[QUOTE=Bradyns;51276632][/QUOTE]
Proud to say I was/still am a part of the Texas Testing :D
We're working our asses off down here
after 2 helium tank failures, ULA's decision to make a rocket without them seems pretty justified now, though i guess space-x does the helium tank a little differently in that its a sphere inside the oxygen tank instead of its own seperate tank
[QUOTE]SpaceX Chief Executive Elon Musk said Nov. 4 he expects the Falcon 9 rocket to return to flight in the middle of December after overcoming a problem he claimed was unprecedented in the history of spaceflight.
Musk, briefly discussing the status of SpaceX during a half-hour interview on the cable news network CNBC Nov. 4, said that investigators had determined what caused the Sept. 1 pad explosion that destroyed a Falcon 9 and its satellite payload during fueling for a static-fire test.
“I think we’ve gotten to the bottom of the problem,” he said. “It was a really surprising problem. It’s never been encountered before in the history of rocketry.”
Musk, confirming earlier discussion about the investigation, said the failure involved liquid helium being loaded into bottles made of carbon composite materials within the liquid oxygen tank in the rocket’s upper stage. This created solid oxygen, which Musk previously said could have ignited with the carbon composite materials. However, he did not go into that level of detail in his CNBC comments.
“It’s never happened before in history, so that’s why it took us a while to sort it out,” Musk said, adding that SpaceX has been working with NASA, the U.S. Federal Aviation Administration and commercial customers on the accident investigation. “This was the toughest puzzle to solve that we’ve ever had to solve.”
[/QUOTE]
[url]http://spacenews.com/musk-predicts-mid-december-return-to-flight-for-falcon-9/[/url]
[thumb]https://pbs.twimg.com/media/CxuwqLYWEAAKy8B.jpg:large[/thumb]
Stage 1 arrived at Vandenberg. RTF shouldn't be too far away now.
[QUOTE=Morgen;51309630][url]http://spacenews.com/musk-predicts-mid-december-return-to-flight-for-falcon-9/[/url][/QUOTE]
Oxigen solidifying inside the throughput tube passing from the oxidiser tank through the fuel tank to the engine however HAS happened before, in fact its something nasa fixed and perfected way before they went to the moon... its something that never should have happened for spacex.
You can say what you want that it igniting due to carbon fiber fuel tanks, but the oxigen solidifying in the first place should never have happened... Its a mistake amateurs make, as i am told.
Heck, Thunderfoot predicted this on day one... all he missed was the carbon fire creating the fuse that lit it.
[url]https://youtu.be/BPv0VZcvm4Q?t=702[/url]
[QUOTE=Blizzerd;51402817] its something that never should have happened for spacex.[/QUOTE]
Good thing that's not what happened, then.
[editline]20th November 2016[/editline]
It had nothing to do with the kerosene tank, and everything to do with the oxygen freezing inside the skin of the carbon fiber helium COPVs.
[QUOTE=OvB;51402879]Good thing that's not what happened, then.
[editline]20th November 2016[/editline]
It had nothing to do with the kerosene tank, and everything to do with the oxygen freezing inside the skin of the carbon fiber helium COPVs.[/QUOTE]
The explosion starts at the bottom half of the second stage... so that implies inside the tube running through the fuel tank connecting the oxidation tank with the engine.
Thus yes, combined with this new info id say thats exactly what happened.
oxygen solidified in that tube (the thing i talked about that should never happen) and ripped the liner the carbon tube is coated with, it then reacted with the carbon fibres somehow and exploded.
or am i wrong somehow?
[QUOTE=Blizzerd;51404356]The explosion starts at the bottom half of the second stage... so that implies inside the tube running through the fuel tank connecting the oxidation tank with the engine.
Thus yes, combined with this new info id say thats exactly what happened.
oxygen solidified in that tube (the thing i talked about that should never happen) and ripped the liner the carbon tube is coated with, it then reacted with the carbon fibres somehow and exploded.
or am i wrong somehow?[/QUOTE]
The explosion happens at the location of the COPV's. The explosion was singled out to be caused by Helium loading and freezing Oxygen. The He tanks are located inside the Oxygen tank. The tube running through the Kerosene tank is metal, while the COPV's are uninsulated carbon fiber. Anything below the oxygen tank is not an area of concern, and has been ruled out already by SpaceX engineers. Their focus is on the COPV's.
