
Apollo 1 237
Last year we looked at the Challenger. This year: Apollo 1. On January 27, 1967, the three-man crew of Gus Grissom, Roger Chaffee, and Ed White who were in training for the first Apollo flight were asphixiated in their capsule during a training exercise. The men reported communications glitches prior to the disaster, and it is believed that a spark in their pure-oxygen atmosphere quickly started an unstoppable blaze, consuming the many flammable components in the capsule. There were three hatches between the men and the outside of the capsule, which were not designed to be opened in less than 90 seconds. In addition, it is doubtful that the astronauts could have opened the internal hatch at all since pressure inside the spacecraft rose rapidly after the fire, exceeding the capacity of the pressure-equalization valves. Future designs were modified to remove most of the flammable components from the crew area and include a new quick-opening hatch. NASA has a retrospective.
The hatches (Score:5, Interesting)
Re:The hatches (Score:5, Informative)
The reason the hatches took no less than 90 seconds to open is because NASA wanted to prevent another Liberty Bell 7 incident (MR-4) where the hatch supposedly blew off prematurely.
You're referring to explosive hatch bolts -- but modern journalists have speculated that a pad leader would not have have allowed an explosive bolt system to be armed during an apparently safe countdown test. The more serious design flaw in the hatch was the fact that it opened inward -- a tradeoff to save weight since the cabin pressure kept it closed, but which sealed the astronauts inside when the fire broke out.
Incompetence (Score:5, Interesting)
Re:Incompetence (Score:2, Informative)
Re:Incompetence (Score:4, Interesting)
Re:Incompetence (Score:3, Informative)
http://www.asktog.com/books/challengerExerpt.html [asktog.com]
Also read Feynman's account (Score:2)
The book What Do You Care What Other People Think? (at least I think that's the title) has an autobiographical account of Richard Feynman's experiences on the investigative team of the Challenger disaster. (This would be the guy who dipped pieces of O-ring plastic into his glass of ice water at a news conference to demonstrate the problem.)
I highly recommend reading it.
Re:Incompetence (Score:1)
Ghee, it had never occured to me that an astronaut sitting in a contraption designed by thousands of people, controlled mainly by computers, was at the mercy of other peoples compentence.
Just kidding, I know what you are saying, that one sounded just a little too obvious.
Re:Incompetence (Score:5, Insightful)
In the case of Apollo 1, NASA was too lazy to use a proper atmosphere
In addition to being more complex, a two-gas system was shown to be dangerous in itself. In Apollo: The Race to the Moon by Murray and Cox, there is a reference to a case where a test pilot nearly died precisely due to errors made in implementing a two-gas atmosphere. It's easy to sit back and blame incompetent bureaucrats, but more often than not the engineers make design tradeoffs with no completely safe alternatives.
Re:Incompetence (Score:1)
When are organizations going to learn that people who don't understand technology shouldn't be making decisions about that technology.
Maybe after a few hundred more NASA disasters, botched software projects, and total-idiot pieces of legislation, people will figure that out.
But that's a big maybe.
Re:Incompetence (Score:3, Informative)
North American was told that the CM would be pressurized at 5psi pure oxygen, which was true during flight. It was fireproofed to these specs. Nobody informed them that launch pressure was sea level. The CM was definitely not fireproof at that pressue.
Re:Incompetence (Score:2)
And this is an excuse why? Really, where else would you launch a space capsule from? Space?
LV
Re:Incompetence (Score:2)
> And this is an excuse why? Really, where else would you launch a space capsule from? Space?
I think in that case he actually means the pressure inside the capsule during launch is kept the same pressure as outside at sea level.
Re:Incompetence (Score:1)
from the earth to the moon (Score:2, Informative)
Re:from the earth to the moon (Score:1)
Incredibly well done, IMHO. Espically the scene where the wives find out...extremely moving.
Re:from the earth to the moon (Score:2, Informative)
Re:from the earth to the moon (Score:2)
a sad day to remember (Score:4, Insightful)
Re:a sad day to remember (Score:3, Insightful)
Why is that important? Because it's easy to read history like it doesn't involve real people. My mother in law still gets teary eyed when she hears the names of the Apollo 1 crew. I think today when I go over there, I'm going to look on the wall at the photo of Grissom, White, and Chaffee and thank them. For what? For having the courage to do something I don't think I could have ever done, and for believing in a dream that still is important today.
Re:a sad day to remember (Score:2, Insightful)
years later, i was standing in a bookstore on newbury street, a sophomore at mit, when i couldn't get the clerk's attention. he told me something had gone wrong with the shuttle and was trying to listen to the radio. i walked across the harvard bridge in the cold to get to the school student center where the nearest tvs i could watch were. and it was as unbelievable as everyone said. we'd scaled back our goals for space flight so radically, yet still there could be a disaster of this magnitude.
i don't have any conclusions from this. would i risk my life for this venture? yes. would i hope it would help us learn something? yes. would i think my life had been wasted? definitely not.
