events unplanned and unexpected

[Bill Thompson]

What fascinates me is the fact that there seems to have been an awful amount of luck involved. When The Eagle was about to touch down, Neil Armstrong had to navigate over some boulders and alarms went off as the stabilizing computers overloaded. I am sure we had picked what we thought was the best place we could find to touch down, and yet if he had allowed for an autopilot to do the work, the landing would not have been successful. There was only a few seconds of fuel left and so it is conceivable if we had been just a little less fortunate there might not have been a safe place available to touch down.

Apollo 1 is another issue. I am sure no one had any idea that a fire could have happened and after the investigation, the conclusion was that it was either one of three things or perhaps all three things that needed improvement. We humans could not have planned for everything that could go wrong no better than we can plan for things to go right.

I saw on NASA TV one of the moonwalkers who was also involved in Skylab give a speech that we were also lucky about solar flares and that each successful mission to the moon was lucky in the sense that it missed any big solar flares that could have harmed or even killed the astronauts when they were walking on the moon.

The last space shuttle disaster is also a sobering thought. We had no idea that the shuttle was doomed. But what is more sobering is the fact that this could have happened on any of the previous shuttle flights.

[truthseeker]

Forgive me if I'm wrong, but didn't one of the NASA engineers express written concern about the last NASA disaster, regarding the fuel tanks?

[mid]

billthompson said:

What fascinates me is the fact that there seems to have been an awful amount of luck involved. When The Eagle was about to touch down, Neil Armstrong had to navigate over some boulders and alarms went off as the stabilizing computers overloaded. I am sure we had picked what we thought was the best place we could find to touch down, and yet if he had allowed for an autopilot to do the work, the landing would not have been successful. There was only a few seconds of fuel left and so it is conceivable if we had been just a little less fortunate there might not have been a safe place available to touch down.

Apollo 1 is another issue. I am sure no one had any idea that a fire could have happened and after the investigation, the conclusion was that it was either one of three things or perhaps all three things that needed improvement. We humans could not have planned for everything that could go wrong no better than we can plan for things to go right.

I saw on NASA TV one of the moonwalkers who was also involved in Skylab give a speech that we were also lucky about solar flares and that each successful mission to the moon was lucky in the sense that it missed any big solar flares that could have harmed or even killed the astronauts when they were walking on the moon.

The last space shuttle disaster is also a sobering thought. We had no idea that the shuttle was doomed. But what is more sobering is the fact that this could have happened on any of the previous shuttle flights.

Yes Bill, it is a rather fascinating thing to contemplate.

However, there wasn't quite so much luck as you may think. On Apollo 11, the low gate phase of the flight, where the CDR had visual contact with the targeted landing area, was a phase in which he had the option to "go manual" and guide the LM to a safe landing area. Neil Armstroing did just that. Be careful about the mythology surrounding the amount of fuel left. There was still about 40 seconds or so of fuel left in the LM when Eagle touched down. Most people don't understand what the calls from Mission Control actually meant fuel-wise, and alot of mis-informed media drama has been introduced into the mix over the years (this is not to say that things weren't a bit tense in the MOCR that afternoon...but it wasn't as close a call as the media tends to paint it).

If we hadn't found a safe place to land within about 50 seconds of that "30 seconds" call, it would've been a shove off and try it on Apollo 12.

On Apollo 1, alot of things needed fixing, not just 3. In an engineering test program, you are correct: no one can plan for everything that could possibly go wrong. We may try to anticipate every possible contingency, but when you're endeavoring to push the envelope into the unknown, it is the unknown that can bite you. We never thought about the possibility of a fire on the ground. We looked at things in the flight realm. Often, we learn the obvious through such occurrances as Apollo 1.

As to the solar flare issue...that would've been Al Bean or Pete Conrad that said that stuff about the solar flares. They were correct. That was an aspect of luck most certainly in Apollo.

And as to the Shuttle disasters, we're talking about a completely different NASA and a completely different management paradigm there. Comparing the Shuttle to Apollo is comparing apples to oranges. But I will concede this: there was alot more luck involved in the sucessful space shuttle flights than there was in the Apollo program.

[mid]

truthseeker said:

Forgive me if I'm wrong, but didn't one of the NASA engineers express written concern about the last NASA disaster, regarding the fuel tanks?

Which disaster, Challenger, perhaps?