[quote]The investigation team has made significant progress on the fault tree. Previously, we announced the investigation was focusing on a breach in the cryogenic helium system of the second stage liquid oxygen tank. The root cause of the breach has not yet been confirmed, but attention has continued to narrow to one of the three composite overwrapped pressure vessels (COPVs) inside the LOX tank. Through extensive testing in Texas, SpaceX has shown that it can re-create a COPV failure entirely through helium loading conditions. These conditions are mainly affected by the temperature and pressure of the helium being loaded.[/quote]
The cause of the explosion was due to the Helium tanks.
[editline]21st November 2016[/editline]
All obvious answers were ruled out in a short matter of time. This is where SpaceX's army of engineers would've found your thing that was a concern decades ago. They didn't, because that didn't happen.
[QUOTE=OvB;51404422]The explosion happens at the location of the COPV's. The explosion was singled out to be caused by Helium loading and freezing Oxygen. The He tanks are located inside the Oxygen tank. The tube running through the Kerosene tank is metal, while the [B]COPV's are uninsulated carbon fiber[/B]. Anything below the oxygen tank is not an area of concern, and has been ruled out already by SpaceX engineers. Their focus is on the COPV's.
The cause of the explosion was due to the Helium tanks.
[editline]21st November 2016[/editline]
All obvious answers were ruled out in a short matter of time. This is where SpaceX's army of engineers would've found your thing that was a concern decades ago. They didn't, because that didn't happen.[/QUOTE]
Im at work atm but id seriously doubt they would use unlined carbon fiber... the simplest deformation or vibration would cause it to spring microleaks all over.
And you know... its on a rocket.
[QUOTE=Blizzerd;51404756]Im at work atm but id seriously doubt they would use unlined carbon fiber... the simplest deformation or vibration would cause it to spring microleaks all over.
And you know... its on a rocket.[/QUOTE]
They are wrapped. I think he meant they aren't insulated from the LOX. In the falcon 9 the COPVs run at 5500 psi and they are submerged in LOX to help densify the helium even more. Now the issue here is that the LOX is exposed directly to the outside of the COPVs and SpaceX are already loading the LOX within 5c of its freezing point. Obviously helium has a lower freezing point than oxygen. The falcon has an aggressive fueling schedule so both liquids are being loaded simultaneously.
So helium freezes the LOX around the COPV. Solid oxygen makes things set on fire almost randomly. Things go boom.
Picture of a COPV from stage 2:
[Thumb]http://www.dahorabataguassu.com.br/imagem/noticias/620/IMAG0013.JPG[/thumb]
Picture of the inside of the second stage LOX tank. Black bits around the edges are the COPVs:
[Thumb]http://spaceflight101.com/falcon-9-amos-6/wp-content/uploads/sites/104/2016/09/9420707_orig.jpg[/thumb]
Issue can probably be worked around by making sure helium isn't loaded until the LOX has loaded past a certain point.
i remember reading somewhere that NASA was concerned about space-x using LOX so close to its freezing point because it could have the potential to freeze and the procedure was so much different from how they handled it for shuttle loadings
[QUOTE=Sableye;51405390]i remember reading somewhere that NASA was concerned about space-x using LOX so close to its freezing point because it could have the potential to freeze and the procedure was so much different from how they handled it for shuttle loadings[/QUOTE]
Yes, because they feared it could cause a freeze plug in the piping i talked about previously and a rupture. resulting in catastrophic explosion.
I got my info concerning this from nasa.
[QUOTE=Sableye;51405390]i remember reading somewhere that NASA was concerned about space-x using LOX so close to its freezing point because it could have the potential to freeze and the procedure was so much different from how they handled it for shuttle loadings[/QUOTE]
They was concerned but for a completely different reason than what you stated. They was concerned for the commercial crew program. With the shuttle you would load the fuel before putting the crew on board. With the Falcon you out the crew on and then load the fuel. Launch abort system is active the whole time through the fuel loading process though and Dragon would have escaped this explosion.
[QUOTE=Morgen;51405702]With the Falcon you out the crew on and then load the fuel. Launch abort system is active the whole time through the fuel loading process though [B]and Dragon would have escaped this explosion[/B].[/QUOTE]
What do you base that on? the same reason why falcon9 shouldn’t have blown up in the first place?
[QUOTE=Blizzerd;51405717]What do you base that on? the same reason why falcon9 shouldn’t have blown up in the first place?[/QUOTE]
The demonstrated abort demo last year showed the abort capabilities.
You can overlay them if you want for a non scientific view:
[video]https://youtu.be/l9kovJ5SyjM[/video]
[media]https://twitter.com/IridiumComm/status/804301527720534016[/media]
[editline]2nd December 2016[/editline]
Full statement from Iridium:
[url]http://investor.iridium.com/releasedetail.cfm?releaseid=1001684[/url]
Get us the fuck outta here elon
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