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SpaceX Vehicles and Missions => SpaceX Missions Section => Topic started by: Chris Bergin on 01/29/2013 08:18 PM

Title: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD (1)
Post by: Chris Bergin on 01/29/2013 08:18 PM
This begins as pre-launch discussion and moves into post-Static Fire failure discussion.

NSF Threads for AMOS-6 : Discussion (https://forum.nasaspaceflight.com/index.php?topic=30981.0) / Updates (https://forum.nasaspaceflight.com/index.php?topic=40868.0) / L2 Coverage (pre-failure) (https://forum.nasaspaceflight.com/index.php?topic=40768.0) / L2 Coverage (post-failure) (https://forum.nasaspaceflight.com/index.php?topic=41066.0) / ASDS (https://forum.nasaspaceflight.com/index.php?board=66.0) / Party (https://forum.nasaspaceflight.com/index.php?topic=40089.msg1520968#msg1520968)
NSF Articles for AMOS-6 : Booster prep (1) (https://www.nasaspaceflight.com/2016/08/spacex-falcon-9-preparation-jcsat-16-amos-6/) / Booster prep (2) (https://www.nasaspaceflight.com/2016/08/by-sea-land-space-spacex-hardware/) / Falcon 9 explodes during AMOS-6 static fire test (https://www.nasaspaceflight.com/2016/09/falcon-9-explodes-amos-6-static-fire/)

September 01 2016, 0907 Local (1307 UTC) : Launch vehicle (Falcon 9-29) and payload destroyed during testing at SLC-40


I'll write it up, although I did have five seconds of thinking "Bloody hell, I wish we made money like space.com" ;D

Article:
http://www.nasaspaceflight.com/2013/01/spacex-win-contract-ahead-crs-2-mission/

Presser:

SPACECOM AND SPACEX ANNOUNCE AGREEMENT FOR AMOS-6 SATELLITE LAUNCH

Hawthorne, CA / Ramat-Gan, Israel, January 29, 2013 – Today, Space Exploration Technologies (SpaceX) and Space Communication Ltd. (Spacecom) announced an agreement to launch Spacecom’s AMOS-6 satellite on SpaceX’s Falcon 9 launch vehicle. Falcon 9 will insert the communications satellite into a geosynchronous transfer orbit (GTO), further enhancing Spacecom’s existing satellite fleet.

The AMOS-6 agreement is the latest in a series of wins for SpaceX.  The company closed out 2012 having signed 14 launch contracts—maintaining the company’s position as the world’s fastest growing launch services provider. 

“This last year has been one of great success and tremendous growth,” said Gwynne Shotwell, President of SpaceX.   “Spacecom was one of our earliest supporters—SpaceX is proud to be their partner and we look forward to launching their AMOS-6 satellite.” 

The AMOS-6 satellite, to be built by Israel Aerospace Industries (IAI), will provide communication services including direct satellite home internet for Africa, the Middle East, and Europe. AMOS-6 will replace AMOS-2, which is expected to end its service in 2016.

"We are excited to partner with SpaceX and its tremendous team. AMOS-6 will be larger and stronger than AMOS-2 and AMOS-3 combined, and signals a new age for Spacecom," commented David Pollack, President and CEO of Spacecom. "As we establish our position as a global satellite operator providing more services and capacity, AMOS-6 will be a key element of our business strategy and future."

The AMOS-6 mission is targeting a 2015 launch from Cape Canaveral, FL.



Other SpaceX resources on NASASpaceflight:
   SpaceX News Articles (Recent) (http://www.nasaspaceflight.com/tag/spacex/)
   SpaceX News Articles from 2006 (Including numerous exclusive Elon interviews) (http://forum.nasaspaceflight.com/index.php?topic=21862.0)
   SpaceX Dragon Articles (http://www.nasaspaceflight.com/tag/dragon/)
   SpaceX Missions Section (with Launch Manifest and info on past and future missions) (https://forum.nasaspaceflight.com/index.php?board=55.0)

   L2 SpaceX Section (https://forum.nasaspaceflight.com/index.php?board=60.0)
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Galactic Penguin SST on 01/29/2013 08:24 PM
Good to see the Israelis willing to continue do business with SpaceX after all the delays with the F9 that made AMOS-4 jumping ship to the Land Launch Zenit.  :)
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Lar on 01/29/2013 08:51 PM
Good to see the Israelis willing to continue do business with SpaceX after all the delays with the F9 that made AMOS-4 jumping ship to the Land Launch Zenit.  :)

Now all SpaceX has to do is up the launch rate. A lot.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: oiorionsbelt on 01/30/2013 04:14 AM
I'll write it up, although I did have five seconds of thinking "Bloody hell, I wish we made money like space.com" ;D
Not the same as making money, but I almost never go to Space.com since finding this site.  :)
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: llanitedave on 01/30/2013 04:19 AM
Yeah, it's changed my surfing habits, too.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: cmj9808 on 01/30/2013 04:36 AM
What confuses me is that Amos-6 weighs 5.5ton/12,125lbs according to SFN report, far beyond Falcon 9 GTO capability(4.85 ton/10,682lbs as described by SpX's F9 page). Or did I miss something?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: QuantumG on 01/30/2013 04:42 AM
No, I don't think you did miss anything, but SpaceX is in the process of updating their line (to v1.1) and, as far as I recall, stats have not been announced for it yet, and 2015 is another 2 years away to boot.


Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Comga on 01/30/2013 05:57 AM
Good to see the Israelis willing to continue do business with SpaceX after all the delays with the F9 that made AMOS-4 jumping ship to the Land Launch Zenit.  :)

So the SpaceCom launch added to the SpaceX manifest in November of 2011 was AMOS-4 and this is AMOS-6? 
Did SpaceX ever remove the first on from their manifest?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: joek on 01/30/2013 05:58 AM
What confuses me is that Amos-6 weighs 5.5ton/12,125lbs according to SFN report, far beyond Falcon 9 GTO capability(4.85 ton/10,682lbs as described by SpX's F9 page). Or did I miss something?
No, I don't think you did miss anything, but SpaceX is in the process of updating their line (to v1.1) and, as far as I recall, stats have not been announced for it yet, and 2015 is another 2 years away to boot.

The published NASA NLS F9 v1.1 performance data (http://elvperf.ksc.nasa.gov/elvMap/elvMap.ui.PerfGraph0?ReqType=Graph&OrbitType=C3&Contract=2&Vehicles=4) does suggest v1.1 is short of putting 5.5tons into GTO.  Maybe that's without a  "delta-v mission kit" (http://forum.nasaspaceflight.com/index.php?topic=15900.msg367231#msg367231) for which we haven't yet seen details for v1.1?


edit: Now back to KSLV-1 (looking good!).  Congrats all and thanks to the NSF crew for the coverage!
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jason1701 on 01/30/2013 06:21 AM
It's possible that the spacecraft will be providing some of the delta-v to get to GTO, in addition to circularizing.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: john smith 19 on 01/30/2013 07:56 AM
Now all SpaceX has to do is up the launch rate. A lot.
Definitely. Did they launch anything that was not ISS related in 2012?

Having a solid launch manifest is good (they've all presumably put down some cash already) but regular launches keep your launch crew sharp and once a year does not really do it.

One a month?

You have to ask what's been on the list since 2009/10. That should be about ready to go.


[edit] I see Spacex are now expecting to do 6 launches this year. This sounds like excellent news and a great chance to show they can handle both the government (NASA initially but they are looking at payloads from the DoD EELV programme as well) and the commercial sector. [edit]
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: russianhalo117 on 01/30/2013 06:04 PM
I'll write it up, although I did have five seconds of thinking "Bloody hell, I wish we made money like space.com" ;D
Not the same as making money, but I almost never go to Space.com since finding this site.  :)
Yep, same here, although I do help Anatoly Zak with his site, but he is really low on funding now so he had to make only an articles abstract publicly available and one now has to pay for the full article. May involve everything if site funding continues to decline. Hard times lay ahead for his site.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: grythumn on 01/30/2013 08:10 PM
What confuses me is that Amos-6 weighs 5.5ton/12,125lbs according to SFN report, far beyond Falcon 9 GTO capability(4.85 ton/10,682lbs as described by SpX's F9 page). Or did I miss something?
No, I don't think you did miss anything, but SpaceX is in the process of updating their line (to v1.1) and, as far as I recall, stats have not been announced for it yet, and 2015 is another 2 years away to boot.

The published NASA NLS F9 v1.1 performance data (http://elvperf.ksc.nasa.gov/elvMap/elvMap.ui.PerfGraph0?ReqType=Graph&OrbitType=C3&Contract=2&Vehicles=4) does suggest v1.1 is short of putting 5.5tons into GTO.  Maybe that's without a  "delta-v mission kit" (http://forum.nasaspaceflight.com/index.php?topic=15900.msg367231#msg367231) for which we haven't yet seen details for v1.1?


edit: Now back to KSLV-1 (looking good!).  Congrats all and thanks to the NSF crew for the coverage!

That's the high-energy orbit graph, wouldn't the elliptical graph be more appropriate for GTO? Punching in an 36km x 27.0 degree elliptical (Not sure if that's standard for GTO, but closest I can find in a couple minutes of searching), the same tool gives a payload of 5715mt. Does that leave enough margin for a kick motor?

Link (http://elvperf.ksc.nasa.gov/elvMap/elvMap.ui.PerfGraph3?ReqType=Query&OrbitType=GTO&Incl=&Option=&Selection=&Contract=2&Drop1=Apogee&Drop2=Incl&Entry1=36000.0&Entry2=27.0&Plot=Ap_Mass&Vehicles=4&Cfgid1=99&Cfgid2=94&image_type=OUTPUT_JPEG&saveAsFile=false)

-R C
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: joek on 01/30/2013 09:54 PM
That's the high-energy orbit graph, wouldn't the elliptical graph be more appropriate for GTO? Punching in an 36km x 27.0 degree elliptical (Not sure if that's standard for GTO, but closest I can find in a couple minutes of searching), the same tool gives a payload of 5715mt. Does that leave enough margin for a kick motor?
Yes, you're right (doh!); elliptical with standard GTO appogee plot...
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: cmj9808 on 01/31/2013 06:41 AM
That's the high-energy orbit graph, wouldn't the elliptical graph be more appropriate for GTO? Punching in an 36km x 27.0 degree elliptical (Not sure if that's standard for GTO, but closest I can find in a couple minutes of searching), the same tool gives a payload of 5715mt. Does that leave enough margin for a kick motor?
Yes, you're right (doh!); elliptical with standard GTO appogee plot...


Well, I think that makes a lot of sense, thanks guys.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: docmordrid on 08/25/2013 09:32 PM
http://www.exim.gov/newsandevents/releases/2013/SpaceX-Launch.cfm

Quote
Ex-Im Bank Approves $105.4 Million Loan to Finance SpaceX Launch

Washington, D.C. – Continuing its support of the space industry in America, the Export-Import Bank of the United States (Ex-Im Bank) has authorized a $105.4 million loan to Space Communication Ltd. of Ramat Gan, Israel, to finance the Space Exploration Technologies (SpaceX) launch of the Amos-6 communications satellite, the purchase of American made-solar arrays, and insurance brokered by Marsh USA (Marsh)

The transaction is Ex-Im Bank’s third in support of a SpaceX launch, and it will support approximately 600 U.S. jobs in California and elsewhere, according to bank estimates derived from Departments of Commerce and Labor data and methodology. In June of 2013, Ex-Im Bank announced that it had approved financing for the launches of two satellites manufactured by Space Systems/Loral LLC, and in November of 2012 the Bank announced that it had approved financing for the launches of two Boeing-manufactured satellites.

“Ex-Im Bank is always ready to help the American space industry boost its international sales and export its products to important markets,” said Ex-Im Bank Chairman and President Fred P. Hochberg. “Our support of American launches and exports levels the playing field for U.S. companies and keeps highly-skilled, well-paying jobs on American soil.”

Satellite financing represents Ex-Im Bank’s most prominent stand-out sector in the Bank's newly transformed portfolio. Just three years ago, satellites accounted for only $50 million in authorizations per year. This year numbers as the third consecutive year in which Ex-Im Bank's satellite sector authorizations will have topped $1 billion.

Amos-6, a geosynchronous satellite, will replace Space Communication’s Amos-2 and cover markets in Central and Eastern Europe and the Middle East. The satellite will also provide pan-European coverage and broadband services in Europe and Africa.

The launch is scheduled for 2015.

Founded in 2002 and headquartered in Hawthorne, Calif., SpaceX designs, manufactures and launches rockets and spacecraft. It is the first private company to build, launch, and dock spacecraft at the International Space Station, a mission previously accomplished only by government space entities. 
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: sublimemarsupial on 08/26/2013 04:47 PM
So does this article give us a good upper bound for the actual cost of a Falcon 9 launch? It states that the loan of $105 million is for the launch, insurance, and for "American made-solar arrays". Anyone have a good idea of the proportion of that amount that would go to the solar arrays?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: IRobot on 08/26/2013 05:08 PM
Don't forget engineering services from SpaceX...
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: sublimemarsupial on 08/26/2013 06:58 PM
Don't forget engineering services from SpaceX...

Yeah, that was what I meant, in that this price give us an upper bound for the actual launch cost including all of the payload specific engineering and processing costs? Subtract off whatever the insurance and solar array costs are and whatever is left is the price spaceX is charging them for the LV hardware plus all the engineering for their payload.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: dcporter on 08/27/2013 03:20 AM
Don't forget engineering services from SpaceX...

Yeah, that was what I meant, in that this price give us an upper bound for the actual launch cost including all of the payload specific engineering and processing costs? Subtract off whatever the insurance and solar array costs are and whatever is left is the price spaceX is charging them for the LV hardware plus all the engineering for their payload.

That's assuming that this loan funds the entire process, which I'm not sure you can assume.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: IRobot on 08/27/2013 08:15 AM
Insurance is what? 5% of the total value? (satellite + launch?)
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: joek on 08/27/2013 08:50 AM
The figure typically mentioned is 15%, but that varies significantly based on the launch vehicle and satellite pedigree, the health of the insurance industry, and what specifically is being insured.  The "what" may include, e.g.: satellite ground handling damage; launch vehicle failure; satellite failure post-separation; satellite failure during first year of operation; ...
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Galactic Penguin SST on 02/03/2015 09:38 AM
I have found some photos of AMOS-6 under construction at Israel Aerospace Industries (https://www.facebook.com/media/set/?set=a.841105292606559.1073741829.227366043980490&type=3) - these were posted last December.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Setys on 04/25/2015 02:48 PM
Launch appears pushed back to February-March 2016

http://www.globes.co.il/en/article-spacecom-to-raise-50m-1001016293 (http://www.globes.co.il/en/article-spacecom-to-raise-50m-1001016293)
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: deruch on 04/26/2015 03:54 AM
Launch appears pushed back to February-March 2016

http://www.globes.co.il/en/article-spacecom-to-raise-50m-1001016293 (http://www.globes.co.il/en/article-spacecom-to-raise-50m-1001016293)

That's weird.  I read the article, which says, "The Amos 6 satellite is meant to replace the Amos 2 satellite, due to go out of service in 2016. In late February, Spacecom announced that the launch window for Amos 6 had been deferred, and that it was expected to be in February-March 2016." 

But Spacecom's website for the AMOS-6 satellite still lists launch target as Q4/2015.  In their media/press releases page, there's no release that mentions a change (though, there isn't one that mentions the details in the Globes article either).  A google search doesn't bring up hits on any such announcement, etc.  I'm not sure where the author is getting this information.  Maybe it isn't public?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: russianhalo117 on 04/26/2015 06:27 PM
Launch appears pushed back to February-March 2016

http://www.globes.co.il/en/article-spacecom-to-raise-50m-1001016293 (http://www.globes.co.il/en/article-spacecom-to-raise-50m-1001016293)

That's weird.  I read the article, which says, "The Amos 6 satellite is meant to replace the Amos 2 satellite, due to go out of service in 2016. In late February, Spacecom announced that the launch window for Amos 6 had been deferred, and that it was expected to be in February-March 2016." 

But Spacecom's website for the AMOS-6 satellite still lists launch target as Q4/2015.  In their media/press releases page, there's no release that mentions a change (though, there isn't one that mentions the details in the Globes article either).  A google search doesn't bring up hits on any such announcement, etc.  I'm not sure where the author is getting this information.  Maybe it isn't public?
give them some time. Once assembly of the SC is complete date will be much firmer.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: cscott on 04/27/2015 07:46 PM
Depending on how you are naming your quarters, it is also possible that January/February 2016 is still "Q4 2015".
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: xm11 on 01/24/2016 07:03 AM
http://www.calcalist.co.il/markets/articles/0,7340,L-3679157,00.html

There Date: Amos 6 will be launched into space in May 2016

Space Communications announced today the launch date of the new satellite revised - out of the sky delayed by over a year. Amos 6 will replace the Amos 2 will provide, among other things broadband services in Africa, cooperation with Facebook
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Prober on 01/24/2016 05:28 PM
http://www.calcalist.co.il/markets/articles/0,7340,L-3679157,00.html

There Date: Amos 6 will be launched into space in May 2016

Space Communications announced today the launch date of the new satellite revised - out of the sky delayed by over a year. Amos 6 will replace the Amos 2 will provide, among other things broadband services in Africa, cooperation with Facebook

appears pressure is building on this launch (good find).

" Space announced in December that previous satellite in the series, Amos 5, is total loss - three weeks after contact with him was lost.

IAI has produced for the four satellites in space first in a series of Amos, Amos 5 satellite when (severed contact with him recently lost) produced "

Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Chris Bergin on 01/24/2016 05:52 PM
http://www.calcalist.co.il/markets/articles/0,7340,L-3679157,00.html

There Date: Amos 6 will be launched into space in May 2016

Space Communications announced today the launch date of the new satellite revised - out of the sky delayed by over a year. Amos 6 will replace the Amos 2 will provide, among other things broadband services in Africa, cooperation with Facebook

Good find. Title updated to reflect.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ElGuapoGuano1 on 01/24/2016 06:08 PM
Chris,  While editing the thread subject you might as well pull out the v1.1.  I'm sure this will fly on the Full Thrust variant. I believe I remember hearing the preferred nomenclature going forward is just Falcon 9 without any addendum.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: macpacheco on 01/24/2016 08:53 PM
wikipedia says AMOS-6 is an electric propulsion satellite, so its very likely going into a sub sync orbit, and then undergo slow transition to its GEO slot.
This suggests this launch will still be able to do ASDS landing attempt.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Dante80 on 01/24/2016 09:14 PM
Amos-6 is about the same weight as SES-9. SES-9 is reported to have an ASDS landing, so it might be safe to assume that this one will have too.

Regarding the mission profile (sub-synchronous or GTO-1800), we will have to see what happens with SES-9 first.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Robotbeat on 01/24/2016 11:58 PM
wikipedia says AMOS-6 is an electric propulsion satellite, so its very likely going into a sub sync orbit, and then undergo slow transition to its GEO slot.
This suggests this launch will still be able to do ASDS landing attempt.
...possibly even RTLS. And this could be something that is being negotiated right now.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: sewebster on 01/25/2016 12:57 AM
wikipedia says AMOS-6 is an electric propulsion satellite, so its very likely going into a sub sync orbit, and then undergo slow transition to its GEO slot.
This suggests this launch will still be able to do ASDS landing attempt.

Is a low thrust engine actually more appropriate for a sub synchronous orbit than a higher thrust engine?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: macpacheco on 01/25/2016 01:17 AM
wikipedia says AMOS-6 is an electric propulsion satellite, so its very likely going into a sub sync orbit, and then undergo slow transition to its GEO slot.
This suggests this launch will still be able to do ASDS landing attempt.

Is a low thrust engine actually more appropriate for a sub synchronous orbit than a higher thrust engine?

It's not about thrust, but about ISP.
Chemical propulsion satellites (aka regular) use hydrazine which sucks at ISP. You just can't drop a regular GEO bird on LEO and hope it will raise itself to GEO. If it gets there, it will be very short of station keeping fuel.

An electric satellite uses ion thrusters, which have ISP much higher even than the best chemical propulsion solution, LH2/LOX.
The low thrust also means a long time until operating station is reached. For that reason you'd still want to launch an all electric satellite as close as possible to GEO as possible.

But this makes it possible to build a massive GEO all electric bird, say 10 tons, with far more useable mission capabilities, launch it to LEO, and do the whole LEO to GEO transition while using less propellant mass than a chemical satellite would from GTO-1500m/s to GEO (actually far less).

Does this make sense ? Not rocket scientist...
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: sewebster on 01/25/2016 02:12 AM
Is a low thrust engine actually more appropriate for a sub synchronous orbit than a higher thrust engine?

It's not about thrust, but about ISP.
Chemical propulsion satellites (aka regular) use hydrazine which sucks at ISP. You just can't drop a regular GEO bird on LEO and hope it will raise itself to GEO. If it gets there, it will be very short of station keeping fuel.

An electric satellite uses ion thrusters, which have ISP much higher even than the best chemical propulsion solution, LH2/LOX.
The low thrust also means a long time until operating station is reached. For that reason you'd still want to launch an all electric satellite as close as possible to GEO as possible.

But this makes it possible to build a massive GEO all electric bird, say 10 tons, with far more useable mission capabilities, launch it to LEO, and do the whole LEO to GEO transition while using less propellant mass than a chemical satellite would from GTO-1500m/s to GEO (actually far less).

Does this make sense ? Not rocket scientist...

I see what you are saying, thanks, but I guess I would assume that a normal GTO would still also be an appropriate target for an electric propulsion satellite. "Normal" satellites still have a lot of work to do to transition from GTO to GEO, right? So natural to replace that with electric. Of course, you can take it further to sub synchronous or even LEO in the extreme in theory (as you point out).
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: deruch on 01/25/2016 06:50 AM
wikipedia says AMOS-6 is an electric propulsion satellite, so its very likely going into a sub sync orbit, and then undergo slow transition to its GEO slot.
This suggests this launch will still be able to do ASDS landing attempt.

Is a low thrust engine actually more appropriate for a sub synchronous orbit than a higher thrust engine?

It's not about thrust, but about ISP.
Chemical propulsion satellites (aka regular) use hydrazine which sucks at ISP. You just can't drop a regular GEO bird on LEO and hope it will raise itself to GEO. If it gets there, it will be very short of station keeping fuel.

An electric satellite uses ion thrusters, which have ISP much higher even than the best chemical propulsion solution, LH2/LOX.
The low thrust also means a long time until operating station is reached. For that reason you'd still want to launch an all electric satellite as close as possible to GEO as possible.

But this makes it possible to build a massive GEO all electric bird, say 10 tons, with far more useable mission capabilities, launch it to LEO, and do the whole LEO to GEO transition while using less propellant mass than a chemical satellite would from GTO-1500m/s to GEO (actually far less).

Does this make sense ? Not rocket scientist...

The big problem with this method is that it would take A Very Long TimeTM.  Sure, your all-electric bird has a great Isp.  But what its engines don't have is very much actual thrust, so it ends up taking "forever" to raise the orbit.  This is a potential problem for 2 reasons.  1. You've lost revenue generating time to orbit raising time.  Depending on a company's economic analysis, maybe this is okay.  It could theoretically be made up for by lengthening the satellite's lifetime on orbit.  2. It means that the satellite also ends up spending quite a long time getting through the Van Allen radiation belts, which is not good for the hardware on the satellite.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: sewebster on 01/25/2016 07:10 AM
The big problem with this method is that it would take A Very Long TimeTM.  Sure, your all-electric bird has a great Isp.  But what its engines don't have is very much actual thrust, so it ends up taking "forever" to raise the orbit.  This is a potential problem for 2 reasons.  1. You've lost revenue generating time to orbit raising time.  Depending on a company's economic analysis, maybe this is okay.  It could theoretically be made up for by lengthening the satellite's lifetime on orbit.  2. It means that the satellite also ends up spending quite a long time getting through the Van Allen radiation belts, which is not good for the hardware on the satellite.

I guess Eutelsat 115 West B already made the transfer using all electric propulsion and is now operational? Edit and ABS-3A?

Here's a paper with a bunch of plots of various tradeoffs for this strategy:
http://erps.spacegrant.org/uploads/images/images/iepc_articledownload_1988-2007/2007index/IEPC-2007-287.pdf
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: deruch on 01/25/2016 07:41 AM
The big problem with this method is that it would take A Very Long TimeTM.  Sure, your all-electric bird has a great Isp.  But what its engines don't have is very much actual thrust, so it ends up taking "forever" to raise the orbit.  This is a potential problem for 2 reasons.  1. You've lost revenue generating time to orbit raising time.  Depending on a company's economic analysis, maybe this is okay.  It could theoretically be made up for by lengthening the satellite's lifetime on orbit.  2. It means that the satellite also ends up spending quite a long time getting through the Van Allen radiation belts, which is not good for the hardware on the satellite.

I guess Eutelsat 115 West B already made the transfer using all electric propulsion and is now operational? Edit and ABS-3A?

Here's a paper with a bunch of plots of various tradeoffs for this strategy:
http://erps.spacegrant.org/uploads/images/images/iepc_articledownload_1988-2007/2007index/IEPC-2007-287.pdf

Great link, thanks!  Just as a note though, macpacheco was talking about going from LEO to GEO, not GTO to GEO.  Though, I should have made clear that he already mentioned my "problem #1" in his post.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: dkovacic on 01/25/2016 10:11 AM
The big problem with this method is that it would take A Very Long TimeTM.  Sure, your all-electric bird has a great Isp.  But what its engines don't have is very much actual thrust, so it ends up taking "forever" to raise the orbit.  This is a potential problem for 2 reasons.  1. You've lost revenue generating time to orbit raising time.  Depending on a company's economic analysis, maybe this is okay.  It could theoretically be made up for by lengthening the satellite's lifetime on orbit.  2. It means that the satellite also ends up spending quite a long time getting through the Van Allen radiation belts, which is not good for the hardware on the satellite.

I guess Eutelsat 115 West B already made the transfer using all electric propulsion and is now operational? Edit and ABS-3A?

Here's a paper with a bunch of plots of various tradeoffs for this strategy:
http://erps.spacegrant.org/uploads/images/images/iepc_articledownload_1988-2007/2007index/IEPC-2007-287.pdf

Great link, thanks!  Just as a note though, macpacheco was talking about going from LEO to GEO, not GTO to GEO.  Though, I should have made clear that he already mentioned my "problem #1" in his post.

This is a great link, it basically shows the tradeoffs and you can simply see that low apogee greatly enhances days spent in LEO and going through Van-Allen belts. A rough estimate would be that LEO-GEO would be at least two times longer than GTO-GEO.
There is a third reason to avoid LEO as starting point for orbit raising - occultation effect. In LEO, satellite spends almost 50% in the Earths shadow, lasting 45 minutes. This leads to frequent temperature cycles. GEO comsats do carry batteries to continue operating during occultation periods, but these are not needed frequently roughly 1h per day during 60 days per year, totaling around 900 charge-discharge cycles for the lifetime of the satellite. Compare it to 200-day orbit raising from LEO with 8 cycles per day leading to 1600 cycles.

So I think pure LEO-to-GEO using electric propulsion is not really viable right now, despite 3x lower launch cost per kg. Various trade offs could be made for all-electric satellites launched to elliptical orbits. For example, 200x5000km orbit requires roughly 1km/s dV from LEO, perigee could be raised above 1200km in less than 10 days, reducing collision hazards and avoiding or reducing propulsion through Earths shadow. Unfortunately, as Figure 2 in the quoted document shows, there is no trick to avoid excessive passing through inner Van-Allen radiation belt - cumulative time will be at least 10 times longer than for GTO starting point.

Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: FutureSpaceTourist on 06/23/2016 10:02 AM
Quote
Peter B. de Selding ‏@pbdes 6m6 minutes ago

Spacecom of Israel: We are planning for an Aug. 22 launch, on SpaceX Falcon 9, of our Amos-6 Ku-/Ka-band telecom sat for 4 deg W.

https://twitter.com/pbdes/status/745918143797862401 (https://twitter.com/pbdes/status/745918143797862401)
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Chris Bergin on 06/23/2016 01:00 PM
Date updated in the thread title.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Kabloona on 06/23/2016 02:15 PM

FCC has posted the latest transmitter permit application here:

https://apps.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=current&application_seq=72213&RequestTimeout=1000

Drone ship coordinates are:

28 6 11 N
74 34 0 W

This is about 45 miles west of the JCSAT-14 coordinates, ie closer to the Cape. This is quite a change, since the SES-9, JCSAT-14, Thaicom-8, and Eutelsat/ABS ASDS positions were all within 11 miles or so of each other.

The AMOS-6 launch date has just been announced as August 22, so this permit may be for AMOS-6, which is listed as 5500 kg. That's 700 kg more than JCSAT-14, which could explain the big difference in ASDS positions.

Also, 5500 kg is probably the upper limit for stage 1 recovery on GTO missions. The SpaceX F9 "capabilities" web page gives an F9 price of $62M for payloads up to 5500 kg to GTO. And LouScheffer's calculations have deduced an upper limit in this ballpark as well.

So AMOS-6 may turn out to be another "limiting case" stage 1 recovery experiment for SpaceX.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: gongora on 06/23/2016 02:38 PM

FCC has posted the latest transmitter permit application here:

https://apps.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=current&application_seq=72213&RequestTimeout=1000

Drone ship coordinates are:

28 6 11 N
74 34 0 W

This is about 45 miles west of the JCSAT-14 coordinates, ie closer to the Cape. This is quite a change, since the SES-9, JCSAT-14, Thaicom-8, and Eutelsat/ABS ASDS positions were all within 11 miles or so of each other.

The AMOS-6 launch date has just been announced as August 22, so this permit may be for AMOS-6, which is listed as 5500 kg. That's 700 kg more than JCSAT-14, which could explain the big difference in ASDS positions.

Also, 5500 kg is probably the upper limit for stage 1 recovery on GTO missions. The SpaceX F9 "capabilities" web page gives an F9 price of $62M for payloads up to 5500 kg to GTO. And LouScheffer's calculations have deduced an upper limit in this ballpark as well.

So AMOS-6 may turn out to be another "limiting case" stage 1 recovery experiment for SpaceX.

So we really don't have any idea yet which launch this is for?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Kabloona on 06/23/2016 02:54 PM
Quote
So we really don't have any idea yet which launch this is for?

The applications usually don't say which commercial customer the launch is for, so it's a bit of a guessing game. But based on the dates given in the permit, it's probably the next GTO launch, which is apparently either JCSAT-16 or AMOS-6, so we can narrow it down to those two possibilities.

Beyond that, roll your own dice. I'm guessing the 5500 kg AMOS-6 explains the significant difference in ASDS positions, but it's admittedly only a guess.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: zubenelgenubi on 07/18/2016 03:58 PM
BUMP: AMOS 6 payload and Falcon 9 hardware

I'm guessing that since no one has reported any deliveries to the Cape, none of the hardware has arrived yet?

Any news of cargo aircraft inbound from Israel landing at the Skid Strip or the SLF?

We're a few days over 1 month from the launch date.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: FutureSpaceTourist on 07/27/2016 09:07 AM
Quote
Peter B. de Selding ‏@pbdes 20m20 minutes ago

New target date for SpaceX launch of Spacecom's Amos-6 geo telecom satellite is 3-4 Sept (was 22 Aug.)

https://twitter.com/pbdes/status/758222044911771648 (https://twitter.com/pbdes/status/758222044911771648)
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Ilikeboosterrockets on 07/31/2016 11:50 PM
Stage 1 possibly spotted headed towards McGregor by reddit user groundedengineer.

https://www.reddit.com/r/spacex/comments/4vfesm/saw_what_looked_like_a_black_shrink_wrapped/
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: The Roadie on 08/02/2016 06:13 PM
JCSAT 14 returned stage (fuselage 024) removed from McGregor test stand this morning after three full duration tests. Presumably to allow 029 to be erected for AMOS-6 testing.

Reported in the Facebook group by member Keith Wallace.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Chris Bergin on 08/05/2016 11:31 PM
Update thread now live:

https://forum.nasaspaceflight.com/index.php?topic=40868.0

--

As we have this news:
https://www.nasaspaceflight.com/2016/08/spacex-falcon-9-preparation-jcsat-16-amos-6/
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Tuts36 on 08/16/2016 04:09 PM
Any word on where the first stage is at this time?  Could the ongoing flooding & highway closures in LA (including sections of I-10 & I-12) cause a significant delay?

EDIT: Ugh, sorry. Please move to discussion thread if needs be :/
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Ben the Space Brit on 08/17/2016 08:46 AM
According to Reddit (https://www.reddit.com/r/spacex/comments/4pv7jl/amos6_launch_campaign_thread/), the core is now en-route to SLC-40 after completing its full-duration test burn at McGreggor.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: linxiaoyi on 08/17/2016 09:34 AM
According to Reddit (https://www.reddit.com/r/spacex/comments/4pv7jl/amos6_launch_campaign_thread/), the core is now en-route to SLC-40 after completing its full-duration test burn at McGreggor.

That's just a speculation
Quote
Hopefully the stage is on its way to the Cape after the (reported) successful full engine burn at McGregor. If the stage arrives this weekend that would be 3 weeks away from a Sept. 3/4 launch date. ~3 weeks is the recent cadence between stage arrival at the Cape and launch.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: cuddihy on 08/17/2016 10:11 AM
Yes, doutbful at this moment (8/17) -- I-10 and I-12 are both still experiencing total closures east of Baton Rouge due to the historic flooding: http://m.roadnow.com/i10/traffic_state.php?i=4&from=f and there's a lot of road work in progress, who knows if there's any lane closures. I'd think SpaceX would wait a couple more days.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: joncz on 08/17/2016 01:16 PM
Hopefully then SpaceX will decide to reroute up to I-20 through Atlanta. :D
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Herb Schaltegger on 08/17/2016 01:18 PM
According to Reddit (https://www.reddit.com/r/spacex/comments/4pv7jl/amos6_launch_campaign_thread/), the core is now en-route to SLC-40 after completing its full-duration test burn at McGreggor.

That's just a speculation

There's L2 information about this, by the way.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ZachS09 on 08/17/2016 03:16 PM
Let me guess this: the MECO-1 time for this mission will be around 156 seconds after launch...

I'm just making an assumption, by the way.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: gongora on 08/17/2016 04:50 PM
Drone Ship Coordinates:
North  28  8  52    West  73  49  48    Autonomous Drone Ship
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Kabloona on 08/17/2016 10:53 PM

FCC has posted the latest transmitter permit application here:

https://apps.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=current&application_seq=72213&RequestTimeout=1000

Drone ship coordinates are:

28 6 11 N
74 34 0 W

This is about 45 miles west of the JCSAT-14 coordinates, ie closer to the Cape. This is quite a change, since the SES-9, JCSAT-14, Thaicom-8, and Eutelsat/ABS ASDS positions were all within 11 miles or so of each other.

The AMOS-6 launch date has just been announced as August 22, so this permit may be for AMOS-6, which is listed as 5500 kg. That's 700 kg more than JCSAT-14, which could explain the big difference in ASDS positions.

Also, 5500 kg is probably the upper limit for stage 1 recovery on GTO missions. The SpaceX F9 "capabilities" web page gives an F9 price of $62M for payloads up to 5500 kg to GTO. And LouScheffer's calculations have deduced an upper limit in this ballpark as well.

So AMOS-6 may turn out to be another "limiting case" stage 1 recovery experiment for SpaceX.

So we really don't have any idea yet which launch this is for?

In hindsight, that must have been for JCSAT-16. That position being 45 miles west of the JCSAT-14 position might explain why JCSAT-16 came back in better condition and why they had enough propellant to do a single engine landing burn.

Now back to AMOS-6...
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: gongora on 08/17/2016 11:53 PM
In hindsight, that must have been for JCSAT-16. That position being 45 miles west of the JCSAT-14 position might explain why JCSAT-16 came back in better condition and why they had enough propellant to do a single engine landing burn.

Now back to AMOS-6...

The satellites for the next several GTO missions are all expected to be heavier (5300-5500kg) than the JCSAT missions.  It will be interesting to see how they do.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: cuddihy on 08/18/2016 02:39 AM
As of 2330 GMT, I-12 and I-10 are both open, btw. Amazing work by Louisiana department of transportation.

Stage route is clear.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Toastmastern on 08/20/2016 10:44 PM
Is the stage still in Texas? I've yet to see any  one spotting the core on the road to Florida.

The latest launches have had the 1st stage at CC 11 days before launch and we are closing in on that date for AMOS-6 now.

Toastmastern
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Herb Schaltegger on 08/20/2016 11:40 PM
Is the stage still in Texas? I've yet to see any  one spotting the core on the road to Florida.

The latest launches have had the 1st stage at CC 11 days before launch and we are closing in on that date for AMOS-6 now.

Toastmastern

Read back a coupe days.

http://forum.nasaspaceflight.com/index.php?topic=30981.msg1570077#msg1570077
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Toastmastern on 08/21/2016 09:11 AM
Is the stage still in Texas? I've yet to see any  one spotting the core on the road to Florida.

The latest launches have had the 1st stage at CC 11 days before launch and we are closing in on that date for AMOS-6 now.

Toastmastern

Read back a coupe days.

http://forum.nasaspaceflight.com/index.php?topic=30981.msg1570077#msg1570077

Yea I know that but I want proof that the stage is on route
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: SmallKing on 08/21/2016 09:22 AM
Is the stage still in Texas? I've yet to see any  one spotting the core on the road to Florida.

The latest launches have had the 1st stage at CC 11 days before launch and we are closing in on that date for AMOS-6 now.

Toastmastern

Read back a coupe days.

http://forum.nasaspaceflight.com/index.php?topic=30981.msg1570077#msg1570077

Yea I know that but I want proof that the stage is on route
Now, I'm pretty sure
via FB group
Quote
Jim West
My son took a video of a rocket leaving McGregor. He put on fb but I can't figure how to move it to this group.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Herb Schaltegger on 08/21/2016 12:59 PM
Is the stage still in Texas? I've yet to see any  one spotting the core on the road to Florida.

The latest launches have had the 1st stage at CC 11 days before launch and we are closing in on that date for AMOS-6 now.

Toastmastern

Read back a coupe days.

http://forum.nasaspaceflight.com/index.php?topic=30981.msg1570077#msg1570077

Yea I know that but I want proof that the stage is on route


If you'd have read the L2 info, the proof doesn't get more solid than that.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Toastmastern on 08/21/2016 01:26 PM
Is the stage still in Texas? I've yet to see any  one spotting the core on the road to Florida.

The latest launches have had the 1st stage at CC 11 days before launch and we are closing in on that date for AMOS-6 now.

Toastmastern

Read back a coupe days.

http://forum.nasaspaceflight.com/index.php?topic=30981.msg1570077#msg1570077

Yea I know that but I want proof that the stage is on route


If you'd have read the L2 info, the proof doesn't get more solid than that.

I didn't ser an image of the stage on route did you?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: DatUser14 on 08/21/2016 01:44 PM
Video posted to the Facebook group showing a stage leaving macgregor yesterday. Probably 029.

Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Herb Schaltegger on 08/21/2016 02:01 PM
Is the stage still in Texas? I've yet to see any  one spotting the core on the road to Florida.

The latest launches have had the 1st stage at CC 11 days before launch and we are closing in on that date for AMOS-6 now.

Toastmastern

Read back a coupe days.

http://forum.nasaspaceflight.com/index.php?topic=30981.msg1570077#msg1570077

Yea I know that but I want proof that the stage is on route


If you'd have read the L2 info, the proof doesn't get more solid than that.

I didn't ser an image of the stage on route did you?

If you'd have read the L2 info AND SEEN WHO POSTED IT, you wouldn't need a photo.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Lar on 08/21/2016 03:31 PM
If you'd have read the L2 info AND SEEN WHO POSTED IT, you wouldn't need a photo.

This back and forth isn't much fun... Be excellent to each other... and also do your homework. And when you urge others to do homework, giving links is helpful. It's OK to link to L2 content from here. Those not in L2 just can't follow the link usefully.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Steven Pietrobon on 08/22/2016 06:48 AM
Apparently Amos booster en route to cape.
https://www.facebook.com/jerry.m.west/videos/10208691238137123/ (https://www.facebook.com/jerry.m.west/videos/10208691238137123/)

The vehicle seemed to be a bit slow turning the corner. Maybe that's one reason SpaceX can't make the booster any longer!
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: QuantumG on 08/23/2016 12:13 AM
I'm really happy for you Falcon, and I'm gunna let you finish, but Endeavour had the best trip through LA.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: NX-0 on 08/24/2016 02:07 PM
No pressure, but...
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Robotbeat on 08/25/2016 08:41 PM
...but if successful, maybe Spacecom's new Chinese owners would prefer a domestic launch vehicle?...
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: rpapo on 08/25/2016 09:40 PM
...but if successful, maybe Spacecom's new Chinese owners would prefer a domestic launch vehicle?...
But if the public statements of the Chinese are to be believed, SpaceX is cheaper than anything they have.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Zed_Noir on 08/26/2016 12:20 AM
...but if successful, maybe Spacecom's new Chinese owners would prefer a domestic launch vehicle?...
But if the public statements of the Chinese are to be believed, SpaceX is cheaper than anything they have.
Well there is also the ITAR issue with US or Euro manufactured Comsats being launch from China.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: AncientU on 08/26/2016 01:49 AM
...but if successful, maybe Spacecom's new Chinese owners would prefer a domestic launch vehicle?...
But if the public statements of the Chinese are to be believed, SpaceX is cheaper than anything they have.
Well there is also the ITAR issue with US or Euro manufactured Comsats being launch from China.

If the Chinese own the factory, what technology will remain to protect?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: IntoTheVoid on 08/26/2016 02:23 AM
...but if successful, maybe Spacecom's new Chinese owners would prefer a domestic launch vehicle?...
But if the public statements of the Chinese are to be believed, SpaceX is cheaper than anything they have.
Well there is also the ITAR issue with US or Euro manufactured Comsats being launch from China.

If the Chinese own the factory, what technology will remain to protect?
From one of the articles above, it must remain Israeli run, regardless of ownership. That may be false cover, but it's something.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Zed_Noir on 08/26/2016 03:04 AM
...but if successful, maybe Spacecom's new Chinese owners would prefer a domestic launch vehicle?...
But if the public statements of the Chinese are to be believed, SpaceX is cheaper than anything they have.
Well there is also the ITAR issue with US or Euro manufactured Comsats being launch from China.

If the Chinese own the factory, what technology will remain to protect?

Doubtful that the Chinese will be allow to buy GEO comsat manufacturers like Airbus, Boeing, Lockheed-Martin, Orbital-ATK, SSL or Thales Alenia. The AMOS-6 transponders is from SSL IIRC.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Barmaglot on 08/26/2016 03:33 AM
If the Chinese own the factory, what technology will remain to protect?

SpaceCom is not the factory, just the operator. Amos-6 is built in Israel Aircraft Industries, which, to the best of my knowledge, is not for sale.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: gongora on 08/26/2016 05:00 AM
I'm a little lost as to the meaning of this whole Chinese launcher conversation.  AMOS-6 is launching on SpaceX in a week, before the company that owns AMOS-6 is sold.  What payload are you talking about launching on a Chinese rocket?  If you know of one, feel free to start a mission thread for it in the appropriate section.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: deruch on 08/26/2016 07:22 AM
If the Chinese own the factory, what technology will remain to protect?

SpaceCom is not the factory, just the operator. Amos-6 is built in Israel Aircraft Industries, which, to the best of my knowledge, is not for sale.

IAI, the company that built Amos-6, is not for sale and is in fact a wholly government-owned (State of Israel) company. 
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: rsdavis9 on 08/29/2016 01:43 PM
Looks like amos-6 is just missing td9. Td9 should be well out to sea of cape canaveral.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: spacenut on 08/29/2016 02:10 PM
There is a 60% chance of rain on Sept 1st.  Do you guys think there might be a delay in launch?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: sevenperforce on 08/29/2016 04:04 PM
I thought the launch was planned for the 3rd.

Speaking of which, is rain actually a problem for launches? I thought the usual weather scrubs were for high-altitude wind. Is there any reason that rain would be a problem for a Falcon 9 FT?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Comga on 08/29/2016 04:04 PM
There is a 60% chance of rain on Sept 1st.  Do you guys think there might be a delay in launch?

Did you mean Sept 3, the NET launch date?
If it rains, there will be a delay.  Of course there "might be a delay".
Given that they don't load the rocket until T-35 minutes, it will be interesting to see how long they go before calling any delay.
The generic, online weather forecast is for a more pleasant night, with much lower probability of rain, on the 5th, but someone here will post the CCAFS weather forecast as the day gets closer.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: The_Ronin on 08/29/2016 06:22 PM
Forecasting FL weather this far in advance is akin to (and reliable as) reading tea leaves.  Wait until PAFB releases the 72 hour forecast.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ZachS09 on 08/29/2016 08:25 PM
This is one of those days where I won't be able to stay up until T0 for the launch and landing.

Because I need my sleep. I'll have to find out what happened the next morning.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: spacenut on 08/29/2016 09:03 PM
I meant the 3rd.  Not the first.  I was looking a a calendar on the first when I typed it.  Yes, early in the morning like that is least likely for thunderstorms.  What about the landing zone where the ship will be? 
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: mme on 08/30/2016 01:24 AM
I thought the launch was planned for the 3rd.

Speaking of which, is rain actually a problem for launches? I thought the usual weather scrubs were for high-altitude wind. Is there any reason that rain would be a problem for a Falcon 9 FT?
I've never seen rain itself listed in an LCC,  but LCC typically include a lot of things that come along with rain.  From Wikipedia (https://en.wikipedia.org/wiki/Launch_commit_criteria#Falcon_9):

Quote
NASA has identified the Falcon 9 vehicle can not be launched under the following conditions. Some can be overridden if additional requirements are met.

* sustained wind at the 162 feet (49 m) level of the launch pad in excess of 30 knots (56 km/h; 35 mph)
* upper-level conditions containing wind shear[quantify] that could lead to control problems for the launch vehicle.
* launch through a cloud layer greater than 4,500 feet (1,400 m) thick that extends into freezing temperatures
* launch within 19 kilometres (10 nmi) of cumulus clouds with tops that extend into freezing temperatures,
within 19 kilometres (10 nmi) of the edge of a thunderstorm that is producing lightning within 30 minutes after the last lightning is observed.
* within 19 kilometres (10 nmi) of an attached thunderstorm anvil cloud
* within 9.3 kilometres (5 nmi) of disturbed weather clouds that extend into freezing temperatures
* within 5.6 kilometres (3 nmi) of a thunderstorm debris cloud,
through cumulus clouds formed as the result of or directly attached to a smoke plume,

The following should delay launch:

* delay launch for 15 minutes if field mill instrument readings within 9.3 kilometres (5 nmi) of the launch pad exceed +/- 1,500 volts per meter, or +/- 1,000 volts per meter
* delay launch for 30 minutes after lightning is observed within 10 nautical miles (19 km; 12 mi) of the launch pad or the flight path

These are NASA criteria, but I don't SpaceX's commercial criteria are much different.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: OnWithTheShow on 08/30/2016 02:34 PM
From the update thread:

Interesting that the Air Force still classifies F9 flights as "expendable".

Do we have an idea of static fire date?  Unless they get it in today I think they will have to delay due to weather.

Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jim on 08/30/2016 02:46 PM
From the update thread:

Interesting that the Air Force still classifies F9 flights as "expendable".


When has one been reused?  And what happens with the second stage or fairing?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: abaddon on 08/30/2016 02:51 PM
When has one been reused?
That doesn't really matter, even if it gets reused even as a building ornament it can hardly be called "expendable".  Also seems a bit dated given SES-10 is confirmed as launching on one this year.
Quote
And what happens with the second stage or fairing?
Do they classify airplanes with a drop tank as "expendable"?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: the_other_Doug on 08/30/2016 02:52 PM
From the update thread:

Interesting that the Air Force still classifies F9 flights as "expendable".


When has one been reused?  And what happens with the second stage or fairing?

Exactly.  At best, an F9 is semi-reusable, since, as you say, the US and fairing are used in a completely expendable mode as of now, and this will continue for the foreseeable future.

Still, the system does feature a design allowing re-usability of a major (and expensive!) piece of the booster.  Certainly, this is not proven yet, but ought to be proven (if it can be) before this year is out.

It will be good to get past the standard line (oft-times quoted by you, Jim) that it's not a re-usable system until it's re-used... :)
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: the_other_Doug on 08/30/2016 02:54 PM
Do they classify airplanes with a drop tank as "expendable"?

Yeah -- under this approach at the nomenclature, the Shuttle was an expendable launch system.

I mean, what happened with the ET?  ;)
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: abaddon on 08/30/2016 02:55 PM
All that said, this is the AMOS thread, so apologies for my participation in the derailment, and let's get back on track :D.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Wolfram66 on 08/30/2016 04:19 PM
Anyone have a time that Elsbeth III left PC? MT.com already has her out of range of shore AIS.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: 411rocket on 08/30/2016 04:42 PM
Anyone have a time that Elsbeth III left PC? MT.com already has her out of range of shore AIS.

6:45 PM yesterday, as posted on Reddit.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Robotbeat on 08/30/2016 05:56 PM
Do they classify airplanes with a drop tank as "expendable"?

Yeah -- under this approach at the nomenclature, the Shuttle was an expendable launch system.

I mean, what happened with the ET?  ;)
But NASA didn't classify Shuttle as an expendable launch vehicle.  If you go here:
https://elvperf.ksc.nasa.gov/

...you see elv launches. As opposed to Shuttle launches. When pages like that were set up, it was assumed everything OTHER THAN SHUTTLE was expendable.

Also, "reusable" means "able to be reused." Doesn't imply they've already been reused.

Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jim on 08/30/2016 06:03 PM
That doesn't really matter, even if it gets reused even as a building ornament it can hardly be called "expendable".

No, it is still an expendable launch vehicle.  Retrieving parts for other uses doesn't change that
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: abaddon on 08/30/2016 06:08 PM
That doesn't really matter, even if it gets reused even as a building ornament it can hardly be called "expendable".

No, it is still an expendable launch vehicle.  Retrieving parts for other uses doesn't change that
I'm going to agree to disagree; I'd call it a "recoverable" launch vehicle if it is recovered but not intended for reflight as a more accurate designation than either "expendable" or "reusable".  That said, the point is really moot, as SES-10 shows.  And frankly, SpaceX clearly plans to recover and reuse AMOS-6's booster.  If they are unable to recover and reuse the booster that might make it "expended" but not "expendable", just like an airplane crashing doesn't suddenly make that kind of airplane expendable.

Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: IntoTheVoid on 08/30/2016 06:19 PM
That doesn't really matter, even if it gets reused even as a building ornament it can hardly be called "expendable".

No, it is still an expendable launch vehicle.  Retrieving parts for other uses doesn't change that

It's not expendable unless SpaceX is willing to throw it away, and since they are clearly making an effort to recover the booster, it is not expendable, regardless of whether they are successful or not, and regardless of what they do with it afterward.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jim on 08/30/2016 06:44 PM
Recovery without reuse means it is expended.  It just happens to fly a little more than others after staging.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Chris Bergin on 08/30/2016 06:44 PM
Let's focus this thread on the mission in question.................from this point onwards.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: spacenut on 08/30/2016 07:28 PM
I live about 150 miles from the Gulf coast.  I'm still wondering about this tropical storm in the southern Gulf now that is supposed to cross north Florida.  I wonder whether it will delay the Amos 6 launch date. 
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: rsdavis9 on 08/30/2016 07:36 PM
http://www.nhc.noaa.gov/refresh/graphics_at4+shtml/152206.shtml?gm_track#contents

at 7am cdt 9/3 it is 100's of miles off cape hatteras.
at 7am cdt 9/1 it is 100 miles west of tampa.
Might interfere with the static test fire.
I think it is very fast moving so it will be bad (10 in rain, 50knot winds) but short.

Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: rsdavis9 on 08/30/2016 07:38 PM
Of course that says nothing about how bad it will be for the barge. A one day delay should make a big difference in wave height.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Flying Beaver on 08/30/2016 07:49 PM
Waves predicted by Windyty for Saturday morning, 1.6M (5.2ft for you Americans and Brits ;)), and wind at 17 knots from 230.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: high road on 08/31/2016 12:41 PM
Did anyone notice that this launch will make the US tie with Russia in number of launches this year? And surpass them later this month with non-SpaceX launches? I have no idea if there was ever a time that Russia did not dwarf all other nations in number of launches, but it's at least a decade ago, and probably before the STS. Pretty historic eh?