Re:a sad day to remember (Score:3, Interesting)
And that's perhaps the most bitter irony of the Challenger disaster: We set our sights lower, but we couldn't eliminate the risks. It seems that people draw one of two conclusions from accidents like Apollo 1 or Challenger:
Obviously, I fall into the latter camp. What is so depressing about the loss of the Challenger crew, in contrast to the loss of the Apollo 1 crew, is that, due to loss of vision and scaled-down expectations, the Challenger crew gave their lives for a program less audacious, less worthy, of the sacrifice than Grissom, et al. This is not meant to denigrate that sacrifice but to lament the reduced times in which we live.
In any event, let us all spend a moment in memory and thanks of these pioneers who gave their all for a vision of the human spirit and its dignity. Ad astra per aspera indeed -- but we will get there.
Re:a sad day to remember (Score:2)
Re:a sad day to remember (Score:2)
If we choose to, we could certainly go to the moon again. The boosters exist, (Shuttle, Ariane, Proton, Titan), the capsules could be developed with (relatively speaking) little trouble. Don't confuse lack of existing hardware with lack of capability.
As the rate things are going, nobody alive today may ever see a human on another world again.
The problem is there is very little point in going. Science is nice, but pure exploration, unlike pure research, rarely goes on to pay the bills. Make no mistake, the great 'explorers' of the past were, to a man, in the game for the profit, *period*. The idea of exploration for explorations sake is very young, and it's far too early to predict if it will last.
Don't forget the entire Mercury-Apollo sequence were political stunts, for political purposes. Our entire space program started as a path to national prestige, and surivives only because it's become a habit to have one, and it's considered a sign of being a Great Nation. (Compare the list of nations in the Nuclear club with a list of nations with an active, independent space program sometime. The almost one-for-one correspondence will surprise you.)
Re:a sad day to remember (Score:2)
It's interesting that you claim that most are 'not done for profit', but then can't really cite any from the age of exploration. Much of the exploration of the Arctic was driven by the search for the mythical Northwest Passage, that is to say, profit. Almost all of the Antarctic exploration was done to explore and claim territory, again, profit. (And its close relative, National Prestige.)The main pole seeking expeditions (1900 onward) are at the beginning of the period where 'exploration for it's own sake' begins to take hold.
I would have said that the idea of, equating everything down to bottom line in an accountants spreedsheet, is more the modern idea (that has yet to stand the test of time.
You may say it, but it's unsupported by history.
What makes us any better/ different from cavemen. monkeys? its the fact that we can do the "unnecessary" things like art and exploration (of knowledge, space and spirituality)
Not really.. The cavemen had art of a wide variety roles, ranging from what appears to be simple decorations to complex religious and magical works.
Well.. (Score:1, Troll)
It was my impression they burned to death in the veritable blast furnace the capsule turned into.
As for design flaws.. the major flaw was the test itself. In space, they would have been okay.
Why?
They used a very high concentration of O2 in the air, and raised the pressure a few PSI above normal, to simulate the forces on the capsule?
The result? ALthough all forces were the same on the capsule, and yes, they would use the same o2 mix in space.. there was WAY, WAY, WAY more oxygen in there considering they were at a few PSI over 1 Atmosphere, rather than a few PSI over vacuum. That's a HUGE difference in the amount of O2 available to burn.
So what would have been a potentially minor smoldering in space turned into a blast furnace on the ground.
Re:Well.. (Score:3, Informative)
Re:Well.. (Score:2)
Death of the crew was from asphyxia due to inhalation of toxic gases due to fire. A contributory cause of death was thermal burns.
which means the fire had a contributing factor to their deaths, not just the smoke.
Re:Well.. (Score:2)
Re:Well.. (Score:2)
> The only part of their bodies that were burned were the exposed surfaces
> (hands, faces) under their suits they were completely unscathed.
Bull-SHIT!
And I QUOTE:
"A medical board was to determine that the astronauts died of carbon monoxide asphyxia, with thermal burns as contributing causes. The board could not say how much of the burns came after the three had died. Fire had destroyed 70% of Grissom's spacesuit, 25% of White's, and 15% of Chaffee's"
How the hell did the mindstrm's post get moderated as a Troll?? The first time I read the report I myself wondered whether they were just guessing in order to save the families (and everyone else) from wondering. Sure it's not pleasant to think about, but it's a valid thing to wonder.
It's quite well known that police and fire departments will mis-quote the cause of death in order to save a family greif. But every so often the expressions and positions of a charred corpse make it clear that the person was getting plenty of oxygen for quite some time while dying. (It is possible to get 3rd degree burns from thermal raditation alone.) Remember how long you can hold your breath?
