Final Radio Transmission From Space Shuttle

Drudge | 2-1-03 | Joe Hadenuf

[Joe Hadenuf]

Final radio transmission between Columbia and Mission Control:

Mission Control: 'Columbia, Houston we see your tire pressure messages and we did not copy your last.'

Columbia: 'Roger, uh, ...' (transmission breaks off after the crew member starts to stay a word beginning with the sound 'buh.')

Burn through??

[PhiKapMom]

Thanks for the links!

[Joe Hadenuf]

I understand it's toxins from the rocket fuel that can possible contaminate pieces of the spacecraft.....

[Tree of Liberty]

I *think* it's a corrosive that emanates from the shuttle on re-entry and has a nasty side-effect of coating the bronchioles in your lungs and severely inhibiting oxygen from being metabolized. That's why they bring out a huge fan in front of a landed orbiter to blow the fumes away.

[Fred Hayek]

Any hydrazine (unless is was in an "intact" container, i.e. pressure vessel or tank) would have evaporated off before it hit the ground, save for trace amounts on the surface of the object. Hydrazine (actually dimethyl hydrazine) is used as a fuel in combination with nitrogen tetroxide as the oxidizer. The combination ignite on contact. Also nasty stuff, need to wear an enviro-suit with supplied air when working with it (as in fueling a Titan).

[Redcloak]

At the press conference, they said that this was in reference to a sensor on the tire that went out. "As if someone cut the wire" was the description. (Or words to that effect.) It doesn't necessarily indicate a problem with the tire, but rather with the sensor itself. Several other sensors went out in the same fashion. I'm wondering if these sensor leads all route through one common point.

This is sounding more and more like a burn-through.

[Tree of Liberty]

The NASA rep said that all the affected sensors were on independent systems. That's when they began to think something was going wrong, according to him.

[Hillarys Gate Cult]

I thought hydrazine was mainly used in APU's. I looks like NASA is trying to get rid of it;
http://www.grc.nasa.gov/WWW/RT1997/6000/6920viterna.htm

[Fred Hayek]

It also had been used as a thruster propellant, unless NASA had found a safer hypergolic fuel. Hydrazine (not sure whether plain hydrazine or dimethyl hydrazine) was also used on small satellite thrusters, that application more of a monopropellant, running the stuff over a catalyst and decomposing - much like hydrogen peroxide and potassium permanganate.

[Redcloak]

They all feed different signal conditioners, but where do the wires physically route from the wing to those sensors? I suspect that a burn-through was occurring at or near that common route.

[Tree of Liberty]

Ahh, I see what you're saying. Could be.

[Tree of Liberty]

You're welcome. I'm not 100% certain that hydrazine has those effects, just that some chemical that the shuttle throws off does, and hydrazine seemed to ring a bell in that respect.

[deport]

From another article........

Even so, experts list six possible causes of the disaster. In order of decreasing likelihood, they are:

¶Problems with the shuttle's tile heat shield, which was apparently damaged slightly at blast off;

¶An explosion of some of the shuttle's fuels and oxidizers, which are under high pressure;

¶The collapse of some part of the shuttle's structure, which is aged;

¶Faulty navigation for the fiery re-entry, possibly caused by a computer problem;

¶The impact of a speeding rock or space debris;

¶Terrorism, perhaps by a technician at the launching site.

[Right_in_Virginia]

I just pray that whatever happened~~happened so quickly that no one on board knew it.

May they rest with the Lord.

[BJungNan]

Perhaps not possible on the shuttle but I have wondered for a long time why they don't have cameras on commercial airliners to record the events. Seems it would be so much easier to just roll the tape to find out what happened.

[eno_]

45 psi - a typical tire pressure, is about three atm. So 3atm on one side and 1atm on the other side of a tire carcass is not so different from 3atm on the inside and 0atm on the outside - only a 50% increase in pressure difference.

[eno_]

I think they were losing sensors in a worrying pattern, rather than getting readings that were outside the normal range.

[Joe Hadenuf]

I think at least one or more of the crew knew they had a huge problem, probably minutes or probably seconds or less just before the event. But as far as any suffering, no, it would have been like turning off a light switch. Over very, very quickly.

[Joe Hadenuf]

Make that......Possibly minutes or maybe seconds or less just before the event. But I do believe they had a brief heads up of something very wrong.