Whether this is related more to the US' increasing number of launches (with SpaceX responsible for most of the increase) or Russia's continuing decline, is still debatable. Don't count your chickens before they hatch fly.

If everybody knows and this horse has been beaten to death already, please tell me where. Way too many threads on here to keep track.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: bdub217 on 08/31/2016 02:06 PM
Please direct me elsewhere if this question has already been addressed.
What goes into a GTO launch window?  This launch is happening in the absolute dead of night.  For ISS rendezvous missions - I get that launch windows are completely dictated by the orbital period of the stations.  For GTO launches, what constrains the launch window?  If there are no orbital physics restraints, what else would push a launch to the earliest of the early morning hours?  Would there be a preference on not wanting to load superchilled liquids in the heat of a florida summer day?  Less likelihood of stray pleasureboats scrubbing a launch?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Ben the Space Brit on 08/31/2016 02:13 PM
You want the satellite to be in sunlight for as long as possible after it detaches from the booster and the solar arrays are deployed. This maximises the battery recharge time after launch. So, ideally, you want S/C separation to be around orbital dawn. You then just calculate backwards from there using launch vehicle performance data to set your launch window.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: spacenut on 08/31/2016 02:38 PM
The storm I was referring to is in the Gulf of Mexico and is supposed to go across North Florida this weekend, bringing lots of rain and thunderstorms.  It may be moving further north.  Not in the Atlantic.  It is supposed to cross Florida west to east. 
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: John Alan on 08/31/2016 02:43 PM
Please direct me elsewhere if this question has already been addressed.
What goes into a GTO launch window?  This launch is happening in the absolute dead of night.  For ISS rendezvous missions - I get that launch windows are completely dictated by the orbital period of the stations.  For GTO launches, what constrains the launch window?  If there are no orbital physics restraints, what else would push a launch to the earliest of the early morning hours?  Would there be a preference on not wanting to load superchilled liquids in the heat of a florida summer day?  Less likelihood of stray pleasureboats scrubbing a launch?

All the above plus what Ben said...
The best reason I can figure is weather... my opinion...  ;)
Florida is known for it's afternoon pop up thunderstorm action... which all dies down by the wee hours of the morning...
Statistically... they are launching at the best time of the day... to avoid a weather related hold or scrub... 
Bonus is the loading of super cold prop in the dark and the pleasure boat crowd sleeping off the evening beer stash...
Not to mention what Ben said... puts the payload in the bright sun just as it needs it to set up shop in orbit.
I would expect SpaceX to continue this 'wee hour of the morning' practice from here on out... if they can.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: CyndyC on 08/31/2016 05:14 PM
I would expect SpaceX to continue this 'wee hour of the morning' practice from here on out... if they can.

Most satellites use a combination of propellant and solar to get to their final destinations. The wee hour for this one is because the satellite is all electric, which incidentally is the weaker form of propulsion.

I can't see that any space company would prefer launches in the middle of the night, regardless of the fringe benefits. It must be a logistical nightmare to make sure all your crew is rested up to perform at their best at 3AM. You'd have to put everyone on a jet lag schedule days in advance.

However, all electric satellites can be seen as preferable for their significantly lower mass absent the mass of propellant. A more comfortable goal would likely be how to get them charged on the ground, not how to get them launched at 3AM.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: baldusi on 08/31/2016 06:06 PM
I would expect SpaceX to continue this 'wee hour of the morning' practice from here on out... if they can.

Most satellites use a combination of propellant and solar to get to their final destinations. The wee hour for this one is because the satellite is all electric, which incidentally is the weaker form of propulsion.

I can't see that any space company would prefer launches in the middle of the night, regardless of the fringe benefits. It must be a logistical nightmare to make sure all your crew is rested up to perform at their best at 3AM. You'd have to put everyone on a jet lag schedule days in advance.

However, all electric satellites can be seen as preferable for their significantly lower mass absent the mass of propellant. A more comfortable goal would likely be how to get them charged on the ground, not how to get them launched at 3AM.
AMOS-6 uses electric for station keeping only. GTO transfer will be chemical.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jim on 08/31/2016 06:40 PM
Ben is right and weather has nothing to do with it nor the other stuff.  The reason is for the spacecraft lighting.  They want the spacecraft to be in full light after separation and during the climb to apogee.  This will help ensure that the spacecraft will be power positive.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: CyndyC on 08/31/2016 06:52 PM
Weather has nothing to do with it. The reason is for the spacecraft lighting.  They want the spacecraft to be in full light after separation and during the climb to apogee.  This will help ensure that the spacecraft will be power positive.

Doesn't it take weeks to get to apogee? So is it safe to assume it takes weeks to fully charge if needing electric only for stationkeeping, and that it manages to stay in the full light vector that it started in?

I said it was all electric based on the much earlier quote below, w/o having read the article myself:

wikipedia says AMOS-6 is an electric propulsion satellite, so its very likely going into a sub sync orbit, and then undergo slow transition to its GEO slot.
This suggests this launch will still be able to do ASDS landing attempt.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Hankelow8 on 08/31/2016 06:53 PM
James Dean says only 40% go for launch at 3am on Saturday
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Kabloona on 08/31/2016 06:55 PM
Weather has nothing to do with it. The reason is for the spacecraft lighting.  They want the spacecraft to be in full light after separation and during the climb to apogee.  This will help ensure that the spacecraft will be power positive.

Doesn't it take weeks to get to apogee? So is it safe to assume it takes weeks to fully charge if needing electric only for stationkeeping, and that it manages to stay in the full light vector that it started in?

I said it was all electric based on the much earlier quote below, w/o having reading the article myself:

wikipedia says AMOS-6 is an electric propulsion satellite, so its very likely going into a sub sync orbit, and then undergo slow transition to its GEO slot.
This suggests this launch will still be able to do ASDS landing attempt.

No, it gets to apogee in a matter of hours. But it's in a highly elliptical orbit with a low perigee. The perigee raising is what takes days, or weeks/months, depending on whether they use biprop or electric to raise perigee.

baldusi says perigee raising will be biprop, so that can be done in a matter of days.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jim on 08/31/2016 07:04 PM
I would expect SpaceX to continue this 'wee hour of the morning' practice from here on out... if they can.


Spacex has no real say in it.  It is driven by spacecraft requirements.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: JasonAW3 on 08/31/2016 07:09 PM
James Dean says only 40% go for launch at 3am on Saturday

Ouch!

      So when is the next launch opportunity?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: CyndyC on 08/31/2016 07:17 PM
I would expect SpaceX to continue this 'wee hour of the morning' practice from here on out... if they can.


Spacex has no real say in it.  It is driven by spacecraft requirements.

I still don't get why they don't just charge up on the ground, if the satellite can reach apogee & sunlight in a matter of hours.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jim on 08/31/2016 07:21 PM
I would expect SpaceX to continue this 'wee hour of the morning' practice from here on out... if they can.


Spacex has no real say in it.  It is driven by spacecraft requirements.

I still don't get why they don't just charge up on the ground, if the satellite can reach apogee & sunlight in a matter of hours.

The batteries are fully charged at launch.  Power positive means they are receiving more power from the solar arrays than they using.  Battery power is only for launch prior to separation and eclipses (which are no greater than 90 minutes) while on station.  Batteries use is avoided when possible.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: virnin on 08/31/2016 07:25 PM
I would expect SpaceX to continue this 'wee hour of the morning' practice from here on out... if they can.


Spacex has no real say in it.  It is driven by spacecraft requirements.

I still don't get why they don't just charge up on the ground, if the satellite can reach apogee & sunlight in a matter of hours.

They DO charge on the ground but everything runs from the batteries from launch until solar arrays are deployed and in sunlight.  The idea is to minimize the time spent on battery power so they have maximum time to recover from some off-nominal situation.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: CyndyC on 08/31/2016 07:50 PM
Thank you for all the answers, which I hope benefitted more than just me since I probably went over my personal daily allotment for questions. I'm probably stressed over the launch time because I've lived all night shifts myself in the past, and haven't really been the same since, although in my case it was to deliver a morning newspaper for a solid year for the business experience, and later to respond to the all too typical middle of the night house & apartment fires as a Red Cross volunteer for 10 years. That's all not to mention should we stay up to watch this launch or not?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: SLC on 08/31/2016 11:28 PM
Did anyone notice that this launch will make the US tie with Russia in number of launches this year? And surpass them later this month with non-SpaceX launches? I have no idea if there was ever a time that Russia did not dwarf all other nations in number of launches, but it's at least a decade ago, and probably before the STS. Pretty historic eh?
...
Historic indeed.  And quite sudden.  For every year of the last decade, Russian launches have roughly equalled US and Chinese added together.  Even as recently as 8th June this was still true; after the Proton launch that day the totals for this year were Russia 14, USA 8, China 6  (I'm getting my data from Anatoly Zak's website at
http://www.russianspaceweb.com/2016.html ).

But after AMOS-6 the totals will be 16, 16, 12 or 13 (depending on Gaofen-10); and Russia will never be ahead again, this year or any other.  Truly the end of an era.

(And apologies from me too if this has been done to death on some other thread I haven't seen ...)
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ZachS09 on 09/01/2016 02:06 AM
James Dean says only 40% go for launch at 3am on Saturday

Ouch!

      So when is the next launch opportunity?

September 4 is the delay date. There's a 60% chance of weather permitting on that day.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Robotbeat on 09/01/2016 02:53 AM
James Dean says only 40% go for launch at 3am on Saturday

Ouch!

      So when is the next launch opportunity?

September 4 is the delay date. There's a 60% chance of weather permitting on that day.
I wish they gave these odds in conditional format, as in:
What are the odd of weather permitting on the 4th /provided/ that the launch is delayed due to weather on the 3rd?

(this value is NOT the same as 60% since the two days have weather that is correlated in some way)
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: gadgetmind on 09/01/2016 10:50 AM
Do we have a guess as to how long the main engine burn will be?

JCSAT-16 cut off at 2:30, so 3s earlier that usual, which let it do a single engine landing. AMOS-6 is a heavy bird at 5.5 tonnes, so they won't be able to do that again. I guess this one is going to come in as hot as JCSAT-14 (4.7mt) or even SES-9 (5.27mt)?

Sounds like it's going to be a lively landing between lack of fuel, high velocity, wind speed and wave height!
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ZachS09 on 09/01/2016 12:59 PM
gadgetmind, it's most likely that AMOS 6's first stage's trajectory will be similar to SES-9 due to the payloads' somewhat equal mass.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Herb Schaltegger on 09/01/2016 01:19 PM
It blew up on the pad during hot fire

Well, damn.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: kdhilliard on 09/01/2016 01:22 PM
It blew up on the pad during hot fire

Do we know if the payload was mated?

~Kirk

Followup:  It was.  Per SpaceX statement (https://twitter.com/SpaceX/status/771357538738577408):
Quote
SpaceX can confirm that in preparation for today’s static fire, there was an anomaly on the pad resulting in the loss of the vehicle and its payload. Per standard procedure, the pad was clear and there were no injuries.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: mlow on 09/01/2016 01:22 PM
I hope no one is hurt. I hope the damage to gse isn't bad. I hope there is a clear and well understood reason for whatever happened. I hope the recovery is swift.

Man this sucks.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: southshore26 on 09/01/2016 01:24 PM
Was the payload already on the rocket or did they just lose the launch vehicle?

This sucks....  :-\
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Bynaus on 09/01/2016 01:24 PM
I hope no one is hurt. I hope the damage to gse isn't bad. I hope there is a clear and well understood reason for whatever happened. I hope the recovery is swift.

Man this sucks.

Agree on all. Oh damn.

I don't want to be too negative, but that was probably it for SpaceX flights this year. I hope I am wrong.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: philw1776 on 09/01/2016 01:29 PM
Unless the root cause is quickly ascribed to a static fire pad test mistake and not the vehicle, that will be it for 2016 launches.
Won't be re-using that core.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: DPX on 09/01/2016 01:29 PM
Better to happen during test on the pad than in flight with payload loss, but still very grim news indeed.

Edit: My wishful thinking re the payload  :-[ No silver lining to this one.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: hans_ober on 09/01/2016 01:31 PM
Was the payload on top? There have been missions with the fairing & payload on top.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Bynaus on 09/01/2016 01:31 PM
Video feed from launch pad here: http://science.ksc.nasa.gov/shuttle/countdown/video/

EDIT: Launch towers intact. Black smoke. Blackened TE in the centre?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: wannamoonbase on 09/01/2016 01:31 PM
Better to happen during test on the pad than in flight with payload loss, but still very grim news indeed.

Do we know if the payload was attached?   48 hrs to launch isn't much time. 
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: jcm on 09/01/2016 01:32 PM
Do we know for sure this was the planned static test? (i.e. we have info it was planned for this morning?)
Obviously seems likely but not automatically the case
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jet Black on 09/01/2016 01:35 PM
Unless the root cause is quickly ascribed to a static fire pad test mistake and not the vehicle, that will be it for 2016 launches.
Won't be re-using that core.

Won't be re-using that pad either for a while, I'd imagine.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: psloss on 09/01/2016 01:35 PM
I hope no one is hurt. I hope the damage to gse isn't bad. I hope there is a clear and well understood reason for whatever happened. I hope the recovery is swift.

Man this sucks.
Agreed, but first and foremost hope everyone is OK.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: cscott on 09/01/2016 01:37 PM
Well, I guess one bright spot is that we'll finally have an answer to all those folks who claimed that the HIF was too close to the pad?  Of course, we don't know what that answer is yet.

This sucks.  Space is hard.  Hope everyone's okay.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ugordan on 09/01/2016 01:39 PM
From a friend at KSC (so this is third-hand info), incident seemed to occur at about F minus-3 minutes, so after prop load while stage was pressurizing to flight level.

I saw a tweet that I can't track down anymore that said the lox tank blew up. Not sure how reliable but if true... again?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: cscott on 09/01/2016 01:39 PM
From a friend at KSC (so this is third-hand info), incident seemed to occur at about F minus-3 minutes, so after prop load while stage was pressurizing to flight level.

So a tank rupture, something like that?  Pre-ignition, though there is plenty of energy around if the tanks pop.

But possibly lots of low energy combustion and not detonation.  All the pieces will still be in the general area to be found and scrutinized.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: gongora on 09/01/2016 01:41 PM
This is a really bad failure for the Commercial Crew side of things.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: cscott on 09/01/2016 01:42 PM
This is a really bad failure for the Commercial Crew side of things.
Wasn't it SpaceX's position that crew should board only *after* propellant load?  And this is why...

It will also give hard data on the effectiveness of slide wire systems and shelter and such, so probably a good thing for overall crew safety, in the long run.  But agreed it certainly looks bad.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: southshore26 on 09/01/2016 01:45 PM
They're taking a firefighter out by air medivac per KSC emergency radio  :'(
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: JWag on 09/01/2016 01:45 PM
Would the second stage prop have been loaded?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jet Black on 09/01/2016 01:47 PM
This is a really bad failure for the Commercial Crew side of things.
Wasn't it SpaceX's position that crew should board only *after* propellant load?  And this is why...

It will also give hard data on the effectiveness of slide wire systems and shelter and such, so probably a good thing for overall crew safety, in the long run.  But agreed it certainly looks bad.

normally people go on after the prop. SpaceX want to put them on before, since they only have 20 minutes or so with the supercooled oxygen.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ugordan on 09/01/2016 01:47 PM
Would the second stage prop have been loaded?

Yes, it would also be finishing up LOX load at that point.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: gongora on 09/01/2016 01:49 PM
This is a really bad failure for the Commercial Crew side of things.
Wasn't it SpaceX's position that crew should board only *after* propellant load?  And this is why...

It will also give hard data on the effectiveness of slide wire systems and shelter and such, so probably a good thing for overall crew safety, in the long run.  But agreed it certainly looks bad.

I'm pretty sure SpaceX wants to board the crew before propellant load.  And not sure how much the escape system would help in a situation like this.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Bubbinski on 09/01/2016 01:49 PM
Were the engines firing or was this explosion during fuel load? Also was the explosion on the rocket or with ground equipment?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Ben the Space Brit on 09/01/2016 01:49 PM
A bad mess. The big worry now is the condition of SLC-40; fixing the pad would probably take longer than any failure investigation and mitigation. If this was a  tank rupture, then most of the force would have been initially lateral; the T/E may be DOA but the pad sockets for core prop loading/drain may be intact if a bit toasty.

Several possibilities occur to me but, for now, everything would be speculation and it would be pointless to raise them.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ugordan on 09/01/2016 01:50 PM
They're taking a firefighter out by air medivac per KSC emergency radio  :'(

Sh*t  :(
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jet Black on 09/01/2016 01:50 PM
Would the second stage prop have been loaded?

Yes, it would also be finishing up LOX load at that point.
Is it possible that it was a problem with the loading side of things rather than the rocket itself?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Galactic Penguin SST on 09/01/2016 01:52 PM
They're taking a firefighter out by air medivac per KSC emergency radio  :'(

Sh*t  :(

On the other hand:

William Harwood ‏@cbs_spacenews
F9/AMOS6: Channel 13 in Orlando quotes 45th Space Wing saying no injuries have been reported
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Galactic Penguin SST on 09/01/2016 01:53 PM
Also from Doug Ellison of UMSF fame, who was at the Cape today:

Doug Ellison
‏@doug_ellison
@NASASpaceflight I drove from CAFS to KSCVC at about 8am - looked like 1st stage only was erected.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: hans_ober on 09/01/2016 01:53 PM
Transporter Erector seems okay. Smoke billowing from the base of the pad. No rocket in sight.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Ben the Space Brit on 09/01/2016 01:54 PM
Also from Doug Ellison of UMSF fame, who was at the Cape today:

Doug Ellison
‏@doug_ellison
@NASASpaceflight I drove from CAFS to KSCVC at about 8am - looked like 1st stage only was erected.

Interesting... Has there been any talk of any of the recovered cores having a test fire today?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: gongora on 09/01/2016 01:56 PM
Also from Doug Ellison of UMSF fame, who was at the Cape today:

Doug Ellison
‏@doug_ellison
@NASASpaceflight I drove from CAFS to KSCVC at about 8am - looked like 1st stage only was erected.

Interesting... Has there been any talk of any of the recovered cores having a test fire today?

It would have been the first two stages, not just the first stage.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Ben the Space Brit on 09/01/2016 01:57 PM
Transporter Erector seems okay. Smoke billowing from the base of the pad. No rocket in sight.

There would only be duralinium confetti left of most of the vehicle; the octoweb and core engines might still be intact and on the pad though.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: MrEarl on 09/01/2016 01:57 PM
WESH is reporting two explosions.  One 20 mins after the first.  Is that true?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: intrepidpursuit on 09/01/2016 01:58 PM
Also from Doug Ellison of UMSF fame, who was at the Cape today:

Doug Ellison
‏@doug_ellison
@NASASpaceflight I drove from CAFS to KSCVC at about 8am - looked like 1st stage only was erected.

Interesting... Has there been any talk of any of the recovered cores having a test fire today?

It would have been the first two stages, not just the first stage.

Yes. The TE can't erect a first stage on its own. That would indicate though that the payload wasn't attached which would be a very good thing.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Blizzzard on 09/01/2016 02:00 PM
Perhaps a pointless thing to say at this time, and assuming the issue has come from the rocket itself - but had this been a flight-proven Falcon 9 - would this have happened?

Very slight silver lining - might actually add more weight to using recovered stages...
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Ben the Space Brit on 09/01/2016 02:02 PM
Perhaps a pointless thing to say at this time, and assuming the issue has come from the rocket itself - but had this been a flight-proven Falcon 9 - would this have happened?

That is strongly dependent on the root cause of the explosion. Any conclusions would be highly speculative at this point.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ugordan on 09/01/2016 02:02 PM
Is it possible that it was a problem with the loading side of things rather than the rocket itself?

What difference does it make? It's an integrated system, one cannot function without the other. Having this failure be down to GSE doesn't make it any better.

On the flip side, this is certainly going to be an interesting data point for pad abort risk assessments, blast overpressures and the like...
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: cscott on 09/01/2016 02:03 PM
Reports of multiple explosions might indicate that some of the pad tankage was compromised by the initial blast and let go.  Which wouldn't mean anything re the initial failure, but would additionally complicate the work of getting the pad back on line.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: rdale on 09/01/2016 02:03 PM
They're taking a firefighter out by air medivac per KSC emergency radio  :'(

They asked the helicopter to land and pick one up so he could see the fire from above.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Ben the Space Brit on 09/01/2016 02:04 PM
Latest photos show that the T/E strongback seems intact! This is bizarre; I'm thinking that it must have been a tank top cap failure that directed most of the explosive force vertically upwards to avoid any collateral damage in that way!
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: GalacticIntruder on 09/01/2016 02:04 PM
Perhaps a pointless thing to say at this time, and assuming the issue has come from the rocket itself - but had this been a flight-proven Falcon 9 - would this have happened?

Very slight silver lining - might actually add more weight to using recovered stages...

The only silver would be if there was no satellite on-board. Blowing up another rocket for another reason, is not good. No way they get to launch again until another drawn out investigation.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jet Black on 09/01/2016 02:05 PM
Is it possible that it was a problem with the loading side of things rather than the rocket itself?

What difference does it make? It's an integrated system, one cannot function without the other. Having this failure be down to GSE doesn't make it any better.

On the flip side, this is certainly going to be an interesting data point for pad abort risk assessments, blast overpressures and the like...

The difference is that if it is GSE side, there would be fewer concerns relating to the rocket once it is fuelled and up in the air. Additionally I'd expect that GSE stuff can be modified (e.g. thicker tank walls) with fewer ramifications.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: cscott on 09/01/2016 02:06 PM
Not a NASA payload==>not a NASA investigation.  The SpaceX investigation need not be drawn out (unless it needs to be because the root cause is elusive).  As pointed out above, it's likely that the pad reconstruction is going to take longer than the investigation.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jet Black on 09/01/2016 02:07 PM
Latest photos show that the T/E strongback seems intact! This is bizarre; I'm thinking that it must have been a tank top cap failure that directed most of the explosive force vertically upwards to avoid any collateral damage in that way!

upright isn't the same as intact though. It may not be usable any more.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Elvis in Space on 09/01/2016 02:08 PM
Not a NASA payload==>not a NASA investigation.  The SpaceX investigation need not be drawn out (unless it needs to be because the root cause is elusive).  As pointed out above, it's likely that the pad reconstruction is going to take longer than the investigation.

So could they move to LC-39 until the mess is cleaned up?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ugordan on 09/01/2016 02:09 PM
The difference is that if it is GSE side, there would be fewer concerns relating to the rocket once it is fuelled and up in the air.

That's not much of a consolation if you consider that the payload is up in the air on the rocket about the same length of time (30 min) as it is on the pad actively being loaded with all kinds of fluids.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: MarekCyzio on 09/01/2016 02:11 PM
Not a NASA payload==>not a NASA investigation.  The SpaceX investigation need not be drawn out (unless it needs to be because the root cause is elusive).  As pointed out above, it's likely that the pad reconstruction is going to take longer than the investigation.

So could they move to LC-39 until the mess is cleaned up?


Cleaning up the mess may be way faster than the necessary investigation and design changes.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ugordan on 09/01/2016 02:11 PM
upright isn't the same as intact though. It may not be usable any more.

Agreed. The discussion about the T/E likely shouldn't be about how "intact" it is, but perhaps how "salvageable".
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: mme on 09/01/2016 02:12 PM
For once I'm in the "there is no silver lining" camp. :(

Hopefully they learn something valuable, but LOV on the pad during a static fire?  Unbelievable.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ElGuapoGuano1 on 09/01/2016 02:12 PM
It's really hard to tell where the smoke it coming from at this point, could either be smoldering remains or some of the GSE still on fire. Just hope no one was seriously injured. Everything is speculation at this point, but it appears SLC-40 will be out of commission for a while. I really hate "bad days".
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: yokem55 on 09/01/2016 02:14 PM
Not a NASA payload==>not a NASA investigation.  The SpaceX investigation need not be drawn out (unless it needs to be because the root cause is elusive).  As pointed out above, it's likely that the pad reconstruction is going to take longer than the investigation.

So could they move to LC-39 until the mess is cleaned up?


Cleaning up the mess may be way faster than the necessary investigation and design changes.
Unless it was a very clear case of human error. There is no idiot proofing of rockets.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jet Black on 09/01/2016 02:14 PM
The difference is that if it is GSE side, there would be fewer concerns relating to the rocket once it is fuelled and up in the air.

That's not much of a consolation if you consider that the payload is up in the air on the rocket about the same length of time (30 min) as it is on the pad actively being loaded with all kinds of fluids.

It's not so much the risk of loss that I am referring to - lets say it is a problem with the lox tanks on the rocket and they need making thicker or the welding needs changing or the piping needs changing, that would have impacts on the performance of the rocket, their manufacturing process and so on. On the other hand, if it is GSE, then only that part needs replacing (say it is a single point fault) and there are no impacts on the rocket performance or manufacturing process.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: pippin on 09/01/2016 02:14 PM
upright isn't the same as intact though. It may not be usable any more.

Agreed. The discussion about the T/E likely shouldn't be about how "intact" it is, but perhaps how "salvageable".

Or "how easily removable".
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: woods170 on 09/01/2016 02:16 PM
Not a NASA payload==>not a NASA investigation.  The SpaceX investigation need not be drawn out (unless it needs to be because the root cause is elusive).  As pointed out above, it's likely that the pad reconstruction is going to take longer than the investigation.

So could they move to LC-39 until the mess is cleaned up?


Cleaning up the mess may be way faster than the necessary investigation and design changes.
The investigation will have to point out if there is in fact a need to change the design. Right now the cause is (publically) unknown. The cause could be something as simple as FUD in the tanks or a production fault. Those generally don't require design changes but changes to procedures.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: pippin on 09/01/2016 02:19 PM
Not a NASA payload==>not a NASA investigation.  The SpaceX investigation need not be drawn out (unless it needs to be because the root cause is elusive).  As pointed out above, it's likely that the pad reconstruction is going to take longer than the investigation.
Baseless speculation.
Nobody knows what happened, yet, so there's no way to tell how long it's going to take.
Other customers than NASA are also not going to put their expensive payloads on the vehicle unless they know what happened and that it got fixed.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: jgoldader on 09/01/2016 02:19 PM
Prayers that nobody was hurt.  Relief it wasn't during flight, that the payload seems to have been spared.  The root cause will be identified and fixed, and Falcons will fly again.  Courage to SpaceX folks during this difficult time.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: rockets4life97 on 09/01/2016 02:21 PM
There is conflicting reports about the payload being on top or not. I think we'll have to wait for an official source from SpaceX or the Amos-6 owner (SpaceCom Israel I think).

Edit: Now official reports from SpaceX that Amos-6 was lost in the incident.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jim on 09/01/2016 02:21 PM
Aside from hardware loss and pad damage, there is loss of confidence and maybe insurance price increases.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jim on 09/01/2016 02:22 PM
I am hearing that the payload was on top
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ugordan on 09/01/2016 02:23 PM
I am hearing that the payload was on top

This close to launch, I would expect the same. Extra bummer.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Dante80 on 09/01/2016 02:24 PM
Hope everyone is alright. This is terrible.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Giovanni DS on 09/01/2016 02:24 PM
How much the fairing could protect the payload? The missile looks still standing in that photo.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Wolfram66 on 09/01/2016 02:24 PM
Video of secondaries on Youtube
https://www.youtube.com/watch?v=Auv1K-ciEWg#action=share

here is a series of reports via http://www.foxnews.com/science/2016/09/01/explosion-rocks-spacex-launch-site-in-florida-during-test.html
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jim on 09/01/2016 02:25 PM
Payload was on top as confirmed by Spacex
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: edkyle99 on 09/01/2016 02:25 PM
I am hearing that the payload was on top
As bad as a launch failure then.  Worse than most launch failures even, since some pad repair will be needed.

The year of "no failures" comes abruptly to an end, with yesterday's apparent CZ-4C failure and now this.

 - Ed Kyle
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: rdale on 09/01/2016 02:26 PM
SpaceX confirms it was a pad issue that caused it.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: cscott on 09/01/2016 02:26 PM
No pressure, but...
Sigh.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Paul_G on 09/01/2016 02:26 PM
Wasn't the takeover of the firm who would operate AMOS-6 contingent on the successful launch of the sattelite?

Paul
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: NX-0 on 09/01/2016 02:27 PM
I guess that sale to the Chinese won't be happening anytime soon.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: meithan on 09/01/2016 02:27 PM
@SpaceflightNow on Twitter (https://twitter.com/SpaceflightNow/status/771352977315684352):

Quote
"SpaceX has confirmed the loss of both the Falcon 9 rocket and its $200 million payload in today’s explosion at the launch pad."
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Wolfram66 on 09/01/2016 02:27 PM
I am hearing that the payload was on top

Do they usually do the Static fire with the payload attached? are there different procedures for static fire WRT Dragon, GTO or LEO launches pertaing to payload onboard?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ElGuapoGuano1 on 09/01/2016 02:27 PM
Thanx for the confirmation Jim, that is a shame. I'm guessing from here on out, the payload won't be on the pad for static fires.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: jak Kennedy on 09/01/2016 02:28 PM
At least the headlines I have read all mention that it happened during a test. Although a test very close to flight! A small improvement though on previous poor reporting.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ugordan on 09/01/2016 02:28 PM
SpaceX confirms it was a pad issue that caused it.

Where? They said "an anomaly on the pad". Of course it was on the pad. Doesn't make it a pad issue, though.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ap12 on 09/01/2016 02:28 PM
KSC video feed shows live view of burning pad. http://kscwmserv1.ksc.nasa.gov/channel4
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: MostlyHarmless on 09/01/2016 02:29 PM
If the mishap occurred at T - 3:00 as was reported earlier, that is around the time that the Flight Termination System is armed.  Probably an odd coincidence, but curious, none-the-less.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Dante80 on 09/01/2016 02:29 PM
This is a really bad failure for the Commercial Crew side of things.
Wasn't it SpaceX's position that crew should board only *after* propellant load?  And this is why...

It will also give hard data on the effectiveness of slide wire systems and shelter and such, so probably a good thing for overall crew safety, in the long run.  But agreed it certainly looks bad.

The idea here is to have the Astronauts seated and the area cleared before the prop load happens. That way you make sure that the pad is clear and that any mishap will be countered by the LAS (it is designed for this contingency, aka a 0-0 launch abort).

The opposite can potentially be more dangerous since the astronauts and the support team have to walk to a loaded and pressurized rocket.

In the end though, the discussion may be informed by the way and reason this mishap happened (during prop load? during pressurization? etc etc).
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: woods170 on 09/01/2016 02:30 PM
I am hearing that the payload was on top

Do they usually do the Static fire with the payload attached? are there different procedures for static fire WRT Dragon, GTO or LEO launches pertaing to payload onboard?
One thing is almost a given now. SpaceX won't be performing static fires with the payload on top from this point forward in time.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Borklund on 09/01/2016 02:30 PM
Not good.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jet Black on 09/01/2016 02:31 PM
Wasn't the takeover of the firm who would operate AMOS-6 contingent on the successful launch of the sattelite?

Paul

That's correct.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: wxmeddler on 09/01/2016 02:31 PM
Live feed with some good close up views from the local TV station helicopter:
https://www.facebook.com/wftv/videos/vb.72447968144/10154195747018145/?type=3&theater (https://www.facebook.com/wftv/videos/vb.72447968144/10154195747018145/?type=3&theater)
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: kirghizstan on 09/01/2016 02:32 PM
So what is the contingency plan for SpaceX KSC operations?  How fast can they get 39 up and running for F9 if the damage at the pad will take a long time to fix?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: edkyle99 on 09/01/2016 02:34 PM
If the mishap occurred at T - 3:00 as was reported earlier, that is around the time that the Flight Termination System is armed.  Probably an odd coincidence, but curious, none-the-less.
Isn't that also around the time that the T/E is being retracted?

 - Ed Kyle
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Endeavour_01 on 09/01/2016 02:34 PM
Terrible thing to see.  :( Best wishes for SpaceX as they look towards solving the problem and returning to flight.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Unobscured Vision on 09/01/2016 02:35 PM
It would be fixed before 39 is ready.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Kosmos2001 on 09/01/2016 02:35 PM
Which is the point of testing the rocket engines while the P/L is on board? If there is any incident, like today's, the P/L is going to be lost anyway.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Tonioroffo on 09/01/2016 02:38 PM
Which is the point of testing the rocket engines while the P/L is on board? If there is any incident, like today's, the P/L is going to be lost anyway.

Time gains, surely?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Ben the Space Brit on 09/01/2016 02:38 PM
So the payload was lost as well?

Even if it wasn't destroyed outright, it would have suffered severe enough damage to be an insurance write-off; it would be cheaper to build a new satellite than try to fix AMOS-6.

Which is the point of testing the rocket engines while the P/L is on board? If there is any incident, like today's, the P/L is going to be lost anyway.

As I understand it, the engines are already flight condition verified after they are fired at McGreggor; it's more of a case to ensure all vehicle systems are ready for flight as an integrated unit (including IU control of all systems and software parameters correct). Any structural failure at CCAFS raises more questions about post-test analysis at McGreggor than anything else (IMO).
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ugordan on 09/01/2016 02:40 PM
If the mishap occurred at T - 3:00 as was reported earlier, that is around the time that the Flight Termination System is armed.  Probably an odd coincidence, but curious, none-the-less.
Isn't that also around the time that the T/E is being retracted?

Yes. Although the remains of this T/E don't look particularly retracted to me.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ugordan on 09/01/2016 02:41 PM
Strongback retraction begins at T-5:30.

Not for the "Full Thrust" variant.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: pippin on 09/01/2016 02:41 PM
I am hearing that the payload was on top

Do they usually do the Static fire with the payload attached? are there different procedures for static fire WRT Dragon, GTO or LEO launches pertaing to payload onboard?
One thing is almost a given now. SpaceX won't be performing static fires with the payload on top from this point forward in time.
Hm, that could definitely slow down their launch ops
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: wannamoonbase on 09/01/2016 02:41 PM
SpaceX confirms it was a pad issue that caused it.

Where? They said "an anomaly on the pad". Of course it was on the pad. Doesn't make it a pad issue, though.

Another learning opportunity and chance to improve.

It's very disappointing that there isn't enough fail safes in the GSE to avoid a loss of vehicle on the ground.  That should be the easiest part of this business.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: woods170 on 09/01/2016 02:42 PM
So the payload was lost as well?

Even if it wasn't destroyed outright, it would have suffered severe enough damage to be an insurance write-off; it would be cheaper to build a new satellite than try to fix AMOS-6.

Which is the point of testing the rocket engines while the P/L is on board? If there is any incident, like today's, the P/L is going to be lost anyway.

As I understand it, the engines are already flight condition verified after they are fired at McGreggor; it's more of a case to ensure all vehicle systems are ready for flight as an integrated unit (including IU control of all systems and software parameters correct). Any structural failure at CCAFS raises more questions about post-test analysis at McGreggor than anything else (IMO)

Emphasis mine.
Cause of this accident is unknown at this time. Let's dispense with the unneccesary speculation shall we? Thank you.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: MostlyHarmless on 09/01/2016 02:42 PM
Granted, the timelines I found apply to a launch -- not sure what variations there might be for a hot-fire test.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: RobW on 09/01/2016 02:42 PM
Is the flight termination system armed during static fires?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: IanH84 on 09/01/2016 02:44 PM
Closeup of the pad from the WFTV stream
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Elvis in Space on 09/01/2016 02:45 PM
SpaceX confirms it was a pad issue that caused it.

Where? They said "an anomaly on the pad". Of course it was on the pad. Doesn't make it a pad issue, though.

Another learning opportunity and chance to improve.

It's very disappointing that there isn't enough fail safes in the GSE to avoid a loss of vehicle on the ground.  That should be the easiest part of this business.

Yeah, well that's the problem isn't it? It's generally easy to prevent the things you know about in advance. It will be another big learning opportunity for Spacex.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jakusb on 09/01/2016 02:45 PM
Closeup of the pad from the WFTV stream
Does not seem retracted.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: WBY1984 on 09/01/2016 02:46 PM
Which is the point of testing the rocket engines while the P/L is on board? If there is any incident, like today's, the P/L is going to be lost anyway.
If the payload is integrated then they can launch sooner once a good static fire is confirmed. Unfortunately, you also run the risk of something like this happening. :(

There is going to be a cascade of consequences stemming from the events of today. Between this and the still-recent CRS-7 failure, it effectively junks an impression that SpaceX likes to put forward - that it has the expertise and reliability necessary to go to Mars. Right now it is unable to even clear its satellite backlog.

The company is still very young, and this demonstrated lack of reliability relative to other companies/organisations underscores how far it has to go before it fulfills its undoubted potential.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: SweetWater on 09/01/2016 02:47 PM
It's a pity about the payload, vehicle, and pad. Glad to hear that, so far, no one seems to have been hurt.

A question for someone more knowledgeable about insuring satellites than me: Do policies for spacecraft typically cover loss or damage incurred on the ground (for example, during transport or prepping for flight), or only during the actual launch of the vehicle? I work in auto claims, and my experience there would lead me to expect most of the liability here to be on SpaceX's side, but I'd be interested in hearing from a knowledgeable source.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: wtrix on 09/01/2016 02:48 PM
Is the flight termination system armed during static fires?

Don't know, but logically - knowing, what's the point of flight termination system, I would be almost certain that it's armed in any test where there's even remote chance that rocket gets airborne.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: IanH84 on 09/01/2016 02:51 PM
FTS is armed during the static fire at T-3:05, same as flight.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: sghill on 09/01/2016 02:55 PM
If the mishap occurred at T - 3:00 as was reported earlier, that is around the time that the Flight Termination System is armed.  Probably an odd coincidence, but curious, none-the-less.
Isn't that also around the time that the T/E is being retracted?

 - Ed Kyle

...And LOX top off termination.  I can see an ice dam build up and resultant poor hose seal or valve sealed shut being a culprit with this one.  The air is positively pregnant with moisture here right now.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: mfck on 09/01/2016 02:56 PM
September 1st. Back to School.

My heart is with SpaceX Team.
Rockets blow up, but humans keep flying.

Per aspera ad astra!
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: as58 on 09/01/2016 02:56 PM
Test fire failures leading to a loss of payload must be rare. Has something like this happened before?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Michael Baylor on 09/01/2016 02:57 PM
Ok, so I wake up this morning, go to check the news as usual, and well this was the last thing I expected to see as the headline story on CNN.

Really not good for SpaceX considering last year's incident as well. If I was a customer and saw SpaceX with two fails in about a year, and ULA with over 100 successful launches in a row... Well... Umm... Really feel sorry for SpaceX though. Launch pad is gone. Time to get Pad 39a ready ASAP I guess. Devastating.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: mn on 09/01/2016 03:02 PM
If I remember correctly I think with the orbcomm mission there was some type of 'almost' anomaly during launch prep or static fire, saw some vague mentions, but never any details (probably details in L2)

edit - add link
Found discussion here: http://forum.nasaspaceflight.com/index.php?topic=33089.360 (http://forum.nasaspaceflight.com/index.php?topic=33089.360), Was just discussion, no idea if anything was ever confirmed, (and there is mention of perhaps something similar during SES-8)
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ZachS09 on 09/01/2016 03:03 PM
When I first heard of this news, my heart just stopped for like a second or two. I am so sorry about what happened.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: MattMason on 09/01/2016 03:03 PM
Which is the point of testing the rocket engines while the P/L is on board? If there is any incident, like today's, the P/L is going to be lost anyway.
If the payload is integrated then they can launch sooner once a good static fire is confirmed. Unfortunately, you also run the risk of something like this happening. :(

There is going to be a cascade of consequences stemming from the events of today. Between this and the still-recent CRS-7 failure, it effectively junks an impression that SpaceX likes to put forward - that it has the expertise and reliability necessary to go to Mars. Right now it is unable to even clear its satellite backlog.

The company is still very young, and this demonstrated lack of reliability relative to other companies/organisations underscores how far it has to go before it fulfills its undoubted potential.

While you note fact, perhaps you can use the Wayback Machine known as the NASA and Air Force archives to count how many rockets were lost over the history of NASA and Cape Canaveral.

And we can make counts of losses from the Russians, ESA and others, too.

Is the loss ratio higher than others? Maybe. But fear, uncertainty and doubt isn't what spaceflight is about, and you know that.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Elvis in Space on 09/01/2016 03:04 PM
Ok, so I wake up this morning, go to check the news as usual, and well this was the lasting thing I expected to see as the headline story on CNN.

Really not good for SpaceX considering last year's incident as well. If I was a customer and saw SpaceX with two fails in about a year, and ULA with over 100 successful launches in a row... Well... Umm... Really feel sorry for SpaceX though. Launch pad is gone. Time to get Pad 39a ready ASAP I guess. Devastating.

It didn't stop the Russian's Proton.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: sivasu on 09/01/2016 03:05 PM
Terrible news.
At least it won't be counted as a launch failure. Or would it?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: rockets4life97 on 09/01/2016 03:06 PM
Terrible news.
At least it won't be counted as a launch failure. Or would it?

Test failure? Not sure.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: GalacticIntruder on 09/01/2016 03:06 PM
This would have a made a great pad abort test with Dragon2. Now they might have to rethink and reprogram some things for even more corner cases.

Hundreds of millions, if not more, in both real losses and deferred revenues. Higher insurance, delays on top of delays, more paperwork, more checks adding more time and money, more projects pushed back. No FH, No MCT reveal. No record launch cadence.

NOT GOOD, anyway shape or form.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: SpaceXSLS on 09/01/2016 03:08 PM
This is terrible news  :'(

Could this jeapordize the company itself? SpaceX might not have a backlog problem anymore  :(

I mean, forget Mars 2018 or the Falcon Heavy, I'd expect the FH by Winter of next year or the year after next if we are lucky, and Mars is still as distant a dream as ever... Am I being too pessimistic about this?

Absolutely terrible that this happened so close to Elon Musk's unveiling of his MCT and associated Mars infrastructure plans, it makes it look like a joke now :(

Yes, you are overreacting.  I am sure that Spacex will take a hit, but I cannot see the failure being a threat to the existence of company.  The cost advantage of Spacex is significant even with the current failure rate.

Good, I know very little about how safe SpaceX is, I'm glad to hear this won't jeapordize its existence at least.

SpaceX has imo captured the hearts and minds of a generation. It would be terrible to see them go into the night like this. :(
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: abaddon on 09/01/2016 03:08 PM
Sad to hear about this.  Unless it can be proven to be the GSE at fault that's likely the last SpaceX launch for the year, and the pressure on their commercial backlog, CRS and CC, and FH development are going to be severe.  All that said I expect they will pick themselves back up off the ground and move forward.  I'm glad that as of now nobody appears to have been injured in the incident.

My condolences and best wishes for the SpaceX team.

Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: teetlebomb on 09/01/2016 03:10 PM
Any word on the condition of the Hangar?

Being that close to the explosion, I would suspect significant damage, at least to the siding of the building, if not the structure itself. And even if Amos-6 wasn't on the rocket at the time, significant damage could have happened to it while in the hangar waiting processing.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: cscott on 09/01/2016 03:11 PM
Note that apparently China had a launch failure yesterday as well.
https://twitter.com/elakdawalla/status/771360284212465665?s=09

I hope the rule of threes isn't in effect.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: padrat on 09/01/2016 03:12 PM
If the payload is not on the rocket for static fire it isn't anywhere near the pad. It's back at the processing building waiting for static fire to occur.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: rickl on 09/01/2016 03:12 PM
Depending on the extent of damage to the pad, could they use this as an opportunity to upgrade LC-40 for Falcon Heavy?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: vandersons on 09/01/2016 03:13 PM
Absolutely gutted for everyone at SpaceX. And just as they were starting to ramp up the launch rate, anouncement of the first relaunch, the imminent release of the Mars plans. Hope they pick this one up swiftly and thoruoghly.
I guess space is still hard.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Chris Bergin on 09/01/2016 03:13 PM
This was always going to include dramatic posts, due to what's happened, but I would urge people to remember that thousands of people read your post.

I don't think you want to be know as "that guy" who posted:

"OMGZ. Rocket dead?" ;)

Let's make posts worth reading....like this one (oh!)

Mods will remove crap posts, so don't quote crap posts and respond with "crap post!". That gives the mods twice the workload.

Thanks for listening. Carry on....
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: woods170 on 09/01/2016 03:13 PM

Arianespace had multiple failures with loss of payload yet still became the worlds leading commercial launch provider. Proton had multiple failures, with loss of payload, yet continues launching commercial and government payload. Older versions of Atlas, Delta had multiple failures with loss of payload yet continued to fly for nearly 4 decades. That goes for multiple versions of Titan as well. All of these vehicles were operated by commercial entities. None of them folded because of failures.

Customers generally understand that space is hard. IMO SpaceX will suffer from this event, but it certainly will not endanger the continued existence of SpaceX as a company.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: SpaceXSLS on 09/01/2016 03:14 PM
If the payload is not on the rocket for static fire it isn't anywhere near the pad. It's back at the processing building waiting for static fire to occur.

Payload was on the pad https://twitter.com/SciGuySpace/status/771352111657385984
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: padrat on 09/01/2016 03:16 PM
If the payload is not on the rocket for static fire it isn't anywhere near the pad. It's back at the processing building waiting for static fire to occur.

Payload was on the pad https://twitter.com/SciGuySpace/status/771352111657385984

I said IF the payload wasn't on the rocket, obviously not the case here...
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: CessnaDriver on 09/01/2016 03:17 PM
Absolutely gutted for everyone at SpaceX. And just as they were starting to ramp up the launch rate, anouncement of the first relaunch, the imminent release of the Mars plans. Hope they pick this one up swiftly and thoruoghly.
I guess space is still hard.

It is. And frankly I expect failures like this and the real test is how well they recover from them.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: SpaceXSLS on 09/01/2016 03:17 PM
If the payload is not on the rocket for static fire it isn't anywhere near the pad. It's back at the processing building waiting for static fire to occur.

Payload was on the pad https://twitter.com/SciGuySpace/status/771352111657385984

I said IF the payload wasn't on the rocket, obviously not the case here...

ok sorry, I thought you hadn't heard it yet...
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: pippin on 09/01/2016 03:17 PM
C'mon SpaceX fanboys. Don't go straight from overly enthusiastic to totally fatalistic.

These things happen in Spaceflight. It's this (and not because they are stupid, wasteful morons) why NASA and all the others who've been in the business for longer are careful and have their cautious procedures.

But it won't be the end for SpaceX. They will learn from it just like everybody else did, they have a well proven vehicle, their customers have seen that and they understand this business and they know SpaceX can fix this.

Does it mean SpaceX is going to land us all on Mars in 5 years? Probably not, but that was never going to happen.

They will fix this, learn from it, become more reliable and iterate. And yes, over the time they will become more like "OldSpace" and then probably someone else comes around with bold plans and aggressive statements and then it's time to remember that only paper rockets are without failure...
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: spacetraveler on 09/01/2016 03:17 PM
This is terrible news  :'(

Could this jeapordize the company itself? SpaceX might not have a backlog problem anymore  :(

I mean, forget Mars 2018 or the Falcon Heavy, I'd expect the FH by Winter of next year or the year after next if we are lucky, and Mars is still as distant a dream as ever... Am I being too pessimistic about this?

Absolutely terrible that this happened so close to Elon Musk's unveiling of his MCT and associated Mars infrastructure plans, it makes it look like a joke now :(

No need to be overly dramatic. Certainly a major setback, but there is no indication SpaceX won't be able to recover.
Arianespace had multiple failures with loss of payload yet still became the worlds leading commercial launch provider. Proton had multiple failures, with loss of payload, yet continues launching commercial and government payload. Older versions of Atlas, Delta had multiple failures with loss of payload yet continued to fly for nearly 4 decades. That goes for multiple versions of Titan as well. All of these vehicles were operated by commercial entities. None of them folded because of failures.

Customers generally understand that space is hard. IMO SpaceX will suffer from this event, but it certainly will not endanger the continued existence of SpaceX as a company.

Very true, a lot the hype and perception of SpaceX is based on their better than average track record of success with a new launch system thus far. A couple additional failures would just put them more in line with historical averages.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Dante80 on 09/01/2016 03:18 PM
Terrible news.
At least it won't be counted as a launch failure. Or would it?

Of course it would, and should. With the payload gone, this is a total launch campaign failure.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: spacetraveler on 09/01/2016 03:19 PM
So what is the contingency plan for SpaceX KSC operations?  How fast can they get 39 up and running for F9 if the damage at the pad will take a long time to fix?

The first task is not to analyze the time needed to get 39 up and running. It will be to fully understand the failure here and develop whatever changes and procedure modifications are needed to prevent it from recurring, since those same procedure changes would also likely need to be implemented at other pads as well.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Galactic Penguin SST on 09/01/2016 03:19 PM
Had this happened without the satellite on top, I would have said that SpaceX has dodged a bullet much like the Grasshopper 2 incident, but since it was on board, it raises the problem that they are very probably the first commercial LSP to write off someone's satellite on the ground (I don't know how the insurers would think about this, for one). Given the uneasiness in the market to adopt them, such problems might scare off some of the customers and others (including NASA for Commercial Crew) would have their uneasiness risen on the company procedures.

The pad doesn't look too battered (much less than the Antares pad, that's for sure; and they have a potential back-up pad well on the way) and investigation should be somewhat easier than in-flight accidents, but I don't know how much psychological impact this weird accident will have for potential clients - maybe even more than a problem in flight since this was supposed to be the "safe part" of the operations.  :-\
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: CraigLieb on 09/01/2016 03:20 PM
Dear SpaceX folks:
You give us hope for a multi-planetary future. Keep on striving and don't lose heart.
Certainly, you will do the hard science to find the cause of this failure and make all the systems more robust.
We will keep the faith with you.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: incoming on 09/01/2016 03:20 PM
there was an earlier post of the countdown events going back to about T-5 min.  I was wondering if anyone has the events for the 5 minutes before that - so from T-10 or so on? Fine if its for launch countdown vs. static fire, it should be close enough.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Herb Schaltegger on 09/01/2016 03:21 PM
Terrible news.
At least it won't be counted as a launch failure. Or would it?

Of course it would, and should. With the payload gone, this is a total launch campaign failure.

Of somewhat more import, it's the first failure of F9 FT, and the second LOV/LOM failure in approximately 14 months. Customer confidence will be shaken at least somewhat, especially given the damage to launch facilities.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: padrat on 09/01/2016 03:21 PM

ok sorry, I thought you hadn't heard it yet...

Oh trust me, I've heard.....

Hi, I'm Padrat, nice to meet you, lol    (inside joke for the space vets on here)
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Lee Jay on 09/01/2016 03:22 PM
In at least one way, this is worse than a launch failure, since that type of failure may leave the pad intact.

I'm really sad about this.  I hope they don't lose too many backlogged customers during the recovery period.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: mfck on 09/01/2016 03:23 PM

ok sorry, I thought you hadn't heard it yet...

Oh trust me, I've heard.....

Hi, I'm Padrat, nice to meet you, lol    (inside joke for the space vets on here)
Padrat, how are the SpaceX folk holding up?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: PreferToLurk on 09/01/2016 03:23 PM


Strongback retraction begins at T-5:30.  Although I saw a CBS news tweet that said something about 5 minutes before ignition.