It is theorized that if you inhale hot enough gases that the excruciating pain in your lungs will cause you to black out quickly, but we don't exactly have too much first hand knowledge of that.
Re:Well.. (Score:2, Informative)
So now that we've got that little bit of science out of the way, the next problem with your "analysis" is that a difference between 1ATM and 16.7PSI does not result in a *HUGE* difference in available O2. For the clueless, 1ATM=14.7 PSI, or a difference of just 2PSI. I'm not going to do the math here, but needless to say, a balloon has a higher PSI than that capsule did. Are you suggesting that a balloon filled with O2 will just smoulder in space? I think not.
The problem of using a pure O2 mixture is simply because O2 is such a volatile thing that the smallest spark can ignite the closest flammable object (wire insulation, if memory serves), and once that's started, anything else in the area is a juicy target for more combustion fun.
Combustibles plus pure oxygen = disaster (Score:5, Interesting)
1. There was WAY too much exposed combustible material inside the capsule. Even if the atmosphere inside the capsule during the test sported a gas mix similar to regular air if a fire broke out it would have been extremely difficult to douse the fire.
2. The fact the atmosphere was close to pure oxygen meant that if a fire broke out it would have burned with extreme ferocity.
That was why by the time Apollo 7 flew in October 1968 the entire capsule owed almost nothing to the original capsule design--all the combustible material were replaced by fire-retardant equivalents and the gas mixture on the launch pad was equivalent to air, which slowly changed to pure oxygen by the time the Apollo CSM was in orbit.
What was not known to the Americans was in the early 1960's during a series of tests to develop Soviet manned space vehicles a fire broke out in a test space capsule design with a cosmonaut in it when it was filled with pure O2--the cosmonaut burned to death.
Re:Well.. (Score:3, Informative)
Re:Well.. (Score:2)
Re:Well.. (Score:2, Informative)
Where did you get this idea? The question of whether or not the external pressure on the capsule is 1ATM or 0ATM is moot, because the whole idea of hatches and airlocks is to keep everything on the inside of the in. In fact, the astronauts would have an EASIER time getting out here on earth because there would be a smaller pressure differential to work against in opening the airlock than there would be enroute to the moon.
The capsule atmosphere after launch was actually much less than sea level (5 psia [yarchive.net]), so the external pressure would make a significant difference. The point of pressurizing to greater than atmospheric during the test was to simulate the pressure difference between the capsule and outside, not the true internal pressure to be used after launch. In fact, since the capsule was designed to contain internal pressure greater than than outside, it probably wouldn't have been structurally possible to hold a sub-atmospheric pressure inside.
So now that we've got that little bit of science out of the way, the next problem with your "analysis" is that a difference between 1ATM and 16.7PSI does not result in a *HUGE* difference in available O2. For the clueless, 1ATM=14.7 PSI, or a difference of just 2PSI.
Bzzzzt. For the clueless, what is generally considered 1 atm (the stuff we breath) consists of about 79% nitrogen. Compare this with 16.7 psi pure O2, and I think you'll see a difference.
I've got no idea why the original post of this thread is now rated "Troll" because the poster is essentially correct in many details, unlike the previous post. If the pressure in the capsule is a constant "few" psi over the outside, there is in fact a "HUGE" difference in the flammability and available oxygen inside when it is pressurized on the ground versus in space. Things are going to be way more flammable at an absolute pressure of 16.7 psi O2 than at the flight level of 5 psi O2 in the cabin. In fact, in normal air, the oxygen partial pressure is about 0.21*14.7 = 3 psi. Imagine having 5x more oxygen available! Anything not already completely oxidized will want to burn (and fast!), even materials that are essentially fire-proof in air and low O2 pressures.
Gee.. thanks for the lesson. (Score:2)
Firstly, I know what pressure is.
Secondly.. no, there is not much difference between 14.7PSI and 16.7PSI (the 2PSI overpressure is to simulate the pressure in outer space.)
The DIFFERENCE is that they were trying to simulate real conditions in space.
But in space, yes, the cabin pressure would be 2PSI higher than outside. Which would make it.. 2PSI!
So. 2PSI of pure oxygen, or 16.7PSI.. which is more? You guessed it.
Re:Well.. (Score:1)
In any case, many scientists have studied the case, and found a primary cause of the fire was the large concentration of oxygen in the cabin. It has nothing to do with how much pressure was in the cabin - what's more important is the concentration of the oxygen. This is obvious when you look at the revisions NASA made to the training sessions - they didn't decrease the pressure in the cabin (except to maybe 14.7 psi), but instead just made the atmosphere have less oxygen in it. (and, of course, they made the door open out)
Re:Well.. (Score:1)
Re:Well.. (Score:1)
Regardless, that wasn't the point of my post. I'm just trying to say that the concentration seemed to be the real problem, not necessarily the pressure.
