Author Topic: SpaceX will almost certainly have another failure within the next 3 years.  (Read 77928 times)

Offline Nomadd

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It is somewhat disquieting to see people discuss failure probabilities almost as if they’ve forgotten that some of these reused F9s will be carrying human payloads which is a completely different aspect than other payloads.

It’s also something of a pointless exercise being as we have no access to Space Xs internal engineering data on the F9s.
When posts start making as little sense as that one it's probably time to put this thread back in it's coma.
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Offline daedalus1

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It is somewhat disquieting to see people discuss failure probabilities almost as if they’ve forgotten that some of these reused F9s will be carrying human payloads which is a completely different aspect than other payloads.

It’s also something of a pointless exercise being as we have no access to Space Xs internal engineering data on the F9s.

I'm just talking about after a successful mission and not being recovered (the booster) afterwards.
This happens to every other booster in the world. SpaceX recovering boosters is a game changer, no one else can compete.

Offline meekGee

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It is somewhat disquieting to see people discuss failure probabilities almost as if they’ve forgotten that some of these reused F9s will be carrying human payloads which is a completely different aspect than other payloads.

It’s also something of a pointless exercise being as we have no access to Space Xs internal engineering data on the F9s.
Facepalm.

Expendable rockets launch crews all the time, and the probability of LOC is exactly precisely what needs to be measured...
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Online envy887

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So if you tell your wife "I'm going to drop this dinner off at mom's house", then you total the car on the way home, and she asks how it went, do you say "No problem, she liked the dinner"?

That's not a good analogy because your wife has a direct interest in the value of the car.
...
Throughout this thread I think it's been clear that when people have been talking about reliability they mean reliability as seen by the customer.  By failure, they have meant a failure to get the customer payload to the place it is meant to reach.
This is, in my mind, the wrong definition of failure.  A better definition would be the more general "did not do what the customer expected for the price the customer paid".  For expendable rockets this is exactly the same as the old definition.  The customer paid to get their payload in a specified orbit.  As long as it gets there they are satisfied.

But a recoverable rocket, when launched by the owner (see the 'direct interest' quote above), has a different definition of failure.  They are expecting to both put the payload in orbit, and get the booster back.  They can tolerate a bigger failure rate during recovery, but it's still a failure.  If it happened on every launch, their business plan would not close, and they would go bankrupt.   That's a failure by any measure.

For Starlink, it's arguable that failing to recover the the booster is MORE of a failure than losing the satellites.  If the second stage fails but the booster is recovered, to redo they need a new second stage (maybe $10M)  plus maybe $15M worth of satellites.  If the payload deployment succeeds, but the booster recovery fails, they need a new first stage at maybe $30M.  Of course there is also reputation, stand-down time, time-to-market, etc., but the general point holds.

Basically once you have a new capability (booster recovery), and you build a new business plan that counts on it, then you have a new and more general definition of failure.   You could succeed perfectly by the old metric but still go out of business due to problems with the launch vehicle.   By common use of business over hundreds of years, these losses would be failures.

IMO losing even a Starlink a mission would at this point, cost them a lot more than losing a booster, particularly a used booster. The time and money cost of a stand down, failure investigation, and RTF effort is probably at least double the value of a used booster.

Online Robotbeat

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It is somewhat disquieting to see people discuss failure probabilities almost as if they’ve forgotten that some of these reused F9s will be carrying human payloads which is a completely different aspect than other payloads.

...
Reuse gives you built-in margin that should make human flights SAFER. Human spaceflight is risky. No need to concern troll about it.
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Offline Star One

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It is somewhat disquieting to see people discuss failure probabilities almost as if they’ve forgotten that some of these reused F9s will be carrying human payloads which is a completely different aspect than other payloads.

...
Reuse gives you built-in margin that should make human flights SAFER. Human spaceflight is risky. No need to concern troll about it.
I wasn’t concern trolling. It seems some on this thread are very easily triggered if that’s their first response.
« Last Edit: 09/04/2020 04:30 pm by Star One »

Offline Star One

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It is somewhat disquieting to see people discuss failure probabilities almost as if they’ve forgotten that some of these reused F9s will be carrying human payloads which is a completely different aspect than other payloads.

It’s also something of a pointless exercise being as we have no access to Space Xs internal engineering data on the F9s.
Facepalm.

Expendable rockets launch crews all the time, and the probability of LOC is exactly precisely what needs to be measured...
Where did I say it shouldn’t be measured? Just that it can’t be measured without large degrees of error. See below.
« Last Edit: 09/04/2020 04:32 pm by Star One »

Offline Star One

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It is somewhat disquieting to see people discuss failure probabilities almost as if they’ve forgotten that some of these reused F9s will be carrying human payloads which is a completely different aspect than other payloads.

It’s also something of a pointless exercise being as we have no access to Space Xs internal engineering data on the F9s.

I'm just talking about after a successful mission and not being recovered (the booster) afterwards.
This happens to every other booster in the world. SpaceX recovering boosters is a game changer, no one else can compete.
Fair enough. But it doesn’t mitigate the fact that no one here can really estimate this without large error margins because no one here has access to Space X’s internal engineering data.
« Last Edit: 09/04/2020 04:31 pm by Star One »

Offline Star One

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It is somewhat disquieting to see people discuss failure probabilities almost as if they’ve forgotten that some of these reused F9s will be carrying human payloads which is a completely different aspect than other payloads.