T-0:05:55   Pressurization for Strongback Retract
T-0:05:30   Strongback Cradles Opening
T-0:05:00   Second Stage Nitrogen Loading Termination
T-0:04:46   Stage 1 & Stage 2 Auto Sequence starts
T-0:04:30   Stage 2 Thrust Vector Control Test
T-0:04:25   Strongback Retraction
T-0:04:10   Vehicle Release Auto Sequence
T-0:03:45   Verify Good Mvac TVC
T-0:03:40   TEA-TEB Ignition System Activation
T-0:03:30   Strongback Retraction complete
T-0:03:25   Flight Termination System to Internal Power
T-0:03:05   Flight Termination System Armed
T-0:03:00   LOX Topping Termination
T-0:03:00   Strongback Securing complete
T-0:02:45   Fuel Trim Valve to Flight Position
T-0:02:40   FTS Countdown Sequence
T-0:02:30   Launch Director: Go for Launch
T-0:02:20   Propellant Tank Pre-Press
T-0:02:00   Range Verification
T-0:02:00   Flight Control to Self Alignment
T-0:01:35   Helium Loading Termination
T-0:01:30   Final Engine Chilldown, Pre-Valves/Bleeders Open
T-0:01:20   Engine Purge
T-0:01:00   Flight Computer to start-up
T-0:01:00   Pad Deck Water Deluge System Activation
T-0:00:55   Second Stage to Flight Pressure
T-0:00:50   First Stage Thrust Vector Actuator Test
T-0:00:40   First Stage to Flight Pressure
T-0:00:20   All Tanks at Flight Pressure
T-0:00:15   Arm Pyrotechnics
T-0:00:10   Latest VC Abort
T-0:00:03   Merlin Engine Ignition
T-0:00:00   LIFTOFF

Source for this?  JCSAT-16 launch had strongback BEGAN retracting at T-03:30, not retraction complete.  Strongback Securing/lockdown was called out at T-02:10, with apparent motion ending around T-02:30.   

FTS times though still seem to line up.  It appears that they are pushing fuel load (and hence full pressurization, and hence strongback retract) back in the sequence as far as possible. 

**Warning** severely premature armchair analysis incoming **Warning**
One thing that might come of this incident is a close look at SpaceX's penchant for continuously shaving margins in order to increase performance.   I think the question might be asked: "would this have happened with the same launch countdown sequence used 2 launches ago?  what about 4 launches ago? are we iterating on our countdown sequence too often?"

Maybe the answer to those questions is simply "NO", but from an outsiders perspective those are important questions to consider. 
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: StarTracker on 09/01/2016 03:24 PM
there was an earlier post of the countdown events going back to about T-5 min.  I was wondering if anyone has the events for the 5 minutes before that - so from T-10 or so on? Fine if its for launch countdown vs. static fire, it should be close enough.

Per the JCSAT-16 timeline, at T-7 engine chill down should have started.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: dorkmo on 09/01/2016 03:24 PM
when they do a static fire do they fully fuel the rocket or is it mostly empty?

do we have an estimate of % full?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Kosmos2001 on 09/01/2016 03:25 PM
This is terrible news  :'(

Could this jeapordize the company itself? SpaceX might not have a backlog problem anymore  :(

I mean, forget Mars 2018 or the Falcon Heavy, I'd expect the FH by Winter of next year or the year after next if we are lucky, and Mars is still as distant a dream as ever... Am I being too pessimistic about this?

Absolutely terrible that this happened so close to Elon Musk's unveiling of his MCT and associated Mars infrastructure plans, it makes it look like a joke now :(

No need to be overly dramatic. Certainly a major setback, but there is no indication SpaceX won't be able to recover.
Arianespace had multiple failures with loss of payload yet still became the worlds leading commercial launch provider. Proton had multiple failures, with loss of payload, yet continues launching commercial and government payload. Older versions of Atlas, Delta had multiple failures with loss of payload yet continued to fly for nearly 4 decades. That goes for multiple versions of Titan as well. All of these vehicles were operated by commercial entities. None of them folded because of failures.

Customers generally understand that space is hard. IMO SpaceX will suffer from this event, but it certainly will not endanger the continued existence of SpaceX as a company.

Yes but in this particular case, the loss of the P/L was more avoidable than in an actual flight, imo.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: yg1968 on 09/01/2016 03:25 PM
In at least one way, this is worse than a launch failure, since that type of failure may leave the pad intact.

I'm really sad about this.  I hope they don't lose too many backlogged customers during the recovery period.

It's hard to say at this point but, in terms of pad damage, it doesn't look as bad as the Antares failure.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: yokem55 on 09/01/2016 03:27 PM
when they do a static fire do they fully fuel the rocket or is it mostly empty?

do we have an estimate of % full?
Test as you fly. It was a full rocket.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jim on 09/01/2016 03:28 PM
Depending on the extent of damage to the pad, could they use this as an opportunity to upgrade LC-40 for Falcon Heavy?

Not feasible
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Lee Jay on 09/01/2016 03:30 PM
In at least one way, this is worse than a launch failure, since that type of failure may leave the pad intact.

I'm really sad about this.  I hope they don't lose too many backlogged customers during the recovery period.

It's hard to say at this point but, in terms of pad damage, it doesn't look as bad as the Antares failure.

Agreed that we don't know yet, but with all that LOX around, it could be a really intense fire too.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: mme on 09/01/2016 03:32 PM

ok sorry, I thought you hadn't heard it yet...

Oh trust me, I've heard.....

Hi, I'm Padrat, nice to meet you, lol    (inside joke for the space vets on here)
It's a rough day for us mere "fans", I can't imagine what it's like for you folks.  Here's hoping for a quick fault determination, resolution and return to flight.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Lee Jay on 09/01/2016 03:33 PM
Has there even been an accidental FTS firing?  (Not saying that's what this was, just asking).
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: LouScheffer on 09/01/2016 03:35 PM
At this stage we can at most bound the consequences.

Best case:  root cause is clear, it's in the ground support equipment, and the same flaw is ruled out at Vandenburg.   SpaceX could launch again in a month or two from Vandenburg, then from the Cape as soon as the pad is fixed or the new pad comes on-line.

Worst case:  root cause is hard to determine, causing a lengthy investigation.  Results reveal changes needed to some fundamental part of the rocket, including those already manufactured, followed by significant re-testing.  (As in the Space Shuttle disasters).  Could result in a 2 year delay..

Given this huge range of possible consequences, it's pretty pointless to speculate on the impact to SpaceX until more is known about the cause.

Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: padrat on 09/01/2016 03:36 PM
Padrat, how are the SpaceX folk holding up?

As best as can be expected I guess.

Obviously things like this really suck and it will take some time to investigate and figure out what happened. But we'll bounce back and hopefully gain a lot of knowledge from this. It'll slow things down, but I'm pretty confident we'll still get there. The important thing is that no one to my knowledge was killed or injured from this. A personal request though for everyone... Yes you are free to post what you want on here (within reason), but maybe ask yourself "is this really the appropriate time to start the SpaceX doom and gloom" Just a thought....

And a little disclaimer, I'm not SpaceX public affairs, so I'm not making any official statements for the company. And even if I did know anything I wouldn't be able to say it anyways, as I'm sure you all know.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: JamesH65 on 09/01/2016 03:36 PM
AIUI, this happened before ignition, so following assumes that.

So bearing in mind the engines were not running, what can cause an explosion? Presumably since the fire was almost about to go ahead, the rocket was fully loaded with propellant, loading complete. What was going on that could actually cause the issue?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Norm38 on 09/01/2016 03:37 PM
I just got out of a meeting, during which my boss looked at his phone and said "A SpaceX rocket just exploded" and I got a big lump in my throat.  My thoughts immediately went to the engines, that it had been an engine failure during the static fire itself.
So I'm actually heartened to hear the reports that the failure occurred before ignition and was (likely?) due to the pad hardware side.  That immediately takes out a lot of variables.  For the moment, it seems that the basic design of the F9 is still sound.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: pippin on 09/01/2016 03:40 PM
AIUI, this happened before ignition, so following assumes that.

So bearing in mind the engines were not running, what can cause an explosion? Presumably since the fire was almost about to go ahead, the rocket was fully loaded with propellant, loading complete. What was going on that could actually cause the issue?

Typical causes for similar incidents with other vehicles in the past have been leaks of all kinds causing a fire.
Structural failure of a tank could also cause a fire and explosion.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: kevinof on 09/01/2016 03:40 PM
My first thought was ground support equipment. Fuel lines under pressure,  stray spark or some screwup and that's all it would take. 



AIUI, this happened before ignition, so following assumes that.

So bearing in mind the engines were not running, what can cause an explosion? Presumably since the fire was almost about to go ahead, the rocket was fully loaded with propellant, loading complete. What was going on that could actually cause the issue?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Kabloona on 09/01/2016 03:42 PM
Has there even been an accidental FTS firing?  (Not saying that's what this was, just asking).

I'm not aware of any. Those systems are designed and tested to be practically impossible to initiate accidentally. I've worked with FTS on Pegasus and TOS, and in my judgment accidental FTS initiation would be one of the least likely scenarios.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jim on 09/01/2016 03:42 PM
another COPV?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ugordan on 09/01/2016 03:42 PM
What was going on that could actually cause the issue?

Overpressurization of some component would be my guess. I'm looking at you, LOX tanks...
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Kabloona on 09/01/2016 03:43 PM
another COPV?

That's what I'm thinking.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Moderas on 09/01/2016 03:43 PM
So bearing in mind the engines were not running, what can cause an explosion?

Falcon itself contains a lot of LOX which can combust under the right conditions. Both falcon and GSE contain TEA/TEB which are hypergolic with LOX so a leak on either sides tanks could easily cause problems. Payload contained Hydrazine, also hypergolic, so if something started up there it could have lead to the rest of the vehicle going with it. Electrical failure on vehicle or ground side could have ignited something. The engines are the only place you want a fire, but certainly not the only place you can get one.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: rnagiuh on 09/01/2016 03:43 PM
It is noteworthy that the issue appears to have been with the pad and ground systems, considering the small statement given by SpaceX, and not the rocket. But it is highly unfortunate that the payload was lost as part of the test. Hopefully if the issue is the GSE thus recovery can be quicker and not cause too much of a delay to the cadence. Best wishes to SpaceX and those who work so hard to get us to Mars.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: TomH on 09/01/2016 03:43 PM
Fueling and launching a rocket has always been a complex task. This is a prime example of why they will never casually hook up some prop lines on that barge, on-load some prop and fly the S1 back from the open sea. From a risk assessment POV, the whole idea is outlandish.

I have to wonder what this does to Musk's unveiling of MCT in Mexico later this month. It might be too close to this and give too much fodder to naysayers. He may well be debating whether to delay the reveal.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: pippin on 09/01/2016 03:44 PM
another COPV?

Hm, now _that_ would really hurt SpaceX' reputation...
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jim on 09/01/2016 03:44 PM
It is noteworthy that the issue appears to have been with the pad and ground systems, considering the small statement given by SpaceX,

The Spacex statement says nothing of the sort.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: kevin-rf on 09/01/2016 03:45 PM
Depending on the extent of damage to the pad, could they use this as an opportunity to upgrade LC-40 for Falcon Heavy?
Not feasible
To add more words to Jim's answer. LC-40 as built for Titan had two holes for the Titan III SRM flame trench. The Titan core was airlit in flight and did not need or have a flame trench. The Falcon 9 only uses one of those holes.  To convert LC-40 for Falcon Heavy a large amount of concrete needs to be removed to add a flame trench for the center core.  So to quote Jim not feasible in a way that is cost effective.

Plus they are working on three heavy capable pads at varying degrees of completeness. 

This is really reminding me of Discover 0 accident. Heart goes out to the SpaceX on this loss.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Kabloona on 09/01/2016 03:45 PM
It is noteworthy that the issue appears to have been with the pad and ground systems, considering the small statement given by SpaceX, and not the rocket.

That's not what they meant by "on the pad." The rocket was on the pad too, and the failure could have started with the rocket.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: vanoord on 09/01/2016 03:45 PM
Is this test done to the exact-same conditions as the test in Texas?

If so, it suggests that either they were 'fortunate' not to have this happen there; or that the fault lies with the pad equipment.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: russianhalo117 on 09/01/2016 03:46 PM
based on what I've seen on all of the NSF public threads and elsewhere, LoV happened in this chunk of the static fire countdown (most notable events in bold):

Excerpt F9FT countdown
T-0:03:40   TEA-TEB Ignition System Auto Sequence
T-0:03:30   Strongback Retraction
T-0:03:25   Flight Termination System to Internal Power
T-0:03:15   FTS on Internal
T-0:03:05   Flight Termination System Armed, FTS Ready for Launch

T-0:02:55   Verify Good Mvac TVC
T-0:02:45   Fuel Trim Valve to Flight Position
T-0:02:40   Stage 1 LOX at Flight Level
T-0:02:40   FTS Countdown Sequence
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Lee Jay on 09/01/2016 03:47 PM
another COPV?

That's what I'm thinking.

Caused by a GSE issue (i.e. over pressurization), or by a flaw in the vehicle systems (relief valve, strut, tank itself, etc.)?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Herb Schaltegger on 09/01/2016 03:47 PM
It is noteworthy that the issue appears to have been with the pad and ground systems, considering the small statement given by SpaceX,

The Spacex statement says nothing of the sort.

Agreed. People are running with the reported statement of an "anomaly on the pad" to vindicate the F9 itself and point at the GSE. The reality is we have no idea what happened - only SpaceX has the first clues to root cause yet, and they obviously won't say much very soon, unless Elon gets bored this weekend on Twitter.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: yg1968 on 09/01/2016 03:47 PM
I just got out of a meeting, during which my boss looked at his phone and said "A SpaceX rocket just exploded" and I got a big lump in my throat.  My thoughts immediately went to the engines, that it had been an engine failure during the static fire itself.
So I'm actually heartened to hear the reports that the failure occurred before ignition and was (likely?) due to the pad hardware side.  That immediately takes out a lot of variables.  For the moment, it seems that the basic design of the F9 is still sound.

Root cause hasn't been announced. "Anomaly on the pad" doesn't mean "pad anomaly".
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: PahTo on 09/01/2016 03:48 PM

Bummer--my thoughts with SpX and the spaceflight community.

Having said that, and in keeping with my career at a project manager, a couple thoughts:

Based on the MARS experience, it would appear SLC40 will be out of commission for quite some time (a year?).  This would indicate ramping up pad 39A completion to get back to launch capability asap.  However, as padrat and others would attest, the skills required to get a pad flight ready are somewhat specialized, so the conundrum:  get 39A ready at the expense of repairing SLC40?  If the team(s) is split, that slows down both efforts.  This is a tough one for sure!

Years ago a number of us questioned (expressed concern?) the proximity of the HIF to 39A.  Others dismissed such questions with variations of "Its a prefab bldg., no big deal".  In light of today's events, I wonder if folks are so cavalier, especially considering the implications of having three flight ready cores in the HIF during a FH test or launch...
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: DragonRider on 09/01/2016 03:49 PM
We don't know the cause but can have some hope that it wasn't F9 given the circumstances, but we'll have to wait and see.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: pippin on 09/01/2016 03:49 PM
It is noteworthy that the issue appears to have been with the pad and ground systems, considering the small statement given by SpaceX,

The Spacex statement says nothing of the sort.

Agreed. People are running with the reported statement of an "anomaly on the pad" to vindicate the F9 itself and point at the GSE. The reality is we have no idea what happened - only SpaceX has the first clues to root cause yet, and they obviously won't say much very soon, unless Elon gets bored this weekend on Twitter.

In all fairness, the first one to come up with that misinterpretation on this thread was Jim himself, IIRC :)
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ZachS09 on 09/01/2016 03:49 PM
I actually can compare this test failure to the infamous Atlas-Able static fire failure more than 50 years ago.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jim on 09/01/2016 03:49 PM
Payload contained Hydrazine, also hypergolic, so if something started up there it could have lead to the rest of the vehicle going with it.

Least likely.   But the payload could be an ignition source if the vehicle collapsed for other reasons
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Ben the Space Brit on 09/01/2016 03:49 PM
only SpaceX has the first clues to root cause yet, and they obviously won't say much very soon, unless Elon gets bored this weekend on Twitter.

Or other hints leak out like the sudden collapse in she share price of a company further up the supply chain (materials smelting and rolling, etc).
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: incoming on 09/01/2016 03:50 PM
there was an earlier post of the countdown events going back to about T-5 min.  I was wondering if anyone has the events for the 5 minutes before that - so from T-10 or so on? Fine if its for launch countdown vs. static fire, it should be close enough.

Per the JCSAT-16 timeline, at T-7 engine chill down should have started.

Source for the timeline is:  http://spaceflight101.com/falcon-9-countdown-timeline/    I haven't been able to find other sources with this level of detail, but most of the major events seem to line up with this one. 

I did see that this timeline applies to Falcon 9 V1.0 (missed that, earlier), so I'm guessing some of the events will have been shifted to accommodate the different fueling requirements.  Does any one have a more current countdown timeline?

The entire timeline I found is:

Time   Event
L-10:00:00   Falcon 9 to Vertical
L-8:30:00   Countdown Initiation, Launch Vehicle Power-Up
L-6:00:00   First Weather Balloon Release
L-5:00:00   Launch Area Evacuation
L-4:45:00   Range Controllers on Station
L-4:35:00   Falcon 9 Attitude Control System N2 Loading
L-4:50:00   Falcon 9 Reconfiguration for Propellant Loading
L-4:37:00   GO for Propellant Loading
L-4:20:00   Rocket Propellant 1 Loading
L-4:00:00   Eastern Range Countdown Initiation
L-4:00:00   LOX Systems Setup & Chilldown Ops
L-3:45:00   LOX Loading
L-2:45:00   Falcon 9 RF & Telemetry Checks
L-2:30:00   Falcon 9 Launch Vehicle Release System Test
L-2:25:00   TEA-TEB Bleed In
L-2:00:00   RP-1 Tanking complete
L-1:45:00   Comm & FTS Checks
L-1:40:00   Data Flow Tests with Downrange Tracking Stations
L-1:30:00   LOX Replenish
L-1:00:00   Weather Briefing
L-0:50:00   RF Link Checks
L-0:45:00   Flight Control System Setup (Flight Software Loading)
L-0:30:00   Final LOX Topping
L-0:27:00   Spacecraft to Internal Power
L-0:13:00   COUNTDOWN HOLD POINT
L-0:13:00   Launch Director Poll
L-0:11:00   Terminal Count Briefing
T-0:10:00   Terminal Countdown
T-0:09:55   Verify that Terminal Countdown has started
T-0:09:50   Range Recorders Start
T-0:09:45   Launch Enable to Flight Mode
T-0:09:30   First Stage Merlin Engine Chilldown, Pre Valves to Open
T-0:09:20   Ground TEA-TEB Setup
T-0:09:17   Merlin 1D: Lox Bleeder Valves Open
T-0:08:15   Engine Trim Valve Cycling
T-0:07:30   Go/No Go for Launch
T-0:07:00   Spacecraft on Internal Power
T-0:07:00   First Stage Heater Shutdown
T-0:07:00   First Stage ACS Close-Out
T-0:06:35   Second Stage Heater Shutdown
T-0:06:25   Falcon 9 to Internal Power
T-0:06:00   Transfer to Internal complete
T-0:05:55   Pressurization for Strongback Retract
T-0:05:30   Strongback Cradles Opening
T-0:05:00   Second Stage Nitrogen Loading Termination
T-0:04:46   Stage 1 & Stage 2 Auto Sequence starts
T-0:04:30   Stage 2 Thrust Vector Control Test
T-0:04:25   Strongback Retraction
T-0:04:10   Vehicle Release Auto Sequence
T-0:03:45   Verify Good Mvac TVC
T-0:03:40   TEA-TEB Ignition System Activation
T-0:03:30   Strongback Retraction complete
T-0:03:25   Flight Termination System to Internal Power
T-0:03:05   Flight Termination System Armed
T-0:03:00   LOX Topping Termination
T-0:03:00   Strongback Securing complete
T-0:02:45   Fuel Trim Valve to Flight Position
T-0:02:40   FTS Countdown Sequence
T-0:02:30   Launch Director: Go for Launch
T-0:02:20   Propellant Tank Pre-Press
T-0:02:00   Range Verification
T-0:02:00   Flight Control to Self Alignment
T-0:01:35   Helium Loading Termination
T-0:01:30   Final Engine Chilldown, Pre-Valves/Bleeders Open
T-0:01:20   Engine Purge
T-0:01:00   Flight Computer to start-up
T-0:01:00   Pad Deck Water Deluge System Activation
T-0:00:55   Second Stage to Flight Pressure
T-0:00:50   First Stage Thrust Vector Actuator Test
T-0:00:40   First Stage to Flight Pressure
T-0:00:20   All Tanks at Flight Pressure
T-0:00:15   Arm Pyrotechnics
T-0:00:10   Latest VC Abort
T-0:00:03   Merlin Engine Ignition
T-0:00:00   LIFTOFF

I think this is pretty outdated - looks like it's pre-densified propellants.  I believe they fuel the rocket much later in the count now. 
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Lee Jay on 09/01/2016 03:50 PM
Can we say with confidence that it wasn't an engine problem, since it hadn't started them yet?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: cscott on 09/01/2016 03:50 PM
Everyone posting v1.0 or v1.1-pre-FT timelines, please stop.  Consider removing your posts.  It's actively unhelpful.  Fuel loading procedures changed significantly for 1.1 FT with its supercooled propellants.

For that matter, we don't even know if the failure happened around T-5 or T-3 yet.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: john smith 19 on 09/01/2016 03:51 PM
At this stage we can at most bound the consequences.
True.
Quote
Worst case:  root cause is hard to determine, causing a lengthy investigation.  Results reveal changes needed to some fundamental part of the rocket, including those already manufactured, followed by significant re-testing.  (As in the Space Shuttle disasters).  Could result in a 2 year delay..
I strongly doubt SX would cease launches for 2 years.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: rnagiuh on 09/01/2016 03:52 PM
It is noteworthy that the issue appears to have been with the pad and ground systems, considering the small statement given by SpaceX,

The Spacex statement says nothing of the sort.

Agreed. People are running with the reported statement of an "anomaly on the pad" to vindicate the F9 itself and point at the GSE. The reality is we have no idea what happened - only SpaceX has the first clues to root cause yet, and they obviously won't say much very soon, unless Elon gets bored this weekend on Twitter.

In all fairness, the first one to come up with that misinterpretation on this thread was Jim himself, IIRC :)

Right, apologies I read too much into their statement; "SpaceX can confirm that in preparation for today's static fire, there was an anomaly on the pad resulting in the loss of the vehicle and its payload. Per standard procedure, the pad was clear and there were no injuries.". Glad that there was no injuries, and all we can do is to look forward to more official updates.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: tp1024 on 09/01/2016 03:53 PM
Can we say with confidence that it wasn't an engine problem, since it hadn't started them yet?

No. It could be a leak in the TEB/TEA lines or tanks of the engines.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: russianhalo117 on 09/01/2016 03:54 PM

Bummer--my thoughts with SpX and the spaceflight community.

Having said that, and in keeping with my career at a project manager, a couple thoughts:

Based on the MARS experience, it would appear SLC40 will be out of commission for quite some time (a year?).  This would indicate ramping up pad 39A completion to get back to launch capability asap.  However, as padrat and others would attest, the skills required to get a pad flight ready are somewhat specialized, so the conundrum:  get 39A ready at the expense of repairing SLC40?  If the team(s) is split, that slows down both efforts.  This is a tough one for sure!

Years ago a number of us questioned (expressed concern?) the proximity of the HIF to 39A.  Others dismissed such questions with variations of "Its a prefab bldg., no big deal".  In light of today's events, I wonder if folks are so cavalier, especially considering the implications of having three flight ready cores in the HIF during a FH test or launch...
Pad is said to have survived well in terms of damage. Charring is heavy but but SLC-40 did not suffer like MARS SLC-0A as that was an above pad explosion. where as the SLC-40 explosion saw flames shooting out the flame trench as well as upwards. Antares explosion was downwards and falling debris.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: John.bender on 09/01/2016 03:54 PM
Dumb question but what is COPV?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: DavidH on 09/01/2016 03:54 PM
Payload contained Hydrazine, also hypergolic, so if something started up there it could have lead to the rest of the vehicle going with it.

Least likely.   But the payload could be an ignition source if the vehicle collapsed for other reasons

Reminds me of the Atlas collapse.
https://www.youtube.com/watch?v=FmrrcAVOV4s (https://www.youtube.com/watch?v=FmrrcAVOV4s)
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: dorkmo on 09/01/2016 03:54 PM
another COPV?

That's what I'm thinking.

seems like these guys go right to the top of the suspect list every time.

if it was copv it seems like it will be rather straight forward to pinpoint in this scenario

time will tell eh. pads still smokin. :/
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: HMXHMX on 09/01/2016 03:56 PM
Dumb question but what is COPV?

Composite Overwrapped Pressure Vessel
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: topsphere on 09/01/2016 03:56 PM
Dumb question but what is COPV?

http://bfy.tw/7Us0
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Norm38 on 09/01/2016 03:57 PM
another COPV?

During the investigation last year I recall talk of the buoyancy force on the COPV tanks being in addition to the g-forces during launch. That put additional stress on the tanks that could not be simulated during any ground testing.

For this failure no g-forces and struts were redesigned.  But a COPV tank itself could have ruptured I suppose.  Not the same failure mode though.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: edkyle99 on 09/01/2016 03:58 PM
Has there even been an accidental FTS firing?  (Not saying that's what this was, just asking).
Yes.  Happened on one of the first Titan 1 R&D missiles.  There were others too, I believe, more related to incorrect tracking data that forced an RSO decision, but hasn't happened in many years since.

 - Ed Kyle
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: jimbowman on 09/01/2016 04:00 PM
Usually the folks at USLaunchReport have a camera(from a distance) on the static fires. Haven't posted anything yet.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Kabloona on 09/01/2016 04:00 PM
Has there even been an accidental FTS firing?  (Not saying that's what this was, just asking).
Yes.  Happened on one of the first Titan 1 R&D missiles.  There were others too, I believe, but hasn't happened in many years since.

 - Ed Kyle

And the designs and qual requirements have improved since then.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: cscott on 09/01/2016 04:01 PM
Only reason to consider the FTS at all is the transition to autonomous FTS.  New hardware => new opportunities for bugs.  But I don't know if this was an autonomous FTS demo mission or not.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: russianhalo117 on 09/01/2016 04:01 PM
Everyone posting v1.0 or v1.1-pre-FT timelines, please stop.  Consider removing your posts.  It's actively unhelpful.  Fuel loading procedures changed significantly for 1.1 FT with its supercooled propellants.

For that matter, we don't even know if the failure happened around T-5 or T-3 yet.

Correct timeline (http://spaceflight101.com/falcon-9-ft-countdown-timeline/):
Falcon 9 FT – Countdown Timeline
All Times Approximate.
Time   Event
L-15:00:00   Falcon 9 to Vertical
L-10:00:00   Countdown Initiation, Launch Vehicle Power-Up
L-6:00:00   First Weather Balloon Release
L-5:00:00   Launch Area Evacuation
L-4:45:00   Range Controllers on Station
L-4:35:00   Falcon 9 Attitude Control System N2 Loading
L-5:00:00   Launch Area Evacuation
L-2:45:00   Falcon 9 RF & Telemetry Checks
L-2:30:00   Falcon 9 Launch Vehicle Release System Test
L-2:25:00   TEA-TEB Bleed In
L-1:45:00   Comm & FTS Checks
L-1:40:00   Data Flow Tests with Downrange Tracking Stations
L-1:00:00   Weather Briefing
L-0:50:00   RF Link Checks
L-0:45:00   Pre-Load Hold Point, Propellant Polls
L-0:45:00   Blast Danger Area Clear, Roadblocks Established
L-0:45:00   Flight Control System Setup (Flight Software Loading)
L-0:45:00   Final Tank Chill-In
L-0:40:00   Ready for Prop Load
L-0:38:00   Launch Readiness Poll
L-0:36:00   Tanks vented for Prop Loading
T-0:35:00   Automated Countdown Sequence, Master Script Running
T-0:34:45   Launch Enable to Flight Mode
T-0:34:30   RP-1 Flow to both Stages
T-0:33:30   Stage 1 Liquid Oxygen Loading
T-0:32:30   Confirm nominal Fuel Flow Rates
T-0:32:00   Latest Prop Flow Start
T-0:29:30   Stage 1 Helium Load
T-0:27:00   Spacecraft to Internal Power
T-0:25:30   Fuel Collector Pre-Valves Closed
T-0:25:00   All three Liquid Helium Pumps active
T-0:22:00   Stage 2 Fuel Loading Complete
T-0:19:30   Stage 2 Liquid Oxygen Loading
T-0:17:20   Stage 1 LOX Flowrate Adjustment for Stage 2 Fast Fill
T-0:13:15   Stage 2 Helium Loading
T-0:13:00   Stage 2 LOX Flow Adjustment for Helium Cryo Load
T-0:13:00   Countdown Recycle Point
T-0:12:45   Merlin 1D & MVac BTV Activation
T-0:10:15   Grid Fin Pneumatics Secured
T-0:10:05   Boostback Hazards Disabled
T-0:10:00   Stage 2 Venting for LOX Fast Fill
T-0:09:50   Flight Software Final Setups complete
T-0:09:45   TEA-TEB Ignition System Setup
T-0:09:45   Stage 2 Transmitter Re-Activation
T-0:09:30   M1D Trim Valve Cycling
T-0:09:15   Stage 1 Helium Topping
T-0:07:45   MVac Fuel Trim Valve Setup
T-0:07:30   Engine Chill Readiness
T-0:07:00   Engine Chilldown (Bleed Valves Open, both Stages
T-0:07:00   Spacecraft on Internal Power
T-0:06:45   Stage 2 Helium Transition to Pipeline
T-0:06:35   MVac Hydraulics at Bleed Pressure
T-0:06:05   M1D Engines to TVC-Null Position
T-0:05:20   Flight Computers in Self-Alignment
T-0:05:20   Stage 1 Fuel Loading Complete
T-0:05:15   Launch Vehicle Heater Deactivation
T-0:05:00   Falcon 9 to Internal Power
T-0:05:00   Range Control Comm Check
T-0:05:00   Second Stage Nitrogen Loading Termination
T-0:04:50   Pressurization for Strongback Retract
T-0:04:40   Stage 2 TVC Bleed
T-0:04:30   Stage 2 RP-1 Bleed
T-0:04:30   Stage 2 Thrust Vector Control Test
T-0:04:20   Verify Good Self-Alignment
T-0:04:10   Strongback Cradles Opening
T-0:04:00   Vehicle Release Auto Sequence
T-0:03:40   TEA-TEB Ignition System Auto Sequence
T-0:03:30   Strongback Retraction
T-0:03:25   Flight Termination System to Internal Power
T-0:03:15   FTS on Internal
T-0:03:05   Flight Termination System Armed, FTS Ready for Launch
T-0:02:55   Verify Good Mvac TVC
T-0:02:45   Fuel Trim Valve to Flight Position
T-0:02:40   Stage 1 LOX at Flight Level
T-0:02:40   FTS Countdown Sequence
T-0:02:35   Strongback Retraction Complete
T-0:02:05   Stage 2 LOX at Flight Level
T-0:02:00   Falcon 9 Transfer to Internal Power Complete
T-0:01:35   Flight Control to Self Alignment
T-0:01:30   Launch Director: Go for Launch
T-0:01:30   Final Engine Chilldown
T-0:01:25   Helium Loading Termination
T-0:01:20   Engine Purge
T-0:01:00   Flight Computer to start-up
T-0:00:50   Stage 1, Stage 2 Pressurization for Flight
T-0:00:50   First Stage Thrust Vector Actuator Test
T-0:00:30   HOLD Call for Abort
T-0:00:20   All Tanks at Flight Pressure
T-0:00:15   Arm Pyrotechnics
T-0:00:10   Latest VC Abort
T-0:00:07   Pad Deck Water Deluge System Activation
T-0:00:03   Merlin Engine Ignition
T-0:00:00   LIFTOFF
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: john smith 19 on 09/01/2016 04:01 PM
another COPV?

Hm, now _that_ would really hurt SpaceX' reputation...
True. However SX have always been very good at learning from their past mistakes. AFAIK they never make the same mistake twice.

On that basis I'd put the COPV's quite far down the list.  Although range safety does quantify their potential in lbs of TNT equivalent.

A key starting question would be where did the explosion/fire start? I'm pretty sure SX have a bunch of CCTV on the pad. Pad? 1st stage? 2nd stage? Payload?

That alone should prune whole branches of the fault tree before they start chewing on the telemetry.

Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Herb Schaltegger on 09/01/2016 04:03 PM
Dumb question but what is COPV?

Composite Overwrap Pressure Vessel - the internal tanks for helium and nitrogen.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: pogo661 on 09/01/2016 04:03 PM
If it was a falcon failure, and its not possible to determine the cause from telemetry, there might be a better chance they'll recover the failed component given the failure was on the ground.  (looking for a silver lining here.)

Is any better telemetry available from the falcon while its on the pad, as compared to once its in flight?   Or does the rocket use radio telemetry at that point in the static fire?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: vanoord on 09/01/2016 04:04 PM
Dumb question but what is COPV?

Composite overwrapped pressure vessel, holds helium for tank pressurisation. Failure of a strut / struts holding a COPV caused the loss of of CRS-7 - it  broke free and ruptured the second stage LOX tank.

https://www.nasaspaceflight.com/2015/07/spacex-falcon-9-failure-investigation-focuses-update/

As noted above, this failure occurred under significant g-loadings - which would not have been a factor while the vehicle was at the pad.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Scylla on 09/01/2016 04:04 PM
A Spanish language news report with zoomed in video of pad. It's a bit blurry but I havn't seen close up views anywhere else yet.

http://youtu.be/fyGMHdsnm4E
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: edkyle99 on 09/01/2016 04:04 PM
If I'm not mistaken, this will have been the most powerful ground explosion ever at the Cape or KSC.  AC-5 was the previous "most powerful". 

Sobering to think what would result from a similar Falcon Heavy incident.

 - Ed Kyle
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: cscott on 09/01/2016 04:05 PM
Photos of the pad seem to show the strong back not retracted.  Can anyone tell if it looks like the cradle arms were opened?  If so, that bounds the time of the incident pretty well.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Galactic Penguin SST on 09/01/2016 04:06 PM
One more thing - since this apparently happened well before ignition, this means that similar risks do exist to any rocket doing a Wet Dress Rehersal (WDR), including these:

- Atlas V (selective Cape flights and all VAFB flights, like the one next door for OSIRIS-Rex)
- Delta IV (all flights)
- Soyuz (selective flights)
- Delta II (selective flights I think?)

Can't remember if Ariane 5 or Antares or others does that.

Yet no-one except SpaceX puts some of the payloads on top of that. Which goes back to my previous post.....
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: russianhalo117 on 09/01/2016 04:07 PM
Photos of the pad seem to show the strong back not retracted.  Can anyone tell if it looks like the cradle arms were opened?  If so, that bounds the time of the incident pretty well.
Well if this is anything to go by:
Excerpt from the current F9FT countdown timeline:
T-0:03:40   TEA-TEB Ignition System Auto Sequence
T-0:03:30   Strongback Retraction
T-0:03:25   Flight Termination System to Internal Power
T-0:03:15   FTS on Internal
T-0:03:05   Flight Termination System Armed, FTS Ready for Launch

T-0:02:55   Verify Good Mvac TVC
T-0:02:45   Fuel Trim Valve to Flight Position
T-0:02:40   Stage 1 LOX at Flight Level
T-0:02:40   FTS Countdown Sequence
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: dnavas on 09/01/2016 04:08 PM
Caused by a GSE issue (i.e. over pressurization), or by a flaw in the vehicle systems (relief valve, strut, tank itself, etc.)?

If another strut went ... yikes.  :(
What systems exist to prevent over-pressurization?  What would have had to have gone wrong?  I'm assuming a fair amount of redundancy between the rocket and the pad equipment....

There's an obvious preference for this to be pad support than rocket for flight purposes (though it's not clear if that helps much, really).  Are we looking for the proverbial "aluminum nut" in a hose/valve/electric-line assembly that's been exposed to too much salty air?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Herb Schaltegger on 09/01/2016 04:08 PM
Photos of the pad seem to show the strong back not retracted.  Can anyone tell if it looks like the cradle arms were opened?  If so, that bounds the time of the incident pretty well.

The best distance views are hard to make out from the angle. It looks like they might be opened, but the entire top of the T/E structure is bent over, whether due to explosive shock, or the heat of the fire is unclear.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: cscott on 09/01/2016 04:08 PM
I'm saying it looks to have happened before T-3:30, given that the strong back is vertical.
If the cradle is open, then after T-4:10.

There's a TEA-TEB system event in that time frame... Which might mean the engines aren't entirely free from suspicion.

OTOH, if it was ignition system initiated, there should be a telltale green color to the first flame, which would be a smoking gun on pad video.

If the cradle is closed, then TEA-TEB are innocent, and we can keep thinking about pressurization, ice dams, and leaks.

In either case, FTS is armed after strong back retract, so we can stop thinking about that.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: dorkmo on 09/01/2016 04:09 PM
Photos of the pad seem to show the strong back not retracted.  Can anyone tell if it looks like the cradle arms were opened?  If so, that bounds the time of the incident pretty well.

i think its possible the arms we're closed bc it looks like they were bent/pulled downward. not a for sure thing though.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: kdhilliard on 09/01/2016 04:12 PM
Do we have a list somewhere showing which previous F9 static fires were done with the payload mounted?

~Kirk
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Lee Jay on 09/01/2016 04:13 PM
Reconstructing things like the TE and other pad systems has historically (in similar events) taken a number of months described by two digits, correct?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: dorkmo on 09/01/2016 04:15 PM
Photos of the pad seem to show the strong back not retracted.  Can anyone tell if it looks like the cradle arms were opened?  If so, that bounds the time of the incident pretty well.

i think its possible the arms we're closed bc it looks like they were bent/pulled downward. not a for sure thing though.

or possibly the rods that connect the top section of the TEL to the rest of it deformed from the heat?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: cscott on 09/01/2016 04:15 PM
Reconstructing things like the TE and other pad systems has historically (in similar events) taken a number of months described by two digits, correct?
Hard to say, since the TE has been rebuilt three or so times at Vandenberg alone, then twice more I think at LC39A?  The pad systems have also been a research project, what with the supercooling apparatus.  The design keeps changing as the rocket evolves.  If you're rebuilding an existing proven design with no changes---who knows?  I don't think we have any evidence on "SpaceX time" for this task, although we have timelines from MARS etc... which is a simpler pad but perhaps more heavily damaged.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: PahTo on 09/01/2016 04:17 PM
Reconstructing things like the TE and other pad systems has historically (in similar events) taken a number of months described by two digits, correct?

That's what I'm thinking/asking, though russianhalo117 reports there are indications the damage isn't as bad as that at MARS.  Let's hope so!  Still will cause some logistical issues, given they're trying to get 39A flight ready and the skill sets required aren't a-dime-a-dozen...
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jim on 09/01/2016 04:17 PM
If it was a falcon failure, and its not possible to determine the cause from telemetry, there might be a better chance they'll recover the failed component given the failure was on the ground.  (looking for a silver lining here.)

Is any better telemetry available from the falcon while its on the pad, as compared to once its in flight?   Or does the rocket use radio telemetry at that point in the static fire?

Better on the pad.  It is hardlined and not subject to transmitter bandwidth.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jim on 09/01/2016 04:18 PM
Dumb question but what is COPV?

Composite overwrapped pressure vessel, holds helium for tank pressurisation. Failure of a strut / struts holding a COPV caused the loss of of CRS-7 - it  broke free and ruptured the second stage LOX tank.

https://www.nasaspaceflight.com/2015/07/spacex-falcon-9-failure-investigation-focuses-update/

As noted above, this failure occurred under significant g-loadings - which would not have been a factor while the vehicle was at the pad.

That was the 2nd incident.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: SWGlassPit on 09/01/2016 04:18 PM
I'm going to venture a guess that rebuilding the other infrastructure -- particularly plumbing and tankage -- is going to be a fair amount more work than the TE itself.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: russianhalo117 on 09/01/2016 04:20 PM
Photos of the pad seem to show the strong back not retracted.  Can anyone tell if it looks like the cradle arms were opened?  If so, that bounds the time of the incident pretty well.

i think its possible the arms we're closed bc it looks like they were bent/pulled downward. not a for sure thing though.
the top third or fourth on the TEL has been bent towards where the rocket once stood. Its current position is not fully indicative of the the position of the TEL at the time of LoV.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: cscott on 09/01/2016 04:21 PM
That was the 2nd incident.

Elaborating for Jim: earlier on in spacex history there was another helium copv failure during static fire. (EDIT: ugordon says 1st orbcomm mission.)

Strictly speaking, that earlier problem was in fact a copv leak.  In CRS-7 the root cause was actually the strut; the COPV by all accounts never let go, the helium leak was from the tubing attached to the COPV.  The tubing eventually twisted itself shut and the helium pressure held steady---good COPV---although by that point it was too late for the LOX tank.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: DragonRider on 09/01/2016 04:21 PM
So rumour is it was a pad issue, hmm.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: kevin-rf on 09/01/2016 04:22 PM
That was the 2nd incident.

What was the first COPV indecent? I seem to have forgotten.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Toast on 09/01/2016 04:22 PM
Dumb question but what is COPV?

Composite overwrapped pressure vessel, holds helium for tank pressurisation. Failure of a strut / struts holding a COPV caused the loss of of CRS-7 - it  broke free and ruptured the second stage LOX tank.

https://www.nasaspaceflight.com/2015/07/spacex-falcon-9-failure-investigation-focuses-update/

As noted above, this failure occurred under significant g-loadings - which would not have been a factor while the vehicle was at the pad.

That was the 2nd incident.

When was the first? I thought the only other Falcon 9 failure was the partial failure due to an engine out on the first stage.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jim on 09/01/2016 04:23 PM
So rumour is it was a pad issue, hmm.

No such rumor
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ugordan on 09/01/2016 04:23 PM
That was the 2nd incident.

What was the first COPV indecent? I seem to have forgotten.

Unless there was another anomaly we never publicly heard of, the original OG-1 static fire (2014?) suffered a copious He leak and subsequent LOX venting to the point of people speculating the tank ruptured.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: DragonRider on 09/01/2016 04:24 PM
Ex-employee on reddit:

No this was an issue with the pad itself, not the rocket.

It's not an assumption. Let's just say I'm connected
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Ben the Space Brit on 09/01/2016 04:24 PM
CRS-7 - IIRC, the COPV struts gave way causing the helium tanks to crash into the upper stage LOX tanks, causing its catastrophic sudden depressurisation and a massive structural failure/break-up just before MECO1.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: mn on 09/01/2016 04:25 PM
That was the 2nd incident.

What was the first COPV indecent? I seem to have forgotten.

Unless there was another anomaly we never publicly heard of, the original OG-1 static fire (2014?) suffered a copious He leak and subsequent LOX venting to the point of people speculating the tank ruptured.

I'll take the liberty of quoting myself further upthread.

If I remember correctly I think with the orbcomm mission there was some type of 'almost' anomaly during launch prep or static fire, saw some vague mentions, but never any details (probably details in L2)

edit - add link
Found discussion here: http://forum.nasaspaceflight.com/index.php?topic=33089.360 (http://forum.nasaspaceflight.com/index.php?topic=33089.360), Was just discussion, no idea if anything was ever confirmed, (and there is mention of perhaps something similar during SES-8)
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: DaveS on 09/01/2016 04:25 PM
So rumour is it was a pad issue, hmm.

No such rumor
Jim is entirely correct. The origin for this seems to have been Eric Berger's Twitter account where he read the official SpaceX statement wrong and tweeted that a pad anomaly had destroyed the F9 and the payload. The statement in fact had nothing of the sort, it was "an anomaly on the pad".
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jim on 09/01/2016 04:26 PM
Ex-employee on reddit:

No this was an issue with the pad itself, not the rocket.

It's not an assumption. Let's just say I'm connected

Likely based on another false report that was spread earlier.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: mme on 09/01/2016 04:26 PM
Dumb question but what is COPV?

Composite overwrapped pressure vessel, holds helium for tank pressurisation. Failure of a strut / struts holding a COPV caused the loss of of CRS-7 - it  broke free and ruptured the second stage LOX tank.

https://www.nasaspaceflight.com/2015/07/spacex-falcon-9-failure-investigation-focuses-update/

As noted above, this failure occurred under significant g-loadings - which would not have been a factor while the vehicle was at the pad.

That was the 2nd incident.
But can the COPV really be blamed for the strut failure?  Or are you lumping in the design that includes placing the COPVs inside the propellent tank?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: DragonRider on 09/01/2016 04:27 PM
No, this is not correct, the supposed ex-employee source on reddit denies that. They state:

I'm not exactly allowed to reveal sources. It'll still be months before things settle down, but it was definitely a pad issue.

Look it may be baloney, we can't say anything for sure, that's why it's a rumour.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: wannamoonbase on 09/01/2016 04:28 PM
It won't take long to figure this out.  I bet we know the cause in less than a week.  Maybe 1-2 days.

Rockets are hard, lots of things can go wrong.  This is obviously an avoidable mistake and I doubt it will be a big problem to fix.  Which will make it even more embarrassing for SpaceX, but they'll recover.

If it is proven to not be a vehicle problem then production needs to go full speed ahead.  Fill the hangers and get ready for RTF.

For all we know at this time, this may not have much of an impact on the VAFB launches.


Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Star One on 09/01/2016 04:28 PM
Ex-employee on reddit:

No this was an issue with the pad itself, not the rocket.

It's not an assumption. Let's just say I'm connected

Likely based on another false report that was spread earlier.

After all how easy these days is it for the pad to cause the launcher's destruction.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Star One on 09/01/2016 04:29 PM
It won't take long to figure this out.  I bet we know the cause in less than a week.  Maybe 1-2 days.

Rockets are hard, lots of things can go wrong.  This is obviously an avoidable mistake and I doubt it will be a big problem to fix.  Which will make it even more embarrassing for SpaceX, but they'll recover.

If it is proven to not be a vehicle problem then production needs to go full speed ahead.  Fill the hangers and get ready for RTF.

For all we know at this time, this may not have much of an impact on the VAFB launches.

Completely unsupportable supposition.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: philw1776 on 09/01/2016 04:29 PM
I give zero cred to a supposed ex-employee being so connected that he/she knows the cause before most likely anybody in SX does
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: cscott on 09/01/2016 04:29 PM
Well, if it's the pad's fault, the responsible piece of equipment has already been thoroughly punished and decommissioned.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: butters on 09/01/2016 04:30 PM
The previous on-pad COPV failure didn't produce nearly as catastrophic an outcome, and during the CRS-7 investigation it was noted that the vent valve is sized to handle a COPV depressurization. Perhaps the vent valve was locked for tank press at the time and its overpressure prevention logic was inhibited?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ugordan on 09/01/2016 04:31 PM
I give zero cred to a supposed ex-employee being so connected that he/she knows the cause before most likely anybody in SX does

On the other hand, just because SX people aren't speaking (smart move BTW), doesn't mean they don't have any hints by now.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: mn on 09/01/2016 04:31 PM
I give zero cred to a supposed ex-employee being so connected that he/she knows the cause before most likely anybody in SX does

I don't know about the ex-employee but I think it is highly likely that SX has a very good idea of what went wrong. (maybe yes, maybe not, but certainly highly likely).
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Ben the Space Brit on 09/01/2016 04:32 PM
It won't take long to figure this out.  I bet we know the cause in less than a week.  Maybe 1-2 days.

That may be a bit too optimistic but I'm not expecting a huge mystery that stretches out for weeks either.

Why? I'd say most of the vehicle's remains will be found and, as the rocket was plugged into the ground data lines until destruction, there is no possibility of loss of telemetry until the actual physical destruction of the data lines or the IU instrumentation package, whichever came first, both of which would have been post-failure (if only by hundredths of seconds). So, SpaceX's engineers will already have quality-A data and that will only improve as more and more debris is brought in an analysed.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: kevin-rf on 09/01/2016 04:32 PM
It won't take long to figure this out.  I bet we know the cause in less than a week.  Maybe 1-2 days.

Rockets are hard, lots of things can go wrong.  This is obviously an avoidable mistake and I doubt it will be a big problem to fix.  Which will make it even more embarrassing for SpaceX, but they'll recover.

If it is proven to not be a vehicle problem then production needs to go full speed ahead.  Fill the hangers and get ready for RTF.

For all we know at this time, this may not have much of an impact on the VAFB launches.

"If" it involves a COPV failure (not strut), it could very well require design work and not be a quick fix. 
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: leetdan on 09/01/2016 04:37 PM
Usually the folks at USLaunchReport have a camera(from a distance) on the static fires. Haven't posted anything yet.

This might be cynical of me, but I wonder if they're shopping the video around.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Star One on 09/01/2016 04:37 PM
Jeff Foust –  ‏@jeff_foust

Oof: Iridium, major SpaceX customer, falling sharply now after a brief rebound. Shares down >6% for the day so far.  http://bit.ly/2ctInIR

https://mobile.twitter.com/jeff_foust/status/771383776450584576
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: cscott on 09/01/2016 04:39 PM


Quote
Parabolicarc.com ‏@spacecom 12m12 minutes ago California, USA

Hearing from a source that whatever went wrong happened very quickly. Windows blown in at KSC before pad fire alarm sounded #SpaceX #Falcon9

https://twitter.com/spacecom/status/771381094092410881 (https://twitter.com/spacecom/status/771381094092410881)
Of course. This was a sudden explosion, not a pad fire. Fire alarms only look for fire not explosions.

They mean that it wasn't something like an anomalous rising pressure in a tank or rising temperature in a compartment or evidence of a small fire on video that would have given spacex time to manually trigger the fire alarm before the whole thing let go.

It's not a huge data point, but it is saying something.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: RonM on 09/01/2016 04:39 PM
It won't take long to figure this out.  I bet we know the cause in less than a week.  Maybe 1-2 days.

That may be a bit too optimistic but I'm not expecting a huge mystery that stretches out for weeks either.

Why? I'd say most of the vehicle's remains will be found and, as the rocket was plugged into the ground data lines until destruction, there is no possibility of loss of telemetry until the actual physical destruction of the data lines or the IU instrumentation package, whichever came first, both of which would have been post-failure (if only by hundredths of seconds). So, SpaceX's engineers will already have quality-A data and that will only improve as more and more debris is brought in an analysed.

That and the pad video cameras. Even if they are only standard cameras that's 30 frames per second and with a good close up. Could easily have a higher frame rate.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: orulz on 09/01/2016 04:42 PM
If this is a pad failure then procedures are a likely culprit. Inadequate inspections, checks, etc?

If the root cause is traced to a procedural issue, that would goes a long way toward showing why rapid launch cadence is difficult to achieve. So many things have to happen in such rapid succession and in exactly the right order and with exactly the right timing, or else *BOOM*. The answer for why ULA can't launch faster than they do is not just that "old aerospace" is inefficient.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: RonM on 09/01/2016 04:43 PM
Usually the folks at USLaunchReport have a camera(from a distance) on the static fires. Haven't posted anything yet.

This might be cynical of me, but I wonder if they're shopping the video around.

They're running a business, right? If they have exclusive footage they should get paid for it. At least get the credit.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: russianhalo117 on 09/01/2016 04:44 PM
It won't take long to figure this out.  I bet we know the cause in less than a week.  Maybe 1-2 days.

That may be a bit too optimistic but I'm not expecting a huge mystery that stretches out for weeks either.

Why? I'd say most of the vehicle's remains will be found and, as the rocket was plugged into the ground data lines until destruction, there is no possibility of loss of telemetry until the actual physical destruction of the data lines or the IU instrumentation package, whichever came first, both of which would have been post-failure (if only by hundredths of seconds). So, SpaceX's engineers will already have quality-A data and that will only improve as more and more debris is brought in an analysed.

That and the pad video cameras. Even if they are only standard cameras that's 30 frames per second and with a good close up. Could easily have a higher frame rate.
highspeed cameras would have been activated around the start of the automated sequence.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ugordan on 09/01/2016 04:45 PM
Even in a "best case" scenario of the root cause being found quickly and pointing to the pad equipment, I don't see FAA signing off on the investigation that soon. I'd also guess that return to flight, at least for east coast launches will occur from LC-39A and FH will be further deprioritized up until the point LC-40 is repaired. They won't risk their only (near-)operational east coast pad for that until they have the two pads back in operation IMHO.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: russianhalo117 on 09/01/2016 04:45 PM
If this is a pad failure then procedures are a likely culprit. Inadequate inspections, checks, etc?

