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Falcon 9 anomaly not related to FTS



 
 
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  #1  
Old September 23rd 16, 11:57 PM posted to sci.space.policy
Fred J. McCall[_3_]
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Posts: 10,018
Default Falcon 9 anomaly not related to FTS

SpaceX today released a preliminary determination that the 'anomaly'
was caused by "a large breach in the cryogenic helium system of the
second stage liquid oxygen tank". They are looking for what could
have caused that.

There ain't no FTS in there, so the FTS couldn't have caused this.
Those who latched onto the FTS as the 'cause' and wouldn't let go (to
the point of claiming things that they couldn't substantiate) should
hang their heads in shame.


--
You are
What you do
When it counts.
  #3  
Old October 3rd 16, 06:22 AM posted to sci.space.policy
William Mook[_2_]
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Posts: 3,840
Default Falcon 9 anomaly not related to FTS

On Saturday, September 24, 2016 at 1:51:26 PM UTC+12, Jeff Findley wrote:
In article ,
says...

SpaceX today released a preliminary determination that the 'anomaly'
was caused by "a large breach in the cryogenic helium system of the
second stage liquid oxygen tank". They are looking for what could
have caused that.

There ain't no FTS in there, so the FTS couldn't have caused this.
Those who latched onto the FTS as the 'cause' and wouldn't let go (to
the point of claiming things that they couldn't substantiate) should
hang their heads in shame.


Yep.

Jeff
--
All opinions posted by me on Usenet News are mine, and mine alone.
These posts do not reflect the opinions of my family, friends,
employer, or any organization that I am a member of.


When I saw the report I felt it reads very much like the S-IVB-503 explosion report which had a similar failure reported in its helium sphere back in the 1960s.

http://heroicrelics.org/info/s-ivb/s...urization.html

https://www.reddit.com/r/spacex/comm...y_faq_summary/

Re-assembling the pieces clearly point to a failed helium sphere - for much the same reasons.

With respect to the FTS. It was worth looking into. Here's why, there are two flight termination systems (FTS), on the Falcon. One for each stage of the rocket. Both are required and enabled at liftoff for range safety.

Each stage FTS "unzips" the fuel tanks with detcord down their side and disables the engines by slicing the combustion chamber open with shaped charges. The engines are disabled first. Then the tanks are split open.

The second stage explosion appeared to come from the explosive in the second stage that disabled the second stage engine. So, that was looked at as a possibility. The helium sphere is also in that region obviously. The FTS was tested during the explosion. This was a second indicator that caused some suspicion of the FTS.

During flight, the stage one FTS is "safed" (switched off, or disabled) after the reentry burn. The stage 2 FTS is safed after the orbital insertion burn.

Review the webcast of any Falcon launch and you can hear the range officer calling these events.

After a successful reentry burn, the stage 1 booster's trajectory puts impact in a relatively small target landing zone.

In the case of the ASDS (barge) the FTS is no longer needed for safety. In the case of return to land, the stage one FTS will remain enabled up to the last few seconds of flight. It is safer to split open the sides of the tanks than to let an uncontrolled failure re-launch the top of the booster in an uncontrolled way. This occurred on the CRS-5 booster landing failure. So, this procedure was included in subsequent landings on land.

  #5  
Old October 3rd 16, 08:37 AM posted to sci.space.policy
Rob[_8_]
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Posts: 57
Default Falcon 9 anomaly not related to FTS

William Mook wrote:
On Saturday, September 24, 2016 at 1:51:26 PM UTC+12, Jeff Findley wrote:
In article ,
says...

SpaceX today released a preliminary determination that the 'anomaly'
was caused by "a large breach in the cryogenic helium system of the
second stage liquid oxygen tank". They are looking for what could
have caused that.

There ain't no FTS in there, so the FTS couldn't have caused this.
Those who latched onto the FTS as the 'cause' and wouldn't let go (to
the point of claiming things that they couldn't substantiate) should
hang their heads in shame.


Yep.

