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

Florida Today ^ | 02/01/03

[twyn1]

Could they have docked with the space station and waited for another shuttle to pick them up?

I don't know how much oxygen and other consumables they would have stockpiled on the shuttle/space station, probably enough for 10 people to wait a couple weeks or so (did they say they have enough supplies for the 3-man crew until the summer??) -- not sure how long it takes to get another shuttle ready for launch, it has to be a few weeks at least -- also, I think they only have one docking port on the station -- they would have had to "dump" this shuttle to allow the other to dock -- could that be done ?? -- I do know there is nothing aboard available to repair the tiles, and they never really looked at any damge that may have been caused -- bad decision ?? yes, but hindsight is always 20/20

[spunkets]

" this insulating "foam" ...?

It's a low density ceramic. The ceramic is full of voids. The voids are not gas filled, but are empty space, that provides for the least thermally conductive material. I don't know exactly what the major ceramic component is for the tiles, but I'd guess it was aluminum oxide, because it has the highest emissivity, very low thermal conduction and is extremely inert. The high emissivity means it radiates whatever heat it picks up fast. Radiation is the only way to get rid of the heat. Any carbon in a composite structure is used as a very high melting thermal conductor to conduct heat to other radiating surfaces where the aluminum oxide that protects the carbon, radiates the heat.

[b4its2late]

Yes, hindsight always 20/20.

[XBob]

it is a relatively dense polyurethane, with a good protective/strong but light fiberglass like coating to protect it from the weather and keep hail from damaging it when it sits out in the weather.

Hurled at hundreds of mph, it probably could do some pretty good damage.

[Quietly]

Link?

[XBob]

I am no expert in foam insulation. However, the pieces of external tank insulation I have examined seemed to be made of high density poly-urethane. It is designed only to keep the liquid oxygen and hydrogen insulated, not to resist re-entry.

The insulation on the shuttle was quite different, ceramics, varying from high density/temp (black on leading edges), medium density/tem (grey on bottom), very low density (white on top - like merangue on a pie), and then various types of woven and sewn 'blankets'. The holding a piece of the 'merangue' type between your fingers would put finger prints into it. I personally don't think that standing on one foot on a one foot square piece of the external tank insulation would damage it much. And the outside coating is tough.

Hurled at hundreds of mph, it probably could do some pretty good damage.

[XBob]

I agree with your thesis.

[aimhigh]

Here's what I found about the tiles:
http://www.howstuffworks.com/question308.htm

The space shuttles are protected by special silica tiles. Silica (SiO2) is an incredible insulator. It is possible to hold a space shuttle tile by the edge and then heat up the center of the tile with a blow torch. The tile insulates so well that no heat makes it out to the edges. This page discusses the tiles:

Aerobraking tiles are produced from amorphous silica fibers which are pressed and sintered, with the resulting tile having as much as 93% porosity (i.e., very lightweight) and low thermal expansion, low thermal conductivity (e.g., the well known pictures of someone holding a Space Shuttle tile by the corners when the center is red hot), and good thermal shock properties. This process can be readily performed in space when we can produce silica of the required purity.

And from another site:
http://www.personal.psu.edu/faculty/r/8/r81/055/space_shuttle/shuttle.html

Shuttle orbiters use a system of 30,000 tiles made of a silica compound that does not ablate, but does rapidly radiate heat away from the orbiter. These tiles can be repaired in space. Major disadvantages are fragility (tiles easily damaged before launch and by orbital debris -- lots of tile damage due to debris since anti-satellite tests in mid-80's) and complexity (many people needed to manually attach tiles to orbiter in a tedious and time-consuming process, and to inspect them all before launch).

It's the easily damaged part that is of interest here. Note they can also be repaired. It would seem logical that every flight would include a space walk to ensure the integrity of the tiles.

[XBob]

I don't think the Colombia could reach the space station, too high. But, if they reacted quickly, they could have landed in Spain.

[spunkets]

Some info on the thermal protection system NASA doc

[SteveH]

Ice?

The thing the Challenger and Columbia have in common is the time of year...

[FReepaholic]

>>...Could they have docked with the space station and waited for another shuttle to pick them up...<<

Nope. Columbia was too heavy for a mission to the ISS.

[isthisnickcool]

I think that this happened, and the tile was lost and the remaining tiles started to delaminate, and a hole burned into the wing...which would explain why they lost sensor data from the left wing.

It also explains what the astronomers in CA saw. They were watching and saw debris comming off the aft end of the shuttle. Lightly at first then a chunk.

Either tiles were lost or breached (gouged) significantly by the impact of the debris from takeoff. Once the tiles either "zippered" off or the heat breached the damaged area the wing/hull was compromised since it cannot withstand much more than 300 degrees.

I think you are correct. Debugged that pretty well.

[Check6]

The accident investigation will conclude that the probably cause is tile loss secondary to impact of ice or insulation, whatever it was. Question is, with film of the launch like this available, why didn't they do a walk to check the condition of the wing? Answer: wishful thinking on the part of mission control folks.

They would have had two weeks plus to mount a rescue mission of some sort. Obviously, lots of work to be done to plug the safety holes in our Space Transportation System.

[XBob]

I used to work on the shuttle, and the various types of tiles are indeed amazing, and the insulating ability is amazing, but they are also amazingly fragile.

Repairing them, well, as each of the 30,000+ tiles is made individually, and is made in a different mold, and is hand fitted and glued onto the shuttle using a very special process, and re-manufacturing them has to be done at Rockwell in California, delaying the launch 'repairing' them was tried, though infrequently, depending on their position and the damage to them. But repairs were not normally made when I was there, 10+ years ago.

[XBob]

The external tank is a whole different story, and is sort of like a gigantic thin, 2 liter soda bottle, with a thin film of insulation, and the insulation is sprayed on each tank where it is manufactured in Mississippi, before it is loaded on the covered barge which carries them, one at a time, to Kennedy Space Center.

[FReepaholic]

>>... why didn't they do a walk to check the condition of the wing...<<

No hand-holds under there. No robot arm on this mission either. They sometimes use the arm with it's camera to check tiles.

I'm not even sure there was an EVA suit onboard for this mission.

[JennysCool]

There seem to have been so many tile-related incidents with regard to the shuttles. Is the tech there now to replace tiling with, for example, a seamless covering for the entire vehicle, or am I straying into the realm of science-fiction?

[XBob]

thanks - very interesting. the TPS system was not my baliwick. Mine was the OHMS/RCS hypergolic systems (the poisons they are telling you to stay away from). One (fuel) will give you cancer, the other (oxidizer) will eat out your lungs.

[Check6]

Thanks for the info.