If the root cause is traced to a procedural issue, that would goes a long way toward showing why rapid launch cadence is difficult to achieve. So many things have to happen in such rapid succession and in exactly the right order and with exactly the right timing, or else *BOOM*. The answer for why ULA can't launch faster than they do is not just that "old aerospace" is inefficient.
your statements are not valid.
Jim take it away with the facts on this.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: mn on 09/01/2016 04:46 PM
Usually the folks at USLaunchReport have a camera(from a distance) on the static fires. Haven't posted anything yet.

This might be cynical of me, but I wonder if they're shopping the video around.

I don't know from where they record, perhaps their camera is located in a secure area and they cannot retrieve it until security is cleared?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: CorvusCorax on 09/01/2016 04:48 PM
Maybe it should be noted that unlike the general public which is relying on rumors and large distance post-event closeups of shaky video, ...

SpaceX will have high res video stream recordings of pad camera from multiple angles, likely including thermal infrared as well as optical - as well as high res telemetry data from both pad equipment and vehicle until the initial explosion and likely well past (usually it takes a few milliseconds, sometimes seconds from the original event till full scale disassembly that stops telemetry)

Considering pad systems like fire suppression obviously kept working they'd likely have had pad equipment data well afterwards too, maybe still do.

If the part at fault was an actuator like a valve, its even possible that the sensors on this very part indicated the malfunction to operators and board computers even before the actual RUD (but too late to do anything about it)

Based on that, I think a claim by somepone at SpaceX - direct or indirect - that pad equipment were at fault - even at such an early time - would be completely credible.

They would most likely be able to tell by now (with high likelyhood) which part caused the RUD and the event chain that lead from part failure to RUD (just like they were able to tell 2nd stage oxygen tank overpressure right after CRS-7)

Finding the root cause might take longer, for that they might have to find debris of said component - be it ground or vehicle side. it's likely to be among the most affected by the fire/explosion.

But I have no doubts they already know what to look for.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Chris Bergin on 09/01/2016 04:49 PM
Dumb question but what is COPV?

http://bfy.tw/7Us0

Whoa, that freaked me out! :)

COPVs were a fun subject during Shuttle:
https://www.nasaspaceflight.com/?s=COPV

---

Not that there is any information this was an issue today of course.

We're all waiting for Elon to say something, like he did after CRS-7. That will likely be the first official info we get to know.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Wolfram66 on 09/01/2016 04:51 PM
Photos of the pad seem to show the strong back not retracted.  Can anyone tell if it looks like the cradle arms were opened?  If so, that bounds the time of the incident pretty well.

i think its possible the arms we're closed bc it looks like they were bent/pulled downward. not a for sure thing though.

or possibly the rods that connect the top section of the TEL to the rest of it deformed from the heat?

It is very possible that the TEL was deformed by the heat of the fire. Having worked on offshore drilling rigs, i have seen the aftermath of blowouts and fires. The effects of fire on the 3/4 inch thick steel of the derrick is amazing. bent and twisted like taffy. :o :-\

http://www.houstonchronicle.com/business/energy/article/Flames-engulf-Mexico-oil-platform-in-Gulf-6173928.php
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jim on 09/01/2016 04:53 PM
including thermal infrared


Not used on RP-1 vehicles
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Lee Jay on 09/01/2016 04:56 PM
I'm stating outright that the root cause here is the ISS and Orbital.  It seems Murphy doesn't want all the cargo resuppliers operational at the same time.

That has to be it.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jim on 09/01/2016 04:58 PM
..

SpaceX will have high res video stream recordings of pad camera from multiple angles,


Don't know that
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: spacenut on 09/01/2016 04:59 PM
Well, at least we know it wasn't the rocket engines.  This took place before firing.  I've heard there were multiple explosions? 
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: edkyle99 on 09/01/2016 05:02 PM
Well, at least we know it wasn't the rocket engines.  This took place before firing.  I've heard there were multiple explosions? 
One big explosion, followed by a big fire and a series of secondary explosions.  Typical of a fire where multiple pressure vessels are present.

 - Ed Kyle
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: yg1968 on 09/01/2016 05:03 PM
No, this is not correct, the supposed ex-employee source on reddit denies that. They state:

I'm not exactly allowed to reveal sources. It'll still be months before things settle down, but it was definitely a pad issue.

Look it may be baloney, we can't say anything for sure, that's why it's a rumour.

Part of me hopes that it's something that is easy to fix. But if it's easy to fix, people will ask "why wasn't it detected?". The COPV would be bad news as it could imply that SpaceX is unable to fix that issue.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: john smith 19 on 09/01/2016 05:04 PM
If this is a pad failure then procedures are a likely culprit. Inadequate inspections, checks, etc?

If the root cause is traced to a procedural issue, that would goes a long way toward showing why rapid launch cadence is difficult to achieve. So many things have to happen in such rapid succession and in exactly the right order and with exactly the right timing, or else *BOOM*. The answer for why ULA can't launch faster than they do is not just that "old aerospace" is inefficient.
I see you are new. Welcome to the site.

Keep in mind that "fast launch cadence" in rocket terms is nothing like the fast cadence of say an F1 pit crew, or an ER team with a patient. It's usually more a question of having something to launch, IE payloads in the pipeline on a regular basis.

It's a weak data point but the DC-X team were ready to re-launch 8 hrs after a previous launch. It was simply the range crew that wanted to go home that delayed it to the following day. While a smaller vehicle (and non orbital) it could be (and often is) argued that LH2 is a much less forgiving fuel to handle than RP1.

AFAIK the usual concern with ELV companies is slow cadence, like the time between launches of SLS for example, where there is a real risk several staff will die or retire between one launch and the next. Nothing keeps a team sharp than the chance to regularly practice their skills in a live environment.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Prober on 09/01/2016 05:07 PM
Well, at least we know it wasn't the rocket engines.  This took place before firing.  I've heard there were multiple explosions? 
One big explosion, followed by a big fire and a series of secondary explosions.  Typical of a fire where multiple pressure vessels are present.

 - Ed Kyle


Yes, best pics I've just found so far...
http://www.wesh.com/news/explosion-reported-at-cape-canaveral/41467356
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: rsdavis9 on 09/01/2016 05:08 PM
Given that booster passed in McGregor.
Then transported to ksc.
Nothing happened to booster during transit.
Then the gse is the only variable.

P.s. also 2nd stage.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: OnWithTheShow on 09/01/2016 05:08 PM
Elon Musk ‏@elonmusk  29s30 seconds ago
Loss of Falcon vehicle today during propellant fill operation. Originated around upper stage oxygen tank. Cause still unknown. More soon.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Kosmos2001 on 09/01/2016 05:09 PM
Originated around upper stage oxygen tank.

Hmm...
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ugordan on 09/01/2016 05:10 PM
Given that booster passed in McGregor.
Then transported to ksc.
Nothing happened to booster during transit.
Then the gse is the only variable.

"Given that this lightbulb worked the last time I turned on the lights, it must work this time as well"

See the problem in that kind of reasoning?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Joaosg on 09/01/2016 05:11 PM
LV related cause :( This means all flights grounded and no immediate cause found. Was hopping for a pad fault that couldn't happen at Vanderberg.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: yatpay on 09/01/2016 05:12 PM
LV related cause :( This means all flights grounded and no immediate cause found. Was hopping for a pad fault that couldn't happen at Vanderberg.

No one said it was LV related. Elon just said "around upper stage oxygen tank". Could still be GSE.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: john smith 19 on 09/01/2016 05:12 PM
Part of me hopes that it's something that is easy to fix. But if it's easy to fix, people will ask "why wasn't it detected?".
True.
Quote
The COPV would be bad news as it could imply that SpaceX is unable to fix that issue.
Just to be clear IIRC it was not the COPV in the LOX tank but the struts holding them that failed and (eventually) caused the COPV's to fail.

Historically COPV's have been pretty reliable components. They have (relatively) generous safety margins for space structures. They should be minimized not because of the danger but the paperwork  they generate to show they've been tested and inspected. IIRC the ones on the SSME's last the life of each orbiter without replacement, roughly 30 flights each.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: cebri on 09/01/2016 05:13 PM
Elon Musk ‏@elonmusk  29s30 seconds ago
Loss of Falcon vehicle today during propellant fill operation. Originated around upper stage oxygen tank. Cause still unknown. More soon.

Well if there is a problem with the rocket... 2 major failures in 14 months... is going to be grounded for a while.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: JDTractorGuy on 09/01/2016 05:15 PM
Elon Musk ‏@elonmusk  29s30 seconds ago
Loss of Falcon vehicle today during propellant fill operation. Originated around upper stage oxygen tank. Cause still unknown. More soon.

Forgive me if this is a stupid question, but what could cause an explosion around that tank?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: kirghizstan on 09/01/2016 05:15 PM
Elon Musk ‏@elonmusk  29s30 seconds ago
Loss of Falcon vehicle today during propellant fill operation. Originated around upper stage oxygen tank. Cause still unknown. More soon.

Well if there is a problem with the rocket... 2 major failures in 14 months... is going to be grounded for a while.


Why, yes that is a lot, but that in no means there needs to be a long downtime.  This could be a very simple fix that has complete before the pad is fully operational again
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: rsdavis9 on 09/01/2016 05:15 PM
Has consideration ever been given to s2 static fire at McGregor?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Joaosg on 09/01/2016 05:16 PM
LV related cause :( This means all flights grounded and no immediate cause found. Was hopping for a pad fault that couldn't happen at Vanderberg.

No one said it was LV related. Elon just said "around upper stage oxygen tank". Could still be GSE.

You and Kablooma ar right. And the wording of the spacex statement on twitter is very interesting. They say the anomaly was on the Launch Complex, so this may be GSE related (stronback bouncing, bad connections, etc..)

(https://pbs.twimg.com/media/CrSLsLqUMAAyjPv.jpg:orig)
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: dorkmo on 09/01/2016 05:16 PM
Elon Musk ‏@elonmusk  29s30 seconds ago
Loss of Falcon vehicle today during propellant fill operation. Originated around upper stage oxygen tank. Cause still unknown. More soon.

Forgive me if this is a stupid question, but what could cause an explosion around that tank?

still dont know if it was an explosion either, could have been a slow burn at first?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: miki on 09/01/2016 05:17 PM
VIDEO!:  https://www.youtube.com/watch?v=_BgJEXQkjNQ   :o
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: tdperk on 09/01/2016 05:17 PM
Around the upper stage LOX tank sounds to me like an umbilical.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: yg1968 on 09/01/2016 05:17 PM
Part of me hopes that it's something that is easy to fix. But if it's easy to fix, people will ask "why wasn't it detected?".
True.
Quote
The COPV would be bad news as it could imply that SpaceX is unable to fix that issue.
Just to be clear IIRC it was not the COPV in the LOX tank but the struts holding them that failed and (eventually) caused the COPV's to fail.

Historically COPV's have been pretty reliable components. They have (relatively) generous safety margins for space structures. They should be minimized not because of the danger but the paperwork  they generate to show they've been tested and inspected. IIRC the ones on the SSME's last the life of each orbiter without replacement, roughly 30 flights each.

Yes, I know about the struts. But wasn't there a COPV problem prior to CRS-7?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: StuffOfInterest on 09/01/2016 05:18 PM
Elon Musk ‏@elonmusk  29s30 seconds ago
Loss of Falcon vehicle today during propellant fill operation. Originated around upper stage oxygen tank. Cause still unknown. More soon.

Forgive me if this is a stupid question, but what could cause an explosion around that tank?


Upper stage fill line blows out spraying LOX all over the side of the rocket?

I can see there being several things that could go wrong around the upper stage but not be part of the upper stage.  Still, this is a lot of word parsing and it could really be something inside of the upper stage as well.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: cebri on 09/01/2016 05:18 PM
Elon Musk ‏@elonmusk  29s30 seconds ago
Loss of Falcon vehicle today during propellant fill operation. Originated around upper stage oxygen tank. Cause still unknown. More soon.

Well if there is a problem with the rocket... 2 major failures in 14 months... is going to be grounded for a while.


Why, yes that is a lot, but that in no means there needs to be a long downtime.  This could be a very simple fix that has complete before the pad is fully operational again

Even if the fix easy, which is total speculation until we know the cause, if there is a problem with the rocket, SpaceX is going to need time to rebuild their confidence again.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: meekGee on 09/01/2016 05:19 PM
I give zero cred to a supposed ex-employee being so connected that he/she knows the cause before most likely anybody in SX does

I don't know about the ex-employee but I think it is highly likely that SX has a very good idea of what went wrong. (maybe yes, maybe not, but certainly highly likely).

Actually, in principle, it could very well be that they "saw it happening" and know exactly what happened.
In practice though, Elon's tweet is counter-indicative of that.

Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Kabloona on 09/01/2016 05:19 PM
Part of me hopes that it's something that is easy to fix. But if it's easy to fix, people will ask "why wasn't it detected?".
True.
Quote
The COPV would be bad news as it could imply that SpaceX is unable to fix that issue.
Just to be clear IIRC it was not the COPV in the LOX tank but the struts holding them that failed and (eventually) caused the COPV's to fail.

Historically COPV's have been pretty reliable components. They have (relatively) generous safety margins for space structures. They should be minimized not because of the danger but the paperwork  they generate to show they've been tested and inspected. IIRC the ones on the SSME's last the life of each orbiter without replacement, roughly 30 flights each.

Yes, I know about the struts. But wasn't there a COPV problem prior to CRS-7?

Yes, there was a leak/overpressure event on the pad on an earlier mission.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Joaosg on 09/01/2016 05:20 PM
VIDEO!:  https://www.youtube.com/watch?v=_BgJEXQkjNQ   :o

WOW. We can see the payload fall seconds after the first explosion. Maybe a dragon could fly away in time.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: yokem55 on 09/01/2016 05:20 PM
"Originated around upper stage lox tank". around

Could have the strong back started to retract while the cradle arms were still around the vehicle?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: dorkmo on 09/01/2016 05:21 PM
definitely an explosion
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: russianhalo117 on 09/01/2016 05:22 PM
VIDEO!:  https://www.youtube.com/watch?v=_BgJEXQkjNQ   :o
can wait for Matthew Travis's 4K videos. Not sure if his closeup cameras would have survivied.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: rsdavis9 on 09/01/2016 05:22 PM
Well the logic actually worked in this case.
Also given that SpaceX engineers no what they are doing when they design the McGregor test. And the last failure was from something nearly impossible to simulate. G force!
Given that booster passed in McGregor.
Then transported to ksc.
Nothing happened to booster during transit.
Then the gse is the only variable.

"Given that this lightbulb worked the last time I turned on the lights, it must work this time as well"

See the problem in that kind of reasoning?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Elmar Moelzer on 09/01/2016 05:22 PM
freak lightning strike of sorts?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Lars-J on 09/01/2016 05:23 PM
VIDEO!:  https://www.youtube.com/watch?v=_BgJEXQkjNQ   :o

Yikes, certainly looks like a high pressure event in the upper stage LOX tank.  :o
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: tdperk on 09/01/2016 05:23 PM
That was quick.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: meekGee on 09/01/2016 05:23 PM
Oh, wow - I'm looking just at the first instance of visible event - it's damn sudden and energetic.

Doesn't look like a fire to me, maybe an over-pressure.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: yg1968 on 09/01/2016 05:24 PM
WOW. We can see the payload fall seconds after the first explosion. Maybe a dragon could fly away in time.

Maybe the crew Dragon but not the cargo Dragon. The cargo Dragon can now survive a CRS-7 type accident by deploying its parachutes but that doesn't help if the accident is at the pad.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: vanoord on 09/01/2016 05:24 PM
To watch frame-by-frame on YouTube:

- pause video
- press . to advance
- press , to go back
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: john smith 19 on 09/01/2016 05:24 PM
Elon Musk ‏@elonmusk  29s30 seconds ago
Loss of Falcon vehicle today during propellant fill operation. Originated around upper stage oxygen tank. Cause still unknown. More soon.
Note what this does not say.

It does not specify upper stage, it says around upper stage O2 tank area.

So could still be GSE in that area. I thought the tanks were filled by umbilicals near the ground feeding both 1st and 2nd stages?

Obviously this focuses the attention to a much smaller area, which should speed up resolving root cause.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ugordan on 09/01/2016 05:26 PM
can wait for Matthew Travis's 4K videos. Not sure if his closeup cameras would have survivied.

Those are only placed immediately before the launch?

This is as good as it's gonna get IMHO.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: vanoord on 09/01/2016 05:27 PM
First frame of the explosion:

Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: OnWithTheShow on 09/01/2016 05:27 PM
Looks like the initial overpressure from the explosion either split a weld seam on the 1st stage or the FTS fired after the 2nd stand exploded. Looks like a vertical split all the way down the 1st stage on the left side.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: dorkmo on 09/01/2016 05:28 PM
i think this is one frame before that

*not an expert* but i looks like the side closest to the TEL was explosing first
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: edkyle99 on 09/01/2016 05:29 PM
Oh, wow - I'm looking just at the first instance of visible event - it's damn sudden and energetic.

Doesn't look like a fire to me, maybe an over-pressure.
Looks to me like Jim was right about this one. 

 - Ed Kyle
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: eeergo on 09/01/2016 05:30 PM
Immediately before/immediately after event.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Tonioroffo on 09/01/2016 05:31 PM
Oh boy, 2nd stage again.  Also looks to fast for hypothetical dragon 2 Escape.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: NX-0 on 09/01/2016 05:31 PM
A couple of things I see (and I am not expert)
1. No retraction of the strongback.
2. Initial burst is white and clean, no black smoke - that's O2.
3. Total collapse of the stack extremely quickly.
4. Fairing hung onto the strongback for, what I consider to be, quite some time before tumbling down, nose first.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Kosmos2001 on 09/01/2016 05:31 PM
At 3:42 there is another explosion.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Kansan52 on 09/01/2016 05:32 PM
Looks like the payload and fairing was intact, held by the TEL, and it's weight caused the damage to the upper part of the TEL. Because when it dropped, there was no sign of the Falcon.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jim on 09/01/2016 05:33 PM

1.  It's a weak data point but the DC-X team were ready to re-launch 8 hrs after a previous launch. It was simply the range crew that wanted to go home that delayed it to the following day. While a smaller vehicle (and non orbital) it could be (and often is) argued that LH2 is a much less forgiving fuel to handle than RP1.

2.  AFAIK the usual concern with ELV companies is slow cadence, like the time between launches of SLS for example, where there is a real risk several staff will die or retire between one launch and the next. Nothing keeps a team sharp than the chance to regularly practice their skills in a live environment.

1.  Not even relevant.  No upper stage or payload. 

2.  No, quick cadence or back to back launches has been just as much a concern.  See Delta II and Atlas II in the 90's
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: eeergo on 09/01/2016 05:33 PM
At 3:42 there is another explosion.

That looks like RP-1, maybe from GSE that wasn't still drained back?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: vt_hokie on 09/01/2016 05:33 PM
That was quick.

But possibly enough time for the launch escape system to save the crew, had this been a launch of Crew Dragon?  I know, we're a long way from that right now, sadly, given today's events.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Shanuson on 09/01/2016 05:34 PM
For me, jumping between before and after event, the center of the first explosion lies not at the 2nd stage but somewhere on the strongback close to the 2nd stage.

Also testfiring the 1st stage at McGregor does not help with 2nd stage problems.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: vanoord on 09/01/2016 05:35 PM
Assuming that the x-shaped lens flare of the initial explosion is centred somewhere near the hottest point, that should theoretically be the point of failure. I've circled it on the frame immediately before the explosion.

(First explosion frame added for comparison)
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Bob Shaw on 09/01/2016 05:35 PM
No question about it being the second stage (or loading thereof). And, of course, that's the part which doesn't return to be torn down. When I went through the YouTube video frame-by frame there seemed to be a distinct horizontal component on both sides of the top of the stage - but that may be a perspective artefact.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: The_Ronin on 09/01/2016 05:36 PM
That looks electrical on the TE.  Umbilical connection shorted?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: M_Puckett on 09/01/2016 05:38 PM
Give me enough O2 and I can make a rock burn.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: JasonAW3 on 09/01/2016 05:38 PM
That looks electrical on the TE.  Umbilical connection shorted?

Damaged grounding strap?  Could cause a build up of static electricity that discharged.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: launchwatcher on 09/01/2016 05:38 PM
i think this is one frame before that

*not an expert* but i looks like the side closest to the TEL was explosing first
Yep.   Definitely looks centered on the edge of the stage or just to the right.
I'm wondering if the dark patch on the left side of the fireball is the remnants of the umbilical at that level (roughly the right size for that?)

The shadows on the vapor clouds from the first stage in that frame is also consistent with the explosion starting on the side of the stage.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jim on 09/01/2016 05:39 PM


You and Kablooma ar right. And the wording of the spacex statement on twitter is very interesting. They say the anomaly was on the Launch Complex, so this may be GSE related (stronback bouncing, bad connections, etc..)


No, again, wrong interpretation.   
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: eeergo on 09/01/2016 05:39 PM
For future reference, some stills from the payload composite hanging on and falling on the pad. Is is really apparent how its weight deformed the top of the TE after the initial upwards draft from the explosion dissipated.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ugordan on 09/01/2016 05:39 PM
Based on the flash location and the fact there was immediate ignition, the common bulkhead looks like a suspect to me.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Joaosg on 09/01/2016 05:39 PM
Gif of the explosion. Seems the umbilical, or any other connection.

Could an O2 rich environment + electricak sparks cause this?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: M_Puckett on 09/01/2016 05:40 PM
2 Questions:

Assuming this was the support equipment and a cause can be quickly identified:

1) How long will it take to repair the pad at Complex 40

2) How close are we to 39a going operational?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: RoboGoofers on 09/01/2016 05:40 PM
What would be the ignition source if it was just an overpressurization?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: RonM on 09/01/2016 05:40 PM
Great footage provided by USLaunchReport.com. Keep up the good work.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: rsdavis9 on 09/01/2016 05:41 PM
So that makes sense for full duration. Maybe 2sec and nozzle would survive. Thereby testing a whole bunch of stuff.
Has consideration ever been given to s2 static fire at McGregor?

Can't do it because it would destroy the Mvac nozzle to fire it at sea level.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: sunbingfa on 09/01/2016 05:41 PM
Very strange for the explosion. There is no sign of eruption of anything before the explosion. Maybe a spark somewhere near upper stage oxygen tank?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: launchwatcher on 09/01/2016 05:42 PM
Gif of the explosion. Seems the umbilical, or any other connection.
there's another frame between the two you showed (look at the bird flying right to left around the lighting tower just to the right of the vehicle).
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: SupaNova on 09/01/2016 05:42 PM
Gif of the first few frames, origin seems to be somewhat towards the strongback.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ncb1397 on 09/01/2016 05:43 PM
2 Questions:

Assuming this was the support equipment and a cause can be quickly identified:

1) How long will it take to repair the pad at Complex 40

Antares pad repair took about 12 months. Of course, that included wrangling about who was going to pay for it.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Galactic Penguin SST on 09/01/2016 05:43 PM
Based on the flash location and the fact there was immediate ignition, the common bulkhead looks like a suspect to me.

Well isn't the common bulkhead where the COPVs are on stage 2?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ugordan on 09/01/2016 05:44 PM
Notice also that the 1st stage LOX tank let go even before that flaming inferno hit the ground.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ZachF on 09/01/2016 05:44 PM
Doing some freeze-framing it looks like the explosion is centered around the umbilical connection.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: mheney on 09/01/2016 05:44 PM
At 3:42 there is another explosion.

That looks like RP-1, maybe from GSE that wasn't still drained back?

If you  watch closely, at about 3:33, there's a fade/cut.  (watch the smoke at the bottom of the frame by the lightning tower.)  So the second explosion was not at 3:42 - there are reports that said the second explosion was some 20 minutes later.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: russianhalo117 on 09/01/2016 05:45 PM
Based on the flash location and the fact there was immediate ignition, the common bulkhead looks like a suspect to me.

Well isn't the common bulkhead where the COPVs are on stage 2?
they were at least when they last caused a launch failure. I don't what changed for the FT variant.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ugordan on 09/01/2016 05:45 PM
Based on the flash location and the fact there was immediate ignition, the common bulkhead looks like a suspect to me.

Well isn't the common bulkhead where the COPVs are on stage 2?

I think they might be located a bit higher than that.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Billium on 09/01/2016 05:46 PM
i think this is one frame before that

*not an expert* but i looks like the side closest to the TEL was explosing first
Yep.   Definitely looks centered on the edge of the stage or just to the right.
I'm wondering if the dark patch on the left side of the fireball is the remnants of the umbilical at that level (roughly the right size for that?)

The shadows on the vapor clouds from the first stage in that frame is also consistent with the explosion starting on the side of the stage.

I'm no expert, but I agree it seems like an explosion on the right side of the rocket, or beside the rocket. I also noticed debris going exactly vertical on the right side immediately after the explosion, which implies to me that the point of explosion was just to the right of the rocket rather than the rocket itself.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: RoboGoofers on 09/01/2016 05:46 PM
Very strange for the explosion. There is no sign of eruption of anything before the explosion. Maybe a spark somewhere near upper stage oxygen tank?

But oxygen doesn't "burn", it oxidizes something else. i'm guessing it would be insulation on the umbilical or somewhere else, or the fuel?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: wolfpack on 09/01/2016 05:47 PM
Looks to me like Jim was right about this one. 

 - Ed Kyle

Unfortunately, that's what happens when you "probably" fix things. Heck, I'm guilty of it myself.

At least this happened on the ground, they'll find all the pieces and get to a real root cause.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: SWGlassPit on 09/01/2016 05:48 PM

1) How long will it take to repair the pad at Complex 40


Won't really have a good answer on this until the damage can be surveyed.  Livestream shows pad 40 still smoldering, so it will be a while before it's cool enough for people to go in and investigate.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Kabloona on 09/01/2016 05:48 PM
Based on the flash location and the fact there was immediate ignition, the common bulkhead looks like a suspect to me.

Well isn't the common bulkhead where the COPVs are on stage 2?

I think they might be located a bit higher than that.

If a COPV let go on the side near the T/E, that might be consistent with what we see on the video.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: jacqmans on 09/01/2016 05:48 PM
Looks like the payload falls down intact and then explodes...
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: pogo661 on 09/01/2016 05:49 PM
Assuming that the x-shaped lens flare of the initial explosion is centred somewhere near the hottest point, that should theoretically be the point of failure. I've circled it on the frame immediately before the explosion.

(First explosion frame added for comparison)

Could that be a jet of vapor, streaming from the upper stage to the right?  The light patch exactly at the point you've marked.  All the other vapor in the photo is drifting to the left.   Could that a leak just before the explosion?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: wolfpack on 09/01/2016 05:51 PM

Antares pad repair took about 12 months. Of course, that included wrangling about who was going to pay for it.

There was also some serious environmental contamination from the Antares' solid second stage, which required cleanup. That isn't the case here. I'm not sure, though, about what the spacecraft's hypergols and the rocket's TEA/TEB mean as far as environmental impacts go.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Galactic Penguin SST on 09/01/2016 05:51 PM
Looks like the payload falls down intact and then explodes...

I'm surprised that it held on to the strongback for that long with everything under vaporized.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: dnavas on 09/01/2016 05:54 PM
I'm no expert, but I agree it seems like an explosion on the right side of the rocket, or beside the rocket. I also noticed debris going exactly vertical on the right side immediately after the explosion, which implies to me that the point of explosion was just to the right of the rocket rather than the rocket itself.

There is definitely a right-leaning start to the explosion.  That said, I would (completely naively) expect that if something caught fire *outside* first, that the second stage letting loose would be a second explosion, and I don't get that sense from the video.  It seems more likely that something went boom and escaped first along the pathway of least resistance -- out the feed-side.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ugordan on 09/01/2016 05:54 PM
Doing some freeze-framing it looks like the explosion is centered around the umbilical connection.

Doesn't look that way to me. The umbilicals are at the 2nd stage-interstage connection, the part the explosion seems to originate at is the structural support and presumably common bulkhead location, circled in red in this image.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: vanoord on 09/01/2016 05:56 PM
Could that be a jet of vapor, streaming from the upper stage to the right?  The light patch exactly at the point you've marked.  All the other vapor in the photo is drifting to the left.   Could that a leak just before the explosion?

Having gone back and forwards again in the video, it doesn't look like it.

There's another frame that I may have been skipping over, so for the sake of neatness, here are the three in sequence:
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: cscott on 09/01/2016 05:56 PM
It does seem clear that strongback was vertical and cradles closed, which puts the event before T-4:10.  FTS was therefore not armed.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: IanH84 on 09/01/2016 05:58 PM
edit: looks like it didn't capture the full frame, I'll try again and fix it later
http://imgur.com/a/WXKge
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: leetdan on 09/01/2016 05:59 PM
Check the audio, there's a small pop about 5 seconds before the sound from the actual explosions arrive.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: mikes on 09/01/2016 06:00 PM
If you download the video from YouTube, then use VLC to synch the sound to allow for the distance from the pad to the camera

 Tools > Track sync > Sync > Audio > -12 seconds

there is a quiet bang about 5 seconds before the first visible explosion.

(Edit: Jinx!)
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Zed_Noir on 09/01/2016 06:00 PM
Can the FTS be activated from the initial explosion? Causing the 1st stage to unzipped.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: russianhalo117 on 09/01/2016 06:02 PM
It does seem clear that strongback was vertical and cradles closed, which puts the event before T-4:10.  FTS was therefore not armed.
actually with the current countdown timeline:
Correct timeline (http://spaceflight101.com/falcon-9-ft-countdown-timeline/):
Falcon 9 FT – Countdown Timeline
All Times Approximate.
Time   Event
L-15:00:00   Falcon 9 to Vertical
L-10:00:00   Countdown Initiation, Launch Vehicle Power-Up
L-6:00:00   First Weather Balloon Release
L-5:00:00   Launch Area Evacuation
L-4:45:00   Range Controllers on Station
L-4:35:00   Falcon 9 Attitude Control System N2 Loading
L-5:00:00   Launch Area Evacuation
L-2:45:00   Falcon 9 RF & Telemetry Checks
L-2:30:00   Falcon 9 Launch Vehicle Release System Test
L-2:25:00   TEA-TEB Bleed In
L-1:45:00   Comm & FTS Checks
L-1:40:00   Data Flow Tests with Downrange Tracking Stations
L-1:00:00   Weather Briefing
L-0:50:00   RF Link Checks
L-0:45:00   Pre-Load Hold Point, Propellant Polls
L-0:45:00   Blast Danger Area Clear, Roadblocks Established
L-0:45:00   Flight Control System Setup (Flight Software Loading)
L-0:45:00   Final Tank Chill-In
L-0:40:00   Ready for Prop Load
L-0:38:00   Launch Readiness Poll
L-0:36:00   Tanks vented for Prop Loading
T-0:35:00   Automated Countdown Sequence, Master Script Running
T-0:34:45   Launch Enable to Flight Mode
T-0:34:30   RP-1 Flow to both Stages
T-0:33:30   Stage 1 Liquid Oxygen Loading
T-0:32:30   Confirm nominal Fuel Flow Rates
T-0:32:00   Latest Prop Flow Start
T-0:29:30   Stage 1 Helium Load
T-0:27:00   Spacecraft to Internal Power
T-0:25:30   Fuel Collector Pre-Valves Closed
T-0:25:00   All three Liquid Helium Pumps active
T-0:22:00   Stage 2 Fuel Loading Complete
T-0:19:30   Stage 2 Liquid Oxygen Loading
T-0:17:20   Stage 1 LOX Flowrate Adjustment for Stage 2 Fast Fill
T-0:13:15   Stage 2 Helium Loading
T-0:13:00   Stage 2 LOX Flow Adjustment for Helium Cryo Load
T-0:13:00   Countdown Recycle Point
T-0:12:45   Merlin 1D & MVac BTV Activation
T-0:10:15   Grid Fin Pneumatics Secured
T-0:10:05   Boostback Hazards Disabled
T-0:10:00   Stage 2 Venting for LOX Fast Fill
T-0:09:50   Flight Software Final Setups complete
T-0:09:45   TEA-TEB Ignition System Setup
T-0:09:45   Stage 2 Transmitter Re-Activation
T-0:09:30   M1D Trim Valve Cycling
T-0:09:15   Stage 1 Helium Topping
T-0:07:45   MVac Fuel Trim Valve Setup
T-0:07:30   Engine Chill Readiness
T-0:07:00   Engine Chilldown (Bleed Valves Open, both Stages
T-0:07:00   Spacecraft on Internal Power
T-0:06:45   Stage 2 Helium Transition to Pipeline
T-0:06:35   MVac Hydraulics at Bleed Pressure
T-0:06:05   M1D Engines to TVC-Null Position
T-0:05:20   Flight Computers in Self-Alignment
T-0:05:20   Stage 1 Fuel Loading Complete
T-0:05:15   Launch Vehicle Heater Deactivation
T-0:05:00   Falcon 9 to Internal Power
T-0:05:00   Range Control Comm Check
T-0:05:00   Second Stage Nitrogen Loading Termination
T-0:04:50   Pressurization for Strongback Retract
T-0:04:40   Stage 2 TVC Bleed
T-0:04:30   Stage 2 RP-1 Bleed
T-0:04:30   Stage 2 Thrust Vector Control Test
T-0:04:20   Verify Good Self-Alignment
T-0:04:10   Strongback Cradles Opening

T-0:04:00   Vehicle Release Auto Sequence
T-0:03:40   TEA-TEB Ignition System Auto Sequence
T-0:03:30   Strongback Retraction
T-0:03:25   Flight Termination System to Internal Power
T-0:03:15   FTS on Internal
T-0:03:05   Flight Termination System Armed, FTS Ready for Launch
T-0:02:55   Verify Good Mvac TVC
T-0:02:45   Fuel Trim Valve to Flight Position
T-0:02:40   Stage 1 LOX at Flight Level
T-0:02:40   FTS Countdown Sequence
T-0:02:35   Strongback Retraction Complete
T-0:02:05   Stage 2 LOX at Flight Level
T-0:02:00   Falcon 9 Transfer to Internal Power Complete
T-0:01:35   Flight Control to Self Alignment
T-0:01:30   Launch Director: Go for Launch
T-0:01:30   Final Engine Chilldown
T-0:01:25   Helium Loading Termination
T-0:01:20   Engine Purge
T-0:01:00   Flight Computer to start-up
T-0:00:50   Stage 1, Stage 2 Pressurization for Flight
T-0:00:50   First Stage Thrust Vector Actuator Test
T-0:00:30   HOLD Call for Abort
T-0:00:20   All Tanks at Flight Pressure
T-0:00:15   Arm Pyrotechnics
T-0:00:10   Latest VC Abort
T-0:00:07   Pad Deck Water Deluge System Activation
T-0:00:03   Merlin Engine Ignition
T-0:00:00   LIFTOFF
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ZachF on 09/01/2016 06:03 PM
Doing some freeze-framing it looks like the explosion is centered around the umbilical connection.

Doesn't look that way to me. The umbilicals are at the 2nd stage-interstage connection, the part the explosion seems to originate at is the structural support and presumably common bulkhead location, circled in red in this image.

Yeah it's blurry, looks like somewhere in this vicinity:
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Mongo62 on 09/01/2016 06:03 PM
It certainly looks like the origin point of the visible explosion was outside the rocket itself. In the first few frames, most of the brightness appears to be reflections off the rocket and T/E, and off the surrounding condensation clouds. So the actual light source must have been intensely bright and probably very concentrated, like a very powerful arc of electricity.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: dorkmo on 09/01/2016 06:05 PM
Check the audio, there's a small pop about 5 seconds before the sound from the actual explosions arrive.

about 1:19 eh?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ugordan on 09/01/2016 06:06 PM
Check the audio, there's a small pop about 5 seconds before the sound from the actual explosions arrive.

I think that's just someone messing around a car or something near the camera.

Interestingly enough, the small first bang heard is the original S2 explosion. The big bang 3 seconds later is the fuel-air type explosion when that fireball hit the ground and mixed up the RP-1 and LOX. Check out that light pole above the number "2" bending by the generated shockwave. I wonder what the extent of damage to the hangar must be.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: meekGee on 09/01/2016 06:06 PM
I think there's too much energy in the initial explosion for it to be umbilicals.

I'd vote COPV, or COPV+bulkhead.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: SWGlassPit on 09/01/2016 06:09 PM
Can the FTS be activated from the initial explosion? Causing the 1st stage to unzipped.

I know nothing about SpaceX's FTS design, but there exist certain conditions that could result in an uncommanded FTS charge initiation, even when safed.  It's somewhere between exceedingly unlikely and practically impossible on the ground, but it is something that is considered in other environments.  Whether a nearby deflagration or detonation could initiate a charge is going to depend on design details I don't know.  I would assume that protecting against that hazard would be part of the design requirements, but again, I don't have any insight into this hardware.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Aerospace Dilettante on 09/01/2016 06:09 PM
Could that be a jet of vapor, streaming from the upper stage to the right?  The light patch exactly at the point you've marked.  All the other vapor in the photo is drifting to the left.   Could that a leak just before the explosion?

Having gone back and forwards again in the video, it doesn't look like it.

There's another frame that I may have been skipping over, so for the sake of neatness, here are the three in sequence:

Anybody have any idea what that apparently rapidly moving object is?  It enters the field of view from the right immediately before the explosion.  It crosses the screen in 15 frames and is in between the the lightning tower and the rocket at detonation.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jet Black on 09/01/2016 06:10 PM
Could that be a jet of vapor, streaming from the upper stage to the right?  The light patch exactly at the point you've marked.  All the other vapor in the photo is drifting to the left.   Could that a leak just before the explosion?

Having gone back and forwards again in the video, it doesn't look like it.

There's another frame that I may have been skipping over, so for the sake of neatness, here are the three in sequence:

Across over the lines of glare should give the centre of the brightest part, even though the explosion itself saturated the camera.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Silmfeanor on 09/01/2016 06:11 PM
I think there's too much energy in the initial explosion for it to be umbilicals.

I'd vote COPV, or COPV+bulkhead.
agreed. There is just not as much explosive energy in the umbilicals. If they would pop you'd get a flow or stream, which might damage later. Not this very sudden very energetic event.
pressure in the stage getting released - either through COPV/associated plumbing is, imho, at this point way more likely.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: vanoord on 09/01/2016 06:12 PM
Across over the lines of glare should give the centre of the brightest part, even though the explosion itself saturated the camera.

Using the lens flare as a crosshair, it's around the point I've circled in red on the first frame.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: envy887 on 09/01/2016 06:14 PM
I think there's too much energy in the initial explosion for it to be umbilicals.

I'd vote COPV, or COPV+bulkhead.
agreed. There is just not as much explosive energy in the umbilicals. If they would pop you'd get a flow or stream, which might damage later. Not this very sudden very energetic event.
pressure in the stage getting released - either through COPV/associated plumbing is, imho, at this point way more likely.

Umbilical could leak, resulting in an explosive mixture of fuel vapors and atmospheric and/or vented/leaked oxygen  later ignited by a spark. The explosion would be initially centered on the source of the spark, not the source of the leak.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: SWGlassPit on 09/01/2016 06:14 PM
Could that be a jet of vapor, streaming from the upper stage to the right?  The light patch exactly at the point you've marked.  All the other vapor in the photo is drifting to the left.   Could that a leak just before the explosion?

Having gone back and forwards again in the video, it doesn't look like it.

There's another frame that I may have been skipping over, so for the sake of neatness, here are the three in sequence:

Anybody have any idea what that apparently rapidly moving object is?  It enters the field of view from the right immediately before the explosion.

Almost undoubtedly a bird or a bug just crossing the field of view.  There are dozens of them throughout the video.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ejb749 on 09/01/2016 06:15 PM
Frame by frame animation...

Edit: Missing Frames added.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ZachF on 09/01/2016 06:15 PM
Across over the lines of glare should give the centre of the brightest part, even though the explosion itself saturated the camera.

Using the lens flare as a crosshair, it's around the point I've circled in red on the first frame.

Using the flare as a crosshair I get a point of origin just outside of the rocket, just above the strongback attachment.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jet Black on 09/01/2016 06:15 PM
I think there's too much energy in the initial explosion for it to be umbilicals.

I'd vote COPV, or COPV+bulkhead.

Not easy to tell how much energy there is nothing seems to shake.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: JDTractorGuy on 09/01/2016 06:16 PM
Could that be a jet of vapor, streaming from the upper stage to the right?  The light patch exactly at the point you've marked.  All the other vapor in the photo is drifting to the left.   Could that a leak just before the explosion?

Having gone back and forwards again in the video, it doesn't look like it.

There's another frame that I may have been skipping over, so for the sake of neatness, here are the three in sequence:

Anybody have any idea what that apparently rapidly moving object is?  It enters the field of view from the right immediately before the explosion.  It crosses the screen in 15 frames and is in between the the lightning tower and the rocket at detonation.

Seems to be a bird or other animal.  It flies harmlessly over the rocket as it explodes.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Kosmos2001 on 09/01/2016 06:16 PM
Peter B. de Selding:
SpaceX explosion didn't involve intentional ignition - E Musk said occurred during 2d stage fueling - & isn't covered by launch insurance.

https://twitter.com/pbdes/status/771409425475174400
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Galactic Penguin SST on 09/01/2016 06:18 PM
In other news....

Peter B. de Selding‏ @pbdes
Spacecom insured Amos-6 for $285M in marine cargo market, not space insurance market. Launch +1 yr policy would kick in at rocket ignition.

Peter B. de Selding‏ @pbdes
@cbs_spacenews Sat was insured as marine cargo for pre-launch phase. Launch policy didn't kick in because no ignition-w/-intent-to-launch.

Does that mean that Spacecom won't get as much insurance payment as if this happened above ground?  :-X
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Aerospace Dilettante on 09/01/2016 06:18 PM

Could that be a jet of vapor, streaming from the upper stage to the right?  The light patch exactly at the point you've marked.  All the other vapor in the photo is drifting to the left.   Could that a leak just before the explosion?

Having gone back and forwards again in the video, it doesn't look like it.

There's another frame that I may have been skipping over, so for the sake of neatness, here are the three in sequence:

Anybody have any idea what that apparently rapidly moving object is?  It enters the field of view from the right immediately before the explosion.  It crosses the screen in 15 frames and is in between the the lightning tower and the rocket at detonation.

And 12 frames after detonation another object enters the frame from the lower left and transits the fire ball at seemingly equal high velocity. 

I'm breaking out my trusty tinfoil chapeau.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Mongo62 on 09/01/2016 06:18 PM
Peter B. de Selding:
SpaceX explosion didn't involve intentional ignition - E Musk said occurred during 2d stage fueling - & isn't covered by launch insurance.

https://twitter.com/pbdes/status/771409425475174400

Ouch. So Spacecom has to eat the cost?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: vanoord on 09/01/2016 06:19 PM
Frame by frame animation...

There's a frame missing - the initial explosion doesn't have the lens flare / cross-hair. It seems to be luck with YouTube whether you pause and get one sequence or the other. (Took me about three times before I noticed it). This is first frame of the explosion:
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Zach Swena on 09/01/2016 06:20 PM
Anyone else hear the vent just prior to the explosion.  To me, the audio sounded like there was a vent event that gained pressure as time went on and ended in an explosion of the second stage originating from the area discussed.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Lar on 09/01/2016 06:20 PM
We have a fair few people doing some good work slicing and dicing the video that USLaunchReport shared.

But I would like to point out this text, attached to the vid on YouTube.

"Ask for permission before using or cutting. Sharing in the original version is fine"

Please keep that in mind, analysis here is likely to be viewed and shared widely.  I'm not sure I see an easy answer. Metadiscussion of this note discouraged, I'm bucking this upstairs.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jet Black on 09/01/2016 06:20 PM
I think there's too much energy in the initial explosion for it to be umbilicals.

I'd vote COPV, or COPV+bulkhead.
agreed. There is just not as much explosive energy in the umbilicals. If they would pop you'd get a flow or stream, which might damage later. Not this very sudden very energetic event.
pressure in the stage getting released - either through COPV/associated plumbing is, imho, at this point way more likely.

The brightness can just be burning. Don't mistake an oversaturated image for lots of energy.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: yokem55 on 09/01/2016 06:20 PM
Peter B. de Selding:
SpaceX explosion didn't involve intentional ignition - E Musk said occurred during 2d stage fueling - & isn't covered by launch insurance.

https://twitter.com/pbdes/status/771409425475174400
Not covered by launch insurance. Do separate transport/handling/integration/testing policies exist? I can't imagine a $200 million asset would be totally unprotected in phases other than launch itself...
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Kabloona on 09/01/2016 06:22 PM
Check the audio, there's a small pop about 5 seconds before the sound from the actual explosions arrive.

I think that's just someone messing around a car or something near the camera.

Interestingly enough, the small first bang heard is the original S2 explosion. The big bang 3 seconds later is the fuel-air type explosion when that fireball hit the ground and mixed up the RP-1 and LOX.

I hear three distinct "initial" sounds:

1:16--a very faint "plonk" like someone hitting a PVC pipe with a hammer in the distance...COPV rupture?
1:18--a faint pop/bang... S2 tank rupture?
1:23--very loud boom...the LOX/RP-1 explosion?

That first sound at 1:16 is unusual and seems to me like it may be the initiating event. A COPV or high pressure line/fitting letting go followed by S2 tank rupture 1-2 seconds later seems consistent.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: bstrong on 09/01/2016 06:22 PM
Superficially, this looks awfully similar to CRS-7: Increased venting of S2 starting about 10s 20s prior to what sure looks to me like an overpressure event leading to a rupture near the top of S2.

First frame showing explosion attached, overprocessed to bring out detail in the fireball and help identify the origin point. My read of it is a tank rupture on the left side.

(And don't worry, this post will be my only attempt at video analysis this time.)
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ZachF on 09/01/2016 06:25 PM
In other news....

Peter B. de Selding‏ @pbdes
Spacecom insured Amos-6 for $285M in marine cargo market, not space insurance market. Launch +1 yr policy would kick in at rocket ignition.

Peter B. de Selding‏ @pbdes
@cbs_spacenews Sat was insured as marine cargo for pre-launch phase. Launch policy didn't kick in because no ignition-w/-intent-to-launch.

Does that mean that Spacecom won't get as much insurance payment as if this happened above ground?  :-X

It probably means many lawyers are pressing their suits and preparing for battle...
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: The_Ronin on 09/01/2016 06:26 PM
Can someone point out this increase venting on S2 before the event?  I keep watching it and I do not see what they are talking about.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: cscott on 09/01/2016 06:26 PM
In other news....

Peter B. de Selding‏ @pbdes
Spacecom insured Amos-6 for $285M in marine cargo market, not space insurance market. Launch +1 yr policy would kick in at rocket ignition.

Peter B. de Selding‏ @pbdes
@cbs_spacenews Sat was insured as marine cargo for pre-launch phase. Launch policy didn't kick in because no ignition-w/-intent-to-launch.

Does that mean that Spacecom won't get as much insurance payment as if this happened above ground?  :-X
I'm reading this as "Spacecom will get a $285M payout from their marine cargo insurance, not <whatever amount> from their space launch insurance, since the incident happened before launch."

They'd be foolish to leave their cargo uninsured for any period of time: the incoming tropical storm could have taken out the payload before launch in some freak accident, for instance.  So it's just a question of who has to pay.

I could be wrong, of course.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Aerospace Dilettante on 09/01/2016 06:27 PM


Anybody have any idea what that apparently rapidly moving object is?  It enters the field of view from the right immediately before the explosion.  It crosses the screen in 15 frames and is in between the the lightning tower and the rocket at detonation.

Seems to be a bird or other animal.  It flies harmlessly over the rocket as it explodes.

I don't know man, watch it in real time, it moves so fast you can hardly see it.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Space Ghost 1962 on 09/01/2016 06:28 PM
In other news....

Peter B. de Selding‏ @pbdes
Spacecom insured Amos-6 for $285M in marine cargo market, not space insurance market. Launch +1 yr policy would kick in at rocket ignition.

Peter B. de Selding‏ @pbdes
@cbs_spacenews Sat was insured as marine cargo for pre-launch phase. Launch policy didn't kick in because no ignition-w/-intent-to-launch.

Does that mean that Spacecom won't get as much insurance payment as if this happened above ground?  :-X
I'm reading this as "Spacecom will get a $285M payout from their marine cargo insurance, not <whatever amount> from their space launch insurance, since the incident happened before launch."

I could be wrong, of course.

Correct

add:

It's considered "transport" until "launch ignition". The premiums for that kind of casualty are considerably less than that of what follows.

Check the audio, there's a small pop about 5 seconds before the sound from the actual explosions arrive.

I think that's just someone messing around a car or something near the camera.

Interestingly enough, the small first bang heard is the original S2 explosion. The big bang 3 seconds later is the fuel-air type explosion when that fireball hit the ground and mixed up the RP-1 and LOX.

I hear three distinct "initial" sounds:
Me too.

Quote
1:16--a very faint "plonk" like someone hitting a PVC pipe in the distance...COPV rupture?
1:18--a faint pop/bang... S2 tank rupture?
1:23--very loud boom...the LOX/RP-1 conflagration?
Or:
1:16-- line/fitting rupture
1:18-- detonation from line arc/ignition
1:23-- tank seam

The payload falling likely led to a hyper tank penetration with secondary ignition/partial detonation/deflagration.

Venting seemed excessive prior to ignition. Coupling failure or pressurization system?

We're all about to see how professional they are about a very difficult situation. One to watch closely.

All launches are hard and dangerous. Because they are launches. All crews face the same.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: dorkmo on 09/01/2016 06:28 PM
Check the audio, there's a small pop about 5 seconds before the sound from the actual explosions arrive.

I think that's just someone messing around a car or something near the camera.

Interestingly enough, the small first bang heard is the original S2 explosion. The big bang 3 seconds later is the fuel-air type explosion when that fireball hit the ground and mixed up the RP-1 and LOX. Check out that light pole above the number "2" bending by the generated shockwave. I wonder what the extent of damage to the hangar must be.

*not an explosion expert*

i think there are a few smaller pops throughout the first few seconds of the "big" explosion. could these be copv's or could it just be plumbing, etc?

it looks like you can see each pop give a flash within the falling orange flames. it'd be cool if someone could adjust the sound delay to the visuals.

*perhaps* the first pop could be a single copv giving way and then others quickly go as choas ensues
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: JDTractorGuy on 09/01/2016 06:29 PM


Anybody have any idea what that apparently rapidly moving object is?  It enters the field of view from the right immediately before the explosion.  It crosses the screen in 15 frames and is in between the the lightning tower and the rocket at detonation.

Seems to be a bird or other animal.  It flies harmlessly over the rocket as it explodes.

I don't know man, watch it in real time, it moves so fast you can hardly see it.

If you pause the video and use , and . to go frame-by-frame, you can tell it's a bird, and that it flies over the vehicle.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: bstrong on 09/01/2016 06:31 PM
Can someone point out this increase venting on S2 before the event?  I keep watching it and I do not see what they are talking about.

Sorry, I meant to say 20s prior, not 10s. Venting starts at about 0:50 in the video. It may not be atypical, but I pointed it out because CRS-7 showed increased venting from the S2 starting about 20s before the stage exploded.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: cscott on 09/01/2016 06:31 PM
Objects close to the camera can "appear" to move at incredibly high speeds if you assume they are far away.   There is an extreme telephoto lens in use here.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: StarryKnight on 09/01/2016 06:31 PM


Anybody have any idea what that apparently rapidly moving object is?  It enters the field of view from the right immediately before the explosion.  It crosses the screen in 15 frames and is in between the the lightning tower and the rocket at detonation.

And 12 frames after detonation another object enters the frame from the lower left and transits the fire ball at seemingly equal high velocity. 

I'm breaking out my trusty tinfoil chapeau.

That's a bird flying much closer to the camera than the launch pad. That's why it crosses the camera field of view so quickly.  It only appears to be flying right above the rocket because with a 2D image like this, you're brain thinks everything is the same distance away.

Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: mmeijeri on 09/01/2016 06:33 PM
I wonder what the extent of damage to the hangar must be.

Hmm, what about the recovered cores? Are they stored in that hangar or is there another one?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Zach Swena on 09/01/2016 06:33 PM
Can someone point out this increase venting on S2 before the event?  I keep watching it and I do not see what they are talking about.