Re:Well.. (Score:1)
Re:Well.. (Score:5, Interesting)
It wasn't just a design fault. It WAS, as you mention, a ridiculous test to put such a high concentration of O2 in the capsule. Much higher than it would ever receive in-flight.
Still it was part of the price paid to advance the space program. As the saying goes, and I don't mean this in a disrespectful way, but to make an omelette, you have to break a few eggs. Going into space is/was, and probably always will be, to some degree, a dangerous endeavor. Just as going into submarine is inherently dangerous.
In the case of a submarine the danger is always implosion. In the case of space, it's explosion. Space is also inherently more dangerous because of the types of fuels involved and the lower degree for margin of error.
Anyway, the only design flaw, in regards to your post, was an overuse of velcro, which happens to be quite flammable, especially in a high oxygen atmostphere. The other flaw (the O2) level, wasn't a design flaw, it was a "execution" (for lack of having the proper vocabulary on hand) flaw.
Re:Well.. (Score:2)
I trained as a SCUBA diver - PADI advanced only but it means I had to learn something about breathing. You definitely use more air when making an effort than at rest. However, loss of air does not mean loss of consciousness even when you are swimming (been there, done that).
I don't know the plastics involved, but unless something was extremely toxic (i.e. giving off cyanide products) when burnt, at least two of the astronauts (judging from suit damage reports) probably received significant burns before they died.
You are partly right though in that if the oxygen level falls below a certain level, the partial pressure of the O2 in the haemoglobin is greater than that in the lungs and O2 is removed from the body. CO also preferentially binds to the haemoglobin in the presence of O2 thus reducing efficiency. However deaths from CO poisoning take over a minute.
Inanimate carbon rod! (Score:2, Funny)
Am I the only one thinking of the Simpsons episode where Homer jimmies the latch with a carbon rod which gets the fame rather than him?
Ah yes, this is Slashdot. I thought not.
--- Some say Netware is just like a wheel/ When you abend it, you can't mend it
A Tribute to the Pioneers (Score:4, Insightful)
by Julia Ecklar
In a tower of flame in capsule twelve
I was there
I know not where they laid my bones
it could be anywhere
but when fire and smoke had faded
a darkness left my sight
and I found my soul in a spaceship's soul (hull?)
Riding home on a trail of light
Chorus:
And my wings are made of tungsten
My flesh of glass and steel
I am the Joy of Terra
for the power that I wield
Once upon a lifetime I died a pioneer
Now I sing within a spaceship's heart...
Does anybody hear?
Before each mornings launch
they know that I am there
To the soul that warms this vessel's hull
they say a silent prayer
I am father ship and spirit
of the dream for which they strive
for I am man (?) at the hands of man
see us rocket for the sky
(Chorus)
My thunder rends the morning skies
Yes, I am here
Though lost to flame when I was man
Now I ride her without fear
For I am more than man now
and man builds me with pride
I lead the way, and I lead the way
of Man's future in the sky
(Chorus)
This song still gives me chills up and down my spine when I listen to it - it is quite possibly the most moving memorial to those who lead the way that I have ever heard.
Ad astra per aspera, Amen.
--
Evan
Re:A Tribute to the Pioneers (Score:3, Interesting)
"I pray for one last landing
On the globe that gave me birth;
Let me rest my eyes on the fleecy skies
And the cool, green hills of Earth."
Re:A Tribute to the Pioneers (Score:1)
Well, I guess that you probably know by now I was one who wanted to fly
I wanted to ride on that arrow of fire right up into heaven
And I wanted to go for every man, every child, every mother of children
I wanted to carry the dreams of all people right up to the stars
And I prayed that I'd find an answer there
Or maybe I would find the song
Giving a voice to all of the hearts that can not be heard
And for all of the ones who live in fear
And all of those who stand apart
My being there would bring us a little step closer together
They were flying for me, they were flying for everyone
They were trying to see, a brighter day for each and everyone
They gave us their light, they gave us their spirit, and all they could be
They were flying for me
And I wanted to wish on the Milky Way and dance upon a falling star
I wanted to give myself, and free myself, and join myself with it all!
Given the chance to dream, it can be done
The promise of tomorrow is real
Children of spaceship Earth, the future belongs to us all
She was flying for me, she was flying for everyone
She was trying to see, a brighter day for each and everyone
She gave us her light, she gave us her spirit, and all she could be
She was flying for me
They were flying for me, they were flying for everyone
They were trying to see, a brighter day for each and everyone
They gave us their light, they gave us their spirit, and all they could be
They were flying for me
Al + O2 = fire (Score:1)
good luck,
sopwath
Cause of the fire (Score:5, Interesting)
Re:Cause of the fire (Score:2)
I believe this is what is thought to have occurred. In fact, the wire was accidently stretched along a hinge of some compartment and repeated openings/closings had worn it through. How did a wire get stretched across a hinge? Apparently the capsule was dropping in transit, falling through the supposedly miniscule distance of under 2 cm, but enough to dislodge the wire.
