Falcon 9 explosion

[Dalhousie]

I suspect that the two failures although somewhat troubling have nothing to do with each other.  The investigation may/may not prove that suspicion.
[/quote]

Regardless of whether they are connected or not, it is still a concern.  Other crewed or potentially crewed launchers of recent have accident rates that are lower.  Soyuz U/U2 and Cz-2 are 97% reliable overal (actual crewed flights better than this, Soyuz U/U2 and Cz-2F are better than 99% when crewed), STS was also better than 99% reliable for launch.

[gwiz]

...STS was also better than 99% reliable for launch.

You could argue that Columbia was lost due to a launch failure, in that the damage was done by a fragment falling off the external tank.

[Jason Thompson]

A concern, but if the launch escape systems are adequate...

I don't have statistics to hand, but the thought does occur that a rocket that astronauts would strap themselves on top of in 1968 had only flown twice before, and on the second flight engines failed and bits fell off it....

[Glom]

A concern, but if the launch escape systems are adequate...

I don't have statistics to hand, but the thought does occur that a rocket that astronauts would strap themselves on top of in 1968 had only flown twice before, and on the second flight engines failed and bits fell off it....

It didn't destroy itself though.

[bknight]

The early Atlas launches weren't that much better.

https://en.wikipedia.org/wiki/List_of_Atlas_launches_(1960%E2%80%9369)#1960

[Peter B]

I suspect that the two failures although somewhat troubling have nothing to do with each other.  The investigation may/may not prove that suspicion.

While I tend to agree that they appear to be two completely unrelated failures, doesn't that make it more troubling rather than less? In other words, two completely unrelated systems failed in ways which would have required the astronauts to undergo an abort if those missions had been manned - one during launch and one while on the pad (well, maybe not the second if it had occurred while preparing for a test-firing - presumably they wouldn't put people into a Dragon capsule for a test firing).

[bknight]

I suspect that the two failures although somewhat troubling have nothing to do with each other.  The investigation may/may not prove that suspicion.

While I tend to agree that they appear to be two completely unrelated failures, doesn't that make it more troubling rather than less? In other words, two completely unrelated systems failed in ways which would have required the astronauts to undergo an abort if those missions had been manned - one during launch and one while on the pad (well, maybe not the second if it had occurred while preparing for a test-firing - presumably they wouldn't put people into a Dragon capsule for a test firing).

See my previous post concerning the Atlas launches, many different part/pieces failed during the initial launch schedule both for the USAF and NASA.  I agree that they will nee to do a recheck on their manufacturing/engineering of the vehicle before manned rating is assigned.

[smartcooky]

The early Atlas launches weren't that much better.

https://en.wikipedia.org/wiki/List_of_Atlas_launches_(1960%E2%80%9369)#1960

Holy Cow... 59 total launch failures and six partial failures out of 247 launches; a failure rate of more than 1 in 4

Four of those 247 launches were manned - John Glenn, Scott Carpenter, Wally Schirra and Gordy Cooper. One of them beat the odds!!

[Glom]

To be fair, reliability can improve with time. What the distribution of those failures?

[JayUtah]

Keep in mind the manned Atlases were uprated for safety.  For ICBMs it's cheaper to make two missiles for every target and count on one of them failing, than to make one single missile per target with high reliability.

Fueling a rocket is hazardous.  The reason the pad is evacuated is because we know it's hazardous.  And the known hazard manifests itself from time to time in actual accidents.  If it didn't, we wouldn't have as much reason to classify it as hazardous.  That said, I think SpaceX has room for improvement, but we won't know how much until we determine how preventable this accident was.

[Luther]

For ICBMs it's cheaper to make two missiles for every target and count on one of them failing, than to make one single missile per target with high reliability.

In this scenario, are you firing both missiles at about the same time, or do you wait to see if the first one scores a hit before firing the second?

In the first case, if you have a 50% failure rate, then I'd say you'll hit about 75% of your targets.

[BazBear]

For ICBMs it's cheaper to make two missiles for every target and count on one of them failing, than to make one single missile per target with high reliability.

In this scenario, are you firing both missiles at about the same time, or do you wait to see if the first one scores a hit before firing the second?

In the first case, if you have a 50% failure rate, then I'd say you'll hit about 75% of your targets.

You've never heard of MIRVs? High value targets would almost certainly get targeted by multiple warheads from multiple missiles. MAD at its "finest".

[Luther]

You've never heard of MIRVs?

Yes I have heard of MIRVs.  Have you ever heard of a coherent conversation?

[BazBear]

You've never heard of MIRVs?

Yes I have heard of MIRVs.  Have you ever heard of a coherent conversation?

My point was that that high a booster failure rate was probably acceptable. I'm not sure what was incoherent about that post; and I meant no offense with the "ever heard of MIRVs?"line. It was mostly meant as rhetorical question.

[bknight]

Keep in mind the manned Atlases were uprated for safety.  For ICBMs it's cheaper to make two missiles for every target and count on one of them failing, than to make one single missile per target with high reliability.

Fueling a rocket is hazardous.  The reason the pad is evacuated is because we know it's hazardous.  And the known hazard manifests itself from time to time in actual accidents.  If it didn't, we wouldn't have as much reason to classify it as hazardous.  That said, I think SpaceX has room for improvement, but we won't know how much until we determine how preventable this accident was.

I was browsing this morning and came up with some tidbits from others.

There are more videos, I selected only two of them.

Seems like some are suspecting an initial failure where the LOX load line makes an S bend.  Any other thoughts?