I heard some sort of vent in the audio more then seeing it in the video.  I retract my previous observation, as it seems they had a fade cut in there, and there is a difference in the background audio noise that I mistook for venting.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: envy887 on 09/01/2016 06:34 PM
I wonder what the extent of damage to the hangar must be.

Hmm, what about the recovered cores? Are they stored in that hangar or is there another one?

They are stored in the LC-39A HIF, some 3 miles away from LC-40.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: dorkmo on 09/01/2016 06:36 PM
Can someone point out this increase venting on S2 before the event?  I keep watching it and I do not see what they are talking about.

Sorry, I meant to say 20s prior, not 10s. Venting starts at about 0:50 in the video. It may not be atypical, but I pointed it out because CRS-7 showed increased venting from the S2 starting about 20s before the stage exploded.

it looks like the video was cropped there. not sure why or how much.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: meekGee on 09/01/2016 06:36 PM
I think there's too much energy in the initial explosion for it to be umbilicals.

I'd vote COPV, or COPV+bulkhead.
agreed. There is just not as much explosive energy in the umbilicals. If they would pop you'd get a flow or stream, which might damage later. Not this very sudden very energetic event.
pressure in the stage getting released - either through COPV/associated plumbing is, imho, at this point way more likely.

The brightness can just be burning. Don't mistake an oversaturated image for lots of energy.
Not the brightness - the behavior of the hot gas.  Looks like there was stored energy.

Even if the source was internal (e.g. COPV) the center of the ignition may be just outside
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: TheMightyM on 09/01/2016 06:37 PM
More from Peter B. de Selding on Twitter:

Quote
SpaceX policy begun this yr of putting sats on rocket for static tests to trim a day frm launch campaign caused insurer upset, but not alot (sic).

I’ll go out on a limb and predict that we don’t see any more comm sats on rockets for static fire tests after this any time soon.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Ben the Space Brit on 09/01/2016 06:37 PM
It looks to me to be an U/S LOX tank rupture, possibly at the common bulkhead. That will at the very least mean a careful look at the design of said bulkhead and how it attaches to the two prop tanks and possibly a redesign.

The good news? As the fault appears to be in the upper stage, the recycled cores should still be clear for reuse.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Saabstory88 on 09/01/2016 06:39 PM
It looks to me to be an U/S LOX tank rupture, possibly at the common bulkhead. That will at the very least mean a careful look at the design of said bulkhead and how it attaches to the two prop tanks and possibly a redesign.

The good news? As the fault appears to be in the upper stage, the recycled cores should still be clear for reuse.

I thought the bulkhead, and furthermore, the tankage was of a common design. If we are looking at common bulkhead failure in the second stage, I would assume the first stage design also would need to be reviewed.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jet Black on 09/01/2016 06:40 PM
I think there's too much energy in the initial explosion for it to be umbilicals.

I'd vote COPV, or COPV+bulkhead.
agreed. There is just not as much explosive energy in the umbilicals. If they would pop you'd get a flow or stream, which might damage later. Not this very sudden very energetic event.
pressure in the stage getting released - either through COPV/associated plumbing is, imho, at this point way more likely.

The brightness can just be burning. Don't mistake an oversaturated image for lots of energy.
Not the brightness - the behavior of the hot gas.  Looks like there was stored energy.

Even if the source was internal (e.g. COPV) the center of the ignition may be just outside

If th source had leaked for even a short time before ignition, the combustible material could spread quickly, particularly if boiling rapidly. When ignited the flames would spread very fast, even if there wasn't a massive amount of energy in the explosion.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: envy887 on 09/01/2016 06:42 PM
I think there's too much energy in the initial explosion for it to be umbilicals.

I'd vote COPV, or COPV+bulkhead.
agreed. There is just not as much explosive energy in the umbilicals. If they would pop you'd get a flow or stream, which might damage later. Not this very sudden very energetic event.
pressure in the stage getting released - either through COPV/associated plumbing is, imho, at this point way more likely.

The brightness can just be burning. Don't mistake an oversaturated image for lots of energy.
Not the brightness - the behavior of the hot gas.  Looks like there was stored energy.

Even if the source was internal (e.g. COPV) the center of the ignition may be just outside

Mixed fuel and oxygen stores a lot of chemical potential energy, which can be released in milliseconds with an ignition source.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: meekGee on 09/01/2016 06:42 PM
I think there's too much energy in the initial explosion for it to be umbilicals.

I'd vote COPV, or COPV+bulkhead.
agreed. There is just not as much explosive energy in the umbilicals. If they would pop you'd get a flow or stream, which might damage later. Not this very sudden very energetic event.
pressure in the stage getting released - either through COPV/associated plumbing is, imho, at this point way more likely.

The brightness can just be burning. Don't mistake an oversaturated image for lots of energy.
Not the brightness - the behavior of the hot gas.  Looks like there was stored energy.

Even if the source was internal (e.g. COPV) the center of the ignition may be just outside

If th source had leaked for even a short time before ignition, the combustible material could spread quickly, particularly if boiling rapidly. When ignited the flames would spread very fast, even if there wasn't a massive amount of energy in the explosion.
True.  Still seems a bit much, but definitely possible
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: PahTo on 09/01/2016 06:43 PM
I wonder what the extent of damage to the hangar must be.

Hmm, what about the recovered cores? Are they stored in that hangar or is there another one?

They are stored in the LC-39A HIF, some 3 miles away from LC-40.

As I noted upthread (now waaay upthread), the LC39A HIF is rather close to pad 39A.  Imagine a similar scenario, but with a FH on (that) pad...
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: pippin on 09/01/2016 06:46 PM
Peter B. de Selding:
SpaceX explosion didn't involve intentional ignition - E Musk said occurred during 2d stage fueling - & isn't covered by launch insurance.

https://twitter.com/pbdes/status/771409425475174400

Ouch. That will hurt
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: HMXHMX on 09/01/2016 06:46 PM
I think there's too much energy in the initial explosion for it to be umbilicals.

I'd vote COPV, or COPV+bulkhead.
agreed. There is just not as much explosive energy in the umbilicals. If they would pop you'd get a flow or stream, which might damage later. Not this very sudden very energetic event.
pressure in the stage getting released - either through COPV/associated plumbing is, imho, at this point way more likely.

The brightness can just be burning. Don't mistake an oversaturated image for lots of energy.
Not the brightness - the behavior of the hot gas.  Looks like there was stored energy.

Even if the source was internal (e.g. COPV) the center of the ignition may be just outside


The failure of the overwrap on a COPV releases a fair amount of stored energy that can provide an ignition source, and the fuel is immediately available (the carbon winding and the matrix material are fuel).
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: dorkmo on 09/01/2016 06:47 PM
https://www.youtube.com/watch?v=ZX1vdPjCh3Q

not sure if they got permission from US Launch Report but here is a video with the audio synced
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: MostlyHarmless on 09/01/2016 06:47 PM
Everyone posting v1.0 or v1.1-pre-FT timelines, please stop.  Consider removing your posts.  It's actively unhelpful.  Fuel loading procedures changed significantly for 1.1 FT with its supercooled propellants.

For that matter, we don't even know if the failure happened around T-5 or T-3 yet.

I apologize for posting unhelpful information.... the offending posts have been removed.  I shan't make this mistake again.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jet Black on 09/01/2016 06:48 PM
I think there's too much energy in the initial explosion for it to be umbilicals.

I'd vote COPV, or COPV+bulkhead.
agreed. There is just not as much explosive energy in the umbilicals. If they would pop you'd get a flow or stream, which might damage later. Not this very sudden very energetic event.
pressure in the stage getting released - either through COPV/associated plumbing is, imho, at this point way more likely.

The brightness can just be burning. Don't mistake an oversaturated image for lots of energy.
Not the brightness - the behavior of the hot gas.  Looks like there was stored energy.

Even if the source was internal (e.g. COPV) the center of the ignition may be just outside

If th source had leaked for even a short time before ignition, the combustible material could spread quickly, particularly if boiling rapidly. When ignited the flames would spread very fast, even if there wasn't a massive amount of energy in the explosion.
True.  Still seems a bit much, but definitely possible

The other thing that occurs to me is that you need a fuel oxygen mix.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: pippin on 09/01/2016 06:49 PM
It probably means many lawyers are pressing their suits and preparing for battle...

Nothing for them to do.
This means SpaceX will have to foot most of the bill if they ever want to see another customer.

There's no way a shipping insurance will cover this.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: PhillyJimi on 09/01/2016 06:50 PM
I am kind of thinking that maybe they really didn't fix the problem that caused the CRS-7 failure.  My spidey senses are telling me this.  Watching the CRS-7 videos again its seems to be just too similar.  Especially considering the 2nd stage wasn't even firing when the explosion happened again.   

I know this is pure speculation at this point but what else are we do today. 
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Billium on 09/01/2016 06:52 PM
It probably means many lawyers are pressing their suits and preparing for battle...

Nothing for them to do.
This means SpaceX will have to foot most of the bill if they ever want to see another customer

Or maybe SpaceX has their own property/liability insurance which would cover this.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: pippin on 09/01/2016 06:55 PM
Or maybe SpaceX has their own property/liability insurance which would cover this.

Yea, that will likely be the case to a certain degree, doubt they will have full coverage, probably some level of insurance making the losses somewhat bearable.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: eeergo on 09/01/2016 06:55 PM
Peter B. de Selding:
SpaceX explosion didn't involve intentional ignition - E Musk said occurred during 2d stage fueling - & isn't covered by launch insurance.

https://twitter.com/pbdes/status/771409425475174400

Ouch. So Spacecom has to eat the cost?

Some background on what this might mean for Spacecom: http://spacewatchme.com/2016/08/israels-spacecom-sold-chinese-group-launch-amos-6/

Basically, Spacecom was in trouble, among other things, after the 2-year postponement of the AMOS-6 launch, and it got sold for $285 million (note AMOS-6 was $195 million), BUT this was contingent on the capability offered by the now-destroyed satellite.

On other news, SpaceFlight101 is reporting some debris arrived in the LC-39A area.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Machdiamond on 09/01/2016 06:56 PM
Kudos to USLaunchReport for being a very patient observer of SpaceX static tests and capturing historical footage.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: envy887 on 09/01/2016 06:56 PM
I wonder what the extent of damage to the hangar must be.

Hmm, what about the recovered cores? Are they stored in that hangar or is there another one?

They are stored in the LC-39A HIF, some 3 miles away from LC-40.

As I noted upthread (now waaay upthread), the LC39A HIF is rather close to pad 39A.  Imagine a similar scenario, but with a FH on (that) pad...

FH is worst case equivalent to 196 tons of TNT. The HIF is 1900 feet from LC-39A, and at that range the only effect should be some broken windows, and possibly some falling flamey bits - but neither are likely to cause major damage to a steel building or anything reasonably sturdy inside it.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Kabloona on 09/01/2016 06:58 PM
It probably means many lawyers are pressing their suits and preparing for battle...

Nothing for them to do.
This means SpaceX will have to foot most of the bill if they ever want to see another customer.

There's no way a shipping insurance will cover this.

Are you sure? PBdSelding later tweeted that the pre-launch phase was insured as marine cargo. Pre-launch means up until ignition for the actual launch.

Quote
41m41 minutes ago
Peter B. de Selding ‏@pbdes
@cbs_spacenews Sat was insured as marine cargo for pre-launch phase. Launch policy didn't kick in because no ignition-w/-intent-to-launch.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: envy887 on 09/01/2016 07:00 PM
More from Peter B. de Selding on Twitter:

Quote
SpaceX policy begun this yr of putting sats on rocket for static tests to trim a day frm launch campaign caused insurer upset, but not alot (sic).

I’ll go out on a limb and predict that we don’t see any more comm sats on rockets for static fire tests after this any time soon.

That means some insurance company was probably on the hook for this. No reason to get "upset" if you aren't liable.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: topsphere on 09/01/2016 07:01 PM
It probably means many lawyers are pressing their suits and preparing for battle...

Nothing for them to do.
This means SpaceX will have to foot most of the bill if they ever want to see another customer.

There's no way a shipping insurance will cover this.

Why? If the customer chose not to get full "space-industry" insurance then that is their prerogative, but they will bear the cost.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: pippin on 09/01/2016 07:02 PM
Are you sure? PBdSelding later tweeted that the pre-launch phase was insured as marine cargo for $285 mil.

Yes, but if that's the case... if I'm not totally mistaken that kind of insurance is for transportation and associated handling. Which is why the rate is lower, these are lower-risk events.

However, putting the payload on top of a fully fueled LV during a test firing is not a normal shipping procedure and would not be covered.

It's like with a rental car: even if you buy all the insurance, if you then go to a skid track and do some crash car racing with it, good luck claiming any damages...

Of course SpaceX is aware of all of this and will have an own scheme in place to at least limit their exposure for this type of testing. I'd hope...
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: cebri on 09/01/2016 07:05 PM
I am kind of thinking that maybe they really didn't fix the problem that caused the CRS-7 failure.  My spidey senses are telling me this.  Watching the CRS-7 videos again its seems to be just too similar.  Especially considering the 2nd stage wasn't even firing when the explosion happened again.   

I know this is pure speculation at this point but what else are we do today.

Isn't out there a report from NASA pretty much saying they were not to happy with SpaceX conclusions in relation to the CRS 7 failure, saying it was not really proven the struts were the ultimate cause of the failure.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: pippin on 09/01/2016 07:05 PM
Why? If the customer chose not to get full "space-industry" insurance then that is their prerogative, but they will bear the cost.

Well, it was SpaceX destroying the cargo.
Of course they might have a contract explicitly stating that if SpaceX does risky things with the cargo they won't be liable for it but I can't imagine any customer being so stupid to sign something like that.

No, this will be SpaceX's bill, but there's quite some chance they have own coverage for at least some of it.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Kabloona on 09/01/2016 07:05 PM
Are you sure? PBdSelding later tweeted that the pre-launch phase was insured as marine cargo for $285 mil.

Yes, but if that's the case... if I'm not totally mistaken that kind of insurance is for transportation and associated handling. Which is why the rate is lower, these are lower-risk events.

However, putting the payload on top of a fully fueled LV during a test firing is not a normal shipping procedure and would not be covered.

It's like with a rental car: even if you buy all the insurance, if you then go to a skid track and do some crash car racing with it, good luck claiming any damages...

Except this was standard procedure (static fire after integration) and I can't imagine them buying satellite insurance with a giant hole in it after shipment to the Cape. Plenty of bad things can happen during integration, satellite gets damaged by accident, a hurricane destroys the HIF, etc. All of those you buy insurance for.

Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: wannamoonbase on 09/01/2016 07:07 PM
Perhaps this has been mentioned and exhausted somewhere in the many posts today, if it has I apologize.

The venting nearer the top of the TE stops a few seconds before the fireworks. 

1) Is it safe to assume that is second stage LOx?
2) Was that normal for that point in time?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jim on 09/01/2016 07:10 PM

Except this was standard procedure (static fire after integration)


Not for every Spacex launch and for none of the other ones.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: yokem55 on 09/01/2016 07:12 PM
Perhaps this has been mentioned and exhausted somewhere in the many posts today, if it has I apologize.

The venting nearer the top of the TE stops a few seconds before the fireworks. 

1) Is it safe to assume that is second stage LOx?
2) Was that normal for that point in time?
LOX vent valve clogged/closed unexpectedly m
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Kabloona on 09/01/2016 07:12 PM

Except this was standard procedure (static fire after integration)


Not for every Spacex launch and for none of the other ones.

Standard as in, the customer agreed to the procedure beforehand and presumably took reasonable precautions with insurance.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: IanH84 on 09/01/2016 07:13 PM
https://www.youtube.com/watch?v=ZX1vdPjCh3Q

not sure if they got permission from US Launch Report but here is a video with the audio synced
I think Kabloona might be onto something.
I hear three distinct "initial" sounds:

1:16--a very faint "plonk" like someone hitting a PVC pipe with a hammer in the distance...COPV rupture?
1:18--a faint pop/bang... S2 tank rupture?
1:23--very loud boom...the LOX/RP-1 explosion?

That first sound at 1:16 is unusual and seems to me like it may be the initiating event. A COPV or high pressure line/fitting letting go followed by S2 tank rupture 1-2 seconds later seems consistent.
Crank up the volume, the first sound could be the creak of metal bending. If that's the case, we might be hearing a strut bend and break, a COPV rupturing or helium hose popping, and the loud boom is the visible explosion.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: topsphere on 09/01/2016 07:13 PM
Why? If the customer chose not to get full "space-industry" insurance then that is their prerogative, but they will bear the cost.

Well, it was SpaceX destroying the cargo.
Of course they might have a contract explicitly stating that if SpaceX does risky things with the cargo they won't be liable for it but I can't imagine any customer being so stupid to sign something like that.

No, this will be SpaceX's bill, but there's quite some chance they have own coverage for at least some of it.

I'm sure this is in the contract and there's no way of us knowing yet - but choosing an insurance package with less cover (i.e. marine insurance pre-launch rather than "space" insurance pre-launch) doesn't pass the buck of responsibility, otherwise no-one would ever buy the highest cover insurance. Unless any negligence on SpaceX's part can be proven then I would be very, very surprised if they have to pay for the cost of the satellite.

Of course, there is the many tens of millions that SpaceX will have to pay in pad repair, inspection, foregone revenues etc. etc.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: pippin on 09/01/2016 07:16 PM
Except this was standard procedure (static fire after integration)
That kind of thing is not a standard practice for marine cargo. Heck, it isn't even for SpaceX let alone other launch providers.
Quote
and I can't imagine them buying satellite insurance with a giant hole in it after shipment to the Cape.
Well, if SpaceX (+ whatever insurance they have) covers extraordinary events it in between, why not?
Quote
Plenty of bad things can happen during integration, satellite gets damaged by accident, a hurricane destroys the HIF, etc. All of those you buy insurance for.
Yes, and all these things _are_ standard risks for any kind of high-value target.

Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Herb Schaltegger on 09/01/2016 07:19 PM
Except this was standard procedure (static fire after integration)
That kind of thing is not a standard practice for marine cargo. Heck, it isn't even for SpaceX let alone other launch providers.
Quote
and I can't imagine them buying satellite insurance with a giant hole in it after shipment to the Cape.
Well, if SpaceX (+ whatever insurance they have) covers extraordinary events it in between, why not?
Quote
Plenty of bad things can happen during integration, satellite gets damaged by accident, a hurricane destroys the HIF, etc. All of those you buy insurance for.
Yes, and all these things _are_ standard risks for any kind of high-value target.



I've spent a lot of professional time parsing insurance contracts. Unless you've seen the applicable policy and all the riders thereto, you have no way to be quite as authoritative about coverage issues IN THIS INSTANCE.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ejb749 on 09/01/2016 07:20 PM
Watching this in slow motion, it appears that in the first frame with fire that there is a long downward finger of flame and smoke that dissipates as the fire ball erupts.  Is there an umbilical that could have come off and sprayed something downward?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: pippin on 09/01/2016 07:20 PM
Not for every Spacex launch and for none of the other ones.

Yep, and that's exactly the point why it isn't practical to have it in the payload insurance and I won't believe it was.
This is a high risk event of which you don't know in advance (when you negotiate the insurance) whether it's going to happen at all. No way you want to cover this.

It's easier for SpaceX to cover it because _they_ know that they will occasionally do a hot fire with payload and it's not just one so it's feasible for them to negotiate insurance or even to self-insure (read: factor it into the launch cost).
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jim on 09/01/2016 07:21 PM

Crank up the volume, the first sound could be the creak of metal bending. If that's the case, we might be hearing a strut bend and break

That would not be heard from this distance
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Mark McCombs on 09/01/2016 07:21 PM
You might think that a rupture disk or pressure relief valve/system would have actuated just prior to ignition.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: pippin on 09/01/2016 07:23 PM
I've spent a lot of professional time parsing insurance contracts. Unless you've seen the applicable policy and all the riders thereto, you have no way to be quite as authoritative about coverage issues IN THIS INSTANCE.

Me too and I've never seen one where individual high-risk activities were optionally included upfront. This doesn't make sense for the insurer or the customer and insurers are very good at passing that kind of stuff on to an entity that has control over it and can value the risk.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: dglow on 09/01/2016 07:24 PM
I think Kabloona might be onto something.
I hear three distinct "initial" sounds:

1:16--a very faint "plonk" like someone hitting a PVC pipe with a hammer in the distance...COPV rupture?
1:18--a faint pop/bang... S2 tank rupture?
1:23--very loud boom...the LOX/RP-1 explosion?

That first sound at 1:16 is unusual and seems to me like it may be the initiating event. A COPV or high pressure line/fitting letting go followed by S2 tank rupture 1-2 seconds later seems consistent.
Crank up the volume, the first sound could be the creak of metal bending. If that's the case, we might be hearing a strut bend and break, a COPV rupturing or helium hose popping, and the loud boom is the visible explosion.

The camera and mic are over 2.5 miles from the pad. We don't know what kind of microphone was in use. Other than the explosion itself, we don't know where those other sounds originated from.

There's a voice that precedes the explosion by several seconds – where was that coming from? I hear what sounds like someone inhaling or gasping right at the point where they would have seen the explosion – but not heard it yet.

To my ears, the faint 'plonk' sounds decidedly sharper and nearer to the camera than the explosion which follows. Again, wild speculation: we don't know the limitations of this recording.

Still, many thanks to USLaunchReport for sharing this video.   :D

Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Oersted on 09/01/2016 07:34 PM
Will this lead to new SpaceX procedures for quick 'n easy mating of the payload after static test firing? Should make for more aggressive, safety-enhancing testing.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jim on 09/01/2016 07:38 PM
Will this lead to new SpaceX procedures for quick 'n easy mating of the payload after static test firing. Should make for more aggressive, safety-enhancing testing.

Not really.  Still constrained by what the payload needs to do after mate.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: CJ on 09/01/2016 07:45 PM
I'm going to speculate wildly here (Mod, please delete if inappropriate);

Point 1; The CRX7 failure occurred in the second stage.
Point 2; This explosion *appears* to have originated in the second stage.

Speculation: to my eyes, this event appears to have been highly energetic from the first moment it appears.

Further speculation; would a COPV failure (sudden release of He into the LOX) fit observations? In other words, one of the COPV He tanks ruptures, resulting in massive overpressure of the LOX, leading to massive and sudden structural failure thereof, and thus an explosion as the LOX mixed with RP1, with ignition sources provided by the structural failure/electrical umbilical?

If the above is true, is point 2 significant (perhaps a COPV, not a strut, caused CRX7?) Or could a strut failure have caused today's explosion? 

One possible silver lining here; the debris to investigate are in a small area on land, not scattered on vast stretches of seabed.

Edit to add; what about lightning? I think we'd have seen a lightning strike, would we would not have seen a step/leader, which is more than enough to fry a human, and thus plenty to cause sparking. Any idea what the electrical field strength was? (I'm probably flat out wrong here, because the scrub limits for a static fire are probably the same as for a launch when it comes to lightning.)

 
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: RotoSequence on 09/01/2016 07:47 PM
Whatever the anomaly was that destroyed the launch vehicle, it was very energetic.  ???
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: PahTo on 09/01/2016 07:51 PM

Thanks for posting the video.  Boy, watching the payload tumble to the ground/from the cradle after the fact sure adds insult to injury...
Again, my thoughts are with all involved.  Glad there weren't any injuries (any followup to reports that a firefighter was injured?)
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Kabloona on 09/01/2016 07:58 PM
The flame in the first frames looks more characteristic of detonation than conflagration to my amateur eyes; it's sharp and white all around.

That may just be sensor saturation. A better indicator of detonation is wave speed. If that had been a high order detonation, the stage would just disappear in one frame. The relatively slow development of the fireball is more characteristic of conflagration.

Edit: or per below post, the sharp white " flame" is just interpolation, not actual footage.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: RoboGoofers on 09/01/2016 07:58 PM
These screen shots were posted by @John_Gardi on Twitter.  Taken from this slow-mo video.

The Slo-mo frames are just interpolated from the existing frames, so it's impossible to conclude anything from them.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: mme on 09/01/2016 08:00 PM
These screen shots were posted by @John_Gardi on Twitter.  Taken from this slow-mo video. ...
Seems to me that there is a bunch of software interpolation creating "detail" not in the source video.  In other words, I think it's inventing frames to smooth the transitions.

Edit:  Ninja's by RoboGoofers
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: cscott on 09/01/2016 08:00 PM

Thanks for posting the video.  Boy, watching the payload tumble to the ground/from the cradle after the fact sure adds insult to injury...
Again, my thoughts are with all involved.  Glad there weren't any injuries (any followup to reports that a firefighter was injured?)
We had a follow-up that it wasn't a medevac, the firefighter just wanted a lift to better observe the fire from above.

I certainly hope that's the case.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: wtrix on 09/01/2016 08:01 PM
Some notes:
1. There's no similarity to CRS-7 event. "Excessive venting" that some people claim here is probably mostly due to the fact that surrounding air was almost saturated with moisture. Pressure vessel overpressure rupture would have caused massive cloud initially, which then would have perhaps detonated. Not the other way around.
2. Fixing blast initiation point by analyzing video frames is not very productive as the surroundings are foggy and this fog reflects blast light towards camera making it bigger and moving the origination point towards the rocket body
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Dagger on 09/01/2016 08:06 PM
Made a little gif. Don't know how accurate it is:

(https://i.makeagif.com/media/9-01-2016/psm9zl.gif)

Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: launchwatcher on 09/01/2016 08:07 PM
Watching this in slow motion, it appears that in the first frame with fire that there is a long downward finger of flame and smoke that dissipates as the fire ball erupts.  Is there an umbilical that could have come off and sprayed something downward?
Some of that looks to me looks like it could be light from the initial fireball illuminating preexisting vapor clouds around the top of the first stage.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: mlindner on 09/01/2016 08:15 PM
My two cents. I might know the cause in my completely unfounded opinion. The main thing that I'm drawing my thoughts from are the intense localized flash of the explosion (as noticed by the flash star in the video film).

I believe this was a pre-detonation of the either a portion of, or completely of the upper stage FTS. There was an intense flash at a single small point. You don't get that level of intense flashes from an ignition. If this was a COPV explosion we should be seeing a spray of LOX or fuel before the explosion occurs.

I look forward to the date that rockets get their FTS removed. Having explosives on a vehicle has always seemed like a bad idea to me despite the good reasons for protection of the public they allow.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Lee Jay on 09/01/2016 08:19 PM
Where are the FTS charges located on this vehicle?  Are they running up the side like on a solid or are they on the tank domes or something?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: cscott on 09/01/2016 08:20 PM
I believe this was a pre-detonation of the either a portion of, or completely of the upper stage FTS. There was an intense flash at a single small point. You don't get that level of intense flashes from an ignition. If this was a COPV explosion we should be seeing a spray of LOX or fuel before the explosion occurs.
FTS was safed at the time, as evidenced in the timeline by cradle closed and strongback vertical.

Still could be an anomalous FTS incident (static discharge?) but should be much much much less likely if FTS is safed.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Kabloona on 09/01/2016 08:21 PM
My two cents. I might know the cause in my completely unfounded opinion. The main thing that I'm drawing my thoughts from are the intense localized flash of the explosion (as noticed by the flash star in the video film).

I believe this was a pre-detonation of the either a portion of, or completely of the upper stage FTS. There was an intense flash at a single small point. You don't get that level of intense flashes from an ignition. If this was a COPV explosion we should be seeing a spray of LOX or fuel before the explosion occurs.

I look forward to the date that rockets get their FTS removed. Having explosives on a vehicle has always seemed like a bad idea to me despite the good reasons for protection of the public they allow.

Except the FTS is, in my experience, one of the most thoroughly designed, tested, and safe systems on the rocket, precisely because Range Safety folks are so concerned about the possibility of accidental initiation. Speaking as someone who has worked with FTS systems, it's practically impossible to initiate them by mistake. So I'd be highly surprised if FTS turns out to be the culprit.

I'd much rather be standing next to an FTS than a fully pressurized COPV, for example.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ellindsey on 09/01/2016 08:26 PM
Accidentally (or deliberately) activated FTS would have activated the FTS for the entire vehicle, not just the second stage.  This failure was too localized to be FTS.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: dnavas on 09/01/2016 08:29 PM
Made a little gif. Don't know how accurate it is:
(https://i.makeagif.com/media/9-01-2016/psm9zl.gif)

It's hard to draw much from attempting to find the 2D mid-point of an over-exposure.  That said, I find it interesting how the payload fairing was illuminated.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: king1999 on 09/01/2016 08:31 PM
Accidentally (or deliberately) activated FTS would have activated the FTS for the entire vehicle, not just the second stage.  This failure was too localized to be FTS.
That exactly looks like what happened. The whole stack just exploded really fast.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Kabloona on 09/01/2016 08:32 PM
Wise words from Jeff Foust.

Quote
1h1 hour ago
Jeff Foust ‏@jeff_foust
You’ll see a lot of amateur speculation and analysis of today’s F9 explosion. Use with caution; almost all of it will turn out to be wrong.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: wtrix on 09/01/2016 08:32 PM
One more nail to the coffin of FTS theory. FTS consists of small linear charge designed to rupture the pressure vessel. It is not designed to explode into a giant fireball 30 feet across in a split second.

There's a remote possibility that FTS initiated on charge detonator level and this caused fuel-air explosion nearby in a very unlikely event. But in order this to happen very unlikely things have to happen.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ugordan on 09/01/2016 08:32 PM
Made a little gif. Don't know how accurate it is:
(https://i.makeagif.com/media/9-01-2016/psm9zl.gif)

It's hard to draw much from attempting to find the 2D mid-point of an over-exposure.

That's why most people that attempt to locate it use the diffraction spikes instead (hence the X shape above). They are much more localized as they trace out the highest intensity light source at that instant. It's reasonable to assume that's where the event originated.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ellindsey on 09/01/2016 08:35 PM
Accidentally (or deliberately) activated FTS would have activated the FTS for the entire vehicle, not just the second stage.  This failure was too localized to be FTS.
That exactly looks like what happened. The whole stack just exploded really fast.
No, it doesn't.  There was a very bright and fast event on the second stage near the oxygen tank.  That opened the kerosene tank, and then the burning fuel and debris falling downward tore apart and ignited the first stage.  A FTS trigger would have been simultaneous on the first and second stages, not starting on the second stage and then proceeding downward like this was.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: SWGlassPit on 09/01/2016 08:36 PM
Accidentally (or deliberately) activated FTS would have activated the FTS for the entire vehicle, not just the second stage.  This failure was too localized to be FTS.
That exactly looks like what happened. The whole stack just exploded really fast.

It really didn't.  There was a localized explosion in the second stage with a relatively slow progressive failure down the stack.  If it was FTS, the whole vehicle would have ceased to exist in the span of two or three frames.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: wtrix on 09/01/2016 08:36 PM
Made a little gif. Don't know how accurate it is:
(https://i.makeagif.com/media/9-01-2016/psm9zl.gif)

It's hard to draw much from attempting to find the 2D mid-point of an over-exposure.

That's why most people that attempt to locate it use the diffraction spikes instead (hence the X shape above). They are much more localized as they trace out the highest intensity light source at that instant. It's reasonable to assume that's where the event originated.

Sorry, but in this case, those spikes (actually in-lens reflections) show the average center of the oversaturated fireball. Nothing else.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: intrepidpursuit on 09/01/2016 08:37 PM
The biggest thing I don't understand is what is the ignition source? Even if the O2 tank had an overpressure, underpressure, or any other failure mode, why would the first thing we see be blinding fire? Some static or something would probably catch it eventually, but without the engines running you could mix O2 and RP-1 and it would still not self detonate.

Am I missing something? I realize my optimism toward SpaceX might make me favor the least damaging outcome, but I just don't see how anything other than an explosive charge could have detonated so quickly. TEA-TEB or hypergolics could easily cause a bad day, but they don't appear to have been involved unless they were being loaded into S2 by the umbilical at the time.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: mlindner on 09/01/2016 08:39 PM
Wise words from Jeff Foust.

Quote
1h1 hour ago
Jeff Foust ‏@jeff_foust
You’ll see a lot of amateur speculation and analysis of today’s F9 explosion. Use with caution; almost all of it will turn out to be wrong.

Agreed, thus why I explicitly put a low emphasis in my post.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: mlindner on 09/01/2016 08:40 PM
Made a little gif. Don't know how accurate it is:
(https://i.makeagif.com/media/9-01-2016/psm9zl.gif)

It's hard to draw much from attempting to find the 2D mid-point of an over-exposure.

That's why most people that attempt to locate it use the diffraction spikes instead (hence the X shape above). They are much more localized as they trace out the highest intensity light source at that instant. It's reasonable to assume that's where the event originated.

Yes this was exactly what I was doing (I was still reading 20 pages back at the time and hadn't seen the gif yet).
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: iamlucky13 on 09/01/2016 08:40 PM

FH is worst case equivalent to 196 tons of TNT. The HIF is 1900 feet from LC-39A, and at that range the only effect should be some broken windows, and possibly some falling flamey bits - but neither are likely to cause major damage to a steel building or anything reasonably sturdy inside it.

There's not really a practical way to get a similar burn rate of separate fuel and oxidizers as you get for TNT. Most of that energy is, as can be seen, is consumed in deflagration, not detonation, so the worst case is not nearly as bad as the TNT equivalent.

That said, according to HYDEsim, 0.2 kT of TNT can damage buildings 1900 feet away, but in this case we're talking about LC-40. The hangar for LC-40 is much closer than that, isn't it?
http://meyerweb.com/eric/tools/gmap/hydesim.html?dll=28.56212,-80.57729&mll=28.56246,-80.57759&yd=0.2&zm=15&op=156

I'm going to speculate wildly here (Mod, please delete if inappropriate);

Point 1; The CRX7 failure occurred in the second stage.
Point 2; This explosion *appears* to have originated in the second stage.

Speculation: to my eyes, this event appears to have been highly energetic from the first moment it appears.

Further speculation; would a COPV failure (sudden release of He into the LOX) fit observations?

You are not the first person to suspect this. In my opinion, it appears consistent with overpressurization, but a problem with GSE  or the valve that handles boiloff might also result in overpressurization.

The CRS-7 failure is believed to have been due to buoyant forces under several G's of loading. The buoyant forces while on the pad are far lower. Even if it was a COPV failure, I would be surprised if it was due to tank buoyancy breaking a strut.

Regardless, don't get too attached to the theory. For almost every high-visibility aerospace accident like this, there's usually half a dozen reasonable-sounding theories proposed early on. Most (sometimes all) of them turn out to be wrong.

Some notes:
1. There's no similarity to CRS-7 event. "Excessive venting" that some people claim here is probably mostly due to the fact that surrounding air was almost saturated with moisture. Pressure vessel overpressure rupture would have caused massive cloud initially, which then would have perhaps detonated. Not the other way around.

A failure of the common bulkhead would have allowed ignition to begin inside the tank.

Watching this in slow motion, it appears that in the first frame with fire that there is a long downward finger of flame and smoke that dissipates as the fire ball erupts.  Is there an umbilical that could have come off and sprayed something downward?

I originally had a similar thought, but the speed of the explosion progression makes me think more likely its due to the tanks failing along a vertical seam (either initial, or after a bulkhead failure). That is why I've started leaning towards over-pressurization, although I'm pondering whether an accidental FTS activation would look the same. A partial vehicle FTS firing seems extremely unlikely, but not completely impossible.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: wtrix on 09/01/2016 08:41 PM
Wise words from Jeff Foust.

Quote
1h1 hour ago
Jeff Foust ‏@jeff_foust
You’ll see a lot of amateur speculation and analysis of today’s F9 explosion. Use with caution; almost all of it will turn out to be wrong.

Agreed, thus why I explicitly put a low emphasis in my post.

BTW, this applies to all amateur accident investigations.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Kabloona on 09/01/2016 08:41 PM
Wise words from Jeff Foust.

Quote
1h1 hour ago
Jeff Foust ‏@jeff_foust
You’ll see a lot of amateur speculation and analysis of today’s F9 explosion. Use with caution; almost all of it will turn out to be wrong.

Agreed, thus why I explicitly put a low emphasis in my post.

I wasn't singling you out; that was for all of us, me included. ;-)
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ugordan on 09/01/2016 08:42 PM
Made a little gif. Don't know how accurate it is:
(https://i.makeagif.com/media/9-01-2016/psm9zl.gif)

It's hard to draw much from attempting to find the 2D mid-point of an over-exposure.

That's why most people that attempt to locate it use the diffraction spikes instead (hence the X shape above). They are much more localized as they trace out the highest intensity light source at that instant. It's reasonable to assume that's where the event originated.

Sorry, but in this case, those spikes (actually in-lens reflections) show the average center of the oversaturated fireball. Nothing else.

Sorry, but there is oversaturation and then there is oversaturation. According to you, those spikes should simply be as wide as the whited-out region, which is clearly not the case. My point is that it takes even more light intensity to produce spiking than it takes to saturate the detector at a region and that it was reasonable to assume that the highest physical brightness point corresponds to the point of origin. The spikes convey additional useful information about the brightness profile above the whited-out region precisely because they are more tightly constrained.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: SWGlassPit on 09/01/2016 08:42 PM
The biggest thing I don't understand is what is the ignition source? Even if the O2 tank had an overpressure, underpressure, or any other failure mode, why would the first thing we see be blinding fire? Some static or something would probably catch it eventually, but without the engines running you could mix O2 and RP-1 and it would still not self detonate.

Am I missing something? I realize my optimism toward SpaceX might make me favor the least damaging outcome, but I just don't see how anything other than an explosive charge could have detonated so quickly. TEA-TEB or hypergolics could easily cause a bad day, but they don't appear to have been involved unless they were being loaded into S2 by the umbilical at the time.

If the fuel-oxygen mix is right, it only takes a tiny spark.  Electrostatic discharge, a momentary arc from a switch opening or closing, really anything.  If you read the history (don't have a link handy, but it's out there) of when they built LC-39A, they had a LOX leak at the pad one day and discovered it when people's cars started bursting into flame.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: vanoord on 09/01/2016 08:42 PM
Sorry, but in this case, those spikes (actually in-lens reflections) show the average center of the oversaturated fireball. Nothing else.

Albeit there's probably a correlation between the centre of the lens flare, the brightest point of the image - and by derivation the hottest point of the fireball, which - given there's about 1/30 of a second between the start of the event and the explosion / lens flare - has a very good chance of being the initial point at which the event occurred.

Occam's Razor; or "if it look like a duck and quacks like a duck, then it probably is a duck".

*Why* it's a duck is a bit more problematic. The video footage almost certainly gives us the location of the failure - but certainly not the cause.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Moderas on 09/01/2016 08:43 PM
The vehicle is sitting in a cloud of concentrated, evaporating oxygen and is holding thousands of kilograms more on board. A small leak and a spark is all that is needed to cause an event big enough to rupture the tanks leading the chain reaction. Oxygen is abundant in this scenario - we don't need an explosive to turn the situation bad.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: intrepidpursuit on 09/01/2016 08:44 PM
Accidentally (or deliberately) activated FTS would have activated the FTS for the entire vehicle, not just the second stage.  This failure was too localized to be FTS.
That exactly looks like what happened. The whole stack just exploded really fast.

It really didn't.  There was a localized explosion in the second stage with a relatively slow progressive failure down the stack.  If it was FTS, the whole vehicle would have ceased to exist in the span of two or three frames.

FTS isn't designed to obliterate the vehicle as much as it is to release the fuel to get rid of its mass, momentum, and explosive potential. When we've seen FTS before it causes a slow conflagration fireball just like we see here after that initial pop at the top of S2. It looked very much like the fireball we saw on GH2, although with a much better vantage point to see details.

For those saying FTS wouldn't cause a fireball, well, what other ignition source was there? We didn't see a green flash.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Robotbeat on 09/01/2016 08:45 PM
The biggest thing I don't understand is what is the ignition source? Even if the O2 tank had an overpressure, underpressure, or any other failure mode, why would the first thing we see be blinding fire? Some static or something would probably catch it eventually, but without the engines running you could mix O2 and RP-1 and it would still not self detonate.

Am I missing something? I realize my optimism toward SpaceX might make me favor the least damaging outcome, but I just don't see how anything other than an explosive charge could have detonated so quickly. TEA-TEB or hypergolics could easily cause a bad day, but they don't appear to have been involved unless they were being loaded into S2 by the umbilical at the time.

If the fuel-oxygen mix is right, it only takes a tiny spark.  Electrostatic discharge, a momentary arc from a switch opening or closing, really anything...
Indeed. You might call this a *static*fire*. Heh.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: rcoppola on 09/01/2016 08:52 PM
Wonder how the Dragon2 Trunk/Capsule would have dealt with this 2nd Stage RUD in a Pad Abort scenario?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: mulp on 09/01/2016 08:53 PM
Ok, the cost to SpaceX for the rocket is manufacturing cost plus the direct opportunity cost of the lost use of its pad and personnel, all readily quantifiable, plus the harder to measure opportunity cost of loss of sales, plus some liability to the customer.

We know SpaceX rocket costs and launch capacity are transitioning to "volume".

The customer cost is the satellite hardware plus opportunity cost of the delay.

How much of the satellite hardware is in "volume" production?

Are things like antennas 3d printed or laser Cut?

Creating the specs for AMOS-6 might take years, but making the parts and integrating them only months. Or the process might still be in the stage of sending out orders for each part to be made custom.

Any idea where the satellite production is for AMOS-6 and for the majority in general?

I'm thinking of PBS NBR special reports this week on the multiple satellite Silicon valley startups getting tens of billions of cash to build satellites in volume, plus all the launcher startups.

Is the destruction of this hardware a really huge cost, or just a lot of labor cost flushed, but easily replaced by everyone working a few more hours a week for awhile and using the overtime to buy new boats?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: SWGlassPit on 09/01/2016 08:57 PM
Accidentally (or deliberately) activated FTS would have activated the FTS for the entire vehicle, not just the second stage.  This failure was too localized to be FTS.
That exactly looks like what happened. The whole stack just exploded really fast.

It really didn't.  There was a localized explosion in the second stage with a relatively slow progressive failure down the stack.  If it was FTS, the whole vehicle would have ceased to exist in the span of two or three frames.

FTS isn't designed to obliterate the vehicle as much as it is to release the fuel to get rid of its mass, momentum, and explosive potential. When we've seen FTS before it causes a slow conflagration fireball just like we see here after that initial pop at the top of S2. It looked very much like the fireball we saw on GH2, although with a much better vantage point to see details.

For those saying FTS wouldn't cause a fireball, well, what other ignition source was there? We didn't see a green flash.

FTS is designed to cease acceleration and disperse the propellants.  This is often accomplished by a linear shaped charge running the length of the vehicle.  I suspect the Falcon is the same way.  You might not see an immediate fireball, but you would see the whole vehicle unzip basically at once if it were FTS, not the several seconds it took to completely come apart.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: DarkenedOne on 09/01/2016 08:59 PM
The vehicle is sitting in a cloud of concentrated, evaporating oxygen and is holding thousands of kilograms more on board. A small leak and a spark is all that is needed to cause an event big enough to rupture the tanks leading the chain reaction. Oxygen is abundant in this scenario - we don't need an explosive to turn the situation bad.

Oxygen alone will not cause an explosion.  It does not react with itself.  You need a fuel source. 
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: SWGlassPit on 09/01/2016 09:00 PM
The vehicle is sitting in a cloud of concentrated, evaporating oxygen and is holding thousands of kilograms more on board. A small leak and a spark is all that is needed to cause an event big enough to rupture the tanks leading the chain reaction. Oxygen is abundant in this scenario - we don't need an explosive to turn the situation bad.

Oxygen alone will not cause an explosion.  It does not react with itself.  You need a fuel source. 
In a sufficiently high concentration of oxygen, many traditionally nonflammable things become quite flammable.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Kabloona on 09/01/2016 09:02 PM
I heard from one of the reddit that some believe a hydrazine leak from the satellite may of caused the initial explosion.  Given the location of the explosion being close the top of the oxygen tank, and the initial size explosion it seems like this is certainly possible.  I know from chemistry that hydrazine is particularly reactive, volatile, and very dangerous.  I am not an expert on launch systems and satellites, but what is the likelihood that this was the case.

Probably near zero. The payload was well above the plane where the first flash occurred, encapsulated in a fairing that remained intact long after the initial explosion. Also there's no way for hydrazine to get *into* the LOX tank, which appeared to rupture, suggesting the event may have started inside the LOX tank.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: vandersons on 09/01/2016 09:04 PM
Have watched the explosion frame by frame now for at least a couple dozen times. The initial bright flash is very baffling. It comes from the area where the LOX appears to be venting so there is lots of O2 there but on the other hand there is also a lot of wind blowing the vapour away so not much could have been just sitting there waiting on a spark to ignite stuff.

With that in mind, what is in that area of the bright flash that could potentially be oxidised in such a flash? From reading up thread the RP1 and LOX filling lines are further down near the interstage, the flash occurred much higher up (that would exclude RP1 leaking). Are any of the fittings near the flash area in any way flammable enough to produce a flash like that given enough O2 was present?

Could a static spark be strong enough to make a hole in the LOX tank and igniting the cork and/or aluminium therefore producing the first bright flash that with additional LOX gushing out of the tank gets bigger very quickly until it ruptures both tanks on S2?

Surprisingly S1 holds out for quite a while. Only until after it has been completely engulfed by the falling flaming fuel and LOX mix it gives up an produces the second big explosion (the third being the payload hitting the ground and blowing its hypergolic's tanks).

The COPV idea kind of doesn't quite add up in my mind. If only the LOX tank would go pop from an overpressure event then the first thing we should be seeing in the sequence is a white cloudy mass of LOX blowing out in various directions but no flames until the cloud hits something combustible and hot enough to start the explosion. It should look similar to how the S2 deflagrated on CRS7 - first a puff of white cloud, then mixing with some RP1, then hitting the exhaust flames and going up in a big fireball. In this case the sequence is very different - very bright flash, fireball starts spreading, some white cloud starts appearing leading the fireball, fuel-air explosion happens that triggers the S1 to blow up as well.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: RoboGoofers on 09/01/2016 09:07 PM
The vehicle is sitting in a cloud of concentrated, evaporating oxygen and is holding thousands of kilograms more on board. A small leak and a spark is all that is needed to cause an event big enough to rupture the tanks leading the chain reaction. Oxygen is abundant in this scenario - we don't need an explosive to turn the situation bad.

someone posted this upthread, but lot of fuel and LOx mixing without an explosion: Atlas 190D

https://www.youtube.com/watch?v=FmrrcAVOV4s (https://www.youtube.com/watch?v=FmrrcAVOV4s)

Quote
13,000 gallons of liquid oxygen and a full load of fuel sloshed over the stand and the nearby terrain.

here's a reference:
https://books.google.com/books?id=OVNuxBlXFHYC&lpg=PA32&ots=RWbZyy0by-&dq=1963%2C%20Atlas%20190D&pg=PA32#v=onepage&q=1963,%20Atlas%20190D&f=false (https://books.google.com/books?id=OVNuxBlXFHYC&lpg=PA32&ots=RWbZyy0by-&dq=1963%2C%20Atlas%20190D&pg=PA32#v=onepage&q=1963,%20Atlas%20190D&f=false)
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: iamlucky13 on 09/01/2016 09:07 PM
Wonder how the Dragon2 Trunk/Capsule would have dealt with this 2nd Stage RUD in a Pad Abort scenario?

Assuming the problem was recognized as severe by the computer and the LAS activated almost instantly, a second later the capsule would be 50+ feet away, and by the next second, roughly 300 feet away, etc.

If you pay attention in the video, after the explosion starts and the main fireball erupts and fades away, the fairing, halves still latched together, is visible falling starting about 7 seconds after the start. Given the smaller cross section of the Dragon 2, it's heat shielding, and potentially also stronger overall construction of the capsule, I think the crew has good odds in this kind of scenario. This is, after all, one of the design scenarios for the LAS.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: mlindner on 09/01/2016 09:07 PM
Check the audio, there's a small pop about 5 seconds before the sound from the actual explosions arrive.

I think that's just someone messing around a car or something near the camera.

Interestingly enough, the small first bang heard is the original S2 explosion. The big bang 3 seconds later is the fuel-air type explosion when that fireball hit the ground and mixed up the RP-1 and LOX.

I hear three distinct "initial" sounds:

1:16--a very faint "plonk" like someone hitting a PVC pipe with a hammer in the distance...COPV rupture?
1:18--a faint pop/bang... S2 tank rupture?
1:23--very loud boom...the LOX/RP-1 explosion?

That first sound at 1:16 is unusual and seems to me like it may be the initiating event. A COPV or high pressure line/fitting letting go followed by S2 tank rupture 1-2 seconds later seems consistent.

Overanalyzation of the events.

1:16--unrelated
1:18--unrelated
1:23--corresponding to visual event at 1:11, there's an approximately 12 second delay

Explosion event at 1:11.721, explosion shockwave arrives at 1:23.817. Total sound delay is 12.096 (with some fake precision).
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: intrepidpursuit on 09/01/2016 09:08 PM
The biggest thing I don't understand is what is the ignition source? Even if the O2 tank had an overpressure, underpressure, or any other failure mode, why would the first thing we see be blinding fire? Some static or something would probably catch it eventually, but without the engines running you could mix O2 and RP-1 and it would still not self detonate.

Am I missing something? I realize my optimism toward SpaceX might make me favor the least damaging outcome, but I just don't see how anything other than an explosive charge could have detonated so quickly. TEA-TEB or hypergolics could easily cause a bad day, but they don't appear to have been involved unless they were being loaded into S2 by the umbilical at the time.

If the fuel-oxygen mix is right, it only takes a tiny spark.  Electrostatic discharge, a momentary arc from a switch opening or closing, really anything...
Indeed. You might call this a *static*fire*. Heh.

That is exactly my point though, the mixture isn't right. They are totally separate until something goes wrong. It seems a stretch to think the O2 tank popped, which popped the RP-1 tank, and static happened at the right time and place to cause a spark, all within a few milliseconds. We should have seen a tank pop before it all went up.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: jgoldader on 09/01/2016 09:09 PM
Anybody familiar enough with S2 to know what's near the center of the "X"?  I believe ugordan was speculating on page 24 that the horizontal feature you can see extending to the left across S2 from the cradle was the clamp that holds S2, which is located near the common bulkhead for the LH2/LOX tanks.

I'm trying hard to remember that even the apparent location of the brightest part of the image (at the center of the X) is only a 2D projection of a 3D event.  The actual problem could have started on the unobserved side of the vehicle and what we're seeing is something propagating around to this side, or it could be a weak point where the event found a place to exit the vehicle, or it could be a secondary result of a primary failure that occurred far away.

So sorry for all those affected.  But I have faith in SpaceX; what they're trying to do is hard, and they only make it *look* easy.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jim on 09/01/2016 09:12 PM
I heard from one of the reddit that some believe a hydrazine leak from the satellite may of caused the initial explosion.  Given the location of the explosion being close the top of the oxygen tank, and the initial size explosion it seems like this is certainly possible.  I know from chemistry that hydrazine is particularly reactive, volatile, and very dangerous.  I am not an expert on launch systems and satellites, but what is the likelihood that this was the case.


The fairing would not have remained intact then
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: DarkenedOne on 09/01/2016 09:13 PM
I heard from one of the reddit that some believe a hydrazine leak from the satellite may of caused the initial explosion.  Given the location of the explosion being close the top of the oxygen tank, and the initial size explosion it seems like this is certainly possible.  I know from chemistry that hydrazine is particularly reactive, volatile, and very dangerous.  I am not an expert on launch systems and satellites, but what is the likelihood that this was the case.

Probably near zero. The payload was well above the plane where the first flash occurred, encapsulated in a fairing that remained intact long after the initial explosion. Also there's no way for hydrazine to get *into* the LOX tank, which appeared to rupture, suggesting the event may have started inside the LOX tank.

The explosion appears close to the base of the payload and the top of the LOX tank.  There is just nothing inside the LOX tank that can cause an explosion as far as I can tell.  It has to be something that mixed with the oxygen outside of the tank.  I think they vent oxygen that boils off right there. 
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Norm38 on 09/01/2016 09:13 PM
Wonder how the Dragon2 Trunk/Capsule would have dealt with this 2nd Stage RUD in a Pad Abort scenario?