It’s also something of a pointless exercise being as we have no access to Space Xs internal engineering data on the F9s.
When posts start making as little sense as that one it's probably time to put this thread back in it's coma.
When responses are as pointless as this it’s worth wondering why you bothered posting.

Offline ChrisWilson68

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So if you tell your wife "I'm going to drop this dinner off at mom's house", then you total the car on the way home, and she asks how it went, do you say "No problem, she liked the dinner"?

That's not a good analogy because your wife has a direct interest in the value of the car.
...
Throughout this thread I think it's been clear that when people have been talking about reliability they mean reliability as seen by the customer.  By failure, they have meant a failure to get the customer payload to the place it is meant to reach.
This is, in my mind, the wrong definition of failure.  A better definition would be the more general "did not do what the customer expected for the price the customer paid".  For expendable rockets this is exactly the same as the old definition.  The customer paid to get their payload in a specified orbit.  As long as it gets there they are satisfied.

But a recoverable rocket, when launched by the owner (see the 'direct interest' quote above), has a different definition of failure.  They are expecting to both put the payload in orbit, and get the booster back.  They can tolerate a bigger failure rate during recovery, but it's still a failure.  If it happened on every launch, their business plan would not close, and they would go bankrupt.   That's a failure by any measure.

For Starlink, it's arguable that failing to recover the the booster is MORE of a failure than losing the satellites.  If the second stage fails but the booster is recovered, to redo they need a new second stage (maybe $10M)  plus maybe $15M worth of satellites.  If the payload deployment succeeds, but the booster recovery fails, they need a new first stage at maybe $30M.  Of course there is also reputation, stand-down time, time-to-market, etc., but the general point holds.

Basically once you have a new capability (booster recovery), and you build a new business plan that counts on it, then you have a new and more general definition of failure.   You could succeed perfectly by the old metric but still go out of business due to problems with the launch vehicle.   By common use of business over hundreds of years, these losses would be failures.

The reason everyone else here is using "failure" to mean loss of the payload is that losing even a small number of payloads can mean loss of an enormous amount of business.  It could mean loss of NSSL.  It could mean loss of commercial crew.  It could mean loss of comsats that don't want the risk.

By this definition of failure, the failure rate needs to be very, very low.  Hence the title of this thread, which worries about the effect of even a single failure in 3 years.

In terms of loss of a booster after delivering satellites, a much higher failure rate is perfectly acceptable.  Up until a few years ago, this "failure" rate was 100%, and SpaceX was still thriving.  Obviously, the lower the loss rate for boosters, the better.  But the loss rate for boosters is already obviously well under 10%, which is more than enough to make reuse wildly successful.  So there's no real concern with loss of Falcon 9 boosters.

The loss of one or two boosters a year is a total non-issue.  But the loss of one or two payloads a year would matter a whole lot.

That's why everyone else hear means "loss of payload" when they are talking about failure.

Offline meekGee

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It is somewhat disquieting to see people discuss failure probabilities almost as if they’ve forgotten that some of these reused F9s will be carrying human payloads which is a completely different aspect than other payloads.

It’s also something of a pointless exercise being as we have no access to Space Xs internal engineering data on the F9s.
When posts start making as little sense as that one it's probably time to put this thread back in it's coma.
When responses are as pointless as this it’s worth wondering why you bothered posting.
Because you were casting aspersions at almost everyone here for daring to talk about probabilities when human lives are at stake.
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Online Robotbeat

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It is somewhat disquieting to see people discuss failure probabilities almost as if they’ve forgotten that some of these reused F9s will be carrying human payloads which is a completely different aspect than other payloads.

...
Reuse gives you built-in margin that should make human flights SAFER. Human spaceflight is risky. No need to concern troll about it.
I wasn’t concern trolling. It seems some on this thread are very easily triggered if that’s their first response.
You were the one triggered about talking about human spaceflight and probabilities of failure. But you did so in a vague way, casting implicit aspersions to people posting here and implying SpaceX’s reuse paradigm makes it disconcertingly unsafe even though NASA has certified it safe for crew. You were very much concern-trolling.

As far as not having access to detailed engineering data, that stuff is ITAR and so literally no US company even CAN make that stuff public. But the professionals at NASA (and elsewhere) whose job it is to determine safety have access to all the data they need, and they considered it safe for crew to a high degree of certainty.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline D_Dom

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To parrott a Chris B football saying, "Play the ball not the man". If you think someone is trolling, calling them out isn't adding to the conversation. This is an interesting topic for me but it touches nerves for some people. Be excellent to each other.
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Offline mulp

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[zubenelgenubi: Removed quoted up-thread bickering.]
But human rated flights assume failure is probable and thus include special features to reduce cost of failure. Just as jet planes assume failure and include special features even tho the failure of a single flight is predicted to be very low.

Most jet plane failures are human error, so that's why the MAX design failure is "shocking". Note they blamed it on pilots even tho it was a management hubris screwups, like the first shuttle disaster.

How comprehensive are SpaceX checklists? And when the Florida temperature is not like Florida will SpaceX managers override the checklist. Sometimes the reasons for each item on the checklist are forgotten to the obscure edge condition that put it on the list.
« Last Edit: 09/19/2020 04:53 pm by zubenelgenubi »

Online Robotbeat

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The nice thing about having a large and recent flight history is it proves that SpaceX's operations are effective in ensuring reliability. Nothing can prove reliability quite as convincingly as actually having a recent, proven record of launch success.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline zubenelgenubi

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Unnecessary, no redeeming value post deleted and thread locked. 🔒
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