For the want of a nail...
Source: One of a zillion books called Apollo, currently on loan to a friend, so I can't provide bibliographic info.
Re:Cause of the fire (Score:2)
It's pretty well established that the notional wire was damage because of the ongoing work in the vicinity of the ECU and poor quality assurance of cable handling and routing.
doesn't this strike you as strange (Score:1)
Dark Forces Are At Work. (Score:2)
Leave it to the Americans ... (Score:3, Redundant)
American endurance has shown throughout the ages, though with a few setbacks like "war against communism" for instances, we never give up. I think that Apollo 1 should set as an example. America's war on terrorism will not stop and we were hit with a big blow, but we got right back up even more pissed off than we were before we got hit. Though not invincible, we as Americans, hold true in our beliefs. Democracy and the value of the individual American will always be held as a wonderful thing.
Is America perfect? No, but I'll tell ya what, I wouldn't turn my back on my country for a damn thing. Patriotism is strong in every American and will always be that way. We've set the groundwork to never have a facist dictator ever lead us (how many other countries can say that? ... yeah about 3). We don't have all the best things, but we sure as hell try to make sure that everyone knows that we're on top in every endeavor we take up.
Though the price was high, NASA has brought us things that were never once thought possible. To be able to sit in the heavens and sustain life. Maybe one day to be able to call even another planet, home. But that doesn't mean that Americans want to do it alone, hence the ISS.
So I'm proud to be an American, and proud to know that 3 men risked their lives to advance science and safety. And I also am more than happy to remember the veterns and fallen soldiers who fought to keep my country a free country. Thank you.
Americans recovered faster (Score:3, Informative)
The Soviet moon program never really recovered from that tragedy, because the a derivative of the Soyuz spacecraft was to have flown to the moon. Realizing its limitations, the Soviets decided to use Soyuz as an Earth-orbiting spacecraft, which has worked well to this day.
Re:Americans recovered faster (Score:2)
Not to mention their inability to make their moon booster (the N1) work. Not to mention their inability to control a spacecraft in the reentry from lunar orbit (the Zond missions). Not to mention that their lander was never really debugged enough for a test launch to even be considered.. Soyuz 1 was just one of *many* problems.
The Soviet moon program never really recovered from that tragedy, because the a derivative of the Soyuz spacecraft was to have flown to the moon.
Zond, did fly to the moon three times, (unmanned), and failed two of the three times during reentry.
Realizing its limitations, the Soviets decided to use Soyuz as an Earth-orbiting spacecraft, which has worked well to this day.
No, Soyuz was meant from day one to be a general purpose earth orbiter. (As the Apollo originally was as well.) Zond was not so much a derivative as it was a paralell line of evolution.
Re:Americans recovered faster (Score:2)
In 1970-71, far too late to effect events, and umanned to boot.
If soyuz 1 had succeeded and fufilled it's planned mission (another soyuz launch and docking/crew transfer) the Soviets may have continued thier lunar program with some pretty risky and downright scary plans.
Maybe, maybe not. The Soyuz was not their lunar spacecraft, Zond/LOK was, and it suffered extreme problems of it's own unrelated to those of Soyuz 1.
So, like apollo 1, Soyuz 1 was a wakeup call for safety that was answered by the Soviets as well.
True, but keep in mind that Soyuz was really unrelated to the Lunar program. Their manned lunar orbiter was a different program.
Re:Leave it to the Americans ... (Score:1, Offtopic)
Re:Leave it to the Americans ... (Score:1, Offtopic)
You should know better than to screw with a patriot ... I'm posting +2 because slashdot moderators feel I can be trusted with that (proof by their moderations ...)
What's next ... you pro communism?
Re:Leave it to the Americans ... (Score:2)
My Heros ! (Score:5, Interesting)
Even though I'm an old poop now, I still keep a few hanging, and one wall, is the crew of the Apollo 1 to remind me not to take things for granted.
Yeah, I know, I sound like a big wuss
In spite of this tragedy, we still managed to put a man on the moon with little more than vaccum tubes and slide rules !
Re:My Heros ! (Score:2)
Not only that... they did it in less that 18 months, following a major re-design of the interior of the CM! Hell, they had the re-designed CM (w/SM and LM) orbiting the moon less that a year later! (Apollo 8)
Amazing stuff, that.
Milalwi
beauracracy, accident, choices (Score:5, Informative)
Re:beauracracy, accident, choices (Score:1)
Rocket Men (Score:2, Insightful)
These early explorers were in many ways treated like lab animals, yet they soared trough the heavens like living gods: can you imagine what it was like being the first humyn to see the earth from space?