It'll depend on if the software is active during a static fire.  Kind of how the CRS-7 parachute deploy software wasn't running.  I hope after this they'll have the Dragon2 primed and ready to abort once the rocket is vertical and into propellant loading.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: mlindner on 09/01/2016 09:15 PM
Crank up the volume, the first sound could be the creak of metal bending. If that's the case, we might be hearing a strut bend and break, a COPV rupturing or helium hose popping, and the loud boom is the visible explosion.

Please... This is an incessant problem on the internet to attribute new failures to previous issues. In engineering its the exception rather than the rule that a new failure is the same failure as before. If something fails its almost certainly something else that failed unless your engineers have no clue what they're doing or root cause was not found. This failure is NOT going to be related to struts. Forget the struts exist. That's a solved problem. Different metal suppliers, different stronger design, additional struts, impossible to be the same problem.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: iamlucky13 on 09/01/2016 09:18 PM
FTS is designed to cease acceleration and disperse the propellants.  This is often accomplished by a linear shaped charge running the length of the vehicle.  I suspect the Falcon is the same way.  You might not see an immediate fireball, but you would see the whole vehicle unzip basically at once if it were FTS, not the several seconds it took to completely come apart.

It would be several shaped charges, not one running the full length across both stages. The second stage disappears instantly. The rest of the rocket took a while. That said, the payload took several seconds to fall off, but cutting line through the length of the tank does not necessarily make the whole tank buckle instantly.

An FTS activation by the controller should have destroyed both stages at once, but it is not entirely out of the question that something else caused a single detonator to go off. Just extremely unlikely due to how carefully tested FTS hardware is.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Firehawk153 on 09/01/2016 09:19 PM
Crank up the volume, the first sound could be the creak of metal bending. If that's the case, we might be hearing a strut bend and break, a COPV rupturing or helium hose popping, and the loud boom is the visible explosion.

Please... This is an incessant problem on the internet to attribute new failures to previous issues. In engineering its the exception rather than the rule that a new failure is the same failure as before. If something fails its almost certainly something else that failed unless your engineers have no clue what they're doing or root cause was not found. This failure is NOT going to be related to struts. Forget the struts exist. That's a solved problem. Different metal suppliers, different stronger design, additional struts, impossible to be the same problem.

I dunno, ever heard of Taurus, OCO, and Glory? Just saying...
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: eeergo on 09/01/2016 09:19 PM

Sorry, but there is oversaturation and then there is oversaturation. According to you, those spikes should simply be as wide as the whited-out region, which is clearly not the case. My point is that it takes even more light intensity to produce spiking than it takes to saturate the detector at a region and that it was reasonable to assume that the highest physical brightness point corresponds to the point of origin. The spikes convey additional useful information about the brightness profile above the whited-out region precisely because they are more tightly constrained.


The reflection off the T/E structure is most certainly biasing any correlation between saturation and 2D projection of the explosion initiation point, I would think. The right third (roughly) of the oversaturated area should be weighted by a function of the T/E reflectivity. In essence, I would argue the true point lies a few pixels more to the left.


Further, look at the symmetry of the expanding LOX cloud a few frames later. The right side is a bit muffled because of the interference with the T/E, obviously, but the near perfect oval shape for most of its circumference suggests the failure point was mostly toward the camera, not facing directly at the erector.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: joncz on 09/01/2016 09:23 PM
I heard from one of the reddit that some believe a hydrazine leak from the satellite may of caused the initial explosion.  Given the location of the explosion being close the top of the oxygen tank, and the initial size explosion it seems like this is certainly possible.  I know from chemistry that hydrazine is particularly reactive, volatile, and very dangerous.  I am not an expert on launch systems and satellites, but what is the likelihood that this was the case.

Probably near zero. The payload was well above the plane where the first flash occurred, encapsulated in a fairing that remained intact long after the initial explosion. Also there's no way for hydrazine to get *into* the LOX tank, which appeared to rupture, suggesting the event may have started inside the LOX tank.

The fairing remained with the payload as they fell free of the strongback.  When the payload impacts the ground, you can see another "explosion," presumably of the satellite's hypergols.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: jongoff on 09/01/2016 09:23 PM
One thought re: speculation about a COPV failure. The COTS-7 failure wasn't thought to be a COPV letting go per se, but a massive helium leak that led to an overpressure. A COPV flat-out failing might happen faster, and could lead to a more energetic explosion. For instance, isn't that how the S-IVB 503 upper stage was lost during a ground test (in very similar circumstances--during fueling before a hot-fire test)?

~Jon
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: MattMason on 09/01/2016 09:27 PM
Wouldn't the color of the initial detonation (orange) suggest an RP-1 leak?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: RoboGoofers on 09/01/2016 09:28 PM
That is exactly my point though, the mixture isn't right. They are totally separate until something goes wrong. It seems a stretch to think the O2 tank popped, which popped the RP-1 tank, and static happened at the right time and place to cause a spark, all within a few milliseconds. We should have seen a tank pop before it all went up.

That's what i believe too.

At least with a copv bursting, it would send shrapnel through the tank walls into the fuel tank causing mixing.  someone mentioned upthread that the bursting of a copv might have enough energy to start the chemical chain reaction (not the kind of "classical" ignition source you'd imagine like a flame or spark), and the copv carbon would be flammable in a high oxygen environment.

Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Carl G on 09/01/2016 09:29 PM
A reminder, stupid posts will be deleted. Rumors from other sites that are stupid will be deleted. Members insisting on posting such things will be banned. People complaining there's speculation on here will also have their posts removed before this is the discussion thread, not the update thread. The update thread is for the official info.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: clegg78 on 09/01/2016 09:29 PM
Wouldn't the color of the initial detonation (orange) suggest an RP-1 leak?

I was thinking the same,  Its not like there was a gush of white vapor (LOX) that lead to an ignition/detonation.   IT was clearly orange fire initially (although energetic and obviously merged with LOX for the big boom at the top).
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jim on 09/01/2016 09:30 PM

Please... This is an incessant problem on this forum to attribute new failures to previous issues. In engineering its the exception rather than the rule that a new failure is the same failure as before. If something fails its almost certainly something else that failed unless your engineers have no clue what they're doing or root cause was not found. This failure is NOT going to be related to struts. Forget the struts exist. That's a solved problem. Different metal suppliers, different stronger design, additional struts, impossible to be the same problem.

I dunno, ever heard of Taurus, OCO, and Glory? Just saying...

AC-70 and AC-71.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: mlindner on 09/01/2016 09:30 PM
Accidentally (or deliberately) activated FTS would have activated the FTS for the entire vehicle, not just the second stage.  This failure was too localized to be FTS.
That exactly looks like what happened. The whole stack just exploded really fast.

It really didn't.  There was a localized explosion in the second stage with a relatively slow progressive failure down the stack.  If it was FTS, the whole vehicle would have ceased to exist in the span of two or three frames.

FTS isn't designed to obliterate the vehicle as much as it is to release the fuel to get rid of its mass, momentum, and explosive potential. When we've seen FTS before it causes a slow conflagration fireball just like we see here after that initial pop at the top of S2. It looked very much like the fireball we saw on GH2, although with a much better vantage point to see details.

For those saying FTS wouldn't cause a fireball, well, what other ignition source was there? We didn't see a green flash.

FTS is designed to cease acceleration and disperse the propellants.  This is often accomplished by a linear shaped charge running the length of the vehicle.  I suspect the Falcon is the same way.  You might not see an immediate fireball, but you would see the whole vehicle unzip basically at once if it were FTS, not the several seconds it took to completely come apart.

I'm somewhat doubting this theory now personally, but the upper stage and bottom stage necessarily have to be on different FTS circuits. What we indeed see is a sudden destruction of the upper stage and the contained liquid fuel of the upper stage falling to the ground and then an explosion indicative of the rupture of the lower stage followed by the impact at the bottom causing complete rupture of the lower stage and subsequent explosion.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: acsawdey on 09/01/2016 09:31 PM
The vehicle is sitting in a cloud of concentrated, evaporating oxygen and is holding thousands of kilograms more on board. A small leak and a spark is all that is needed to cause an event big enough to rupture the tanks leading the chain reaction. Oxygen is abundant in this scenario - we don't need an explosive to turn the situation bad.

someone posted this upthread, but lot of fuel and LOx mixing without an explosion: Atlas 190D

https://www.youtube.com/watch?v=FmrrcAVOV4s (https://www.youtube.com/watch?v=FmrrcAVOV4s)

Quote
13,000 gallons of liquid oxygen and a full load of fuel sloshed over the stand and the nearby terrain.

here's a reference:
https://books.google.com/books?id=OVNuxBlXFHYC&lpg=PA32&ots=RWbZyy0by-&dq=1963%2C%20Atlas%20190D&pg=PA32#v=onepage&q=1963,%20Atlas%20190D&f=false (https://books.google.com/books?id=OVNuxBlXFHYC&lpg=PA32&ots=RWbZyy0by-&dq=1963%2C%20Atlas%20190D&pg=PA32#v=onepage&q=1963,%20Atlas%20190D&f=false)

Atlas 190D had only fuel on board no LOX:

Quote
The launch crew managed to
drain the LOX tank but ended up depressurizing it in the process, and so
it collapsed, dropping the Agena.

http://www.spacebanter.com/showthread.php?t=51063 (http://www.spacebanter.com/showthread.php?t=51063)
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: eeergo on 09/01/2016 09:32 PM

That is exactly my point though, the mixture isn't right. They are totally separate until something goes wrong. It seems a stretch to think the O2 tank popped, which popped the RP-1 tank, and static happened at the right time and place to cause a spark, all within a few milliseconds. We should have seen a tank pop before it all went up.


The RP-1 tank is pressurized too. A sudden catastrophic loss of pressure from the top tank (coupled with the immediate boiling and aerosolization of the remaining LOX) would have caused a very traumatic upward force event for the common bulkhead to withstand, causing it to fail upward and providing a kerosene spray from below. This, provided the bulkhead hadn't failed beforehand, causing the visible wall rupture.


A burning RP-1 stream starts to appear in the image (see arrow) at frame 10 after the explosion already: around 160 ms after the explosion started.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: MattMason on 09/01/2016 09:33 PM
That is exactly my point though, the mixture isn't right. They are totally separate until something goes wrong. It seems a stretch to think the O2 tank popped, which popped the RP-1 tank, and static happened at the right time and place to cause a spark, all within a few milliseconds. We should have seen a tank pop before it all went up.

That's what i believe too.

At least with a copv bursting, it would send shrapnel through the tank walls into the fuel tank causing mixing.  someone mentioned upthread that the bursting of a copv might have enough energy to start the chemical chain reaction (not the kind of "classical" ignition source you'd imagine like a flame or spark), and the copv carbon would be flammable in a high oxygen environment.

And if either tank burst, logic suggests the integrity of the second stage would've failed far more quickly and the payload fairing would've fallen or been pushed away much earlier.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: glennfish on 09/01/2016 09:33 PM
I think there's evidence that the explosion initiated to the side of the rocket, not on or in the rocket.  The USLaunchReport video as a reference.   There is a fragment that has a trajectory that traces back to the strongback, not the rocket.  Reference images attached
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Lar on 09/01/2016 09:38 PM
Deleted a couple of "what is this thing transversing the vid" ... it's a bird.

People, it's fun to speculate but please review the thread before you post, and think. At least a little.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Space Ghost 1962 on 09/01/2016 09:38 PM
I think there's evidence that the explosion initiated to the side of the rocket, not on or in the rocket.  The USLaunchReport video as a reference.   There is a fragment that has a trajectory that traces back to the strongback, not the rocket.  Reference images attached

Interesting. Can be ballistically reconstructed. Anyone up for this?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: atsf90east on 09/01/2016 09:38 PM
I noticed this too.  I'm not familiar with the LOX fill line interface with the vehicle, but if the explosion started inside the second stage, wouldn't this object be blown outward, and not upward?

I think there's evidence that the explosion initiated to the side of the rocket, not on or in the rocket.  The USLaunchReport video as a reference.   There is a fragment that has a trajectory that traces back to the strongback, not the rocket.  Reference images attached
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: TheTraveller on 09/01/2016 09:41 PM
So what is Object X?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: MattMason on 09/01/2016 09:44 PM
I think there's evidence that the explosion initiated to the side of the rocket, not on or in the rocket.  The USLaunchReport video as a reference.   There is a fragment that has a trajectory that traces back to the strongback, not the rocket.  Reference images attached

Interesting. Can be ballistically reconstructed. Anyone up for this?

I'm sure you're asking the right people, if NSF's CRS-7 forum investigation and F9 water landing video reconstruction are any indications. :)
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: dorkmo on 09/01/2016 09:46 PM
So what is Object X?

i think what you circled on the left side is some liquid oxygen that is being pushed away

and what you circled on the right side is the claw that holds onto the stage that is part of the Erector
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: RoboGoofers on 09/01/2016 09:47 PM
I think there's evidence that the explosion initiated to the side of the rocket, not on or in the rocket.  The USLaunchReport video as a reference.   There is a fragment that has a trajectory that traces back to the strongback, not the rocket.  Reference images attached

it could also coming toward the camera.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: bstrong on 09/01/2016 09:48 PM
So what is Object X?

That's what I was calling evidence of the LOX tank rupturing at top left, near the vents.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Wolfram66 on 09/01/2016 09:49 PM
So what is Object X?

i think what you circled on the left side is some liquid oxygen that is being pushed away

and what you circled on the right side is the claw that holds onto the stage that is part of the Erector

Correct. That is simply a backlit O2 vapor cloud. move along...
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: dorkmo on 09/01/2016 09:49 PM
I think there's evidence that the explosion initiated to the side of the rocket, not on or in the rocket.  The USLaunchReport video as a reference.   There is a fragment that has a trajectory that traces back to the strongback, not the rocket.  Reference images attached

it could also coming toward the camera.

also spinning as it is catching different light from the flame
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ChrisWilson68 on 09/01/2016 09:53 PM
WOW. We can see the payload fall seconds after the first explosion. Maybe a dragon could fly away in time.

Maybe the crew Dragon but not the cargo Dragon. The cargo Dragon can now survive a CRS-7 type accident by deploying its parachutes but that doesn't help if the accident is at the pad.

It's hard to know if people would have survived if they had been in a crew Dragon on this rocket.  If there was no warning, the Dragon would have been subjected to a significant overpressure before it could have taken off.  Maybe the Dragon could have protected crew members from such an overpressure, maybe not.

There's also the issue of whether the overpressure would have damaged the SuperDraco engines and/or their prop tanks and/or the abort control system.  If any of those things failed, the crew would have died.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: mvpel on 09/01/2016 09:56 PM
I've attached the one close-up I had of of the apparently relevant area of the CRS-8 booster which I took back in April. I'm not sure if there's anything visible that might be useful, but worth a shot I guess.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: dorkmo on 09/01/2016 09:57 PM
WOW. We can see the payload fall seconds after the first explosion. Maybe a dragon could fly away in time.

Maybe the crew Dragon but not the cargo Dragon. The cargo Dragon can now survive a CRS-7 type accident by deploying its parachutes but that doesn't help if the accident is at the pad.

It's hard to know if people would have survived if they had been in a crew Dragon on this rocket.  If there was no warning, the Dragon would have been subjected to a significant overpressure before it could have taken off.  Maybe the Dragon could have protected crew members from such an overpressure, maybe not.

There's also the issue of whether the overpressure would have damaged the SuperDraco engines and/or their prop tanks and/or the abort control system.  If any of those things failed, the crew would have died.

its hard to say for sure but the payload seemed to be alright till it hit the ground. the dragon in the previous second stage mishap also survived till it hit the sea.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: rcoppola on 09/01/2016 10:00 PM
WOW. We can see the payload fall seconds after the first explosion. Maybe a dragon could fly away in time.

Maybe the crew Dragon but not the cargo Dragon. The cargo Dragon can now survive a CRS-7 type accident by deploying its parachutes but that doesn't help if the accident is at the pad.

It's hard to know if people would have survived if they had been in a crew Dragon on this rocket.  If there was no warning, the Dragon would have been subjected to a significant overpressure before it could have taken off.  Maybe the Dragon could have protected crew members from such an overpressure, maybe not.

There's also the issue of whether the overpressure would have damaged the SuperDraco engines and/or their prop tanks and/or the abort control system.  If any of those things failed, the crew would have died.
(In this scenario) It was the trunk I was most concerned with as a Crew Abort needs the trunk healthy and fully attached for proper abort profiles. (COG, etc)
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: TrueBlueWitt on 09/01/2016 10:00 PM
WOW. We can see the payload fall seconds after the first explosion. Maybe a dragon could fly away in time.

Maybe the crew Dragon but not the cargo Dragon. The cargo Dragon can now survive a CRS-7 type accident by deploying its parachutes but that doesn't help if the accident is at the pad.

It's hard to know if people would have survived if they had been in a crew Dragon on this rocket.  If there was no warning, the Dragon would have been subjected to a significant overpressure before it could have taken off.  Maybe the Dragon could have protected crew members from such an overpressure, maybe not.

There's also the issue of whether the overpressure would have damaged the SuperDraco engines and/or their prop tanks and/or the abort control system.  If any of those things failed, the crew would have died.


Edit:
Very high probability of survival..
Note that the Payload and Fairing fell into the conflagration intact, significantly after the initial explosion.
It appears the top of S2 and Payload was still held in place by the strongback, which ultimately was not strong enough to hold it up. This, however, would give it a lot more time than in a situation where the strongback is retracted.
[size=78%]Super Draco's reach full thrust in <100ms, which from the video looks like they would have pulled away. [/size]
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: john smith 19 on 09/01/2016 10:06 PM
Just seen the video. From the flash to bang time can anyone confirm the mike was about 2.55 miles (4000 m) from the rocket?

The updates section reports that debris "small enough to fit in a shoe box" were found in a parking lot 1.8miles from the pad.  I suspect given the completeness of the destruction that will not be the farthest that debris is found.

NASA did do studies to estimate the explosive power of LOX/RP1 explosions for Saturn 1 and V but I think they were looking at a rupture/ignition/fire where this looks like an explosion.

AFAIK NASA never actually went as far as loading up a full Saturn 1 and testing their model but this will give them a data point to compare with.  :(
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: iamlucky13 on 09/01/2016 10:06 PM
One thought re: speculation about a COPV failure. The COTS-7 failure wasn't thought to be a COPV letting go per se, but a massive helium leak that led to an overpressure. A COPV flat-out failing might happen faster, and could lead to a more energetic explosion. For instance, isn't that how the S-IVB 503 upper stage was lost during a ground test (in very similar circumstances--during fueling before a hot-fire test)?

~Jon

Good memory. I've been trying to recall on-pad explosions in general, and it sounds like this could have some similarities. It doesn't look like the accident report is on NTRS, but other documents there discuss it:
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19970009949.pdf

Quote
The group finally traced the source of the explosion to one of the eight ambient-temperature helium storage spheres located on the thrust structure of the J -2 engine. The exploding sphere ruptured the propellant fill lines, allowing liquid oxygen and liquid hydrogen to mix and ignite, setting off an explosion that wrecked the stage. Further analysis showed that the sphere had been welded with pure titanium weld material, rather than the alloy material specified.

So it doesn't sound like an over-pressurization of the propellant tanks, but an initial event external to the propellant tanks.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Damon Hill on 09/01/2016 10:08 PM
I'm impressed by the sheer energy of the initial explosion, which seems centered slightly <outside> the second stage; it propelled at least one largish piece of hardware seemingly upwards.  The deflagrations that followed seemed slower in comparison.

It will be interesting to see what telemetry says in the seconds leading up to the initial explosion.  If everything looks normal, then bang!, it may point to an external cause.

We'll just have to wait for the full analysis of all data.  That will determine return to flight, but I doubt it'll be before the end of fall, unless it's clearly not the rocket's fault.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: TheTraveller on 09/01/2016 10:12 PM
So what is Object X?

That's what I was calling evidence of the LOX tank rupturing at top left, near the vents.

Does look like a panel has opened as the black outlined object looks solid under enhancement and something is venting out to the left.

Is there maybe a bulge on the left side of the 2nd stage 18ms before the fireball?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Grendal on 09/01/2016 10:18 PM
Hopefully someone has a video of the event from a different angle.  It appears to me that the event happened just outside of the second stage.  The video we have makes the determination more difficult because of the angle.  Thanks to USLaunchreport for providing this video for all of us to speculate with.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: jgoldader on 09/01/2016 10:19 PM
Does look like a panel has opened as the black outlined object looks solid under enhancement and something is venting out to the left.

You have to be careful in over-interpreting the dark "thing."  The flame is back-lighting an oxygen vapor cloud, and the camera's response and dynamic lighting conditions might be doing very weird things. Notice how the shroud looks black on the left-hand edge in your cropped center frame? It *could* be a piece of debris, or it could be a curl of vapor.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: mleigh on 09/01/2016 10:21 PM
NASA Statement on SpaceX Incident
Press Release From: NASA HQ
Posted: Thursday, September 1, 2016

“We remain confident in our commercial partners and firmly stand behind the successful 21st century launch complex that NASA, other federal agencies, and U.S. commercial companies are building on Florida’s Space Coast. Today’s incident -- while it was not a NASA launch -- is a reminder that spaceflight is an incredible challenge, but our partners learn from each success and setback.

“The situation at the Cape is being evaluated, and it’s too early to know whether the incident will affect the schedule for upcoming NASA-related SpaceX launches to the International Space Station. If there are SpaceX mission delays, other cargo spacecraft will be able to meet the station’s cargo needs, and supplies and research investigations are at good levels.

“The launch for NASA’s OSIRIS-REx mission remains on track for Sept. 8. Initial assessments indicate the United Launch Alliance Atlas V rocket and OSIRIS-REx spacecraft are healthy and secure in the Vertical Integration Facility at Space Launch Complex-41, which is 1.1 miles from SpaceX’s launch pad where the incident occurred.”

// end //

From: http://spaceref.com/news/viewpr.html?pid=49385
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: cscott on 09/01/2016 10:22 PM
Does look like a panel has opened as the black outlined object looks solid under enhancement and something is venting out to the left.

You have to be careful in over-interpreting the dark "thing."  The flame is back-lighting an oxygen vapor cloud, and the camera's response and dynamic lighting conditions might be doing very weird things. Notice how the shroud looks black on the left-hand edge in your cropped center frame? It *could* be a piece of debris, or it could be a curl of vapor.
It could also be a JPEG/MPEG compression artifact, which create hard edges where none actually exist.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: robertross on 09/01/2016 10:29 PM
NASA Statement on SpaceX Incident
Press Release From: NASA HQ
Posted: Thursday, September 1, 2016

“We remain confident in our commercial partners and firmly stand behind the successful 21st century launch complex that NASA, other federal agencies, and U.S. commercial companies are building on Florida’s Space Coast. Today’s incident -- while it was not a NASA launch -- is a reminder that spaceflight is an incredible challenge, but our partners learn from each success and setback.

“The situation at the Cape is being evaluated, and it’s too early to know whether the incident will affect the schedule for upcoming NASA-related SpaceX launches to the International Space Station. If there are SpaceX mission delays, other cargo spacecraft will be able to meet the station’s cargo needs, and supplies and research investigations are at good levels.

“The launch for NASA’s OSIRIS-REx mission remains on track for Sept. 8. Initial assessments indicate the United Launch Alliance Atlas V rocket and OSIRIS-REx spacecraft are healthy and secure in the Vertical Integration Facility at Space Launch Complex-41, which is 1.1 miles from SpaceX’s launch pad where the incident occurred.”

// end //

From: http://spaceref.com/news/viewpr.html?pid=49385

Well I certainly have my doubts as to SpaceX being able to have the root cause & solution figured out in around 70+ days (thinking static fire), let alone having the pad reconfigured.

I'm sure the strongback is in serious condition (metal fatigue due to heat), including the hydraulic cylinders, and pad commodity lines. Maybe December...but that could be pushing it; I'd put my money on February.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: dnavas on 09/01/2016 10:36 PM
Further, look at the symmetry of the expanding LOX cloud a few frames later. The right side is a bit muffled because of the interference with the T/E, obviously, but the near perfect oval shape for most of its circumference suggests the failure point was mostly toward the camera, not facing directly at the erector.

The first 'fire' frame is clearly brighter than the one after it.  That first frame shows highlighting of the fairing and erector which, if they both are primary reflections, would indicate a light source away from the body of the rocket, as you suggest, otherwise the fairing wouldn't be lit/flaring.  The shape of that highlighting also seems to indicate a right (towards erector) bias, however.

The frames thereafter show a distinct red shift (from green) and the lighting beneath the blast zone indicate a somewhat more centered bright zone (a bit farther from the erector and directed more towards the camera).  That zone doesn't appear to change for several frames, even as the conflagration proceeds.

The diffraction X pattern, on the other hand, shifts from frame to frame until smoke obscures enough to remove it entirely, so while I'm sympathetic to the argument that it is likely useful, the frame-to-frame instability of it makes me concerned.

I fear that attempts to locate the failure by locating the source of the brightest point may not be wise.  Anything other than elevation is going to be hard to determine, and there's no guarantee that the source of initial ignition is a reasonable proxy for the failure point.  It still seems most likely to me that the failure happened inside the rocket, and what we see is aftermath.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Rocket Science on 09/01/2016 10:36 PM
Every time we have one on these events my thoughts are always the same. Better now than when we have a crew on board. Pick up the pieces, find the cause(s), fix them and get flying again. Best of luck to the teams at SpaceX.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: eeergo on 09/01/2016 10:38 PM
Quick&dirty attempt at recreating the trajectory of the fragment propelled upward -which, by the way, to me doesn't mean the explosion originated outside: it could well be a T/E panel or a torn piece of 2nd stage wall located over the failure point.


What is apparent from trying to follow it when it passes in front of the saturated fireball is that it's coming toward the camera, as it appears precisely where you would expect after it clears the brightest part of the cloud.


The last 2-3 crops show it being carried sideways to the left by the wind draft.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ChrisWilson68 on 09/01/2016 10:43 PM
Every time we have one on these events my thoughts are always the same. Better now than when we have a crew on board. Pick up the pieces, find the cause(s), fix them and get flying again. Best of luck to the teams at SpaceX.

Yes, and this is exactly why I think it's so much more dangerous to put a crew on SLS than a crew on either commercial crew vehicle.  Atlas V and Falcon 9 have lots of non-crew launches to find problems before crews are put on them.  SLS does not.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Khadgars on 09/01/2016 10:49 PM
Every time we have one on these events my thoughts are always the same. Better now than when we have a crew on board. Pick up the pieces, find the cause(s), fix them and get flying again. Best of luck to the teams at SpaceX.

Agreed.  SpaceX will be able to recover from this.  I don't think however, that they will be able to survive another failure in the near to mid future.

I believe SpaceX should takes its time investigating this, and all of their procedures.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Khadgars on 09/01/2016 10:52 PM
Every time we have one on these events my thoughts are always the same. Better now than when we have a crew on board. Pick up the pieces, find the cause(s), fix them and get flying again. Best of luck to the teams at SpaceX.

Yes, and this is exactly why I think it's so much more dangerous to put a crew on SLS than a crew on either commercial crew vehicle.  Atlas V and Falcon 9 have lots of non-crew launches to find problems before crews are put on them.  SLS does not.

Complete nonsense.  Please show me where launching fewer times has resulted in greater chance of loss of vehicle?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Scylla on 09/01/2016 10:52 PM
Eric Bowen ‏@scrappydog
@elonmusk Would the Dragon escape pod have survived this event?

Elon Musk
Elon Musk – Verified account ‏@elonmusk

@scrappydog yes. This seems instant from a human perspective, but it really a fast fire, not an explosion. Dragon would have been fine.
https://twitter.com/elonmusk/status/771479910778966016
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Nomadd on 09/01/2016 10:59 PM
Every time we have one on these events my thoughts are always the same. Better now than when we have a crew on board. Pick up the pieces, find the cause(s), fix them and get flying again. Best of luck to the teams at SpaceX.

Yes, and this is exactly why I think it's so much more dangerous to put a crew on SLS than a crew on either commercial crew vehicle.  Atlas V and Falcon 9 have lots of non-crew launches to find problems before crews are put on them.  SLS does not.

Complete nonsense.  Please show me where launching fewer times has resulted in greater chance of loss of vehicle?
The fact that most LOVs are early in the program seems pretty obvious. The Shuttle was an exception.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: adriankemp on 09/01/2016 11:03 PM
There is a lot of talk about COPV which to me can't possibly be very high on the failure list -- my thinking follows, please set me straight on anything I'm missing:

1 - The tank was fairly full at this time, based on the extreme nature of the event and the timeline.

2 - The COPVs would be already charged, as they are not supercooled and are far harder to fill quickly

3 - The pressure differential inside and outside the COPVs was decreasing with every passing second (understanding that the differential was still extremely large)

So then, to me it seems utterly unlikely that a COPV let go while it's job was actually getting easier by the second.

Is there some counter intuitive effect with them that would make this likely or plausible?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ChrisGebhardt on 09/01/2016 11:04 PM
Every time we have one on these events my thoughts are always the same. Better now than when we have a crew on board. Pick up the pieces, find the cause(s), fix them and get flying again. Best of luck to the teams at SpaceX.

Yes, and this is exactly why I think it's so much more dangerous to put a crew on SLS than a crew on either commercial crew vehicle.  Atlas V and Falcon 9 have lots of non-crew launches to find problems before crews are put on them.  SLS does not.

Complete nonsense.  Please show me where launching fewer times has resulted in greater chance of loss of vehicle?
The fact that most LOVs are early in the program seems pretty obvious. The Shuttle was an exception.

And Proton... and Delta II... and Taurus XL... and Soyuz...
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: A_M_Swallow on 09/01/2016 11:04 PM
Some questions to be answered when the investigation is complete and the behaviour of the crew capsule has been modelled in this situation.

1. Is there a high probability that the launch abort system would have flown the crew to safety including missing any debris if this particular explosion had happened on a manned vehicle?
2. Would the sensors in the Falcon 9 have both detected the problem and triggered the abort before the explosion hit the Dragon? Are more sensors needed?
3. Should the launch abort system be armed during hot fires? At what time in the count down? (Killing the ground crew should be avoided.)
4. Does the ground equipment, pipes and tanks need instrumentation that can trigger the abort system?
5. Can the abort control system handle the ground equipment signal arm being retracted without triggering a false alarm?
6. As an option can some payloads be saved using a similar launch abort system?
7. Does NASA need to check that Orion and the other CCDev vehicles can handle similar situations?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: glennfish on 09/01/2016 11:07 PM
Quick&dirty attempt at recreating the trajectory of the fragment propelled upward -which, by the way, to me doesn't mean the explosion originated outside: it could well be a T/E panel or a torn piece of 2nd stage wall located over the failure point.


What is apparent from trying to follow it when it passes in front of the saturated fireball is that it's coming toward the camera, as it appears precisely where you would expect after it clears the brightest part of the cloud.


The last 2-3 crops show it being carried sideways to the left by the wind draft.

You did a much better job than I could have done.   Now, as a trajectory model, please explain how a panel from the 2nd stage gets blown to the right, then produces an arc up and to the left.  :)

You clearly demonstrated the point I was trying to make, albeit, we disagree as to why.  Great work!!! :)
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: alang on 09/01/2016 11:08 PM
Every time we have one on these events my thoughts are always the same. Better now than when we have a crew on board. Pick up the pieces, find the cause(s), fix them and get flying again. Best of luck to the teams at SpaceX.

Yes, and this is exactly why I think it's so much more dangerous to put a crew on SLS than a crew on either commercial crew vehicle.  Atlas V and Falcon 9 have lots of non-crew launches to find problems before crews are put on them.  SLS does not.

Complete nonsense.  Please show me where launching fewer times has resulted in greater chance of loss of vehicle?
The fact that most LOVs are early in the program seems pretty obvious. The Shuttle was an exception.

The smaller the sample size the less you can estimate. Proof only exists in logic and mathematics.

Also, when software is involved, mean time between failure no longer works - I think that has been understood for decades.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Herb Schaltegger on 09/01/2016 11:09 PM
There is a lot of talk about COPV which to me can't possibly be very high on the failure list -- my thinking follows, please set me straight on anything I'm missing:

1 - The tank was fairly full at this time, based on the extreme nature of the event and the timeline.

2 - The COPVs would be already charged, as they are not supercooled and are far harder to fill quickly

3 - The pressure differential inside and outside the COPVs was decreasing with every passing second (understanding that the differential was still extremely large)

So then, to me it seems utterly unlikely that a COPV let go while it's job was actually getting easier by the second.

Is there some counter intuitive effect with them that would make this likely or plausible?

As was discussed extensively following the CRS-7 failure, composites don't "like" repeated cryogenic soak cycles, and there was some concern - before fault was pinned on a strut failure rather than the COPV itself - that perhaps SpaceX's practice of repeated tanking and tests prior to flight could have contributed.

To that point, although Elon pointed blame squarely at the failed strut, a GAO report regarding of NASA's handling of the CRS-7 failure investigation pointed out that the root cause was not 100% certain, with several other possible causes (I don't have a link handy and can't recall what other possible causes were implicated).
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: sunbingfa on 09/01/2016 11:10 PM

@scrappydog yes. This seems instant from a human perspective, but it really a fast fire, not an explosion. Dragon would have been fine.
https://twitter.com/elonmusk/status/771479910778966016

Elon is say this starts as a fire not explosion, meaning starting from outside? (anything from the pressuring environment inside F9 will be an explosion)
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Khadgars on 09/01/2016 11:16 PM
Every time we have one on these events my thoughts are always the same. Better now than when we have a crew on board. Pick up the pieces, find the cause(s), fix them and get flying again. Best of luck to the teams at SpaceX.

Yes, and this is exactly why I think it's so much more dangerous to put a crew on SLS than a crew on either commercial crew vehicle.  Atlas V and Falcon 9 have lots of non-crew launches to find problems before crews are put on them.  SLS does not.

Complete nonsense.  Please show me where launching fewer times has resulted in greater chance of loss of vehicle?
The fact that most LOVs are early in the program seems pretty obvious. The Shuttle was an exception.

And Proton... and Delta II... and Taurus XL... and Soyuz...

You are acting like SLS won't have a test flight (2 actually).  By this logic, a vehicle gets safer the longer and more often you fly it.  Except, that is not always the case.

In my opinion, what you are seeing here is SpaceX doing too much, too quickly that has resulted in two failures in just over a year.  Completely unrelated to SLS, so please leave it out of the discussion.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Herb Schaltegger on 09/01/2016 11:16 PM

@scrappydog yes. This seems instant from a human perspective, but it really a fast fire, not an explosion. Dragon would have been fine.
https://twitter.com/elonmusk/status/771479910778966016

Elon is say this starts as a fire not explosion, meaning starting from outside? (anything from the pressuring environment inside F9 will be an explosion)

He is absolutely NOT saying that. He's explaining the difference between a deflagration (very fast fire) versus explosion. This was the same discussion people had following the loss of Challenger (STS-51L). The famous "explosion" was not in fact an explosion, but a deflagration of the hypergolic propellants in the RCS and OMS pods following aerodynamic breakup of the stack.

Here, he's saying the vehicle didn't "explode," it burned very quickly ("deflagrated" is the engineering term) but he's NOT addressing the cause of the fire or the ignition point.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: mvpel on 09/01/2016 11:19 PM
Elon is say this starts as a fire not explosion, meaning starting from outside? (anything from the pressuring environment inside F9 will be an explosion)

I think he's talking about the difference between a detonation and a deflagration, a distinction which Destin explains in the first Smarter Every Day:

https://www.youtube.com/watch?v=4OvywNsWWd4

It would be interesting if one of the video mavens could estimate the Falcon 9's flame front speed given the frame rate and the estimated size of the first frame's fireball.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: alang on 09/01/2016 11:22 PM
If this does turn out to be the second stage again then I think that SpaceX has to ask some very difficult management questions.
I doubt that working on the  second stage is 'sexy'. The 'sexy' things to work on will be the reusable first stage, Falcon Heavy core, Raptor and BFS/BFR.
I hate to reason from analogy and I am sure that mechanical engineering isn't as flaky as software 'engineering' but my experience suggests that trouble shooting never gets rewarded, if you solve a problem then people assume you caused it in the first place and people on the upward career path avoid projects that are associated with failure or don't deliver anything new. Even in a support team one is only judged by a contribution to delivery project. I doubt that a company with a large staff turnover will nurture staff who do what is necessary in an undramatic way.


Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: mme on 09/01/2016 11:32 PM
If this does turn out to be the second stage again then I think that SpaceX has to ask some very difficult management questions.
I doubt that working on the  second stage is 'sexy'. The 'sexy' things to work on will be the reusable first stage, Falcon Heavy core, Raptor and BFS/BFR.
I hate to reason from analogy and I am sure that mechanical engineering isn't as flaky as software 'engineering' but my experience suggests that trouble shooting never gets rewarded, if you solve a problem then people assume you caused it in the first place and people on the upward career path avoid projects that are associated with failure or don't deliver anything new. Even in a support team one is only judged by a contribution to delivery project. I doubt that a company with a large staff turnover will nurture staff who do what is necessary in an undramatic way.
That is a lot of alluding.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: alang on 09/01/2016 11:33 PM
If this does turn out to be the second stage again then I think that SpaceX has to ask some very difficult management questions.
I doubt that working on the  second stage is 'sexy'. The 'sexy' things to work on will be the reusable first stage, Falcon Heavy core, Raptor and BFS/BFR.
I hate to reason from analogy and I am sure that mechanical engineering isn't as flaky as software 'engineering' but my experience suggests that trouble shooting never gets rewarded, if you solve a problem then people assume you caused it in the first place and people on the upward career path avoid projects that are associated with failure or don't deliver anything new. Even in a support team one is only judged by a contribution to delivery project. I doubt that a company with a large staff turnover will nurture staff who do what is necessary in an undramatic way.
That is a lot of alluding.
I like to think it is a lot of iffing than alluding.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: eeergo on 09/01/2016 11:34 PM

You did a much better job than I could have done.   Now, as a trajectory model, please explain how a panel from the 2nd stage gets blown to the right, then produces an arc up and to the left.  :)

You clearly demonstrated the point I was trying to make, albeit, we disagree as to why.  Great work!!! :)

Thanks, but I stand by my interpretation (and in fact I would like to know what your proposed mechanism for the trajectory is if the debris is blown from the T/E side)

The trajectory can easily be identified as coming from the rocket as follows:

If the failure point on S2 was ~45º to the right of the line joining the F9 and the camera, and we assume an upper part of the S2 LOX tank wall was blown outward from an interior event, to then hinge on its upper section for a few milliseconds, until being ripped off the structure by the expanding cloud of oxidizer, centrifugal forces would blow it upward (and it would rotate along the axis parallel to the "hinge"). Further, if the "hinge" was at an angle with respect to the ground, or if hinge failure/departure from the rest of the stage happened before it reached a 180º pivoting, some of the centrifugal force would be propelling it toward the camera. This, plus a bit of wind drag pushing the piece to the left (the "vertical" trip is about 3x faster than the time period around the upper section of the arc) could perfectly explain the trajectory we see.

Or, it could just be a piece from the T/E that was blown off from the overpressure.

Either way, my point was: it's not clear at all from the available footage whether the explosion originated in the vehicle or the umbilicals (and in fact, I personally lean for the former) but certainly the flying debris doesn't tell us much either way.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Rocket Science on 09/01/2016 11:35 PM
CNN USA is going to report on the event during this half hour is anyone wants to DVR it...
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Martin.cz on 09/01/2016 11:48 PM
Thinking about possible causes second stage FTS came to my mind but I guess that's nonsense. While from the video it kinda looked like some localized high energy event followed by a slower deflagration, I'm sure FTS activation would look a lot different, eq. unzipping the tanks, not a localized flashy "boom".

Also the initial localized high energy event (if there really was any) might really just be the stage 2 tank/s failing under pressure in a fiery manner, followed by a slower burning once the internal pressure equalized.

BTW, a few observations/questions about the USLaunchReport video:
-the fireball suddenly brightens about 3-4 seconds into the fire - could it be some of the stage 1 tanks still holding pressure until then and bursting or maybe pressure vessels going off ?
- if is unfortunately plainly visible how the poor satellite falls down & explodes into million pieces (internal pressure vessels & fuel I guess)...
- after a minute after the explosion where the ramp is still burning there are still intermittent audible bursts/explosions - any candidates for that ? COPVs going off, GSE pressure vessels bursting due to the heat or echo of the initial bursts ?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: CameronD on 09/01/2016 11:50 PM
Either way, my point was: it's not clear at all from the available footage whether the explosion originated in the vehicle or the umbilicals (and in fact, I personally lean for the former) but certainly the flying debris doesn't tell us much either way.

Even watching it on super-slow-mo is inconclusive. :(

To my eye it has all of the hall-marks of a static (electricity) ignition which could happen in either the umbilicals or the rocket if the fuel flow-rates were just a teeny bit too high and the conditions were just right (wrong).  Anyone know what the weather (wind speed, humidity) was like at the pad?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: CJ on 09/01/2016 11:57 PM
I'm going to speculate wildly here (Mod, please delete if inappropriate);

Point 1; The CRX7 failure occurred in the second stage.
Point 2; This explosion *appears* to have originated in the second stage.

Speculation: to my eyes, this event appears to have been highly energetic from the first moment it appears.

Further speculation; would a COPV failure (sudden release of He into the LOX) fit observations?

You are not the first person to suspect this. In my opinion, it appears consistent with overpressurization, but a problem with GSE  or the valve that handles boiloff might also result in overpressurization.

The CRS-7 failure is believed to have been due to buoyant forces under several G's of loading. The buoyant forces while on the pad are far lower. Even if it was a COPV failure, I would be surprised if it was due to tank buoyancy breaking a strut.

Regardless, don't get too attached to the theory. For almost every high-visibility aerospace accident like this, there's usually half a dozen reasonable-sounding theories proposed early on. Most (sometimes all) of them turn out to be wrong.

One thing I won't do is get too attached to my theory; I'm well aware that I have a pretty consistent track record on theories: mostly wrong. :)

As for the COPV tanks, is this the first time the S2 was fueled? If so, and given the massive change in thermal environment (being suddenly bathed in subcooled LOX) it does make me wonder.

The GSE or press valve is of course another suspect. 

And... I know the FTS is being ruled out because it would have unzipped the whole vehicle, but... that's if it was a commanded FTS. What if it's a short to the wire to the detonator in the S2 FTS det cord? There's an easy way to rule out the FTS entirely though; where is it? If the FTS det cord on S2 isn't in the area of the umbilical connections (the event apparently became visible in that general area) then it can't be the FTS. If, however, it was just the S2 FTS for whatever reason, and it's in that general area, wouldn't the event look much like this? A high energy initial event (the unzipping) and then a growing deflagration emanating from the point where the LOX and RP1 come into contact with each other.


Until I can find some weather data for that time, I still have a lightning step/leader charge event on my suspect list, too.

Heck, at this juncture, about the only thing not on my suspect list is the ASDS.

Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ChrisWilson68 on 09/01/2016 11:57 PM
Every time we have one on these events my thoughts are always the same. Better now than when we have a crew on board. Pick up the pieces, find the cause(s), fix them and get flying again. Best of luck to the teams at SpaceX.

Yes, and this is exactly why I think it's so much more dangerous to put a crew on SLS than a crew on either commercial crew vehicle.  Atlas V and Falcon 9 have lots of non-crew launches to find problems before crews are put on them.  SLS does not.

Complete nonsense.  Please show me where launching fewer times has resulted in greater chance of loss of vehicle?
The fact that most LOVs are early in the program seems pretty obvious. The Shuttle was an exception.

And Proton... and Delta II... and Taurus XL... and Soyuz...

When the number of failures is small (one would hope) compared to the number  of launches, of course statistics make it likely that for some launch vehicles the failures come after a number of successful flights.

The question to ask is this: wasn't Shuttle safer after Challenger than before?  And wasn't Shuttle safer after Columbia than before?

You could ask the same about Delta II and Taurus XL failures -- in each case, changes were made that should prevent similar failures in the future.  There's no doubt in my mind that if Delta II and Taurus XL continued to fly the flights after their failures would have a lower failure rate in the long term.

The Russian failures may be an exception -- there's been an apparent decline in quality, probably related to political and economic issues.  I don't see any reason to think the same would happen at ULA or SpaceX in the forseeable future.

You can ride SLS if you want.  There's no way I'd choose that over a commercial crew vehicle for myself, my friend, my family, or anyone else.  And I think the reasons for that are sound.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Lee Jay on 09/02/2016 12:03 AM
That sure looked like an explosion to me, rather than a fast fire.  Sounded like that too.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: OneSpeed on 09/02/2016 12:19 AM
As discussed upthread, the epicentre of the fireball may or may not be the source of the explosion, but if it is, the pixel at the centre of the fireball appears to correspond exactly with the LOX umbilical attachment point.

Edit: or the common bulkhead?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: HMXHMX on 09/02/2016 12:27 AM
OK, I should have my head examined, since I'm going out on a limb here, but...

...COPVs composite matrix cracks form due to normal pressure cycling from any pressurization event, like acceptance testing.  LOX infiltrates these micro cracks and thus LOX or cold GOX is now in contact with a fuel source (carbon fiber and epoxy).  Normally it is in equilibrium, not having an ignition source available, but something (static electricity from mechanical motion of tank wall due to filling?) provides a suitable ignition source.  (Of course, ignition source is always considered to be "free" in these cases.)

COPV fiber ignites and burns, taking a few seconds, and then tank bursts abruptly as hoop fibers burn away.  This overpressure event fails the common bulkhead and stage sidewall since the vent can't possibly keep up with the massive release of helium into a LOX tank with perhaps 1-3% of ullage.  Mixing of propellants occurs and we see first evidence of explosion.

Personally, I think this is what happened in the in-flight failure as well, but I lack the data to make the argument persuasive.  This time, SpaceX may be able to recover sufficient debris to make a determination.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Space OurSoul on 09/02/2016 12:30 AM
Apparently not having learned not to speculate, I submit that the following fits what we can observe: that the umbilical connection partially disconnected. This could possibly cause aerosolization of RP-1 (like a finger almost fully closing a garden hose), and such aerosolization seems a requirement to explain the initial flash. It's also consistent with the subsequent downward-pointing flame (some of the RP-1 being aerosolized, but lots of it just dripping). If the umbilical were to part from the vehicle slowly and progressively, it could also provide a spark as the electricals parted, and in fact you'd expect the electricals to part company after the fluids started leaking since the electrical connections can travel a short distance (the length of the "prongs" in the plugs) before losing contact, whereas fluids will find any gap however small.
This is also consistent with the debris that flies straight up, which is otherwise difficult to reconcile with a cause within the vehicle. Lastly, we observe a lessening of the (GOX?) venting just prior to the explosion, consistent with a loss of pressure elsewhere in the system, i.e. at the umbilical interface.
I'm sure I'm wrong for reasons I haven't thought of, or insufficient knowledge, so I welcome counter-arguments.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: dnavas on 09/02/2016 12:32 AM
Either way, my point was: it's not clear at all from the available footage whether the explosion originated in the vehicle or the umbilicals (and in fact, I personally lean for the former) but certainly the flying debris doesn't tell us much either way.

Even watching it on super-slow-mo is inconclusive. :(

Agreed.  Having initially discounted external sources given the lack of a post-initial-conflagration stage 2 event, I have to say that there is enough there to my untrained eye to reconsider.  The first frame seems to show an unshadowed event -- the lens artifacts that disappear in a few frames, the light up the fairing that disappears in two frames, the light reflecting off the far right lightning suppression structure which dims markedly after a single frame -- had an explosive exit occurred, I would have expected debris to obscure above and/or below immediately.  This does happen a few frames later as smoke builds.  I could be convinced that stage 2 lets go after the initial spark (liquid oxy plus ... almost any metal?) as watching the event in slow motion does convey the feeling that the initial burst has mounting momentum until somewhat after the initial shiny.  At the same time it's just as likely that this is a result of the amount of time required to get optimal mixing conditions.

Frustrating -- it would be useful to have seen many such explosions, but I'm sort of glad I haven't.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: cscott on 09/02/2016 12:39 AM
As discussed upthread, the epicentre of the fireball may or may not be the source of the explosion, but if it is, the pixel at the centre of the fireball appears to correspond exactly with the LOX fuel line attachment point.
Nope, that's the structural support at the common bulkhead. The umbilical attachment is lower.  Look earlier in the thread for a good picture.

And for everyone basing opinions on "super slow mo"---you do know that all those extra frames are made up, right?  You're basing your opinion on details fabricated by an interpolation algorithm.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: c on 09/02/2016 12:40 AM
Just seen the video. From the flash to bang time can anyone confirm the mike was about 2.55 miles (4000 m) from the rocket?

Sound to the camera from the first detonation is 12 seconds. Sound speed at sea level (well, those pads are about 30’ above but who’s counting) is 340 m/s * 12 seconds = a tad over 4 km.

USLaunchReport likes to record static fire tests from an old testing area just northwest of the KSC industrial area.  It's just over 4 km from pad 40.

Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Elmar Moelzer on 09/02/2016 12:49 AM
SpaceX - Static Fire Anomaly - AMOS-6 - 09-01-2016
USLaunchReport - slow down & close up at 1080P 60fps

https://www.youtube.com/watch?v=XF253Gbi2S4
Not really 60 FPS but the same video "slowed down" with repeating frames.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: iamlucky13 on 09/02/2016 12:52 AM
That sure looked like an explosion to me, rather than a fast fire.  Sounded like that too.

There's nuanced terminology in play here. An explosion is a rapid increase in volume and or pressure. A detonation is supersonic combustion - not necessary, but usually an explosion. A deflagration is subsonic combustion, most commonly not an explosion, but it can be. When a deflagration is an explosion, that rapid expansion means it is rapidly displacing air, so it creates a sound wave, and you will get a boom - sometimes even a very punctuated one.

A decent number of people are aware these distinctions exist, but mix up the details. I think Musk is doing the same in the process of trying to downplay the risk to a Dragon crew in these conditions.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: c on 09/02/2016 12:52 AM
Check the audio, there's a small pop about 5 seconds before the sound from the actual explosions arrive.

I think that's just someone messing around a car or something near the camera.

Interestingly enough, the small first bang heard is the original S2 explosion. The big bang 3 seconds later is the fuel-air type explosion when that fireball hit the ground and mixed up the RP-1 and LOX.

I hear three distinct "initial" sounds:

1:16--a very faint "plonk" like someone hitting a PVC pipe with a hammer in the distance...COPV rupture?
1:18--a faint pop/bang... S2 tank rupture?
1:23--very loud boom...the LOX/RP-1 explosion?

That first sound at 1:16 is unusual and seems to me like it may be the initiating event. A COPV or high pressure line/fitting letting go followed by S2 tank rupture 1-2 seconds later seems consistent.

FWIW, the area this video was filmed contains metal scrap, old vehicles, etc.

The "plonk" sounds like an empty 55-gallon drum ever so slightly expanding/contracting, there's a bit of reverb on the back-end of that sound. I'd guess it's local to the camera.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: iamlucky13 on 09/02/2016 12:54 AM
Apologies if I missed this upthread, and I have to point out the scales aren't the same, but the comparison is interesting:

https://fat.gfycat.com/ConcernedGreedyIbisbill.webm
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Kabloona on 09/02/2016 12:55 AM
Quote
And... I know the FTS is being ruled out because it would have unzipped the whole vehicle, but... that's if it was a commanded FTS. What if it's a short to the wire to the detonator in the S2 FTS det cord?

Once again, not possible. The safe/arm device which contains the FTS detonator typically has both mechanical and electrical inhibits to accidental initiation in the "safe" position. FTS was safed at the time of the accident.

You could take a hammer and a 12 volt car battery to pretty much any aerospace qualified FTS safe/arm device, and as long as it's in the "safe" position, not be able to set off the detonator after an hour of beating/zapping it.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Kabloona on 09/02/2016 12:58 AM
Quote
The "plonk" sounds like an empty 55-gallon drum ever so slightly expanding/contracting, there's a bit of reverb on the back-end of that sound. I'd guess it's local to the camera.

Or the reverb is from a high-pressure component letting go inside the S2, which is just like a very distant, oversized 55-gallon drum.  ;)
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: glennfish on 09/02/2016 12:59 AM
As discussed upthread, the epicentre of the fireball may or may not be the source of the explosion, but if it is, the pixel at the centre of the fireball appears to correspond exactly with the LOX umbilical attachment point.