[scooter]

I think he's talking Columbia, and the "fuel tank" shedding foam.
Both Shuttle accidents involved "out of family" anomolies. Challenger was launched in unusually cold conditions, with a less than perfect O ring/SRB joint design. Primary O ring erosion and even burnthru had been seen before, but the secondary was intact. Lack of redundancy was accepted as safe. It was recognized and concerned engineers argued the point, to no avail. "Go Fever" prevailed.
In Columbia, the shedding was seen after launch and finally seen as a "post flight turnaround" issue. The debris shedding was "normal" on launch, and the "in flight anomoly" status had been dropped. Previous flights had seen significant tile damage and returned safely. A non-redundant system was compromised on many flights with questionable after-action. Some engineers expressed concerns about damage, no followup options were taken.
Incidently, it was not the stabilization computers that overloaded, it was the nav function. Neil was in firm control, though time was of the essence (they realized early in the descent that they were running long on their trajectory).
Dave

[truthseeker]

Yes sorry I cant be more specific.

It was a channel 4 TV documentary, one of the engineers put his concerns in a letter, but was ignored.

And it was regarding challenger.

Found some similar info here -:

www.npr.org/templates/story/story.php?storyId=5175151

Cheers

[scooter]

While the NPR account has some technical inaccuracies, the gist of it is correct. The shuttle was launched after the managers at Thiokol overruled the engineers and have the go.
Management vs engineers...a concern that still exists today. Mission paralysis vs get the job done...a real challenge, especially in manned space flight.

[Jason Thompson]

We never thought about the possibility of a fire on the ground. We looked at things in the flight realm.

Having recently watched the episode From The Earth To The Moon that deals with the Apollo 1 fire, I'm curious about this. There are numerous scenes where Harisson Storms claims that North American sent memos amd reports to NASA advising them not to test at high pressure with pure oxygen due to the risk of fire. Now I noticed that these scenes were sort of couched in terms that may suggest they were purely for artistic licence (the original statement is made in a review board discussion that is off the record, and later Storms's boss tells him that North American will not contest the review board's findings and will forget those files exist in order to ensure future harmonious relations with NASA), but is there any truth to these suggestions? If so then someone clearly did consider the dangers of the tests before it happened.

[mid]

truthseeker said:

Yes sorry I cant be more specific.

It was a channel 4 TV documentary, one of the engineers put his concerns in a letter, but was ignored.

And it was regarding challenger.

Found some similar info here -:

www.npr.org/templates/story/story.php?storyId=5175151

Cheers

I rather thought it might be Challenger, and you're correct.

Challenger was a sad testimony to the state of NASA in the mid-1980s.

The basis of it is this:

Engineeering data from Thiokol was concrete in describing primary O-ring and secondary O-ring erosion observed in the SRM field joints as a function of decreasing launch temperatures.

The fact is , there were several instances of primary O-ring blow-by, and some instances of secondary O-ring erosion found in the coolest of the launch temperatures as of STS-51L.

This data had been plotted on a graph and clearly indicated that as temperature dropped, the danger increased, and extrapolating existing data indicated that there was a point where it would be likely to experience secondary O-ring blow-by at a certain temperature. It was in the upper-20s the night before Challenger's launch in January of 1986. The lowest temperature prior to that was, I believe 51 degrees farenheit. And on that mission secondary O-ring erosion was experienced.

So what you had was a bunch of engineeers saying the obvious: 'Look, extrapolating this data tells us we could be in a critical zone here. We don't have any hard data to back this up, but the trend is obvious. This launch is going to take place when these O-rings have been exposed to below freezing temperatures. We are potentially in danger here. We should scrub until it gets warmer...into the realm where our data shows we haven't had any serious erosion problems and we know we're ok.'

A resonable, logical thing to state, and a reasonable, logical reason to scrub, based upon the NASA paradigm that used to exist in the Apollo days.

But as scooter said, we found engineeers and management having a battle...a battle which should never have happened. The new NASA paradigm showed through very clearly there. "Success before safety" (although I have and had no idea what success meant in terms of launching STS-51L, or any other STS mission).

The difference was that back in the day, the paradigm was "Safety before Success," or perhaps more properly stated, "Success THROUGH Safety."

In 1969, for instance, a decision to launch was made on the following premise:

"OK, prove to me we're safe, and we GO."

In 1986, that had somehow shifted to :

"OK, prove to me that we're not safe, or else we go."

Read carefully. There is a vast and critical difference in those two statements. The former resulted in the success of Apollo. The latter resulted in the death of 7 people on the morning of 28 January 1986.

Challenger was a horrid piece of decision making, a decision made by management rather than engineeering specialists. Challenger should have never launched that day. They should never have even ingressed the crew that morning.

But Thiokol engineeers did indeed argue against it, and warn of the possible consequences...those consequences being swiftly proven as correct 1 minute 14 seconds into that flight.

[mid]

jasonthompson said:

We never thought about the possibility of a fire on the ground. We looked at things in the flight realm.

