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Off Topic => General Discussion => Topic started by: mako88sb on September 01, 2016, 02:18:21 PM

Title: Falcon 9 explosion
Post by: mako88sb on September 01, 2016, 02:18:21 PM
An unfortunate situation that was not caused by the Falcon 9. Some sort of launch pad anomaly.

@elonmusk
Loss of Falcon vehicle today during propellant fill operation. Originated around upper stage oxygen tank. Cause still unknown. More soon.

Some info here.
https://www.reddit.com/live/xix3m9uqd06g

The mishap
Title: Re: Falcon 9 explosion
Post by: bknight on September 01, 2016, 03:40:14 PM
Sickening video for sure, but happily safety precautions prevented loss of life.
Title: Re: Falcon 9 explosion
Post by: Allan F on September 01, 2016, 04:40:32 PM
Looks like something happened at the interstage? The side towards the camera blew out?
Title: Re: Falcon 9 explosion
Post by: gwiz on September 02, 2016, 07:38:29 AM
Looked more like the upper part of the second stage to me, near where the venting was pre-explosion.
Title: Re: Falcon 9 explosion
Post by: mako88sb on September 02, 2016, 10:55:55 AM
Here's a quote and image from FB SpaceX group user Ross Sackett;

"I used a trick we sometimes use to fix the position of a star in an astrophoto(graphy.) While the fireball is burned into the image making it hard to locate the center, the lens flares (probably diffraction spikes) are centered on the brightest part. Make of this what you will."

This centers near an S bend in a large strongback (electrical?) conduit near the level of the common bulkhead in S2. There are other connections to S2 near there.

L2 SpXers sound like they're focussing on something, but will wait for Musk to pull the trigger publicly.

(https://thespaceport.us/forum/uploads/monthly_09_2016/post-10859-0-53379000-1472805441_thumb.jpg)
Title: Re: Falcon 9 explosion
Post by: bknight on September 02, 2016, 01:56:40 PM
Here's a quote and image from FB SpaceX group user Ross Sackett;

"I used a trick we sometimes use to fix the position of a star in an astrophoto(graphy.) While the fireball is burned into the image making it hard to locate the center, the lens flares (probably diffraction spikes) are centered on the brightest part. Make of this what you will."

This centers near an S bend in a large strongback (electrical?) conduit near the level of the common bulkhead in S2. There are other connections to S2 near there.

L2 SpXers sound like they're focussing on something, but will wait for Musk to pull the trigger publicly.

(https://thespaceport.us/forum/uploads/monthly_09_2016/post-10859-0-53379000-1472805441_thumb.jpg)

That is a unique way to look at something that bright and intense.  Not knowing he geometry of the second stage, it does look like it would be around the LH tankage and/or fill lines
Title: Re: Falcon 9 explosion
Post by: Glom on September 02, 2016, 02:09:53 PM
At least the payload was a Facebook satellite rather than something noble.
Title: Re: Falcon 9 explosion
Post by: Dalhousie on September 02, 2016, 11:08:41 PM
That is a unique way to look at something that bright and intense.  Not knowing he geometry of the second stage, it does look like it would be around the LH tankage and/or fill lines

F9 does not use LH2, but kerosene (and LO2)
Title: Re: Falcon 9 explosion
Post by: Dalhousie on September 02, 2016, 11:09:53 PM
An unfortunate situation that was not caused by the Falcon 9. Some sort of launch pad anomaly.

We don't know that, just because it did not happen in flight does not rule out a problem with the rocket, as opposed to the pad or the procedures.
Title: Re: Falcon 9 explosion
Post by: gwiz on September 03, 2016, 07:17:53 AM
At least the payload was a Facebook satellite rather than something noble.
It was owned by Spacecom, an Israeli satellite communications company, who were to lease part of the capacity to Facebook.  Its primary purpose was to replace Amos 2, an aging Spacecom satellite.
Title: Re: Falcon 9 explosion
Post by: bknight on September 03, 2016, 10:14:42 AM
That is a unique way to look at something that bright and intense.  Not knowing he geometry of the second stage, it does look like it would be around the LH tankage and/or fill lines

F9 does not use LH2, but kerosene (and LO2)

I stand corrected, than you for the information.
Title: Re: Falcon 9 explosion
Post by: mako88sb on September 03, 2016, 12:44:40 PM
An unfortunate situation that was not caused by the Falcon 9. Some sort of launch pad anomaly.

We don't know that, just because it did not happen in flight does not rule out a problem with the rocket, as opposed to the pad or the procedures.

Yes, you are correct but they seem to think there might have been some sort of hydraulic leak from the strongback RP-1 line resulting in a hydrocarbon aerosol that mixed with the GOX boiloff. The latest info:

"- Yesterday, at SpaceX's Launch Complex 40 at Cape Canaveral Air Force Station, an anomaly took place about eight minutes in advance of a scheduled test firing of a Falcon 9 rocket.