Look at the debris trajectory debate I tried to start.  You're about 5 meters to the left of where things started me thinks.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: CameronD on 09/02/2016 01:00 AM
Frustrating -- it would be useful to have seen many such explosions, but I'm sort of glad I haven't.

I've seen a few explosions in my time.. they all look like this. :)

As discussed upthread, the epicentre of the fireball may or may not be the source of the explosion, but if it is, the pixel at the centre of the fireball appears to correspond exactly with the LOX fuel line attachment point.
Nope, that's the structural support at the common bulkhead. The umbilical attachment is lower.  Look earlier in the thread for a good picture.

RP-1 has similar properties to Jet-A1 and one of those is very low conductivity.  It's also well known in the aviation industry that static ignition can occur within fuel pipes, tanks and hoses if the flow rate is too high and the conditions are right.

If I'm seeing what I think I am (very slim chance of that, but still non-zero at this point!) the purported umbilical disconnection could be a result of it being blown off the coupling by an explosion inside the pipework itself?

And for everyone basing opinions on "super slow mo"---you do know that all those extra frames are made up, right?  You're basing your opinion on details fabricated by an interpolation algorithm.

Well.. one can still hope it might show something obscured ms later by by the cloud. :)

Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Rocket Science on 09/02/2016 01:04 AM
I find the "shape" of the detonation interesting as it has more in the horizontal than the vertical component...
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: CameronD on 09/02/2016 01:07 AM
I find the "shape" of the detonation interesting as it has more in the horizontal than the vertical component...

Horizontal rupture rather than a vertical 'tin can'??
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Rocket Science on 09/02/2016 01:09 AM
I find the "shape" of the detonation interesting as it has more in the horizontal than the vertical component...

Horizontal rupture rather than a vertical 'tin can'??
Perhaps a tank dome...
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: OneSpeed on 09/02/2016 01:11 AM
As discussed upthread, the epicentre of the fireball may or may not be the source of the explosion, but if it is, the pixel at the centre of the fireball appears to correspond exactly with the LOX umbilical attachment point.

Look at the debris trajectory debate I tried to start.  You're about 5 meters to the left of where things started me thinks.

I'm not saying you're wrong, just that that the epicentre of the fireball is where I marked it on the second stage.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: CameronD on 09/02/2016 01:17 AM
I find the "shape" of the detonation interesting as it has more in the horizontal than the vertical component...

Horizontal rupture rather than a vertical 'tin can'??
Perhaps a tank dome...
RP-1 tank or LOX??
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: c on 09/02/2016 01:19 AM
Quote
The "plonk" sounds like an empty 55-gallon drum ever so slightly expanding/contracting, there's a bit of reverb on the back-end of that sound. I'd guess it's local to the camera.

Or the reverb is from a high-pressure component letting go inside the S2, which is just like a very distant, oversized 55-gallon drum.  ;)

Y'all are way too damn smart here  :)  I guess the next step is to calculate the decibels of that sound at source using inverse square. At 4 km the "plonk" had to be fairly loud there at the pad. Or find another audio source and start triangulating. 

Hmmm... gonna be a long night. I need to go check the property as H. Hermine is trying desperately to come in thru the front door. Then I can start in on the fun stuff  ;)

Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Herb Schaltegger on 09/02/2016 01:20 AM
I find the "shape" of the detonation interesting as it has more in the horizontal than the vertical component...

Horizontal rupture rather than a vertical 'tin can'??
Perhaps a tank dome...
RP-1 tank or LOX??


Common bulkhead between the two perhaps.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: CameronD on 09/02/2016 01:23 AM
FWIW, this "event" even made news over here.  I first heard about it on the car radio on the way to work this morning..

http://www.abc.net.au/news/2016-09-02/spacex-rocket-explodes-on-launch-site-at-cape-canaveral/7807196

http://www.news.com.au/technology/science/space/explosion-at-spacex-launch-pad/news-story/c5ee6e6c83e386cfc1a88e1500253216

Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Rocket Science on 09/02/2016 01:29 AM
I find the "shape" of the detonation interesting as it has more in the horizontal than the vertical component...

Horizontal rupture rather than a vertical 'tin can'??
Perhaps a tank dome...
RP-1 tank or LOX??


Common bulkhead between the two perhaps.
You beat me to it Herb! :)
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: bstrong on 09/02/2016 01:42 AM
Personally, I think this is what happened in the in-flight failure as well, but I lack the data to make the argument persuasive.  This time, SpaceX may be able to recover sufficient debris to make a determination.

Before SpaceX announced the results of their investigation, I was convinced the in-flight failure involved combustion inside the LOX tank (since I thought I saw combustion at the vent ports and the MVac chill-down exhaust plume in the videos), but I couldn't come up with a plausible fuel source. Your theory makes a lot of sense to me.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: CameronD on 09/02/2016 01:43 AM
I find the "shape" of the detonation interesting as it has more in the horizontal than the vertical component...

Horizontal rupture rather than a vertical 'tin can'??
Perhaps a tank dome...
RP-1 tank or LOX??


Common bulkhead between the two perhaps.

Watching the footage again (several times) it does seem as if the entire S2 RP-1 load gets dumped out on the ground, leaving only a few streaks dripping from the payload (upper) end of the stage as it falls.  By then the fire on the rocket is mostly out (there being no RP-1 left to burn)... so you might be onto something there. :)
 
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Brovane on 09/02/2016 01:44 AM
If NASA is not comfortable with the fueling of the Dragon with astronauts on-board after this accident.  Can SpaceX forgo super-chilling the propellants(accepting the performance lose) so the F9 can be fueled before the astronauts board? 
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ww2planes1 on 09/02/2016 01:52 AM
Do we have any confirmation of when in the countdown the anomaly occurred? Is it possible that SpaceX had significant advance warning that something was off-nominal?

I ask this because it was posted way up in this thread (albeit by a third-party source, not from an official SpaceX source), that the failure occurred at about the T-3 minute mark to the hot fire.  The countdown for an F9 Full Thrust shows that by the three minute mark, we should have seen that the strongback cradles were open and possibly that the retraction had begun.
T-0:04:10   Strongback Cradles Opening
T-0:03:30   Strongback Retraction

Plainly, the cradles were still closed and the rocket was at least 4-5 minutes away from being ready for the static fire, which means one of three things:
1) SpaceX uses a modified timeline for their static fires which compresses the strongback events.  I think this is unlikely as it reduces the value of the static fire, since it is no longer a true simulation of the launch countdown.
2) The guy who said they were at about 3 minutes was wrong and they were earlier in the count (prior to T-4:10 when the strongback cradles open), or SpaceX was working to a fairly loose schedule and they were going to do the fire when they were ready for it. This is definitely the most probable reason, but not the only reasonable one.
3) SpaceX had noticed an issue during the count and was in a hold or abort case when the catastrophic anomaly occurred.  This would be interesting because it would mean that the SpaceX team may have a lot more to go on than if this were a sudden event in an otherwise nominal countdown. 
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: the_other_Doug on 09/02/2016 01:55 AM
The visual evidence is inconclusive, I think.  It's consistent with either an explosive (as in combustion happening) deflagration from within stage 2, or with an explosion in the TEL right at the upper stage 2 umbilical port.  The end result is the same either way.

It seems pretty obvious that the explosion began at the umbilicals.  Now, I've seen estimates of this occurring anywhere from T-4:20 to T-3:10.  At some point between those two times, the strongback was supposed to retract.

What happens to the stack if the strongback starts to retract but the clamps holding stage 2 right under the payload shroud fail to open?  Would this slightly deform the rocket, the TEL, or both?  I ask because it's very obvious that the clamps were still closed, else the payload and fairing would not have been held up for as long as they were.  Indeed, it looks as if the payload only fell because the TEL bent from the spot of the initial explosion and tipped the payload and shroud out of the clamps.

I'd have to think that the rocket would fail before the TEL, if it began to retract without opening the upper clamps.  But maybe this is a convoluted series of events that starts with a semi-failed strongback release and results in a deformed umbilical port slipping and sparking right where a little LOX and RP1 are starting to leak from fill ports due to bending motions.

I'd think that if stage 2 overpressurized we'd have heard something along those lines somewhere, that's the kind of reading SpaceX would definitely have quite shortly after the event.  I'm guessing it's a GSE/TEL issue, but one that may have several small and almost inconsequential events combining to cause the big LOV event.

Beyond that, even with the good video feed we do have, this just isn't something we can do a lot of useful speculation about until we get more information from the people running the investigation, i.e., SpaceX...
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Rocket Science on 09/02/2016 02:06 AM
If we have a "graphics wiz" that can superimpose a Falcon cutaway over a video still, that would be great! :)
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Kabloona on 09/02/2016 02:10 AM
Quote
I'd think that if stage 2 overpressurized we'd have heard something along those lines somewhere, that's the kind of reading SpaceX would definitely have quite shortly after the event. 

There are indications SpaceX already has a pretty good idea what happened, but they are being cautious about making public pronouncements. Nothing to be gained by jumping the gun.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: CJ on 09/02/2016 02:14 AM
Quote
And... I know the FTS is being ruled out because it would have unzipped the whole vehicle, but... that's if it was a commanded FTS. What if it's a short to the wire to the detonator in the S2 FTS det cord?

Once again, not possible. The safe/arm device which contains the FTS detonator typically has both mechanical and electrical inhibits to accidental initiation in the "safe" position. FTS was safed at the time of the accident.

You could take a hammer and a 12 volt car battery to pretty much any aerospace qualified FTS safe/arm device, and as long as it's in the "safe" position, not be able to set off the detonator after an hour of beating/zapping it.

IMHO, we need to be clear here; there's a difference between the detonators and the explosive. The explosive itself is quite safe; you can toss a chunk into a fire with no ill effect (or whack it with a hammer, etc). That's why you safe explosive egress systems on military aircraft by taking out the detonators, not the explosives.  The explosive itself (with no detonator present) is pretty much inert, and about as dangerous as a similar sized chunk of wax (unless exposed to very high temperatures/pressures such as from a high-order explosion, usually provided by a detonator).

Detonators, on the other hand, are very twitchy beasts. Hitting one with a hammer is not a good idea.

What this means in practice is that if the detonators were installed, accidental initiation via static charge or electrical fault is possible. If they are physically not in the det cord, it's pretty much impossible. If the detonators are not installed for a static fire, what I postulated is impossible. If the mechanical safing you mention involves physically removing the detonators, and that was in effect, what I postulated is impossible. However, if the detonators were physically present in the det cord, then what I postulated is not impossible (though still very unlikely) no matter what safeguards there are. 

To be clear, I'm not taking about an accidentally commanded FTS initiation, but an electrostatic event caused by a ground leader event (also called a step leader, and more than enough to kill a human) triggering a single detonator (I know them monitor the field density as part of the launch criteria, but do those apply for a static fire?). I think this scenario very unlikely, but possible, if and only if the location of the det cord is in the area the explosion was first seen. (Caveat: this scenario is also impossible sans significant electrostatic buildup).

For those curious on what a step leader is, here's a link;
http://www.lightningsafety.noaa.gov/science/science_initiation_stepped_leader.htm


 
 
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: LouScheffer on 09/02/2016 02:16 AM
It definitely starts with a bright flash, then decreases in brightness for a few frames, then increases again.

To see this, look at the  US Launch report video (https://www.youtube.com/watch?v=_BgJEXQkjNQ) and single-step it, looking not at the explosion but on the light cast on the rightmost lightning tower top.  This does not saturate or run into JPG artifacts.  Looking at the leftmost tower, the initial flash does not illuminate it, but once the fireball is bigger than the rocket it's illuminated as well.  So the initial flash is smaller than the rocket diameter and on the erector side.

To me, this seems like some initial fire/explosion that peaks fast (less than one frame) then decreases in brightness.  But it breaches the tank, and when the propellants rush out of the tank, they burn, and the brightness goes up again.

Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Kabloona on 09/02/2016 02:19 AM
Quote
And... I know the FTS is being ruled out because it would have unzipped the whole vehicle, but... that's if it was a commanded FTS. What if it's a short to the wire to the detonator in the S2 FTS det cord?

Once again, not possible. The safe/arm device which contains the FTS detonator typically has both mechanical and electrical inhibits to accidental initiation in the "safe" position. FTS was safed at the time of the accident.

You could take a hammer and a 12 volt car battery to pretty much any aerospace qualified FTS safe/arm device, and as long as it's in the "safe" position, not be able to set off the detonator after an hour of beating/zapping it.

IMHO, we need to be clear here; there's a difference between the detonators and the explosive. The explosive itself is quite safe; you can toss a chunk into a fire with no ill effect (or whack it with a hammer, etc). That's why you safe explosive egress systems on military aircraft by taking out the detonators, not the explosives.  The explosive itself (with no detonator present) is pretty much inert, and about as dangerous as a similar sized chunk of wax (unless exposed to very high temperatures/pressures such as from a high-order explosion, usually provided by a detonator).

Detonators, on the other hand, are very twitchy beasts. Hitting one with a hammer is not a good idea.

What this means in practice is that if the detonators were installed, accidental initiation via static charge or electrical fault is possible. If they are physically not in the det cord, it's pretty much impossible. If the detonators are not installed for a static fire, what I postulated is impossible. If the mechanical safing you mention involves physically removing the detonators, and that was in effect, what I postulated is impossible. However, if the detonators were physically present in the det cord, then what I postulated is not impossible (though still very unlikely) no matter what safeguards there are. 

To be clear, I'm not taking about an accidentally commanded FTS initiation, but an electrostatic event caused by a ground leader event (also called a step leader, and more than enough to kill a human) triggering a single detonator (I know them monitor the field density as part of the launch criteria, but do those apply for a static fire?). I think this scenario very unlikely, but possible, if and only if the location of the det cord is in the area the explosion was first seen. (Caveat: this scenario is also impossible sans significant electrostatic buildup).

For those curious on what a step leader is, here's a link;
http://www.lightningsafety.noaa.gov/science/science_initiation_stepped_leader.htm

Yes, and what I'm saying is that the detonator is typically *inside* the safe/arm device, which has both electrical and mechanical inhibits to accidental initiation. The safe/arm device is designed to be shock resistant, so you can beat on it with a hammer and zap it with current and still not be able to set off the detonator inside, when the device is "safed." And even if the detonator does go off in the "safe" position, the mechanical inhibit prevents the shock wave from reaching the FTS explosive and setting it off.

The safe/arm device I worked with had an electromechanical rotor inside which contained the detonator. In the "safe" position, the rotor moved the detonator out of the path of the main explosive train, so that in "safe" position, even if the detonator went off, the shock wave could not reach the explosive train to initiate it.

So to summarize, the safe/arm device is typically designed such that when in the "safe" condition, even accidental detonator initiation will not propagate to the main FTS charge.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: dorkmo on 09/02/2016 02:19 AM
here's a link to the last launch count down. gives a look at where the umbilicals and such are

https://www.youtube.com/watch?v=OERDIFnFvHs?t=13m29s
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: bstrong on 09/02/2016 02:28 AM
It definitely starts with a bright flash, then decreases in brightness for a few frames, then increases again.

Are you taking into account the effect of the camera's autoexposure adjustments over that time period? Watch the sky away from the rocket to get an idea of how the exposure is changing.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: CJ on 09/02/2016 02:32 AM
Yes, and what I'm saying is that the detonator is typically *inside* the safe/arm device, which has both electrical and mechanical inhibits. The safe/arm device is designed to be shock resistant, so you can beat on it with a hammer and zap it with current and still not be able to set off the detonator inside, when the device is "safed."

If that device includes some way of 100% isolating the detonators from an electrical surge of a magnitude inherent in a step leader (on the order of tens of thousands of volts), then what I'm postulating is impossible.

Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: punder on 09/02/2016 02:33 AM
Just impressions from watching the video at regular speed. The piece of flying debris that's been talked about looks like it bounced off the tower rather than originating from it. And the tower was deformed by the weight of the payload and fairing sitting on the cradle arms, suddenly without the support of the rocket structure.

Guess I'm not adding much. What a crappy day. The repercussions (so to speak) are going to be huge. Sad.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Kabloona on 09/02/2016 02:35 AM
Yes, and what I'm saying is that the detonator is typically *inside* the safe/arm device, which has both electrical and mechanical inhibits. The safe/arm device is designed to be shock resistant, so you can beat on it with a hammer and zap it with current and still not be able to set off the detonator inside, when the device is "safed."

If that device includes some way of 100% isolating the detonators from an electrical surge of a magnitude inherent in a step leader (on the order of tens of thousands of volts), then what I'm postulating is impossible.

Once again, it's not just a matter of electrical inhibits/isolation. Typically there is also a *mechanical barrier* between detonator and main charge that prevents shock wave transmission in the "safe" condition.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: CJ on 09/02/2016 02:47 AM
Yes, and what I'm saying is that the detonator is typically *inside* the safe/arm device, which has both electrical and mechanical inhibits. The safe/arm device is designed to be shock resistant, so you can beat on it with a hammer and zap it with current and still not be able to set off the detonator inside, when the device is "safed."

If that device includes some way of 100% isolating the detonators from an electrical surge of a magnitude inherent in a step leader (on the order of tens of thousands of volts), then what I'm postulating is impossible.

Once again, it's not just a matter of electrical inhibits/isolation. Typically there is also a *mechanical barrier* between detonator and main charge that prevents shock wave transmission in the "safe" condition.

AH! My apologies, I misunderstood. I thought that was for safing the system manually, not remotely changeable on the pad. I stand corrected.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: CameronD on 09/02/2016 02:56 AM
Yes, and what I'm saying is that the detonator is typically *inside* the safe/arm device, which has both electrical and mechanical inhibits. The safe/arm device is designed to be shock resistant, so you can beat on it with a hammer and zap it with current and still not be able to set off the detonator inside, when the device is "safed."

If that device includes some way of 100% isolating the detonators from an electrical surge of a magnitude inherent in a step leader (on the order of tens of thousands of volts), then what I'm postulating is impossible.

Once again, it's not just a matter of electrical inhibits/isolation. Typically there is also a *mechanical barrier* between detonator and main charge that prevents shock wave transmission in the "safe" condition.

..and IIRC, the FTS charge runs vertically up the side of the tank.  The post-explosion tank rupture (that caused S2 to spill it's hydrocarbon guts all over the pad) definitely appears to be horizontal running the FTS system right out of the picture.

FWIW, I don't see any evidence of any kind of lightning event here and the towers are intended to protect the rocket from that.  Static-induced sparks during fuelling are well-documented, more common that you might think and a different beastie entirely.

Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Kabloona on 09/02/2016 03:01 AM
Yes, and what I'm saying is that the detonator is typically *inside* the safe/arm device, which has both electrical and mechanical inhibits. The safe/arm device is designed to be shock resistant, so you can beat on it with a hammer and zap it with current and still not be able to set off the detonator inside, when the device is "safed."

If that device includes some way of 100% isolating the detonators from an electrical surge of a magnitude inherent in a step leader (on the order of tens of thousands of volts), then what I'm postulating is impossible.

Once again, it's not just a matter of electrical inhibits/isolation. Typically there is also a *mechanical barrier* between detonator and main charge that prevents shock wave transmission in the "safe" condition.

AH! My apologies, I misunderstood. I thought that was for safing the system manually, not remotely changeable on the pad. I stand corrected.

Here's what a typical safe/arm device looks like. The silver flex line coming out of the top is the explosive train leading to the main FTS charge.

http://www.eba-d.com/products/electro-mechanical-safe-arm-sa-device/

One electrical connector receives commands to rotate the internal detonator(s) between the safe and armed positions. The other connector receives the "fire" command to set off the detonator.

Usually the safe/arm commands can be sent to it either through ground lines during static fire tests or actual launches, or via flight computer autonomously for in-flight arming/safing.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: mn on 09/02/2016 03:03 AM
here's a link to the last launch count down. gives a look at where the umbilicals and such are

https://www.youtube.com/watch?v=OERDIFnFvHs?t=13m29s

And while you were posting this I was grabbing a screen shot.

So here are the umbilicals. Not the best angle but quite clear that the connection is at the bottom of the stage.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Flying Beaver on 09/02/2016 03:14 AM
CRS-8 2nd Stage overlayed:

 https://www.youtube.com/watch?v=wdlaYaah6Qk&feature=youtu.be
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: glennfish on 09/02/2016 03:15 AM
Just impressions from watching the video at regular speed. The piece of flying debris that's been talked about looks like it bounced off the tower rather than originating from it. And the tower was deformed by the weight of the payload and fairing sitting on the cradle arms, suddenly without the support of the rocket structure.

Guess I'm not adding much. What a crappy day. The repercussions (so to speak) are going to be huge. Sad.

The trajectory has that part going a few hundred yards off the bounce point in your theory.  Other than super balls, most materials will crumple on impact rather than bounce.  I don't buy the bounce idea, but... maybe it is a superball.  If you look at the part as it tumbles, it seems to be a "cap" to something.  Are there "cap" structures on the strongback?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: glennfish on 09/02/2016 03:18 AM

You did a much better job than I could have done.   Now, as a trajectory model, please explain how a panel from the 2nd stage gets blown to the right, then produces an arc up and to the left.  :)

You clearly demonstrated the point I was trying to make, albeit, we disagree as to why.  Great work!!! :)

Thanks, but I stand by my interpretation (and in fact I would like to know what your proposed mechanism for the trajectory is if the debris is blown from the T/E side)

The trajectory can easily be identified as coming from the rocket as follows:

If the failure point on S2 was ~45º to the right of the line joining the F9 and the camera, and we assume an upper part of the S2 LOX tank wall was blown outward from an interior event, to then hinge on its upper section for a few milliseconds, until being ripped off the structure by the expanding cloud of oxidizer, centrifugal forces would blow it upward (and it would rotate along the axis parallel to the "hinge"). Further, if the "hinge" was at an angle with respect to the ground, or if hinge failure/departure from the rest of the stage happened before it reached a 180º pivoting, some of the centrifugal force would be propelling it toward the camera. This, plus a bit of wind drag pushing the piece to the left (the "vertical" trip is about 3x faster than the time period around the upper section of the arc) could perfectly explain the trajectory we see.

Or, it could just be a piece from the T/E that was blown off from the overpressure.

Either way, my point was: it's not clear at all from the available footage whether the explosion originated in the vehicle or the umbilicals (and in fact, I personally lean for the former) but certainly the flying debris doesn't tell us much either way.

My problem with your hinge idea is that it has to hinge somewhere on the cylinder of the rocket.  That's ok, but if you use your own trajectory plot, it has to hinge THROUGH the strongback at the beginning of the journey.  It's a nice concept, but the starting point of that fragment doesn't strike me as a hinge action from the skin of the stage.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jim on 09/02/2016 03:20 AM
Apparently not having learned not to speculate, I submit that the following fits what we can observe: that the umbilical connection partially disconnected. This could possibly cause aerosolization of RP-1 (like a finger almost fully closing a garden hose), and such aerosolization seems a requirement to explain the initial flash. It's also consistent with the subsequent downward-pointing flame (some of the RP-1 being aerosolized, but lots of it just dripping).


RP-1 was already loaded.  There would not be any pressure in that part of the umbilical.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: CJ on 09/02/2016 03:28 AM


Here's what a typical safe/arm device looks like. The silver flex line coming out of the top is the explosive train leading to the main FTS charge.

http://www.eba-d.com/products/electro-mechanical-safe-arm-sa-device/

One electrical connector receives commands to rotate the internal detonator(s) between the safe and armed positions. The other connector receives the "fire" command to set off the detonator.

Usually the safe/arm commands can be sent to it either through ground lines during static fire tests or actual launches, or via flight computer autonomously for in-flight arming/safing.

Thanks for the link!

You're 100% right; it does indeed mechanically separate the detonators from the ordinance train by remote command. Thus, a detonator going off in that state (unarmed) wouldn't trigger the det cord, and we were before the point where they'd arm it.

No matter what the real cause is, I hope they determine it with absolute certainty. Any degree of uncertainty would make this even worse IMHO.





Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: russianhalo117 on 09/02/2016 03:29 AM
Apparently not having learned not to speculate, I submit that the following fits what we can observe: that the umbilical connection partially disconnected. This could possibly cause aerosolization of RP-1 (like a finger almost fully closing a garden hose), and such aerosolization seems a requirement to explain the initial flash. It's also consistent with the subsequent downward-pointing flame (some of the RP-1 being aerosolized, but lots of it just dripping).


RP-1 was already loaded.  There would not be any pressure in that part of the umbilical.
correct as they were in the Stage 2 LOX loading steps of the static test countdown at the time of the event(s).
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: intrepidpursuit on 09/02/2016 03:31 AM
Here is a possible scenario that seems to fit the pieces we have. The fact that the explosion seems to be centered on the middle of the upper stage at a very narrow vertical position is part of what's been troubling me.

Failure of a valve or sensor causes the O2 tank to over pressure during loading. The first thing that goes is the common bulkhead, mixing RP-1 and O2 before there are any obvious visual cues. Once a catastrophic failure like this has happened inside the stage, static could come from fluid reversing direction down a loading pipe or the bulkhead sliding down the inside of the tank. The resulting explosion could arise anywhere in the tank and where it would be most powerful is right where the propellants are mixing and the tank wall is already compromised by the tearing away of the bulkhead. This would all happen very quickly, but it allows the first visual sign of it to be the fiery explosive rupture of the overall S2 tank right at the line of the bulkhead.

Of course, that doesn't actually tell us root cause or even whether the fault lies with GSE, the rocket or something else (like russian UFO birds). But that explanation of what we are seeing answers all of my questions and falls in line with what we have heard so far.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: punder on 09/02/2016 03:34 AM
Just impressions from watching the video at regular speed. The piece of flying debris that's been talked about looks like it bounced off the tower rather than originating from it. And the tower was deformed by the weight of the payload and fairing sitting on the cradle arms, suddenly without the support of the rocket structure.

Guess I'm not adding much. What a crappy day. The repercussions (so to speak) are going to be huge. Sad.

The trajectory has that part going a few hundred yards off the bounce point in your theory.  Other than super balls, most materials will crumple on impact rather than bounce.  I don't buy the bounce idea, but... maybe it is a superball.  If you look at the part as it tumbles, it seems to be a "cap" to something.  Are there "cap" structures on the strongback?

Not a theory, just an impression as I said. Caveat: the scotch kicked in a couple hours ago.

"A few hundred yards" seems just as speculative. But strong dense objects can do amazing things when propelled at high velocities in energetic events.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Brovane on 09/02/2016 03:38 AM
Is the decision to have the payload attached our not attached during a static fire at the discretion of the customer?

I was looking back at static fire video and JCSAT-14,16 no payload attached and the same with EUTELSAT-ABS.

However Thaicom-8 payload was attached.  Also for CRS-8, CRS-9 Dragon was attached.

SpaceX really dodged a bullet that this didn't happen on CRS-9. 
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Prober on 09/02/2016 03:40 AM
time for a lessons learned?


https://www.youtube.com/watch?v=OpH684lNUB8


Maybe dropping the trunk is a good idea now?



Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Kabloona on 09/02/2016 03:41 AM
Just impressions from watching the video at regular speed. The piece of flying debris that's been talked about looks like it bounced off the tower rather than originating from it. And the tower was deformed by the weight of the payload and fairing sitting on the cradle arms, suddenly without the support of the rocket structure.

Guess I'm not adding much. What a crappy day. The repercussions (so to speak) are going to be huge. Sad.

The trajectory has that part going a few hundred yards off the bounce point in your theory.  Other than super balls, most materials will crumple on impact rather than bounce.  I don't buy the bounce idea, but... maybe it is a superball.  If you look at the part as it tumbles, it seems to be a "cap" to something.  Are there "cap" structures on the strongback?

Not a theory, just an impression as I said. Caveat: the scotch kicked in a couple hours ago.

"A few hundred yards" seems just as speculative. But strong dense objects can do amazing things when propelled at high velocities in energetic events.

I had the same first impression, that the object rebounded off the top of the T/E towards the camera.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: chalz on 09/02/2016 03:42 AM
Slightly off topic question. A helicopter could be heard later in the video. Presumably this is from the airbase. Was it in the air at the time or did they scramble it after the explosion?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: the_other_Doug on 09/02/2016 03:43 AM
The thing about all the LOX overpressure speculation is that we know what that looks like -- it starts to puff out in big streams from the lox vents.  That wasn't happening.  There was no apparent change in the LOX venting in the seconds prior to the explosion.

As for seeing LOX vent spikes, that's normal.  I've seen that in the launches many times, right before the strongback was retracted.  I think it has to do with blowing out the fill lines, or something.  But again, I didn't see any LOX vent spikes within, say, five to ten seconds prior to the blast.

Whatever happened, I don't think it was the LOX tank overpressurizing in stage 2...
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: dorkmo on 09/02/2016 03:46 AM
Slightly off topic question. A helicopter could be heard later in the video. Presumably this is from the airbase. Was it in the air at the time or did they scramble it after the explosion?

someone said earlier there was a medvac helicopter that picked up someone with the fire department to scout out the fire. long distance video from the vab showed a heli pretty close to the pad. not sure if its the same as you are hearing.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Saabstory88 on 09/02/2016 03:48 AM
The thing about all the LOX overpressure speculation is that we know what that looks like -- it starts to puff out in big streams from the lox vents.  That wasn't happening.  There was no apparent change in the LOX venting in the seconds prior to the explosion.

As for seeing LOX vent spikes, that's normal.  I've seen that in the launches many times, right before the strongback was retracted.  I think it has to do with blowing out the fill lines, or something.  But again, I didn't see any LOX vent spikes within, say, five to ten seconds prior to the blast.

Whatever happened, I don't think it was the LOX tank overpressurizing in stage 2...

Perhaps I misunderstand, but if the problem revolved around the mechanism or control structure designed to vent the LOX, then wouldn't an overpressure event happen and have no obvious outward cause?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: dnavas on 09/02/2016 03:48 AM
It definitely starts with a bright flash, then decreases in brightness for a few frames, then increases again.

Looking at the leftmost tower, the initial flash does not illuminate it, but once the fireball is bigger than the rocket it's illuminated as well.

We agree -- that's what I saw as well.  You can also see the center of the peak lighting change between the first and third frames of the explosion on the fairing (in your video -- in mine it's the first and second :shrug: ).  The lens artifact shifts left as well, and though it shifts again to the right a bit after that, I take that to mean that the bright bits are becoming obscured by whatever soot, smoke or debris may now exist between there and the camera.

Of course, that shift could be from any number of causes.  Maybe the feed got disconnected and liqO2 is being sprayed away from the erector, or maybe the stage is splitting from right to left.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Kabloona on 09/02/2016 03:50 AM
time for a lessons learned?

Maybe dropping the trunk is a good idea now?

What lesson? The trunk is required for passive aerodynamic stability after SD's stop firing, while the stack is coasting up to apogee. Without the trunk, the capsule will tumble immediately after SD's stop firing, with unpleasant consequences for passengers.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: CameronD on 09/02/2016 03:51 AM
Whatever happened, I don't think it was the LOX tank overpressurizing in stage 2...

Agreed ..but I figure there aren't that many things up there that can cause an explosion like this.

We can plainly see the RP-1 tank rupture, but if RP-1 loading is complete and the tank is full it isn't going to explode on it's own even with a decent-sized spark nearby.  Can't be very many scenarios to check off of the list..


EDIT:  How about thermal failure?.. maybe a valve chilling down too fast or something (like part of a tank shell) not properly insulated that freezes, cracks and sparks??  LOX can do nasty things to gear that's not ready for it.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: punder on 09/02/2016 03:57 AM
The event is so sudden, instantaneous really, that it makes me think the most likely cause is failure of the common bulkhead with instant mixing of the LOX and kero. What is the pressure differential between the tanks?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Kabloona on 09/02/2016 04:01 AM
The event is so sudden, instantaneous really, that it makes me think the most likely cause is failure of the common bulkhead with instant mixing of the LOX and kero. What is the pressure differential between the tanks?

Don't know, but Helodriver got a closeup photo of the returned stage outside Hawthorne showing the pressure gauges for the tanks. IIRC, one was around 10 psi and the other was less than 5 psi, so the difference there was in the single digits.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: CameronD on 09/02/2016 04:02 AM
The event is so sudden, instantaneous really, that it makes me think the most likely cause is failure of the common bulkhead with instant mixing of the LOX and kero. What is the pressure differential between the tanks?

That wouldn't cause a bang in and of itself - this stuff is well below ignition point.  There'd first be a spray of stuff outward like we saw with the S2 launch failure.  This time the 'bang' seems to happen first.

..and it must have been at or near the bottom of the RP-1 tank for it to lose it's contents downwards like that.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Prober on 09/02/2016 04:04 AM
time for a lessons learned?

Maybe dropping the trunk is a good idea now?

What lesson? The trunk is required for passive aerodynamic stability after SD's stop firing, while the stack is coasting up to apogee. Without the trunk, the capsule will tumble immediately after SD's stop firing, with unpleasant consequences for passengers.


know that, several fixes for that but you need to drop some weight in my view or?


btw: doesn't SpaceX use the helium for the release of Dragon from the Falcon 9?   
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: intrepidpursuit on 09/02/2016 04:04 AM
The event is so sudden, instantaneous really, that it makes me think the most likely cause is failure of the common bulkhead with instant mixing of the LOX and kero. What is the pressure differential between the tanks?

That wouldn't cause a bang in and of itself - there'd first be a spray of stuff outward like we saw with the S2 launch failure.  This time the 'bang' seems to happen first.

In CRS-7 it appeared that the LOX tank ruptured at the top rather than at the common bulkhead. If the Common bulkhead ruptures we won't see it right away but allows the fuel to mix to setup a scenario for a kaboom. Then there just has to be an ignition source.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: John-H on 09/02/2016 04:06 AM
From the location of the umbilical, can I assume that the fuel goes directly to the tank, while the LOX pipe runs through  or around the fuel tank. If there is a leak in this pipe,  an explosive mixture could build up and then go off suddenly, causing a flash and then a tank breech.

John 
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: jongoff on 09/02/2016 04:09 AM
In some ways I hope for SpaceX's case that is was some sort of subtle vehicle failure--one they can catch and design-out, not a GSE failure. The reason I say this is that the last time a US rocket blew up on the pad without an engine failure of some sort was over half a century ago. There've been well over 1000, and possibly over 2000 liquid fueled rocket launches since then, without any of them blowing up on the pad due to GSE issues. So having a pad systems failure actually makes SpaceX look a lot less professional than if it was a subtle design flaw.

On the what actually happened, it still really looks like the failure started inside the stage, not an external explosion that happened to rupture the tanks. That's not objective fact, and I may be misreading it, but that's what it looked like from the video. I just don't see some sort of "both umbilicals leaked in just the right way to also catch a spark" sort of scenario as being realistic. It's wild speculation, but I still think something to do with the common bulkhead did it.

People keep pointing out that it didn't look like the CRS-7 overpressurization, but that was a much slower event caused by a tube breaking, which meant you would've had choked flow out of a small diameter line. If you had a more rapid overpressurization event, it might look totally differently. A COPV failing more dramatically for instance might happen much. much faster, especially if it ruptured the common bulkhead. If say a dome came off of a COPV, it would probably be going fast enough that the whole bulkhead would be ruptured in less than one frame of the video. And the energy from that sort of a failure would not only mix the propellants, but could also quite possibly ignite the mixed propellants.

My Rambling $.02

~Jon
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: CameronD on 09/02/2016 04:10 AM
From the location of the umbilical, can I assume that the fuel goes directly to the tank, while the LOX pipe runs through  or around the fuel tank. If there is a leak in this pipe,  an explosive mixture could build up and then go off suddenly, causing a flash and then a tank breech.

No, the LOX is colder than the RP-1 and at a higher pressure.  If there's a leak in the pipe LOX might enter the RP-1 tank (which is already full) and get released from a vent someplace which might then go 'bang' somewhere else.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: punder on 09/02/2016 04:14 AM
The event is so sudden, instantaneous really, that it makes me think the most likely cause is failure of the common bulkhead with instant mixing of the LOX and kero. What is the pressure differential between the tanks?

That wouldn't cause a bang in and of itself - there'd first be a spray of stuff outward like we saw with the S2 launch failure.  This time the 'bang' seems to happen first.

In CRS-7 it appeared that the LOX tank ruptured at the top rather than at the common bulkhead. If the Common bulkhead ruptures we won't see it right away but allows the fuel to mix to setup a scenario for a kaboom. Then there just has to be an ignition source.

Electric signal and power wires could be sheared by a bulkhead that fails catastrophically under pressure? The liquid forms a short across suddenly exposed lines of different potential.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: OneSpeed on 09/02/2016 04:16 AM
If we have a "graphics wiz" that can superimpose a Falcon cutaway over a video still, that would be great! :)

I'm hardly a 'graphics wiz', but it looks like the epicentre is adjacent the common bulkhead.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Craftyatom on 09/02/2016 04:20 AM
Is the decision to have the payload attached our not attached during a static fire at the discretion of the customer?

I was looking back at static fire video and JCSAT-14,16 no payload attached and the same with EUTELSAT-ABS.

However Thaicom-8 payload was attached.  Also for CRS-8, CRS-9 Dragon was attached.

SpaceX really dodged a bullet that this didn't happen on CRS-9.

I believe earlier info says it's the customer's decision.  CRS flights are attached because it's SpaceX's ship, and they decide to do it that way, for both mating and testing reasons (helps build confidence in attachments, resonance modes, electrical systems, etc).

Customers are generally given the choice between having their payload on during the static fire, which speeds up the timeline a bit and gives better test data, or not having it attached, which means the payload won't be damaged in the event of an anomaly.

I personally hope SpaceX and its customers continue to mate prior to static firing.  The chance of the type of anomaly seen today occurring is low, even before taking into account the fact that SpaceX will be taking a long, hard look at every inch of these systems in the next 6 months.  Choosing to give up test data because of such a slim chance seems a waste to me, but then again, it depends on whether your "launch insurance" is also "integration and testing insurance".
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: intrepidpursuit on 09/02/2016 04:22 AM
The event is so sudden, instantaneous really, that it makes me think the most likely cause is failure of the common bulkhead with instant mixing of the LOX and kero. What is the pressure differential between the tanks?

That wouldn't cause a bang in and of itself - there'd first be a spray of stuff outward like we saw with the S2 launch failure.  This time the 'bang' seems to happen first.

In CRS-7 it appeared that the LOX tank ruptured at the top rather than at the common bulkhead. If the Common bulkhead ruptures we won't see it right away but allows the fuel to mix to setup a scenario for a kaboom. Then there just has to be an ignition source.

Electric signal and power wires could be sheared by a bulkhead that fails catastrophically under pressure? The liquid forms a short across suddenly exposed lines of different potential.

There is very little wiring inside the tanks and nothing would run through the common bulkhead. But I agree that once you have a massive failure like that there are lots of moving parts (that shouldn't be) and the potential of something producing a spark is much greater.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Kabloona on 09/02/2016 04:26 AM
In some ways I hope for SpaceX's case that is was some sort of subtle vehicle failure--one they can catch and design-out, not a GSE failure. The reason I say this is that the last time a US rocket blew up on the pad without an engine failure of some sort was over half a century ago. There've been well over 1000, and possibly over 2000 liquid fueled rocket launches since then, without any of them blowing up on the pad due to GSE issues. So having a pad systems failure actually makes SpaceX look a lot less professional than if it was a subtle design flaw.

On the what actually happened, it still really looks like the failure started inside the stage, not an external explosion that happened to rupture the tanks. That's not objective fact, and I may be misreading it, but that's what it looked like from the video. I just don't see some sort of "both umbilicals leaked in just the right way to also catch a spark" sort of scenario as being realistic. It's wild speculation, but I still think something to do with the common bulkhead did it.

People keep pointing out that it didn't look like the CRS-7 overpressurization, but that was a much slower event caused by a tube breaking, which meant you would've had choked flow out of a small diameter line. If you had a more rapid overpressurization event, it might look totally differently. A COPV failing more dramatically for instance might happen much. much faster, especially if it ruptured the common bulkhead. If say a dome came off of a COPV, it would probably be going fast enough that the whole bulkhead would be ruptured in less than one frame of the video. And the energy from that sort of a failure would not only mix the propellants, but could also quite possibly ignite the mixed propellants.

My Rambling $.02

~Jon

All good thoughts. Only problem is, repercussions from a COPV failure (ie major redesign) are going to be a lot more painful for them than a simple GSE issue. So I'm going to take the other side and hope it was in fact a GSE issue.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: punder on 09/02/2016 04:30 AM
The event is so sudden, instantaneous really, that it makes me think the most likely cause is failure of the common bulkhead with instant mixing of the LOX and kero. What is the pressure differential between the tanks?

That wouldn't cause a bang in and of itself - there'd first be a spray of stuff outward like we saw with the S2 launch failure.  This time the 'bang' seems to happen first.

In CRS-7 it appeared that the LOX tank ruptured at the top rather than at the common bulkhead. If the Common bulkhead ruptures we won't see it right away but allows the fuel to mix to setup a scenario for a kaboom. Then there just has to be an ignition source.

Electric signal and power wires could be sheared by a bulkhead that fails catastrophically under pressure? The liquid forms a short across suddenly exposed lines of different potential.

There is very little wiring inside the tanks and nothing would run through the common bulkhead. But I agree that once you have a massive failure like that there are lots of moving parts (that shouldn't be) and the potential of something producing a spark is much greater.

Conduits outside the tanks and maybe electrical interfaces with the t/e. Conductive liquids, flying metal and sheared wires...
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: CameronD on 09/02/2016 04:51 AM
Conduits outside the tanks and maybe electrical interfaces with the t/e. Conductive liquids, flying metal and sheared wires...

The liquids in this case are non-conductive and hundreds of degrees F below ignition point.  No, I'm sticking with Jon's idea that a COPV failure or some similar plumbing failure inside the stage itself triggered the bulge pointed out several pages upthread. :)
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: intrepidpursuit on 09/02/2016 04:58 AM
Conduits outside the tanks and maybe electrical interfaces with the t/e. Conductive liquids, flying metal and sheared wires...

The liquids in this case are non-conductive and hundreds of degrees F below ignition point.  No, I'm sticking with Jon's idea that a COPV failure or some similar plumbing failure inside the stage itself triggered the bulge pointed out several pages upthread. :)

O2 overpressure alone doesn't make a kaboom, just a pop. There has to be a mixing of fuels an an ignition source in order to cause an explosive boom like we saw. That is what we are trying to explain. Elon already confirmed the problem was in the S2 O2 tank, that is not in question.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: nisse on 09/02/2016 04:58 AM
Is it really a fireball we see at first? Could a stuck lox-venting-valve cause an overpressure explosion? I mean they are near oxygen freezing temperatures which could form solid oxygen that plugs some venting valve. Once you have a overpressure explosion the rest you see happens.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: RotoSequence on 09/02/2016 05:14 AM
Elon already confirmed the problem was in the S2 O2 tank, that is not in question.

Elon confirmed that the problem "originated around (the) upper stage oxygen tank (https://twitter.com/elonmusk/status/771394161756942336)," not necessarily that the fault was in or of the O2 tank itself.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: northenarc on 09/02/2016 05:21 AM
 My take is its failure of a COPV, or associated helium plumbing, and sudden pressure introduction blew off/out one of the umbilical lines or associated internal plumbing which started a rapid external fire that propagated back inwards and further over pressured the LOX tank until the 'horizontal failure' seen on the video.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: winkhomewinkhome on 09/02/2016 05:27 AM
Is it possible that what occurred with S2 is analogous with what happened with Apollo One - and electrical short exposed to a pure or close to pure oxygen environment.

I believe early in this thread, Jim answered someone's question regarding batteries, onboard power, shore power charging the system until just prior to or at launch.

Perhaps not the O2 umbilical, but rather the power came loose, arced and sparked into the high levels of O2, and from there things went south...

Any idea on the voltages, amperage, etc of the shore power connection(s)?  As the Boss so poetically put it, you can't have a fire without a spark.

To those at SpaceX, Mr Musk, and this NSF community - keep the faith, and continue to fight the good fight.

Thank you!
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: jongoff on 09/02/2016 05:36 AM
All good thoughts. Only problem is, repercussions from a COPV failure (ie major redesign) are going to be a lot more painful for them than a simple GSE issue. So I'm going to take the other side and hope it was in fact a GSE issue.

My concern is that if it's just a "simple GSE issue", why didn't they catch it? It's not like this type of failure is very common. If it is an easy problem, it kind of makes you wonder if there are other easy problems they've been overlooking? I'm hoping it's something more subtle because even though it'll be more painful to fix, I think it bodes better for SpaceX if they didn't screw up something that nobody's screwed up since the 60s.

~Jon
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: jongoff on 09/02/2016 05:38 AM
Conduits outside the tanks and maybe electrical interfaces with the t/e. Conductive liquids, flying metal and sheared wires...

The liquids in this case are non-conductive and hundreds of degrees F below ignition point.  No, I'm sticking with Jon's idea that a COPV failure or some similar plumbing failure inside the stage itself triggered the bulge pointed out several pages upthread. :)

O2 overpressure alone doesn't make a kaboom, just a pop. There has to be a mixing of fuels an an ignition source in order to cause an explosive boom like we saw. That is what we are trying to explain. Elon already confirmed the problem was in the S2 O2 tank, that is not in question.

That's the thing, rapidly shearing metal and exposing fresh, unoxidized aluminum or titanium (if they have any in the tanks) may be able to release enough energy to set off a LOX/Kero mix without a separate ignition source.

~Jon
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Michael Baylor on 09/02/2016 05:49 AM
Some of the media stories about the incident are totally pathetic and inaccurate. Drives me crazy!
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: CameronD on 09/02/2016 05:53 AM
Some of the media stories about the incident are totally pathetic and inaccurate. Drives me crazy!

Let's put it this way.. they know less they we do and aren't paid to get their facts right - just to get the story out there before the next guy.

I find them amusing. :)
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Michael Baylor on 09/02/2016 05:56 AM
I have seen this discussed briefly, but any thoughts on it being the same issue as with the CRS-7 failure? A faulty steel strut, while certainly possible, just doesn't seem like the type of thing you could be 100% certain about. I am sure SpaceX ruled out all other possible alternatives that they could think of, but that doesn't mean that it is impossible for them to miss something. Maybe some kind of design flaw with the second stage that has been problematic on multiple occasions?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Michael Baylor on 09/02/2016 05:59 AM
Some of the media stories about the incident are totally pathetic and inaccurate. Drives me crazy!

Let's put it this way.. they know less they we do and aren't paid to get their facts right - just to get the story out there before the next guy.

I find them amusing. :)
Totally true, they just take some random journalist and get them on the story, even if they have never heard of SpaceX before.

They also like to over dramatize things, so that they get keep their viewers entertained. CNN for example, called the failed landings setbacks, while failing to mention that they are experimental in an article today. They just wanted more exciting explosions to discuss.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: CameronD on 09/02/2016 06:08 AM
Conduits outside the tanks and maybe electrical interfaces with the t/e. Conductive liquids, flying metal and sheared wires...

The liquids in this case are non-conductive and hundreds of degrees F below ignition point.  No, I'm sticking with Jon's idea that a COPV failure or some similar plumbing failure inside the stage itself triggered the bulge pointed out several pages upthread. :)

O2 overpressure alone doesn't make a kaboom, just a pop. There has to be a mixing of fuels an an ignition source in order to cause an explosive boom like we saw. That is what we are trying to explain. Elon already confirmed the problem was in the S2 O2 tank, that is not in question.

That's the thing, rapidly shearing metal and exposing fresh, unoxidized aluminum or titanium (if they have any in the tanks) may be able to release enough energy to set off a LOX/Kero mix without a separate ignition source.

You can actually see that's true in the video: following the initial bang, the entire stack unzips from top to bottom leaving the payload hanging by itself several stories up.

Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Rocket Science on 09/02/2016 06:29 AM
If we have a "graphics wiz" that can superimpose a Falcon cutaway over a video still, that would be great! :)

I'm hardly a 'graphics wiz', but it looks like the epicentre is adjacent the common bulkhead.
Thank you, you're still a "wiz" in my books! :) It pretty much confirms my estimation of the location of common bulkhead that may have failed. The area would possibly lead to a "pseudo" horizontally shaped detonation cloud with more energy directed in this direction than vertically.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: chalz on 09/02/2016 06:49 AM
Slightly off topic question. A helicopter could be heard later in the video. Presumably this is from the airbase. Was it in the air at the time or did they scramble it after the explosion?

someone said earlier there was a medvac helicopter that picked up someone with the fire department to scout out the fire. long distance video from the vab showed a heli pretty close to the pad. not sure if its the same as you are hearing.
It seemed like a really quick response time but I just noticed an edit in the video around 3:32 so there could have been much more time between explosion and response. More likely medics than the air force then.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: deruch on 09/02/2016 06:50 AM
Having just read this thread, I haven't seen any discussion of some new alterations in SpaceX's countdown procedures to allow some window extension--first mentioned in relation to JCSAT-16's static fire (https://www.nasaspaceflight.com/2016/08/spacex-static-fire-test-jcsat-16s-falcon-9/).  Were the additional holds incorporated for all subsequent static fires/launches?  Could these changes have any bearing on this failure?

Quote from: Chris Bergin
An additional element was added for Wednesday’s test, per L2 info (https://forum.nasaspaceflight.com/index.php?topic=40768.msg1567989#msg1567989), with a couple of holds added ahead of the terminal count to demonstrate performance during simulated window extensions.

Due to Falcon 9 now using super cooled propellent [sic], holds after prop loading begins around T-30 minutes provide an additional challenge of keeping the prop cold enough in the run up to T-0.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: HighEnergy on 09/02/2016 06:57 AM
Not COPV or FTS.  Explosion is an external air burst.  No debris until much later, other than the big cap-like thing  that's shot straight up and tumbles.
Maybe a crack in the unconstrained S curve of this line (see attached) especially if that's the RP-1 line.  High pressure though the crack or pinhole would make an aerosol.  A line in that acoustic environment shouldn't have an unconstrained S.
   
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: TakeOff on 09/02/2016 06:58 AM
Can one rule out that both failures of the upper stage have the same root cause? That the diagnose of the first failure's cause was mistaken? It was hard to investigate.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: wtrix on 09/02/2016 07:06 AM
Not COPV or FTS.  Explosion is an external air burst.  No debris until much later, other than the big cap-like thing  that's shot straight up and tumbles.
Maybe a crack in the unconstrained S curve of this line (see attached) especially if that's the RP-1 line.  High pressure though the crack or pinhole would make an aerosol.  A line in that acoustic environment shouldn't have an unconstrained S.
 

For my eye, that's the most plausible scenario this far. Due to the initial size of the fireball it seemed as fuel-air mixture being initiated by any spark. How the fuel-air mixture was created in first place, is another question. My guesses:
1. This s-bend fracture
2. Filling valve blocked from full closure
3. Any other tube fracture near the rocket

One thing to be noted is that those images and this video is 2D. Rocket itself however, is a 3D object and the initiation of the blast could have been still outside the S2 even if from image it seems at the S2 body line.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Johnnyhinbos on 09/02/2016 07:29 AM
(http://uploads.tapatalk-cdn.com/20160902/5bbb7557d872e53b5910bdcc824bf39d.jpg)

Over on the Facebook SpaceX group user Ross Sackett posted this photo with the following caption:

"I used a trick we sometimes use to fix the position of a star in an astrophoto.  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."

All credit for image and words to Facebook user Ross Sackett


Sent from my iPhone using Tapatalk Pro
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ZachF on 09/02/2016 07:39 AM
Not COPV or FTS.  Explosion is an external air burst.  No debris until much later, other than the big cap-like thing  that's shot straight up and tumbles.
Maybe a crack in the unconstrained S curve of this line (see attached) especially if that's the RP-1 line.  High pressure though the crack or pinhole would make an aerosol.  A line in that acoustic environment shouldn't have an unconstrained S.
 

That seems like a highly probably scenario... That is roughly the exact right area the explosion seems to have originated.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ricmsmith on 09/02/2016 07:44 AM
Not COPV or FTS.  Explosion is an external air burst.  No debris until much later, other than the big cap-like thing  that's shot straight up and tumbles.
Maybe a crack in the unconstrained S curve of this line (see attached) especially if that's the RP-1 line.  High pressure though the crack or pinhole would make an aerosol.  A line in that acoustic environment shouldn't have an unconstrained S.
 