Having recently watched the episode From The Earth To The Moon that deals with the Apollo 1 fire, I'm curious about this. There are numerous scenes where Harisson Storms claims that North American sent memos amd reports to NASA advising them not to test at high pressure with pure oxygen due to the risk of fire. Now I noticed that these scenes were sort of couched in terms that may suggest they were purely for artistic licence (the original statement is made in a review board discussion that is off the record, and later Storms's boss tells him that North American will not contest the review board's findings and will forget those files exist in order to ensure future harmonious relations with NASA), but is there any truth to these suggestions? If so then someone clearly did consider the dangers of the tests before it happened.

It is exceedingly difficult to watch documentaries on Apollo without finding fault in the "Hollywood" that is interjected to embellish and add intrigue to a story.

The truth is that alot of people at NAA werer dissatisfied with the Block 1 Apollo CM, and with alot of the practices employed by NAA in managing people and the spacecraft's construction. It was, quite frankly, a mess of a spacecraft.

This however is not hidden information. It was acknowledged by NAA and NASA during the investigation into the Apollo 1 fire. There was no conspiracy here. Apollo 1 was the result of what we'd call GO fever...rushing at breakneck pace to accomplish a daunting goal, and finding that the result is that blinders get put up to what in hindsight seems obvious.

There were several memoranda written regarding potential hazards of using the 100% oxygen atmosphere in the Apollo spacecraft in the mid-60s. But the fact is that such an atmosphere had always been used, and no one ever thought about the hazards in a plugs-out ground test. Quite frankly, that was a shock to everyone in the program when it happened. We always considered in-flight hazards. No one could've imagined a fire on the pad like that one. In hindsight, of course, it seems obvious that we should've seen what the hazards were, especially given the mess that the wiring was in spacecraft 012. But again, the GO fever blinders were on.

Apollo 1 was a wake up call, and as horrible as it seems in saying this, it provided exactly what was needed to get back on track the right way and succeed.

Everyone, North American and NASA, got a graphic and horrendous wake-up call that day in 1967.

And as horrific as the event was, Amercica used it to learn, and move on, unlike the Soviets, who often sacrificed crew safety for success, and failed miserably as a result in their lunar mission efforts.

I often think about the timing of Apollo1, and consider what might have happened if that fire had occurred on the pad with a fully loaded LV sitting underneath them, or perhaps if the vehicle launched and the fire occurred on-orbit...

Apollo may have stopped dead in its tracks.

Again, at the risk of minimizing what happened to three fine men in January 1967 (and believe me, I still remember the day), we got lucky then. We had the right people, with the right stuff, to take the lessons that Apollo 1 taught us so painfully, and move on to complete success. What happened as a result of Apollo one was a testament to the character of the people who made Apollo happen.

[Obviousman]

Everyone seems to have an opinion on this, so I'll add my 2c worth - as a non-engineer.

The Apollo 1 fire was a preventable tragedy. The problem was they didn't really see the events happening. It was one example of the Reason model of accidents.

NAA didn't like using 100% O2, but the alternative was to go for a mixed gas system. Although technically achievable, it would have required additional development time and added unwanted weight to the spacecraft.

IIRC, the fire risk of some material was incorrectly tested for an Earth-normal atmosphere rather than 100% O2 - though I am not sure about this point.

The amount of Velcro and it's positioning was limited, but these limits were being exceeded.

There were many faults with the Block I CM, but it was quite reasonably decided to fix them with the Block II and fly the Block I in the initial orbital test. They knew there were faults, but at no time did they think it was unsafe.

There was poor workmanship with some aspects of the Block I CM, but a programme of improved quality control was being implimented and it was believed that this issue was being addressed.

A crucial factor was that it was decided to conduct the CM pressure test simultaneously with the plugs-out test (to save time). This meant that the CM was pressurised with 100% O2 well above the 'normal' O2 pressure of the CM (in order to obtain the correct pressure differential). It also meant that many spacecraft systems were operating / energized that might not be in that condition during the originally planned pressure test.

The CM hatch had focussed on unintentional desealing in space, so it was designed to be sealed by positive pressure in the CM cabin - as a safety measure.

Finally, the plugs-out test wasn't considered to be "hazardous" (because no propellents were in the Saturn 1B), so possible fire response measures were not taken.

Then, on the evening of 27 JAN 67, all the 'holes' in our defences lined up.

Poor workmanship / design flaws led to a system shorting out. The short, in conjunction with 100% O2 at a greater pressure than expected led to a small fire on materials that should not normally have been expected to be flammable. The fire in the enriched and pressurised O2 atmosphere quickly spread to other materials and became a major fire. The fire raised the cabin pressure in the cabin, and because of the hatch design, the crew were unable - despite their best efforts - to undo and release the hatch. The pressurised 100% O2 atmosphere accelerated the fire and also produced noxious fumes which quickly overcame the crew. When the fire caused a rupture in the pressure hull of the CM, the pad crew weren't equipped to fight a major fire. By the time the pad crew could fight and contain the fire, and release the hatch from the CM, the Apollo 1 crew had been asphixiated and were dead.