And yet, it is the fate of all pioneers for the trails they first blazed to be trod by myriad lesser souls. As the unspoiled lands explored by Lewis, Clark, and Sacajawea [powersource.com] are now criss-crossed by highways, so the ethereal realm of the early astronauts is now a playground for billionaires [asia1.com.sg].
Oh well, on to Mars, I suppose.
Re:Rocket Men (Score:1)
What the hell is a humyn?????
Re:Rocket Men (Score:2)
Can someone answer this for me? (Score:2)
Re:Can someone answer this for me? (Score:1)
When the spacecraft leaves the atmosphere the internal pressure of the capsule is much lower than it is at sea level. (It would be prohibitively expensive to pressurize the capsule to 1 ATM.)
If at that time the astronauts still had any nitrogen in their bloodstream it would come out of solution and form bubbles, etc...
Re:Can someone answer this for me? (Score:1)
Close, but not quite. It is true that to a certain point, divers can use pure O2 to prevent the bends (And often do during their decompression stages), but after a certain point, pure oxygen becomes poisonous, and so an inert gas (almost always pure helium) must be put into the mix. Since helium is inert, it doesn't cause the nitrogen narcosis problems at depth.
Re:Can someone answer this for me? (Score:3, Informative)
Not quite. Divers almost never breath pure O2 in the water. Oxygen under pressure is toxic, and can cause seizures (bad when you're under water). The only exception to this would be what's called an oxygen rebreather. It's a closed circuit breathing system using pure O2. CO2 is scrubbed out with a chemical absorbant. The main feature of these systems is no exhaust bubbles. They were popular with military frogmen for sneaking into harbors and the like during WWII and sometime after, but they could only be 'safely' used shallower than about 30 feet. Deeper than that is asking for trouble.
Nowadays closed circuit breathing systems use mixed gases for breathing and computers to maintain the proper O2 proportion.
When divers do breath pure oxygen is out of the water in a decompression chamber. The idea is to 'wash' (not really what's happening, but the simple way to expain it) the nitrogen out of the divers tissues quicker than breathing air which is 80%+ nitrogen. It's not so much to directly prevent decompression sickness as it is to shorten decompression times.
Fire is always a big concern when doing this, minimum combustibles in the chamber, absolutely no grease or oil on anything and usually special breathing masks that dump the exhaled gas outside the chamber. I used to be in that biz.
Re:Can someone answer this for me? (Score:1)
Nitrogen also has the dual effect of being absorbed into the tissue structure. Because Nitrogen is more soluble under pressure, as you ascend it comes out of solution and forms tiny bubbles which tend to accumulate in your joints with great pain, causing you to "bend" over. The effect is quite distinct from narcosis, and may not show up for many hours until you're home with a beer in your hand watching Lost In Space.
The effect of O2 is quite different. Simply, under two atmospheres of pressure it becomes toxic. Breath pure oxygen while 33 ft under the water and you will go into convulsions and almost certainly die. Because Air(TM) is only one fifth Oxygen, you need to go five times deeper before you run the risk of dying from air.
For this reason, deep divers phase out both O2 and N2, and substitute the volume with Helium, which has no nasty effects other than making you sound like Donald Duck(TM).
In space, US astronauts going outside in space suits still use a low pressure pure oxygen environment, otherwise their suits are too inflexible. This not only means No Smoking, but also brings the risk of the bends because they're coming from a nitrogen-rich air environment, so the astronauts have to sit around breathing pure O2 through a face mask for a couple of hours before they suit up and go outside. Thus an emergency spacewalk from the shuttle would incapacitate the participant, demand an immediate re-entry, and a few days in a decompression chamber.
More lessons from Apollo 1 (Score:2, Informative)
Apollo 7 and on also gave the astronauts complete and independent use of an emergency hatch opener, a lesson tragically learned from Apollo 1.
Re:More lessons from Apollo 1 (Score:2)
Umm, from my Chemistry and Physics background, having a 20% Oxygen 80% Nitrogen atmosphere at full pressure or a 100% Oxygen atmosphere at 1/5 pressure should not change the physics and chemistry of a fire. In either case you have exactly the same number of oxygen molecules occupying the same volume. (I could be wrong, but with my MSc in Physics, I'll want to hear from someone who *really* knows, not some other schmuck like you or me with a semi-informed opinion
However, if you wanted to test the system at sea level and wanted to keep the system handling only Oxygen, then you'd be forced to use 100% Oxygen at full atmospheric pressure. Now *that* was a mistake.
BTW: I'm quite annoyed at all the people saying "we didn't know an oxygen atmosphere was that dangerous".
This was a standard Tombstone Technology incident. The US AirForce and others published lots of information in the preceeding 5-10 years showing just how dangerous a fire in a full oxygen atmosphere was, but *numerous* people have to die in numerous incidents (or one big/famous one) to make the awareness of the information global. Other sections of the NASA article that the slashdot article links to itself lists 6-12 references to prior publications that clearly indicated the danger of a fire in a 100% oxygen atmosphere.