- The anomaly on the pad resulted in the loss of the vehicle.

- This was part of a standard pre-launch static fire to demonstrate the health of the vehicle prior to an eventual launch.

- At the time of the loss, the launch vehicle was vertical and in the process of being fueled for the test. At this time, the data indicates the anomaly originated around the upper stage liquid oxygen tank. Per standard operating procedure, all personnel were clear of the pad. There were no injuries.

To identify the root cause of the anomaly, SpaceX began its investigation immediately after the loss, consistent with accident investigation plans prepared for such a contingency. These plans include the preservation of all possible evidence and the assembly of an Accident Investigation Team, with oversight by the Federal Aviation Administration and participation by NASA, the United States Air Force and other industry experts. We are currently in the early process of reviewing approximately 3000 channels of telemetry and video data covering a time period of just 35-55 milliseconds.

As for the Launch Pad itself, our teams are now investigating the status of SLC-40. The pad clearly incurred damage, but the scope has yet to be fully determined. We will share more data as it becomes available."



Title: Re: Falcon 9 explosion
Post by: Dalhousie on September 04, 2016, 01:28:21 AM
Apposite opinion piece http://arstechnica.com/science/2016/09/we-love-spacex-and-we-hope-it-reaches-mars-but-we-spacex-to-focus/
Title: Re: Falcon 9 explosion
Post by: Count Zero on September 04, 2016, 02:29:48 AM
Scary.  You can see the radiant heat burning the paint off the towers.
Title: Re: Falcon 9 explosion
Post by: bknight on September 04, 2016, 10:06:26 AM
Scary.  You can see the radiant heat burning the paint off the towers.

Quote
The booster that two NASA astronauts might climb on top of in two years—or less—has just suffered two failures in 15 months.

I suspect that the two failures although somewhat troubling have nothing to do with each other.  The investigation may/may not prove that suspicion.
Title: Re: Falcon 9 explosion
Post by: Dalhousie on September 04, 2016, 09:16:29 PM

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.
Title: Re: Falcon 9 explosion
Post by: gwiz on September 05, 2016, 07:41:05 AM
...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.
Title: Re: Falcon 9 explosion
Post by: Jason Thompson on September 05, 2016, 04:20:06 PM
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.... :)
Title: Re: Falcon 9 explosion
Post by: Glom on September 06, 2016, 06:10:41 AM
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.
Title: Re: Falcon 9 explosion
Post by: bknight on September 06, 2016, 10:04:51 AM
The early Atlas launches weren't that much better.

https://en.wikipedia.org/wiki/List_of_Atlas_launches_(1960%E2%80%9369)#1960
Title: Re: Falcon 9 explosion
Post by: Peter B on September 06, 2016, 10:46:10 AM
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).
Title: Re: Falcon 9 explosion
Post by: bknight on September 06, 2016, 02:43:42 PM
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.
Title: Re: Falcon 9 explosion
Post by: smartcooky on September 07, 2016, 03:46:42 AM
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!!
Title: Re: Falcon 9 explosion
Post by: Glom on September 07, 2016, 04:11:58 AM
To be fair, reliability can improve with time. What the distribution of those failures?
Title: Re: Falcon 9 explosion
Post by: JayUtah on September 08, 2016, 10:03:06 AM
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.
Title: Re: Falcon 9 explosion
Post by: Luther on September 08, 2016, 12:18:01 PM
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.

Title: Re: Falcon 9 explosion
Post by: BazBear on September 09, 2016, 02:42:20 AM
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 (https://en.wikipedia.org/wiki/Multiple_independently_targetable_reentry_vehicle)? High value targets would almost certainly get targeted by multiple warheads from multiple missiles. MAD (https://en.wikipedia.org/wiki/Mutual_assured_destruction) at its "finest".
Title: Re: Falcon 9 explosion
Post by: Luther on September 09, 2016, 11:21:33 AM
Quote from: BazBear link=topic=1190.msg39310#msg39310 date=1473403340[/quote
You've never heard of MIRVs (https://en.wikipedia.org/wiki/Multiple_independently_targetable_reentry_vehicle)?

Yes I have heard of MIRVs.  Have you ever heard of a coherent conversation?
Title: Re: Falcon 9 explosion
Post by: BazBear on September 09, 2016, 02:49:51 PM
Quote from: BazBear link=topic=1190.msg39310#msg39310 date=1473403340[/quote
You've never heard of MIRVs (https://en.wikipedia.org/wiki/Multiple_independently_targetable_reentry_vehicle)?

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.
Title: Re: Falcon 9 explosion
Post by: bknight on October 16, 2016, 09:16:17 AM
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?