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Disaster in 1967, how many of us could have warned them? 9

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It worked until it failed, which was NASA's way; they flew Mercury and Gemini with pure oxygen without any issues.

6.4 million pounds of rocket to launch 110,000 pounds of spacecraft -- every pound extra was a potential dealbreaker. The amount of hardware required to implement a dual gas atmosphere for that long a flight would have meant ditching something else in the weight budget.

Hindsight is always great; it was a known risk, but Apollo 1's fatal error wasn't the oxygen, per se, but the fact that the cabin was pressurized to 3x the pressure of the nominal flight atmosphere. Had Apollo 1 been pressurized to the 5 psi that was planned for flight, the fire might not have even gotten started.


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Disaster in 1967, how many of us could have warned them?
Click to expand...
No-one could have warned them, anymore than any-one could have warned them about O-rings and extreme cold.
(Talk to the hand, the face NASA's culture wasn't listening.)
All those unknowing, engineers had to do is ask a welder how they felt about that.
Click to expand...
Many years ago, when smoking had not been banned from most construction sites, the welders used to play a trick on the new guys.
They would ask to borrow a cigarette to light their own cigarette.
They would hold the lit cigarette against the unlit nozzle of a cutting torch and hit the oxygen trigger.
Almost instantly the cigarette would burn down to the filter.
Poof, gone.




--------------------
Ohm's law
Not just a good idea;
It's the LAW!
 
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Thanks, waross... hadn't heard of that. I forgot, when I worked at DB in the summer the 'guys' would occasionally 'pinch' out a cigarette with the heavy gloves... I've never seen them ox'ed.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik
 
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After some rather scary incidents with shop oxygen distribution pipelines, we obtained a copy of
ASTM-G88 › Standard Guide for Designing Systems for Oxygen Service. It is a real eyeopener how easily pure oxygen can make all sorts of normally safe materials combust and explode. Once you are aware of the risks there are many possibilities to engineer the risk to acceptable levels.
ASTM has a series of documents on the subject. ASTM G-88 was first published in August 31, 1984.

Attached - presents the fact the prior to the Apollo 1 fire much of the test data now used as the foundation for our current standards and practices did not exist.
NASA and ASTM – A Partnership for Oxygen System Success, Harold Beeson, Ph.D., Chief, NASA WSTF Materials and Components Laboratories Office, Presented to the ASTM G04 Committee, October 10, 2017
 
 https://files.engineering.com/getfile.aspx?folder=1ec38d92-0c9b-4c93-a1ed-8390fa596a9e&file=20170009954-1.pdf
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My former roommate at school, his wife's father's company supplied some of the wiring harnesses for the Apollo capsule. He was sued, but he was able to prove that his wiring was not responsible for the fire.

John R. Baker, P.E. (ret)
Irvine, CA
Siemens PLM:

The secret of life is not finding someone to live with
It's finding someone you can't live without
 
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I am reminded of the Hindenburg, which of course, burned because of a bunch of flammable stuff it carried on board.
So, instead. they proceeded to use airplanes, which also carried a bunch of flammable stuff on board called "fuel", with the occasional flaming-fireball as a result.
But realistically, if they didn't launch any astronauts until it was known to be "safe", they wouldn't have sent anyone into space yet.
 
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Painting your Hydrogen bag with flammable paint doped with Al powder isn't the best of plans.
The bulk gas delivery guys hate LOX, they would rather handle LH2.
I have seen photos of a parking lot after a LOX tanker had a pump casing split and dump the entire load.
The cars were just outlines on the ground.
There were lumps where the iron engine blocks were, everything else was gone.
And the asphalt was just 6" deep loose gravel.
Everything that the free energy said was oxidize did, completely.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed
 
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I just saw an article on the Hindenberg recently where it indicated it was a static discharge the initiated the fire from the mooring lines. It was a result of recent film that showed a different angle. All the earlier films were from the same location. It explained the 4 minute delay, caused by capitance buildup, from the mooring lines being 'grounded' to the initiation of the fire... I'll see if I can dig it up. It was possibly initiated by the wetted surface caused by the rain.


-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik
 
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Its to do with partial pressures and time.

I used to do mixed gas scuba diving.

1.6 bar PP and you start running the risk of a O2 hit.

1 bar there there is no issues for a very long time.
 
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I was always under the impression that breathing pure O2 would poison a person?
Click to expand...

Obviously, not, and you didn't even bother to do the research. As indicated earlier, all the previous US manned missions used around 5 psi oxygen, which is physiologically safe.

No matter what it was pure stupidity.
Click to expand...

Based on what? There is no oxygen toxicity, if the pressure is sufficiently low. Likewise, the risk of fire is manageable if precautions are taken and the pressure is kept low. And again, Apollo 1 was overpressured to 16 psi pure oxygen, to simulate the pressure differential in space; THIS was the fatal error, not the pure oxygen, per se. The "smart" solution would have been to add a bunch weight and time to redesign and retrofit the spacecraft and "lose" the space race to the Soviets.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! faq731-376 forum1529 Entire Forum list
 
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To minimise volume and weight, it should be as concentrated as can be safe.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik
 
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Alistair Heaton said:
1 bar there there is no issues for a very long time.
Click to expand...

...for small values of "a very long time".

At ppO[sub]2[/sub] of 1 bar, the NOAA recommendation (widely adopted in the rest of the diving world) is to restrict exposure to 300 minutes per single exposure, or cumulatively in any 24 Hr period. Beyond that, you start to accumulate damage to the lungs and eyes.

Returning to real life after breathing pure oxygen for a while offers its own surprises - finding your sinuses filled with a gas that's readily absorbed by the surrounding tissues makes you pull a collection of funny faces.

A.
 
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300 mins is longer than my bladder could last and wasn't into catheterisation of myself for a hobby.

We used to run at 0.6 bottom gas and 1.4 deco.

There are acute O2 poisoning limits as well which we downloaded the computers to keep track of .

It's all to do with free radicals.
 
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I understand that pure oxygen also 'ages' tissue.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik
 
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Scuba, and diving in general, seem very different than space to me; you have a fixed amount of premixed gas, of which you consume the oxygen at some efficiency. Eventually, you run out of gas and you have to come up. Additionally the pressures required for diving are drastically different than space travel.

The stated O2 pressure in Apollo is about double that of the atmospheric partial pressure of O2 at sea level, but which is below the level of pressure where oxygen toxicity supposedly occurs.

[URL unfurl="true" said:
https://en.wikipedia.org/wiki/Oxygen_toxicity#:~:text=Lung%20toxicity,-The%20curves%20show&text=Pulmonary%20toxicity%20occurs%20only%20with,50%25%20at%20normal%20atmospheric%20pressure.[/URL]]Pulmonary toxicity occurs only with exposure to partial pressures of oxygen greater than 0.5 bar (50 kPa), corresponding to an oxygen fraction of 50% at normal atmospheric pressure.
Click to expand...

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