And don't give me any bull about why they built the door as it was. After the fire they made a door which opened outwards in 3 seconds with as little as a half pound of force, and the door was counterweighted to hold itself open.
Now it *is* true that no-one knew how easily a fire could start in an atmosphere like that. If I remember correctly from reading a more fully detailed report, as a result of the Appolo 1 fire it was discovered that a spark, just one bloody spark, can cause a fire up to two feet away in a pure oxygen environment at atmospheric pressures. (Remember the last time you saw the sun-rays shining in through the window, and you thought to yourself, "wow, look at all that dust".)
I found some paragraphs of the NASA pages linked to in this story to be somewhat self serving and incomplete.
Re:More lessons from Apollo 1 (Score:2)
I'd like to draw attention to an earlier portion of your response: I'll want to hear from someone who *really* knows. Why do you do that with the atmosphere, yet take such a combative attitude about the door? Anyhow, from someone who does know:
The problem isn't always getting up there (Score:3, Insightful)
Perhaps some other slashdotter will post the link to the story about this - some sci-fi author (Spider Robinson) wrote about it (in the context of whether it made sense to spend piles of cash developing a pen that could write in space).
It just illustrates the point that space is the most unforgiving environment we're aware of. The Antarctic and the deep sea floor might be close competitors, but space still has them beat. If engineers and astronauts can overcome the kinds of challenges space presents, that is quite an achievement.
We talk about the trickle down from space technologies... and we bitch about the costs of the space program. Quite frankly, it isn't that expensive when you think of the things that have worked there way down to us from that program, that might not have otherwise been developed.
Add to that the fact that one of the major things lacking in our modern world is aspirations and dreams. The dream of getting off the planet to Mars, and then to other systems, should be a powerful draw. It offers us new horizons, new frontiers, a chance to be new pioneers, not just custodians of the remnants of the past. It offers us opportunities to expand our horizons, to learn, and maybe one day to discover other life forms. That has to be the single greatest opportunity I can imagine, and if the dream of going to space doesn't fire your blood, then you're already dead.
Besides, we'd better get some of our populace into some other stable biosphere just in case a big chunk of space debris decides to make a bank shot and knock Earth into the Sun. (With apologies to Dave Lister, cosmic pool player extrordinaire).
Re:The problem isn't always getting up there (Score:2)
This is an urban legend. The space pen was developed privately, and donated to NASA.
The Link (Score:4, Insightful)
BTW, you'll notice I never mentioned who'd developed it. And the discussion about the merits of these kinds of projects is hardly urban myth, thanks very much. The point is people question whether these kinds of projects are worthwhile. Moreso, admittedly, if it is public money. But even if it is not. (and I never suggested it was!)
Re:The problem isn't always getting up there (Score:2)
Re:The problem isn't always getting up there (Score:3, Insightful)
I would have to contend that the deep-sea floor is a far more unforgiving environment. We're talking about a pressure differential of thousands of atmospheres as opposed to one. A tiny leak deep-sea can mean instant death. And rescue is no more of a possibility than it is on Mars.
Re:The problem isn't always getting up there (Score:3, Interesting)
Don't get me wrong: The sea floor is a very demanding environment. It is the best place we have on earth to train for space (not the same challenges, but the same degree of risk almost). But it doesn't quite have the cornucopia of threats (sudden and gradual) that space has, some of which (such as the gravity issues) are very hard to deal with effectively.
Re:The problem isn't always getting up there (Score:2)
Point.
I wasn't thinking about radiation or (lack of) gravity, I guess that evens things up a bit. I wasn't aware of the heat disposal problem. That's interesting; I guess I'd always assumed that a vacuum would act as a heat sink, but it can't really conduct heat(?)
Re:The problem isn't always getting up there (Score:2)
The gravity effects are scary. You can (in theory) put in spin-habs and such and there are fancy treadmills that help the astronauts keep up bone density, but I don't know if they've gotten over some of the effects like the immune system depression. (I think I read about that in an Analog issue a while ago).
Let us just say space is nasty. The sea floor is nasty. The antarctic is nasty. Other planets will be nasty. But overcoming such challenges is part of the path to progress and growth. And at least it will never be boring!
Their deaths saved thousands more - and still do (Score:5, Insightful)
So they commissioned research to do so. And the result was the ionization-type smoke detector. Which you can now buy at any hardware store for as low as ten dollars, and which is required by zoning for virtually all human-habitable houses in the US and many other countries.
These devices have saved many thousands of lives so far, and will continue to do so.