Jeff
--
All opinions posted by me on Usenet News are mine, and mine alone.
These posts do not reflect the opinions of my family, friends,
employer, or any organization that I am a member of.


When I saw the report I felt it reads very much like the S-IVB-503 explosion report which had a similar failure reported in its helium sphere back in the 1960s.

http://heroicrelics.org/info/s-ivb/s...urization.html

https://www.reddit.com/r/spacex/comm...y_faq_summary/

Re-assembling the pieces clearly point to a failed helium sphere - for much the same reasons.

With respect to the FTS. It was worth looking into. Here's why, there are two flight termination systems (FTS), on the Falcon. One for each stage of the rocket. Both are required and enabled at liftoff for range safety.

Each stage FTS "unzips" the fuel tanks with detcord down their side and disables the engines by slicing the combustion chamber open with shaped charges. The engines are disabled first. Then the tanks are split open.

The second stage explosion appeared to come from the explosive in the second stage that disabled the second stage engine. So, that was looked at as a possibility. The helium sphere is also in that region obviously. The FTS was tested during the explosion. This was a second indicator that caused some suspicion of the FTS.


There is some other self-made expert on Youtube who has found that
the explosion originated in the tower. He concludes that there has been
an explosion around the LOX line feeding the second stage tank, he
thinks it is because improper insulation material for the purpose has
been used that can explode when soaked with LOX.

How can it be that you are so sure the explosion originated inside the
rocket and hist analyses of the same material indicates the explosion
started in the tower?
  #7  
Old October 3rd 16, 12:30 PM posted to sci.space.policy
Rob[_8_]
external usenet poster
 
Posts: 57
Default Falcon 9 anomaly not related to FTS

William Mook wrote:
Well, I didn't read the conclusions you refer to, from the 'Youtube expert' you cite, so I don't know why this person you mention said what they did. I can only say why I said what I did.


I would expect that, when you are so interested in finding the cause
of the mishap, you would follow other people's attempts as well.
  #8  
Old October 3rd 16, 07:35 PM posted to sci.space.policy
Fred J. McCall[_3_]
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Posts: 10,018
Default Falcon 9 anomaly not related to FTS

William Mook wrote:

On Monday, October 3, 2016 at 8:37:40 PM UTC+13, Rob wrote:
William Mook wrote:
On Saturday, September 24, 2016 at 1:51:26 PM UTC+12, Jeff Findley wrote:
In article ,
says...

SpaceX today released a preliminary determination that the 'anomaly'
was caused by "a large breach in the cryogenic helium system of the
second stage liquid oxygen tank". They are looking for what could
have caused that.

There ain't no FTS in there, so the FTS couldn't have caused this.
Those who latched onto the FTS as the 'cause' and wouldn't let go (to
the point of claiming things that they couldn't substantiate) should
hang their heads in shame.

Yep.

Jeff
--
All opinions posted by me on Usenet News are mine, and mine alone.
These posts do not reflect the opinions of my family, friends,
employer, or any organization that I am a member of.

When I saw the report I felt it reads very much like the S-IVB-503 explosion report which had a similar failure reported in its helium sphere back in the 1960s.

http://heroicrelics.org/info/s-ivb/s...urization.html

https://www.reddit.com/r/spacex/comm...y_faq_summary/

Re-assembling the pieces clearly point to a failed helium sphere - for much the same reasons.

With respect to the FTS. It was worth looking into. Here's why, there are two flight termination systems (FTS), on the Falcon. One for each stage of the rocket. Both are required and enabled at liftoff for range safety.

Each stage FTS "unzips" the fuel tanks with detcord down their side and disables the engines by slicing the combustion chamber open with shaped charges. The engines are disabled first. Then the tanks are split open.

The second stage explosion appeared to come from the explosive in the second stage that disabled the second stage engine. So, that was looked at as a possibility. The helium sphere is also in that region obviously. The FTS was tested during the explosion. This was a second indicator that caused some suspicion of the FTS.


There is some other self-made expert on Youtube who has found that
the explosion originated in the tower. He concludes that there has been
an explosion around the LOX line feeding the second stage tank, he
thinks it is because improper insulation material for the purpose has
been used that can explode when soaked with LOX.