I don't know if Frank Borman ever actually said it, but in FTETTM it was well stated:

"It was a failure of imagination".

It's worth noting some of the changes that occurred because of the fire:

- The tests were redesignated as 'hazardous'.
- The amount of distribution of combustible material was severely constrained.
- Hatch design changed for rapid opening.
- Emergency procedures reviewed.
- CM atmosphere would be mixed during launch, reverting to 100% O2 once in space.

[Obviousman]

As far as CHALLENGER is concerned...

As people have stated, there were concerns about the SRB joint O-rings. Though some people opposed the launch, they were over-ruled because they could not provide solid data on the field joints actually being unsafe - it was interpolation of existing data. One of the main oppoenents was asked to "...take off his engineering hat, and put on his management hat..." about the recommendations. He subsequently said "... I wouldn't want to stand before a Board Of Inquiry and explain why I justified this launch..." (or something similar) - he was right.

The NASA reps also displayed concern that the contractors were delaying the launch because of temperature limits, asking something to the effect of "... when can we launch? Next spring?"

There was a programme in place to replace the field joint O-rings, but it wasn't given the priority that it (subsequently) deserved.

There was also the pressure (although it was said that it was perceived and not real) to launch in time for the State Of The Union address by President Regan. He wanted to announce educational reforms with a "teacher in space".

There were also problems with the Shuttle supply chain, and their availability. A lot of parts were being 'cannabalised' from 'off-line' spacecraft to support the current launch.

Overall, IMO, this was an indication of NASA's darkest hour. Although no-one in NASA thought it was actually unsafe to launch, they let perceived pressures guide them towards unwise decisions. I don't blame anyone in this event, but NASA should use it it as an example of poor decision-making.

[Jason Thompson]

With respect to mid and Obviousman, I know the sequence of events and what led to the fire. Perhaps I should rephrase the question. My understanding is as follows:

The spacecraft was designed to operate with a 100% oxygen atmosphere, but at 5psi in space. Hazards were identified on this basis with regard to flammables in the capsule. I understand that the general view is that no-one made the connection between the difference in environment between pure oxygen at 5psi in space and pure oxygen at 17psi on the ground during the tests. The suggestion from FTETTM is that someone did make the connection and advised NASA that testing at pressure was a fire hazard. In other words, the impression is that 'Go fever' made people overlook a recommendation, not that it made no-one at all think the test was hazardous. That's what I want clarified: did no-one really think of it, or was it thought of by someone but dismissed? Specifically, were there any memos or reports regarding the hazards of a high-pressure, pure oxygen environment during ground testing?

[Obviousman]

jasonthompson said:

With respect to mid and Obviousman, I know the sequence of events and what led to the fire. Perhaps I should rephrase the question. My understanding is as follows:

The spacecraft was designed to operate with a 100% oxygen atmosphere, but at 5psi in space. Hazards were identified on this basis with regard to flammables in the capsule. I understand that the general view is that no-one made the connection between the difference in environment between pure oxygen at 5psi in space and pure oxygen at 17psi on the ground during the tests. The suggestion from FTETTM is that someone did make the connection and advised NASA that testing at pressure was a fire hazard. In other words, the impression is that 'Go fever' made people overlook a recommendation, not that it made no-one at all think the test was hazardous. That's what I want clarified: did no-one really think of it, or was it thought of by someone but dismissed? Specifically, were there any memos or reports regarding the hazards of a high-pressure, pure oxygen environment during ground testing?

From my viewing of FTETTM, I don't agree with the inference. IIRC, the words "We begged them not to use 100% O2" were used, but not in connection with any deadline pressures.

I'll have a look at the series again when I have a chance (I'm going through THE WEST WING series at the moment - great stuff).

[Jason Thompson]

Sorry, Obvousman, but pressure was specifically mentioned. During the 'off-the-record' discussion with Harisson Storms and Joe Shea at the review board a heated argument developed in which Storms finally yelled, 'And we begged you not to test at high pressure.'

Other lines I recall from that episode (which I watched a few days ago, BTW):

'The fire wasn't caused by Velcro, it was caused by 100% pure oxygen, under pressure.'

'But you weren't testing in space, you were testing at sea level, where the atmospheric pressure is already 14.8psi. So, to simulate a positive pressure, you guys tanked up the cabin to 17psi. At 17 psi pure oxygen, velcro explodes!'

'We've got boxes of files containing memos begging them not to test at high pressure.'