These devices use a small radioactive source to ionize smoke particles, so they don't need to depend on natural ionization and can thus detect extremely miniscule amounts of smoke. This greatly increases their sensitivity, giving much earlier warning. The anti-nuclear hysteria was in full cry at the time. So it's unlikely a private company would have tried to design and market such a device for consumers. But for a NASA project, for short-term use above the atmosphere, it made sense. Once the device was done and its characteristics known, it was easy to show that a tiny amount of short-lived isotope, whose radiation doesn't leak beyond the container during the device's service life, was a miniscule risk compared to the number of lives saved. And a classic NASA spinout occurred.
So the fire and the deaths of the three astronauts was the direct cause of the invention and introduction of practical domestic smoke detectors, which otherwise certainly would not have been introduced for decades, if ever.
Re:Their deaths saved thousands more - and still d (Score:3, Interesting)
Re:Their deaths saved thousands more - and still d (Score:2)
>So they commissioned research to do so.
>And the result was the ionization-type smoke detector.
Today the research would have to be kept secret,
until it was patented. The patent royalties would
have to be high enough that nobody could make a
household smoke detector to be sold at a consumer
price level.
US vs USSR Engineering Parable? (Score:3, Funny)
The Russians used a pencil.
Re:US vs USSR Engineering Parable? (Score:2)
The Russians used a pencil.
you mean the fisher space pen [thewritersedge.com] - AG7, designed to work in zero-g environments. Well may the Russians have used pencils but NASA had these pens for good reasons. Using pencils would result in the astronauts breathing in fine graphite particles
Also heres an article describing how Buzz Aldrin used his pen to fire the LM engines to get off the moon.
http://www.thewritersedge.com/story.main.cfm
A little bit of knowledge gleaned from Apollo (Score:3, Interesting)
Muller hypothesized that the periodic cratering is due to a star that orbits the sun. Every 26 million years, it comes swinging closer into the sundragging debris from the Oort cloud. Some of that debris ends up hitting either the earth or the moon.
500 million years ago is referred to as the Cambrian explosion because the fossil record shows a huge proliferation of different species. There have been a number of hypothesis as to what precipated the increase in life forms and Muller's data does an excellent job of supporting comet/asteroid impact. There's more at Lawrence Livermore [lbl.gov]
It may be that the Apollo program has yielded a significant clue as to why we aren't all just a bunch of jellyfish.
Genuine Surprise that no-one's mentioned this book (Score:2, Informative)
Probably one of the best, most accessible books on the subject of Apollo.
A sick feeling I had in 1967 (Score:2, Interesting)
I told my wife afterward that I thought the people at the MSC would wind up killing someone.
When the account fo the horrible pad accident was published, I felt sick about it; not because I could have done anything that might have prevented it, but because there was nothing I could do despite my offhand conviction.
Saturn V review (Score:2)
Re:Why don't we have an "Ask Slashdot" on the topi (Score:2)
commercilization of space is mankinds only hope... expecting a politician to do the right thing is the same as believing that they plan to keep those promises they made during an election year.
OK, now I'm disturbed... (Score:2, Flamebait)
THIS is flamebait:
If Apollo 11 can commemorate the deaths of Gagarin [astronautix.com] and Komarov [astronautix.com] alongside the friends they lost on Apollo 1, why can't I even reference Soyuz 1 [astronautix.com] and Soyuz 11 [astronautix.com] missions in passing on Slashdot?
Re:OK, now I'm disturbed... (Score:1)
I hope this post gets smacked as flamebait, because I sure as hell know it is.
Re:Rosaviakosmos, anyone? (Score:2)
1.) Not all of those 200 Russians killed were cosmonauts. The vast majority of those deaths were ground crew killed in fuel-related explosions.
2.) Not all of those 200 were even working on the manned space program. The two accidents I can think of (1973 and 1980) weren't anywhere near Baikonur [astronautix.com]. Counting deaths at Plesetsk Cosmodrome [astronautix.com] would be like including deaths at Vandenberg AFB [astronautix.com]. (In fact, how did you arrive at 200, anyway?)
3.) Not all killed cosmonauts were Russian [astronautix.com].
4.) Ten deaths are a tragedy, 200 are a statistic? Where have I heard that before? [bbc.co.uk]
"Having only had a handful of Americans killed is quite an accomplishement if you ask me."
Apollo 1 + STS-51L = 10
Soyuz 1 + Soyuz 11 = 4
Re:Rosaviakosmos, anyone? (Score:2)
Re:Rosaviakosmos, anyone? (Score:2)
Re:They died as Hero's (Score:1)
I have to agree with you that the USA has made a lot of bad choices in the last 200+ years, but compare the USA to any other country that has obtained world leader status and you will see that we're a lot better than "the lesser of two evils". That's why people will risk their lives in leaky boats and sealed cargo containers to get here. Yes I am an American and damn proud to be one. We make mistakes and do stupid things but that doesn't stop most of the rest of the world from wanting that visa.
And the space program is one of our finest acheivements.
Re: wrong (Score:1)
Re:Humorless fool. (Score:1)