goals were not consistent with flight safety. Dan Goldin is responsible for this disaster because he was the NASA Administrator who permitted NASA's flight safety to be compromised.

Dan Goldin needs to be put before a public hearing to discuss this matter and defend his decision. It is not Ron Dittemore who deserves this kind of treatment. The Shuttle Program Manager is following directives from Washington DC. His goal is safe flight. He clearly did not realize the safety factors involved with the ET insulation changes nor the ice build up.

The question is whether or not Dan Goldin ever requested NASA exception from the Clinton-Gore policy.

[snopercod]

A waterproofing substance is sprayed on the craft at turnaround after repairs.

The whole bird is waterproofed before OPF rollout. They don't want any water getting in between the tiles, then freezing on orbit, possibly popping off a tile.

The stuff they used is called (or contains) "DMES". Don't know what it stands for.

[spunkets]

"Am I close to correct?"

That's it. The speeds would be the same. They would decrease their reentry angle to keep the temps the same. It would just take longer to slow down.

[spunkets]

"DMES"

dimethylethylsilane...coating a surface with this stuff makes the surface hydrophobic. Water doesn't wet it at all, really beads up, and dosn't stick.

[Cold Heat]

They are really distancing themselves from any ice build-up. They claim that icing was minimal and within specs, (whatever they are)

Now having said that, the ice could have formed on the way up. It would have weighted the foam which may have caused it to separate and fall.

I just don't know, but I too was affected in the contracting field by the freon ban.

That is when orange clean and all that other useless cleaning crap was forced on us. We had major problems cleaning carbons and contaminates from high voltage equipment, resulting in breaker failures and perhaps some injuries and deaths.

[Jim Noble]

>>The issue is that the risk could be 99.9% safety margin. That means a 1/1000 risk. That risk could bite you. In order to get a system that has 1/10,000 risk, it would cost the nation an extra billion dollars. Is that worth it? <<

Is it worth it for flight test? Probably not.

Is it worth it for a system designed for flight rates of 1/month in order to be cost justified? Almost certainly.

The STS was sold to a (venal, whorish, ground-looking) Congress under false pretenses. I understand that if Congress didn't let the shuttle fly we wouldn't fly at all.

Ordinarily, I'm a "half a loaf is better than none" guy.

But this half loaf's design can't sustain it's mission, IMO, which is not to flight test experimental TPS designs but to put stuff and people in space, and bring the people back.

[Budge]

Briefing has started on NASA Channel.

[spunkets]

" The observation of the color of the plume gives you the ability to discern the contents of the plume."

The color percieved depends on the sorce of illumination. Those flicks have 2, the sun and those large flames from the booster rockets. Those large flames are yellow. If the dust is yellow it will look yellow. If it's white, it will also look yellow.

[snopercod]

Thanks. It was considered "hazardous", and the spraying was only done with an evacuated bay and breathing apparatus for the applicators.

[Budge]

Okay, call me confused, but isn't movement from right to left?

Wouldn't that put the debris ahead of the shuttle?

[Cold Heat]

Left to right.

[Cold Heat]

C-span 1

[freepersup]

Your theory and observation about the numerous eyewitness reports and captures on film and video of 'illuminated pieces' trailing the shuttle over first CA., NV., AZ., NM., & then TX without any sensors indicating this, tells us that the initial loss of 'parts', are- the shuttle parts lacking sensor indicators.

That scenario fits with the tiles, as they lack the ability to 'self report' conditions by way of sensors/instrumentation.

The one characteristic of this disaster (unique to the chain of events as we are coming to understand them) is the fact that there was almost zero warning in relation to the degree of devastation and the corrollary to the fact that there was almost an instantaneous loss of all data.

In other words, were any other shuttle components to begin destructing, chances are a sensor would alert the aircrew and ground personnel to the problem as it unfolded. The shuttle may have been destroyed just the same, but the trail to the root cause or the trail to the initial location of the failed component would be far clearer than exists in this circumstance.

Total destruction with little warning or data. Tiles peeling off fit this profile. A fatal action was unfolding in slow motion which reached critical mass with catastrophic consequences.

[Budge]

I thought it was right to left. Makes a big differennce.

[snopercod]

The drag was trying to roll the vehicle to the left, while the flight control system was commanding the elevons to roll it back to the right.

Actually, the drag would tend to YAW the vehicle to the left. The loss of lift on that side would tend to ROLL the vehicle to the left.

I don't know enough about the orbiter flight control system to predict how it would react to something like this. I know there are IMUs [Inertial Measurement Units] which are the main "attitude gyroscopes". There are also accelerometers, but I don't recall their function.

On a light aircraft, the turn coordinator gyro responds to both roll and yaw. Certainly the shuttle FCS responds independently to yaw and roll inputs.

Any FCS experts out there?

[Cold Heat]

The wiring to indicate a single tile loss would weigh more than the shuttle payload.There are thousands of tiles.

The tile system works well and has for thirty years. The critical item is to keep things from hitting the shuttle.