How can it be that you are so sure the explosion originated inside the
rocket and hist analyses of the same material indicates the explosion
started in the tower?


Well, I didn't read the conclusions you refer to, from the 'Youtube expert' you cite, so I don't know why this person you mention said what they did. I can only say why I said what I did.

(1) There was a lens flare that pointed directly to a point in the rocket that coincided with where one of the two FTS charges were.


Cite for the FTS being located there?


http://imgur.com/evh5kNe

(2) The timing of the explosion occurred at the precise moment where an end to end FTS test was being done.


Cite for timing of this purported FTS test?


So, it was a natural conclusion as to the *possibility*.


Only for the loonytoon brigade.

snip Mookie Mulch


--
"Ordinarily he is insane. But he has lucid moments when he is
only stupid."
-- Heinrich Heine
  #9  
Old October 4th 16, 06:59 AM posted to sci.space.policy
William Mook[_2_]
external usenet poster
 
Posts: 3,840
Default Falcon 9 anomaly not related to FTS

On Tuesday, October 4, 2016 at 12:30:13 AM UTC+13, Rob wrote:
William Mook wrote:
Well, I didn't read the conclusions you refer to, from the 'Youtube expert' you cite, so I don't know why this person you mention said what they did. I can only say why I said what I did.


I would expect that, when you are so interested in finding the cause
of the mishap, you would follow other people's attempts as well.


I have followed SpaceX's efforts quite closely and Scott Manley. I don't know this person you cite. You didn't name them nor give any links. Their idea must have been eliminated by the logic of my search algorithms - since I eliminated anything outside the body of the rocket as the cause.

The helium sphere and detcord were early suspects for the reasons I've already stated. If it wasn't the FTS then its a big mystery as to why a helium sphere would fail like that. When the S-IVB-503 test detonated in 1967 due to helium sphere failure, it was due to poor welds. A composite over-wrapped helium tank doesn't have welds like that. So, the failure mode is unknown at the present time. Though the microscopic examination of the parts pretty much points to the helium spheres failing.

Musk himself hasn't ruled out sabotage.

http://www.nbcnews.com/tech/tech-new...losion-n658821

So, its an ongoing investigation.

  #10  
Old October 4th 16, 07:02 AM posted to sci.space.policy
William Mook[_2_]
external usenet poster
 
Posts: 3,840
Default Falcon 9 anomaly not related to FTS

On Tuesday, October 4, 2016 at 12:08:39 AM UTC+13, Jeff Findley wrote:
In article ,
says...

On Saturday, September 24, 2016 at 1:51:26 PM UTC+12, Jeff Findley wrote:
In article ,
says...

SpaceX today released a preliminary determination that the 'anomaly'
was caused by "a large breach in the cryogenic helium system of the
second stage liquid oxygen tank". They are looking for what could
have caused that.

There ain't no FTS in there, so the FTS couldn't have caused this.
Those who latched onto the FTS as the 'cause' and wouldn't let go (to
the point of claiming things that they couldn't substantiate) should
hang their heads in shame.

Yep.


Not sure why you felt the need to keep supporting your position that the
FTS was the cause, because it wasn't.


Beause of the location nature and timing of the explosion indicated very possibly the FTS. Microscopic examination of the parts that were gathered together after the explosion indicated that there were no explosive residue. Re-assembly of the parts pointed clearly to a failed helium pressure tank. Why that tank would fail is still unknown. Sabotage hasn't been eliminated.

http://www.nbcnews.com/tech/tech-new...losion-n658821


So, I snipped everything you
wrote about the FTS.


Your loss.

SpaceX has determined that there was a failure somewhere in the helium
pressurization system of the 2nd stage.


Correct for the reasons indicated. The FTS was also checked as the source as well, for the reasons indicated.

Jeff
--
All opinions posted by me on Usenet News are mine, and mine alone.
These posts do not reflect the opinions of my family, friends,
employer, or any organization that I am a member of.

 




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