This seems like a probable scenario to me too.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: RotoSequence on 09/02/2016 08:03 AM
Not COPV or FTS.  Explosion is an external air burst.  No debris until much later, other than the big cap-like thing  that's shot straight up and tumbles.
Maybe a crack in the unconstrained S curve of this line (see attached) especially if that's the RP-1 line.  High pressure though the crack or pinhole would make an aerosol.  A line in that acoustic environment shouldn't have an unconstrained S.
 

It definitely looks like it's some sort of fuel line, but the part we see looks like a housing, rather than a naked pipe. There's cabling of some sort that is in nearly direct contact with the second stage at the approximate center of the diffraction lines as well. If leaking fuel lines were an issue, the pending inclement weather may have exacerbated some sort of ground fault.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Blizzzard on 09/02/2016 08:04 AM
Twitter User TJ Lee did an interesting video edit here, superimposing the Dragon abort test over the video of today's accident:
https://twitter.com/StateMachines/status/771535425328459780
Dragon would have had plenty of time to escape.

This is very interesting (assuming frame rates are matched exactly)! I wonder what the lag would be though? Surely this is best case. What trigger would the F9 systems have to detect a problem and launch the Dragon V2 abort that quickly? (speculation) If the 'explosion' does happen to be something like a fast-fire external to the rocket, would the rocket even be able to tell something was wrong before the damaging explosions happen?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: woods170 on 09/02/2016 08:19 AM
time for a lessons learned?

<snip>

Maybe dropping the trunk is a good idea now?




IMO no it isn't because D2 needs the trunk for aerodynamic stability during abort. If the trunk is not there the entire aerodynamic shape of D2 will have to be altered or some other means of stability will have to be added to the design. Given that the trunk is mostly an empty shell it should not be too hard to "harden" it against over-pressure events coming from below. Given that the trunk has been in the design particularly for pad abort, I thinks it is pretty safe to conclude that the D2 trunk design already is optimised for over-pressure events from below. We also know that the trunk-to-capsule interface is hardened with a wipple-shield. That serves dual purposes:
1. MMOD protection of the primary heatshield in orbit
2. Protection of the capsule against high-velocity debris from a launcher mishap.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Post-It on 09/02/2016 08:55 AM
Not COPV or FTS.  Explosion is an external air burst.  No debris until much later, other than the big cap-like thing  that's shot straight up and tumbles.
Maybe a crack in the unconstrained S curve of this line (see attached) especially if that's the RP-1 line.  High pressure though the crack or pinhole would make an aerosol.  A line in that acoustic environment shouldn't have an unconstrained S.
 

99.9% sure that is an A/C duct.  There aren't any propellant feed lines that far up the TEL.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: CJ on 09/02/2016 09:06 AM

If we assume the event originated in the second stage, as it appears to do, I find it interesting that both of SpaceX's LOV/LOM events originated in the second stage, and did so while that stage's engine was not running.

Could be just a coincidence - and I don't like coincidences.

Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Star One on 09/02/2016 09:07 AM
Some of the media stories about the incident are totally pathetic and inaccurate. Drives me crazy!

Rather like much of the speculation on here. Neither serves any useful purpose towards getting to the root cause.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: vanoord on 09/02/2016 09:23 AM
Not COPV or FTS.  Explosion is an external air burst.  No debris until much later, other than the big cap-like thing  that's shot straight up and tumbles.

I'd concur that the initial blast looks like the ignition of vapour outside the vehicle.

There's no sign of any deformation of the upper stage before the blast (and even if there's a video frame skipped, that's 1/30 of a second); and the shape of the fireball as it ignites is more vertical than horizontal, i.e. as if a cloud of vapour has built up outside the vehicle and then been ignited.

That doesn't preclude a leak from the vehicle being ignited, but I'd be surprised if it turned out to be a catastrophic failure of a COPV / LOX tank rupture.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: JamesH65 on 09/02/2016 09:32 AM

If we assume the event originated in the second stage, as it appears to do, I find it interesting that both of SpaceX's LOV/LOM events originated in the second stage, and did so while that stage's engine was not running.

Could be just a coincidence - and I don't like coincidences.

There are two stages. Let's say chances of a problem in any particular are 50:50,  or 1/2. That means the chances of something happening twice in the same stage are 1/4. ie one in four. That a much higher chance of happening in the same stage than throwing 2 sixes in a row.

It's a coincidence until shown otherwise.

So much jumping to conclusions here, without really thinking about the issue.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: vapour_nudge on 09/02/2016 09:37 AM
JCM how do you classify this event?  A payload and rocket were lost at the launch pad but it wasn't a launch failure as it wasn't a launch attempt. Watching your website to see how you classify it as it is probably the launch log of choice on the web
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jet Black on 09/02/2016 10:10 AM
Not COPV or FTS.  Explosion is an external air burst.  No debris until much later, other than the big cap-like thing  that's shot straight up and tumbles.
Maybe a crack in the unconstrained S curve of this line (see attached) especially if that's the RP-1 line.  High pressure though the crack or pinhole would make an aerosol.  A line in that acoustic environment shouldn't have an unconstrained S.
 

It definitely looks like it's some sort of fuel line, but the part we see looks like a housing, rather than a naked pipe. There's cabling of some sort that is in nearly direct contact with the second stage at the approximate center of the diffraction lines as well. If leaking fuel lines were an issue, the pending inclement weather may have exacerbated some sort of ground fault.

One thing worth noting, if the center of the diffraction lines are useful for determining the brightest part of the flame (I think they are) this may point to the center of ignition, but not the center of the source of the fuel for the explosion.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: vaporcobra on 09/02/2016 10:11 AM
Twitter User TJ Lee did an interesting video edit here, superimposing the Dragon abort test over the video of today's accident:
https://twitter.com/StateMachines/status/771535425328459780
Dragon would have had plenty of time to escape.

This is very interesting (assuming frame rates are matched exactly)! I wonder what the lag would be though? Surely this is best case. What trigger would the F9 systems have to detect a problem and launch the Dragon V2 abort that quickly? (speculation) If the 'explosion' does happen to be something like a fast-fire external to the rocket, would the rocket even be able to tell something was wrong before the damaging explosions happen?

Probably something similar to the escape system on the Saturn series. I believe 3-4 continuous lines were strung along the outside of the rocket, with escape being triggered the moment that one of those wires were broken. Extraordinarily simple circuit that worked surprisingly well. I'm sure SpaceX's avionics have access to a vastly more granular and detailed array of data from which to decide, ranging from pressure sensors to stress, acoustic, tensile, and more. So similar concept but far less likely to experience false-positive or false-negative events.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jet Black on 09/02/2016 10:25 AM

Over on the Facebook SpaceX group user Ross Sackett posted this photo with the following caption:

"I used a trick we sometimes use to fix the position of a star in an astrophoto.  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."

All credit for image and words to Facebook user Ross Sackett


I suggested this pages ago, when the images of the explosions were first released.  :)

To explain to people who might not know, why this works;

Basically recording media (film/the detector in a camera) can only record brightness levels up to the point that they saturate, so in a film, that's when all of the chemicals are activated and in a CCD, when it is sending its maximum signal. Any light in addition to that is not recorded. Diffraction however occurs around the edges of objects, particularly sharp edges like the stops and the iris in cameras. Now the diffracted light is much lower intensity than the direct light and can still be recorded, but the most diffraction will come from the brightest point. and so that is where the majority of the diffraction should have originated.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Roy_H on 09/02/2016 10:28 AM
I don't have a video editor so these are just screen grabs. Is there any frames in between?
Note the bird passing the lightning tower, I used that to compare frames.

Can anybody assign time to this in terms of T-x minutes?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: vaporcobra on 09/02/2016 10:32 AM
I don't have a video editor so these are just screen grabs. Is there any frames in between?
Note the bird passing the lightning tower, I used that to compare frames.

Can anybody assign time to this in terms of T-x minutes?

Not sure about the frame question, but I do believe F9 was at approximately T-3:00 to ignition.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jet Black on 09/02/2016 10:34 AM
I don't have a video editor so these are just screen grabs. Is there any frames in between?
Note the bird passing the lightning tower, I used that to compare frames.

Can anybody assign time to this in terms of T-x minutes?

Not sure about the frame question, but I do believe F9 was at approximately T-3:00 to ignition.

earlier than that as the strongback wasn't retracted. There's a good bit of discussion about this earlier on.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: deruch on 09/02/2016 10:36 AM
I don't have a video editor so these are just screen grabs. Is there any frames in between?
Note the bird passing the lightning tower, I used that to compare frames.

Can anybody assign time to this in terms of T-x minutes?

Not sure about the frame question, but I do believe F9 was at approximately T-3:00 to ignition.

That was what someone mentioned they heard second hand (?) earlier in the thread.  However, the cradle arms were not open nor was the strongback retracted at the time of the failure.  Ergo, it must have been before that point in the countdown (~T-3:30). 

edit: ninja'd by Jet Black
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Kojak on 09/02/2016 10:37 AM

If we assume the event originated in the second stage, as it appears to do, I find it interesting that both of SpaceX's LOV/LOM events originated in the second stage, and did so while that stage's engine was not running.

Could be just a coincidence - and I don't like coincidences.

There are two stages. Let's say chances of a problem in any particular are 50:50,  or 1/2. That means the chances of something happening twice in the same stage are 1/4. ie one in four. That a much higher chance of happening in the same stage than throwing 2 sixes in a row.

It's a coincidence until shown otherwise.

So much jumping to conclusions here, without really thinking about the issue.

I'd say it's actually 1/2, for ANY stage (1/4 for FS + 1/4 for SS)
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Archibald on 09/02/2016 11:21 AM
Just caught the news (I first saw the thread "Rebuilding LC-40")

 Hmmm, what rebuilding ? didn't SpaceX already rebuild it from the days of the Titan IVs ? 

Checked the SpaceX section

...oh crap.

Wow...

... a big KABOOM like in the ole days.

Compared to Atlas AC-5 it lacks the hydrogen on top to boost the fire. In league with Proton (july 2013) and Antares (October 2014)

It was a quiet day at the Cape, when all of sudden - all hell broke loose -
 massive explosion in eerie silence ;
... and then, as Amos 6 and the fairing fall to their destruction into the inferno, BRAAAAAAOOOMMM the sound hit. With the unfortunate camera rocket by explosions, blam blam blam.

How long The Cape hasn't seen such a big explosion ? 1998 and Titan IV maybe ? or Delta in January 1997 ? (the one which turned the parking lot into a Moonscape)

Space is hard.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: kevinof on 09/02/2016 11:25 AM


Space is hard.

Space is not just hard, it's very unforgiving.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: toruonu on 09/02/2016 11:30 AM
The only silver lining I can think of is that it's good it didn't happen on the SES-10 booster as that would have immediately been labelled as reuse doesn't work and you cannot trust a flown booster. Right now it happened to a brand new booster and once we know the actual cause it'll get fixed etc, but it may be something that was immaterial to the rocket (i.e. GSE fault) or it would have been eliminated by a previous flight making the re-used booster inherently safer bet.

Anyway, good luck to SpaceXers to get back up and keep going.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: coal_burner on 09/02/2016 11:30 AM
Wasn't spacex's original FTS plan to just open the vent valve on the rp-1 tank and allow the pressure in the lox tank to tear the common bulkhead free and simultaneously tear the outer shell?
I seem to remember their first flight being pushed back as they tried and failed to convince the appropriate governing body that ordnance wasn't needed for their FTS.

If their rp-1 vent valve opened yesterday, quickly dropping the tank pressure to atmospheric,  it would have shot out a bunch of cold and invisible helium gas. The first really visible thing would have been the escaping fuel/lox mixture as it was being ignited by sparks made by the bulkhead scraping down along the tank wall stiffeners.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: vapour_nudge on 09/02/2016 11:32 AM


Space is hard.

Space is not just hard, it's very unforgiving.

Well, space wasn't involved today. I'd say the ground is hard. Very sad to see this happen. Let's hope they can turn it around fast. Also, great that these things happen now so they can be ironed out before the first human space flight on the F9. I'm sad for the satellite owner too.  I'm eager to see what pad damage there is
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: glennfish on 09/02/2016 11:35 AM
Not COPV or FTS.  Explosion is an external air burst.  No debris until much later, other than the big cap-like thing  that's shot straight up and tumbles.
Maybe a crack in the unconstrained S curve of this line (see attached) especially if that's the RP-1 line.  High pressure though the crack or pinhole would make an aerosol.  A line in that acoustic environment shouldn't have an unconstrained S.
 

I like that.  Here's some thoughts as to why you might be right.

A typical weaponized fuel-air mixture burns at between 4,200 and 5,400 feet per second.

The horizontal diameter of the first frame showing an explosion shows pixel saturation of about 35 feet across and 85 feet tall.

Assuming 60 fps, and the pixel integration begins at the instant of detonation, that implies a detonation velocity of between 2,000 and 5,000 feet per second.

I think air-burst is the right term.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: AncientU on 09/02/2016 11:44 AM
Somewhere in the volumes of written word from the last 24 hours, there was the phrase from SpaceX, "Catastrophic abort."  This seems to indicate that something was seen before the dramatic failure we are focusing on, and an attempt to abort the static fire was initiated -- but too late.

Since they have been through this sequence 60 times or so (two per launch, the static fire and launch itself), it is unlikely a basic process/procedure flaw.  Equipment aging or fatigue failures, possibly leading to lox leak and explosive atmosphere on the upper TEL is a possibility.  (Obviously, lots of things are possibilities...)
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jet Black on 09/02/2016 11:44 AM
Not COPV or FTS.  Explosion is an external air burst.  No debris until much later, other than the big cap-like thing  that's shot straight up and tumbles.
Maybe a crack in the unconstrained S curve of this line (see attached) especially if that's the RP-1 line.  High pressure though the crack or pinhole would make an aerosol.  A line in that acoustic environment shouldn't have an unconstrained S.
 

Just playing devil's advocate here. I agree with the airburst, but how about a crack or a pinhole in the rocket itself as the source? Is there anything that would preclude that or make one more likely than the other? (I'm half wondering whether the supercooled oxygen might be causing more damage to the GSE side of things than people imagine - though I counter that with the necessity for fuel in the explosion)

as a slight, but related aside, what is the viscocity of the supercooled oxygen like compared to normal lox? If that sort of s curve exists within lox lines, I wonder if something might happen to the fluid dynamics of the system? (asking more because I am interested than speculating on whether it is related to the issue or not)
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Hywel1995 on 09/02/2016 11:52 AM
Weren't SpaceX holding the old NASA radars systems by LC-40 ready for Boca?

Any status on those?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Saabstory88 on 09/02/2016 11:57 AM
Could T-3 mins indicate that there was an issue and that the string back was in the process of being re-secured to the vehicle?

The video has a cut right a dozen or so seconds before the explosion. Maybe something like the failure of the umbilical to spool out, causing the fill / drain lines to connections to become fouled?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: alang on 09/02/2016 12:00 PM
Not COPV or FTS.  Explosion is an external air burst.  No debris until much later, other than the big cap-like thing  that's shot straight up and tumbles.
Maybe a crack in the unconstrained S curve of this line (see attached) especially if that's the RP-1 line.  High pressure though the crack or pinhole would make an aerosol.  A line in that acoustic environment shouldn't have an unconstrained S.
 

A non engineer like me would assume that the S is there to cope with thermal expansion/contraction in a long pipe. If that is so then to what extent should it be constrained and how without removing the benefit it is intended to supply?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: vanoord on 09/02/2016 12:04 PM
Just playing devil's advocate here. I agree with the airburst, but how about a crack or a pinhole in the rocket itself as the source? Is there anything that would preclude that or make one more likely than the other? (I'm half wondering whether the supercooled oxygen might be causing more damage to the GSE side of things than people imagine - though I counter that with the necessity for fuel in the explosion)

Are the second stages put through a tanking cycle at MacGregor?

I appreciate that the MVac can't be started, but if the upper stage have been though a cycle, that would presumably have shown up any such defects. (In any instance, I'd assume the S2 tanks would be pressure tested before leaving the factory.)

If the stage had been fully pressurised and tested, then it puts a bit more suspicion on the pad equipment.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: glennfish on 09/02/2016 12:04 PM
Not COPV or FTS.  Explosion is an external air burst.  No debris until much later, other than the big cap-like thing  that's shot straight up and tumbles.
Maybe a crack in the unconstrained S curve of this line (see attached) especially if that's the RP-1 line.  High pressure though the crack or pinhole would make an aerosol.  A line in that acoustic environment shouldn't have an unconstrained S.
 

ANOTHER reason you might be right.  The detonation profile appears to be taller than wider.  If RP-1 was becoming an aerosol, being heavier than air, the aerosol would be sinking over time, which would make a detonation cross section that's taller than wider.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: glennfish on 09/02/2016 12:17 PM
Just impressions from watching the video at regular speed. The piece of flying debris that's been talked about looks like it bounced off the tower rather than originating from it. And the tower was deformed by the weight of the payload and fairing sitting on the cradle arms, suddenly without the support of the rocket structure.

Guess I'm not adding much. What a crappy day. The repercussions (so to speak) are going to be huge. Sad.

The trajectory has that part going a few hundred yards off the bounce point in your theory.  Other than super balls, most materials will crumple on impact rather than bounce.  I don't buy the bounce idea, but... maybe it is a superball.  If you look at the part as it tumbles, it seems to be a "cap" to something.  Are there "cap" structures on the strongback?

Not a theory, just an impression as I said. Caveat: the scotch kicked in a couple hours ago.

"A few hundred yards" seems just as speculative. But strong dense objects can do amazing things when propelled at high velocities in energetic events.

Ya, you're right. There's only data for the horizontal travel distance, not the to camera distance.  When it crosses the tower, it's moved at least 50 yards from the explosion center.  How far towards the camera is speculative.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: jgoldader on 09/02/2016 12:23 PM

Ya, you're right. There's only data for the horizontal travel distance, not the to camera distance.  When it crosses the tower, it's moved at least 50 yards from the explosion center.  How far towards the camera is speculative.

I don't have an easy way to d/l the video and no software to analyze it; but if the angular "diameter" of the part can be measured, the angular diameter is inversely proportional to the distance.  I.e., if it looks twice the size in the last frame as compared to the first frame, it's half as far away in the last frame as it was in the first frame.

It's tempting to want to do a kinematic analysis of the part's flight, but I'd not trust the timestamps on a downloaded file that had been compressed for Youtube any farther than I could kick the bits in the file.  You could get the initial vertical velocity and see if friction was important (which depends on the mass/area ratio) but not sure that would give any useful info.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Brovane on 09/02/2016 12:34 PM

I believe earlier info says it's the customer's decision.  CRS flights are attached because it's SpaceX's ship, and they decide to do it that way, for both mating and testing reasons (helps build confidence in attachments, resonance modes, electrical systems, etc).

Customers are generally given the choice between having their payload on during the static fire, which speeds up the timeline a bit and gives better test data, or not having it attached, which means the payload won't be damaged in the event of an anomaly.

I personally hope SpaceX and its customers continue to mate prior to static firing.  The chance of the type of anomaly seen today occurring is low, even before taking into account the fact that SpaceX will be taking a long, hard look at every inch of these systems in the next 6 months.  Choosing to give up test data because of such a slim chance seems a waste to me, but then again, it depends on whether your "launch insurance" is also "integration and testing insurance".

Assuming after this that the insurers providing coverage for the pre-launch activities will sign off on the payload being mated during a static fire. 
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: JebK on 09/02/2016 12:36 PM
Are there any other cases where there has been a complete loss of launch vehicle and payload days before T-0?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jim on 09/02/2016 12:41 PM

I believe earlier info says it's the customer's decision.  CRS flights are attached because it's SpaceX's ship, and they decide to do it that way, for both mating and testing reasons (helps build confidence in attachments, resonance modes, electrical systems, etc).

Customers are generally given the choice between having their payload on during the static fire, which speeds up the timeline a bit and gives better test data, or not having it attached, which means the payload won't be damaged in the event of an anomaly.

I personally hope SpaceX and its customers continue to mate prior to static firing.  The chance of the type of anomaly seen today occurring is low, even before taking into account the fact that SpaceX will be taking a long, hard look at every inch of these systems in the next 6 months.  Choosing to give up test data because of such a slim chance seems a waste to me, but then again, it depends on whether your "launch insurance" is also "integration and testing insurance".

There is no valid test data that can be gained by having the spacecraft on the vehicle during static fire.  It is only a time saving measure.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ApolloStarbuck on 09/02/2016 12:43 PM
If we have a "graphics wiz" that can superimpose a Falcon cutaway over a video still, that would be great! :)

I'm hardly a 'graphics wiz', but it looks like the epicentre is adjacent the common bulkhead.


Also not a graphics wiz
 :)


photo edited for switched fuel and oxidizer notations.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: yoram on 09/02/2016 12:44 PM
Yes it happened to the Russians several times. The most famous one is probably the "Nedelin disaster" with an early ICBM, which resulted in a high number of fatalities too.

https://en.wikipedia.org/wiki/Nedelin_catastrophe

There was also one interesting case where the recovery rocket saved the payload (including crew) from an explosion on the pad

https://en.wikipedia.org/wiki/Soyuz_7K-ST_No._16L

Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jim on 09/02/2016 12:45 PM
1.  Not COPV or FTS.  Explosion is an external air burst.  No debris until much later, other than the big cap-like thing  that's shot straight up and tumbles.
2.  Maybe a crack in the unconstrained S curve of this line (see attached) especially if that's the RP-1 line.  High pressure though the crack or pinhole would make an aerosol.  A line in that acoustic environment shouldn't have an unconstrained S.
   


1.  It is an air burst because of a rupture.  Rupture came first.

2. That would be an AC line.  The second stage umbilical is lower
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ugordan on 09/02/2016 12:48 PM
Also not a graphics wiz
 :)

You switched the fuel and LOX tank positions. The LOX tank is noticeably bigger so when in correct position, the bulkhead is roughly in the same place as the apparent blast origin.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: glennfish on 09/02/2016 12:50 PM

Ya, you're right. There's only data for the horizontal travel distance, not the to camera distance.  When it crosses the tower, it's moved at least 50 yards from the explosion center.  How far towards the camera is speculative.

I don't have an easy way to d/l the video and no software to analyze it; but if the angular "diameter" of the part can be measured, the angular diameter is inversely proportional to the distance.  I.e., if it looks twice the size in the last frame as compared to the first frame, it's half as far away in the last frame as it was in the first frame.

It's tempting to want to do a kinematic analysis of the part's flight, but I'd not trust the timestamps on a downloaded file that had been compressed for Youtube any farther than I could kick the bits in the file.  You could get the initial vertical velocity and see if friction was important (which depends on the mass/area ratio) but not sure that would give any useful info.

That's a good idea, but the imaging doesn't support it.  The order is from 1:11 to 1:14 in the video.  The lighting levels and background levels are swinging wildly.  While the object is coming towards the camera, the illumination either obscures parts, the orientation of the object shifts to narrow end towards camera, or it breaks up while inside the fireball.

Image order  Left down, then right down.  I tried to enhance to bring out the edges, didn't always work.  :)
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jim on 09/02/2016 12:53 PM

Probably something similar to the escape system on the Saturn series. I believe 3-4 continuous lines were strung along the outside of the rocket, with escape being triggered the moment that one of those wires were broken. Extraordinarily simple circuit that worked surprisingly well. I'm sure SpaceX's avionics have access to a vastly more granular and detailed array of data from which to decide, ranging from pressure sensors to stress, acoustic, tensile, and more. So similar concept but far less likely to experience false-positive or false-negative events.

No, again, most data goes overboard as telemetry and vehicle avionics doesn't see it.  Abort systems pick a few critical parameters (like tank pressures, breakwires, engine temps, etc) and just monitor them.  "Stress, acoustic, tensile, and more" are foreign to launch vehicle control avionics.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ricmsmith on 09/02/2016 12:57 PM

I believe earlier info says it's the customer's decision.  CRS flights are attached because it's SpaceX's ship, and they decide to do it that way, for both mating and testing reasons (helps build confidence in attachments, resonance modes, electrical systems, etc).

Customers are generally given the choice between having their payload on during the static fire, which speeds up the timeline a bit and gives better test data, or not having it attached, which means the payload won't be damaged in the event of an anomaly.

I personally hope SpaceX and its customers continue to mate prior to static firing.  The chance of the type of anomaly seen today occurring is low, even before taking into account the fact that SpaceX will be taking a long, hard look at every inch of these systems in the next 6 months.  Choosing to give up test data because of such a slim chance seems a waste to me, but then again, it depends on whether your "launch insurance" is also "integration and testing insurance".

There is no valid test data that can be gained by having the spacecraft on the vehicle during static fire.  It is only a time saving measure.

Is there a cost saving as well, perhaps from not having to have payload service structure at the pad or roll back to the assembly building after the test for example?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: TaurusLittrow on 09/02/2016 01:02 PM
Are there any reliable (if not official) reports on the condition of the pad and GSE? Not speculation based on videos. I can't imagine even extensive repairs would pose a time constraint on future launches given the comparatively "benign" fuel involved in the event (no toxic solid fuel residue). Still, it would be nice to know the extent of the repairs necessary.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: jgoldader on 09/02/2016 01:07 PM

I don't have an easy way to d/l the video and no software to analyze it; but if the angular "diameter" of the part can be measured, the angular diameter is inversely proportional to the distance.  I.e., if it looks twice the size in the last frame as compared to the first frame, it's half as far away in the last frame as it was in the first frame.


That's a good idea, but the imaging doesn't support it.  The order is from 1:11 to 1:14 in the video.  The lighting levels and background levels are swinging wildly.  While the object is coming towards the camera, the illumination either obscures parts, the orientation of the object shifts to narrow end towards camera, or it breaks up while inside the fireball.

I figured it wouldn't work, that's why my post was loaded with weasel words; but thanks for trying!
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Kabloona on 09/02/2016 01:08 PM
...I can't imagine even extensive repairs would pose a time constraint on future launches given the comparatively "benign" fuel involved in the event (no toxic solid fuel residue). ...

You might want to read Wolfram66's post on the potential effects of petroluem fires on structural steel:

https://forum.nasaspaceflight.com/index.php?topic=30981.msg1576421#msg1576421

No one yet knows the extent of damage, but even "benign" fuel can do serious damage that could take a long time to repair.

Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Lee Jay on 09/02/2016 01:09 PM
SpaceX decided to immerse their COPVs in their propellant.  Given that choice, why did they choose to immerse them in the LOX, which is nasty stuff both chemically and thermally, instead of in the comparatively benign RP1?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ugordan on 09/02/2016 01:10 PM
Much lower temperature -> lower pressure per kg of loaded He -> more helium per bottle?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Rocket Science on 09/02/2016 01:20 PM
Are there any reliable (if not official) reports on the condition of the pad and GSE? Not speculation based on videos. I can't imagine even extensive repairs would pose a time constraint on future launches given the comparatively "benign" fuel involved in the event (no toxic solid fuel residue). Still, it would be nice to know the extent of the repairs necessary.
After they do a survey they will still have to take in the environmental impact for the clean up procedures and to contain any residue from the combustion products. The firefighters more than likely have placed booms and berms either yesterday or today.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: cscott on 09/02/2016 01:20 PM


Somewhere in the volumes of written word from the last 24 hours, there was the phrase from SpaceX, "Catastrophic abort." 

Nope, this was never said by SpaceX.

Other persistent misunderstandings: there were early conflicting reports that the incident happened at T-3 and T-5.  Evidence from the timeline and strongback/cradle position indicates that it happened some time before T-4:10, which is when the cradle is opened.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jet Black on 09/02/2016 01:28 PM

Probably something similar to the escape system on the Saturn series. I believe 3-4 continuous lines were strung along the outside of the rocket, with escape being triggered the moment that one of those wires were broken. Extraordinarily simple circuit that worked surprisingly well. I'm sure SpaceX's avionics have access to a vastly more granular and detailed array of data from which to decide, ranging from pressure sensors to stress, acoustic, tensile, and more. So similar concept but far less likely to experience false-positive or false-negative events.

No, again, most data goes overboard as telemetry and vehicle avionics doesn't see it.  Abort systems pick a few critical parameters (like tank pressures, breakwires, engine temps, etc) and just monitor them.  "Stress, acoustic, tensile, and more" are foreign to launch vehicle control avionics.

Are there likely to be breakwires and things on this system, given that they plan to use it with a system that has an LAS.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: glennfish on 09/02/2016 01:33 PM
1.  Not COPV or FTS.  Explosion is an external air burst.  No debris until much later, other than the big cap-like thing  that's shot straight up and tumbles.
2.  Maybe a crack in the unconstrained S curve of this line (see attached) especially if that's the RP-1 line.  High pressure though the crack or pinhole would make an aerosol.  A line in that acoustic environment shouldn't have an unconstrained S.
   


1.  It is an air burst because of a rupture.  Rupture came first.

2. That would be an AC line.  The second stage umbilical is lower

Just to debate the idea that the rupture came first.  Based on the detonation profile that implies a fuel-air explosion, the absence of any visible plume changes prior to the explosion 1st frame, an oxygen tank rupture would create a plume, and would not itself cause a detonation.  An RP-1 rupture might not show a plume but would provide the material needed for a fuel-air explosion.  If there were an RP-1 rupture, how would that occur?

We go from one frame where there is no indication of abnormal plumes to a frame where the detonation is about 35 X 85 feet across.  In 1/60th of a second you have to fill that volume with RP-1 aerosol (not liquid) and it has to explode during that same window.

Can you explain how a rupture does that please?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: baldusi on 09/02/2016 01:34 PM
SpaceX decided to immerse their COPVs in their propellant.  Given that choice, why did they choose to immerse them in the LOX, which is nasty stuff both chemically and thermally, instead of in the comparatively benign RP1?
It's colder, and He expansion per J/kg is the highest of any element, basically, they can increase density by 20x "for free".
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: john smith 19 on 09/02/2016 01:41 PM
SpaceX decided to immerse their COPVs in their propellant.  Given that choice, why did they choose to immerse them in the LOX, which is nasty stuff both chemically and thermally, instead of in the comparatively benign RP1?
It's colder, and He expansion per J/kg is the highest of any element, basically, they can increase density by 20x "for free".
Also as a gas is compressed it get hot.  Depending on the fill rate you could end up creating bubbles of RP1  vapor or start to polymerize it into a tarry mix.In the LOX tank you make O2 bubbles which vent (usually) harmlessly and top up with more LOX.

This has been a standard trick to squeeze more performance out of a design since at least Saturn 1 and possibly before.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jim on 09/02/2016 01:45 PM
Can you explain how a rupture does that please?

That is the only way the propellants became available to burn
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: jaufgang on 09/02/2016 01:50 PM
1.  Not COPV or FTS.  Explosion is an external air burst.  No debris until much later, other than the big cap-like thing  that's shot straight up and tumbles.
2.  Maybe a crack in the unconstrained S curve of this line (see attached) especially if that's the RP-1 line.  High pressure though the crack or pinhole would make an aerosol.  A line in that acoustic environment shouldn't have an unconstrained S.
   


1.  It is an air burst because of a rupture.  Rupture came first.

2. That would be an AC line.  The second stage umbilical is lower

Just to debate the idea that the rupture came first.  Based on the detonation profile that implies a fuel-air explosion, the absence of any visible plume changes prior to the explosion 1st frame, an oxygen tank rupture would create a plume, and would not itself cause a detonation.  An RP-1 rupture might not show a plume but would provide the material needed for a fuel-air explosion.  If there were an RP-1 rupture, how would that occur?

We go from one frame where there is no indication of abnormal plumes to a frame where the detonation is about 35 X 85 feet across.  In 1/60th of a second you have to fill that volume with RP-1 aerosol (not liquid) and it has to explode during that same window.

Can you explain how a rupture does that please?
Keep in mind there is an entire half of the rocket that is not visible in this video. Who knows what was happening on the far side of the rocket moments before it detonated?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: punder on 09/02/2016 01:50 PM
Ya, you're right. There's only data for the horizontal travel distance, not the to camera distance.  When it crosses the tower, it's moved at least 50 yards from the explosion center.  How far towards the camera is speculative.

Hoping against hope the problem started outside the vehicle... although that's not much consolation. But it just seems too rapid a burst not to have come from the tanks. But what do I know.

On the subject of the line with the S-curve, the line looks like sheet metal, not a heavy pipe you'd push dangerous pressurized fuel through. Jim must be right, as usual.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: glennfish on 09/02/2016 01:57 PM
Can you explain how a rupture does that please?

That is the only way the propellants became available to burn

Do you know where the 2nd stage RP1 lines are on the strong back?  Knowing that could help localize whether the detonation is consistent with their position, or not.  i.e. a fuel line problem is another source. 
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jim on 09/02/2016 02:00 PM

Do you know where the 2nd stage RP1 lines are on the strong back?  Knowing that could help localize whether the detonation is consistent with their position, or not.  i.e. a fuel line problem is another source. 

There is no RP-1 flowing at that time.
RP-1 lines are at the bottom of the stage
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Saabstory88 on 09/02/2016 02:06 PM

Do you know where the 2nd stage RP1 lines are on the strong back?  Knowing that could help localize whether the detonation is consistent with their position, or not.  i.e. a fuel line problem is another source. 

There is no RP-1 flowing at that time.
RP-1 lines are at the bottom of the stage

Even if the fuel is not flowing, do they drain the fill line after S2 fuel is full?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: punder on 09/02/2016 02:08 PM

Do you know where the 2nd stage RP1 lines are on the strong back?  Knowing that could help localize whether the detonation is consistent with their position, or not.  i.e. a fuel line problem is another source. 

There is no RP-1 flowing at that time.
RP-1 lines are at the bottom of the stage

Well, what happens in the lines when propellants are not flowing? Are they still filled with propellants? Are they pressurized? Is there air in the fuel line?

Wups, Saab beat me to it.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: glennfish on 09/02/2016 02:11 PM

Do you know where the 2nd stage RP1 lines are on the strong back?  Knowing that could help localize whether the detonation is consistent with their position, or not.  i.e. a fuel line problem is another source. 

There is no RP-1 flowing at that time.
RP-1 lines are at the bottom of the stage

It wouldn't have to be flowing.  Only leaking during fueling.  That's why I'm wondering where the 2nd stage RP1 lines are.

reference:  http://www.sciencedirect.com/science/article/pii/S1877705814036583
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Saabstory88 on 09/02/2016 02:20 PM
lot of discussion about what is where on the tower in relation to the explosion. 

this wired article has a couple of closeups of the tower and stage in the area you guys are talking about.  Older Falcon variant i think, but i doubt the geometry has changed much

http://www.wired.com/2012/05/the-launch-pad-spacex-falcon-9-ready-for-liftoff/

also here's a hi res closeup i found linked off reddit of interstage area, a little lower down, good view of the service lines on the tower

http://i.imgur.com/7LL2HUp.jpg

bottom line - unless i'm looking at the images wrong, there isn't much beyond ECS (AC) and power running up past the lower part of the 2nd stage.

Here is an image of a more up to date iteration of the vehicle: https://c2.staticflickr.com/2/1671/26217360302_b66c3e384e_o.jpg

Edit: And the fairing version:
https://c2.staticflickr.com/6/5766/23526044959_5bfe74bc88_o.jpg
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jim on 09/02/2016 02:25 PM
It wouldn't have to be flowing.  Only leaking during fueling. 


And that would be seen and they would not have completed the tanking
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jim on 09/02/2016 02:26 PM

Well, what happens in the lines when propellants are not flowing? Are they still filled with propellants? Are they pressurized? Is there air in the fuel line?

Wups, Saab beat me to it.

Standard practice would be to not to hold pressure after loading
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: yokem55 on 09/02/2016 02:28 PM
Curious, anyone know what kind of refrigerant gets used for the fairing's AC? I know a lot of big commercial air chillers use ammonia, which if there is a leak in the system can make a pretty flammable concoction...
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: meekGee on 09/02/2016 02:31 PM
I agree with the air-burst observation, but also finding it hard to come up with sources for such a nice fuel aerosol other than from the rocket.

It could still be something simple like a fill port, I'm really hoping it was not a tank structural thing.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Kryten on 09/02/2016 02:32 PM
Are there any other cases where there has been a complete loss of launch vehicle and payload days before T-0?
As well as the Russian incidents that have already been mentioned, there was a relatively recent fatal incident of this type in Brazil; https://en.wikipedia.org/wiki/VLS-1_V03
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: glennfish on 09/02/2016 02:34 PM
It wouldn't have to be flowing.  Only leaking during fueling. 


And that would be seen and they would not have completed the tanking

Well, I guess you blew my hypothesis out of the water.   :)

I'm almost ready to embrace a conspiracy theory.   8)

Two things bother me greatly.

1.  The onset speed of the detonation.
2.  The trajectory of that "thingee" that flies over the plume apparently from the strongback.

I'm sure the answers will come forward...
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: mn on 09/02/2016 02:39 PM
There have been lots of posts about the possibility of a leak outside the vehicle catching fire, (far to many to know which one to quote)

(Aside from the fact (as has been pointed out over and over again) that the fuel lines are at the bottom of the stage, not where the fire occurred.)

Question: if we assume for a moment that the vehicle is intact and the fuel is coming from a leak outside the vehicle: would a fuel air mixture burning in open air breach the oxygen tanks? We know it makes for a nice fireball but as explained earlier it is not a bomb just a fire (to use laymen's terms for detonation vs deflagration).

So would a burning fuel/air mixture outside the vehicle rupture the vehicle tanks from the outside? or just burn to depletion?
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: DaveS on 09/02/2016 02:42 PM
Curious, anyone know what kind of refrigerant gets used for the fairing's AC? I know a lot of big commercial air chillers use ammonia, which if there is a leak in the system can make a pretty flammable concoction...
None, they use air to create a positive pressure inside the fairing. What you're thinking is cooling while the AC is used to maintain a clean environment.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ugordan on 09/02/2016 02:44 PM
There have been lots of posts about the possibility of a leak outside the vehicle catching fire, (far to many to know which one to quote)

To me, they all look like wishful thinking, just like like IDA-1 destroying the LOX tank on CRS-7 theories were. Wishing for the "better" outcome scenario (pad fault vs. vehicle) and then looking for scenarios which might fit.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jim on 09/02/2016 02:49 PM
Curious, anyone know what kind of refrigerant gets used for the fairing's AC? I know a lot of big commercial air chillers use ammonia, which if there is a leak in the system can make a pretty flammable concoction...
None, they use air to create a positive pressure inside the fairing. What you're thinking is cooling while the AC is used to maintain a clean environment.

The air is also cooled along with being filtered. But at that point in the countdown, it should be GN2
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: DaveS on 09/02/2016 02:50 PM
Curious, anyone know what kind of refrigerant gets used for the fairing's AC? I know a lot of big commercial air chillers use ammonia, which if there is a leak in the system can make a pretty flammable concoction...
None, they use air to create a positive pressure inside the fairing. What you're thinking is cooling while the AC is used to maintain a clean environment.

The air is also cooled along with being filtered. But at that point in the countdown, it should be GN2
Yes, passive air cooling and I was not 100% certain if they did a air/GN2 change-over for the PLF purge.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: WHAP on 09/02/2016 02:53 PM
JCM how do you classify this event?  A payload and rocket were lost at the launch pad but it wasn't a launch failure as it wasn't a launch attempt. Watching your website to see how you classify it as it is probably the launch log of choice on the web

I'm not JCM, but do my own tracking of launches.  Even though the payload was lost in a prelaunch exercise, it counts as a failure in my book.  You don't necessarily have to distinguish between a launch failure or a ground failure.  But it's a fact that the vehicle failed to get the payload to orbit.  It's not like the vehicle failed without the payload and you just get a new booster and have a successful mission a few months later.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: BrightLight on 09/02/2016 02:58 PM
I don't know if this was previously reported on this site or thread but:
"The satellite was backed by a policy worth almost $300 million, said the person, who requested anonymity because the person wasn’t authorized to speak publicly. SpaceX declined to comment."

http://www.bloomberg.com/news/articles/2016-09-02/when-a-commercial-rocket-blows-up-who-pays
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: JWag on 09/02/2016 03:00 PM
The LOX dome in the common bulkhead impinges the RP-1 tank, is that correct?

Bolded red here (side view): < Payload ] ( LOX ) RP1) |< M-vac

So it would take an RP-1 overpressurization (or LOX depress) to invert the dome. Right?

My own pet theory is that an RP-1 overpress inverted the bulkhead, overpressing the LOX tank and splitting the two at the now-weakened bulkhead. Hot twisted bulkhead metal ignited the mixing propellants.

Still, given the energy, it's difficult to imagine how the payload wasn't propelled upwards with the pressure from the LOX if the tank split circumferentially. Sort of like how STS-51L's ET was propelled forward when the aft LH2 dome split off.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Toast on 09/02/2016 03:01 PM
JCM how do you classify this event?  A payload and rocket were lost at the launch pad but it wasn't a launch failure as it wasn't a launch attempt. Watching your website to see how you classify it as it is probably the launch log of choice on the web

I'm not JCM, but do my own tracking of launches.  Even though the payload was lost in a prelaunch exercise, it counts as a failure in my book.  You don't necessarily have to distinguish between a launch failure or a ground failure.  But it's a fact that the vehicle failed to get the payload to orbit.  It's not like the vehicle failed without the payload and you just get a new booster and have a successful mission a few months later.

I agree. When I actually get around to updating the launch reliability statistics I've posted around here, I will be tallying it as a failure as well, since the rocket (and perhaps more importantly) the payload were destroyed.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: whitelancer64 on 09/02/2016 03:02 PM
JCM how do you classify this event?  A payload and rocket were lost at the launch pad but it wasn't a launch failure as it wasn't a launch attempt. Watching your website to see how you classify it as it is probably the launch log of choice on the web

I'm not JCM, but do my own tracking of launches.  Even though the payload was lost in a prelaunch exercise, it counts as a failure in my book.  You don't necessarily have to distinguish between a launch failure or a ground failure.  But it's a fact that the vehicle failed to get the payload to orbit.  It's not like the vehicle failed without the payload and you just get a new booster and have a successful mission a few months later.
Yeah, that's how I've got it in my SpaceX launches spreadsheet.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Wolfram66 on 09/02/2016 03:05 PM
Here's a distillation of discussion.

Fuel loading....
*Ploink* LOX tank/line failure. possible weld brittle failure of LOX tank dome due to deep cryo-LOX
Rapid release of LOX slush
*crinkling noise* Expansion/deformation of outer skin of S2 due to growing overpressure
pressure and deformation find the weakest point... the umbilical
Power/data + Fueling(possible) Umbilical detach or fail and spark leading to Fuel-Air detonation at single point [as seen in video]
a Jet of LOX-RP1 escaping near the partially detached & still live Power/data port would be like a static spark while filling your gas tank or any non-positive pressurized oil rig electrical device during a Natural Gas "Kick"/Blowout, only 1000 time more energetic
 = RUD

that's my 1.5 Cents.
Please discuss among yourselves while i go back to work
Cheers  ;)
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: jaufgang on 09/02/2016 03:05 PM
Two things bother me greatly.

1.  The onset speed of the detonation.
2.  The trajectory of that "thingee" that flies over the plume apparently from the strongback.


I've looked closely at that "thingee" flying straight up from the strongback, stepping forwards and backwards in the video fame by frame several times. One thing I noticed is that if you assume that it originated at an elevation at or above where the explosion seems to be centered, and if you try to visually extrapolate the reverse-trajectory while stepping the video backwards, it seems like that part must have been launched a few frames after the initial explosion began (i.e. running backwards it seems it would reach it's expected starting point before the shrinking fireball disappears).  That might indicate that it was launched from some part on the strongback due to pressure buildup from the original explosion coming from a point on the rocket to the left and possibly a bit below.

Of course my technique is very inaccurate and I could be wrong about the timing of the trajectory but that's what it looks like to me.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: jongoff on 09/02/2016 03:21 PM
SpaceX decided to immerse their COPVs in their propellant.  Given that choice, why did they choose to immerse them in the LOX, which is nasty stuff both chemically and thermally, instead of in the comparatively benign RP1?

Someone may have already answered this, but the main reason is dry mass savings. GHe at LOX temps (90K) is about ~3x denser than the same pressure of GHe at room temperature (300K), or chilled Kerosene temps. Because pressure tank mass scales linearly with Pressure x Volume, a higher GHe storage density means you reduce the mass and volume of helium for the stage dramatically, saving a lot of dry mass on the stage. I should note that the GHe is warmed by some sort of device (not positive how on F9 US) before being routed back to the tanks, to reduce its density before putting it into the tanks as pressurant. This fits in with SpaceX's push for bleeding edge performance on its engines and stages...

~Jon
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: glennfish on 09/02/2016 03:25 PM


Question: if we assume for a moment that the vehicle is intact and the fuel is coming from a leak outside the vehicle: would a fuel air mixture burning in open air breach the oxygen tanks? We know it makes for a nice fireball but as explained earlier it is not a bomb just a fire (to use laymen's terms for detonation vs deflagration).

So would a burning fuel/air mixture outside the vehicle rupture the vehicle tanks from the outside? or just burn to depletion?

If you can create either an RP1 or an ammonia aerosol, and then provide an ignition source, it will detonate.  The shock-wave would rupture the tanks.

If it's not an aerosol, it will burn.

In the available video, it looks like the detonation speed is between 2,000 and 5,000 feet per second.  That would create a major shock-wave.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: jongoff on 09/02/2016 03:28 PM

Well, what happens in the lines when propellants are not flowing? Are they still filled with propellants? Are they pressurized? Is there air in the fuel line?

Wups, Saab beat me to it.

Standard practice would be to not to hold pressure after loading

And without pressure in the RP-1 line, I don't see any way it could've created an aerosol for a fuel-air explosion.

Also, when they're doing LOX loading, is the RP-1 in the tanks pressurized? Because if there's no pressurized fuel source at this point in the prop loading process (in the tanks or the feedlines) that would make an external fuel/air explosion seem a lot less likely, wouldn't it?

~Jon
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: glennfish on 09/02/2016 03:30 PM
Two things bother me greatly.

1.  The onset speed of the detonation.
2.  The trajectory of that "thingee" that flies over the plume apparently from the strongback.


I've looked closely at that "thingee" flying straight up from the strongback, stepping forwards and backwards in the video fame by frame several times. One thing I noticed is that if you assume that it originated at an elevation at or above where the explosion seems to be centered, and if you try to visually extrapolate the reverse-trajectory while stepping the video backwards, it seems like that part must have been launched a few frames after the initial explosion began (i.e. running backwards it seems it would reach it's expected starting point before the shrinking fireball disappears).  That might indicate that it was launched from some part on the strongback due to pressure buildup from the original explosion coming from a point on the rocket to the left and possibly a bit below.

Of course my technique is very inaccurate and I could be wrong about the timing of the trajectory but that's what it looks like to me.

If you make the following assumption, do you come to the same conclusion?

1.  The vertical component is < 50% of the total velocity
2.  The horizontal component towards the camera and left is > 50% of the total velocity.

Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: M.E.T. on 09/02/2016 03:35 PM
Not sure where to ask this type of question, and I think it is obvious why one would ask it after such an event, but how tight is security in the launch industry? Meaning throughout the process, from origin of the rocket up to ignition?


Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: AncientU on 09/02/2016 03:38 PM
The LOX dome in the common bulkhead impinges the RP-1 tank, is that correct?

Bolded red here (side view): < Payload ] ( LOX ) RP1) |< M-vac

So it would take an RP-1 overpressurization (or LOX depress) to invert the dome. Right?

My own pet theory is that an RP-1 overpress inverted the bulkhead, overpressing the LOX tank and splitting the two at the now-weakened bulkhead. Hot twisted bulkhead metal ignited the mixing propellants.

Still, given the energy, it's difficult to imagine how the payload wasn't propelled upwards with the pressure from the LOX if the tank split circumferentially. Sort of like how STS-51L's ET was propelled forward when the aft LH2 dome split off.

This is a key indication that the initial explosion was external to the tank.

A detonation inside the tank would be vastly more energetic than the pressure from a COPV failure -- which itself would have sufficient energy to launch the payload upwards.  It just sat there...

External explosion compromises the second stage tankage, fuel/lox waterfalls onto pad below, lower stage detonates, and finally, payload comes tumbling down.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: b ramsey on 09/02/2016 03:43 PM
Have there been any helicopter aerial views of the pad anywhere on the net post accident. I haven"t seen any yet.  Question is how long is the pad out of commission per how much damage is there.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: ugordan on 09/02/2016 03:49 PM
Also, when they're doing LOX loading, is the RP-1 in the tanks pressurized? Because if there's no pressurized fuel source at this point in the prop loading process (in the tanks or the feedlines) that would make an external fuel/air explosion seem a lot less likely, wouldn't it?

On JCSat-16 webcast, at T-4m 50s there was a callout "stage 1, stage 2 pressing for strongback retract".

I believe that was a standard procedure for all F9s, perhaps not pressed all the way to flight level, but certainly under pressure.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: jaufgang on 09/02/2016 03:51 PM
Two things bother me greatly.

1.  The onset speed of the detonation.
2.  The trajectory of that "thingee" that flies over the plume apparently from the strongback.


I've looked closely at that "thingee" flying straight up from the strongback, stepping forwards and backwards in the video fame by frame several times. One thing I noticed is that if you assume that it originated at an elevation at or above where the explosion seems to be centered, and if you try to visually extrapolate the reverse-trajectory while stepping the video backwards, it seems like that part must have been launched a few frames after the initial explosion began (i.e. running backwards it seems it would reach it's expected starting point before the shrinking fireball disappears).  That might indicate that it was launched from some part on the strongback due to pressure buildup from the original explosion coming from a point on the rocket to the left and possibly a bit below.

Of course my technique is very inaccurate and I could be wrong about the timing of the trajectory but that's what it looks like to me.

If you make the following assumption, do you come to the same conclusion?

1.  The vertical component is < 50% of the total velocity
2.  The horizontal component towards the camera and left is > 50% of the total velocity.

Yes, whether or not I'm right or wrong, I don't see how the horizontal component matters at all.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: chuck34 on 09/02/2016 04:00 PM
lot of discussion about what is where on the tower in relation to the explosion. 

this wired article has a couple of closeups of the tower and stage in the area you guys are talking about.  Older Falcon variant i think, but i doubt the geometry has changed much

http://www.wired.com/2012/05/the-launch-pad-spacex-falcon-9-ready-for-liftoff/

also here's a hi res closeup i found linked off reddit of interstage area, a little lower down, good view of the service lines on the tower

http://i.imgur.com/7LL2HUp.jpg

bottom line - unless i'm looking at the images wrong, there isn't much beyond ECS (AC) and power running up past the lower part of the 2nd stage.

Here is an image of a more up to date iteration of the vehicle: https://c2.staticflickr.com/2/1671/26217360302_b66c3e384e_o.jpg

Edit: And the fairing version:
https://c2.staticflickr.com/6/5766/23526044959_5bfe74bc88_o.jpg

Posting from my phone, so apologies for this not being the most readable.

That second pic there shows that there is a bit of a "cradle" on the strong back right about where the intertank is, if I'm looking at it right.  This perks my interest and goes along with something else I've been wondering.  Watching the video, my mind sees relative motion between the rocket and strong back (very small probably nothing).  I've been thinking this was a trick of how far away the camera is etc.  But what if it isn't?  What if there was some relative motion there?  Could this "cradle" have actually punctured the skin of the rocket?  Does anyone know the wind speeds, it looked like a relatively stiff breeze from looking at the vent gasses (not really a good judge of things).  I'm sure there are wind constraints even for a static test right?

I honestly think I'm crazy on this theory, but thought I'd throw it out to be debunked here.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: cscott on 09/02/2016 04:04 PM


Not sure where to ask this type of question, and I think it is obvious why one would ask it after such an event, but how tight is security in the launch industry? Meaning throughout the process, from origin of the rocket up to ignition?

It's an Air Force Base.  Security is very high.  See Jim's posts earlier in this thread for more details.
Have there been any helicopter aerial views of the pad anywhere on the net post accident. I haven"t seen any yet.  Question is how long is the pad out of commission per how much damage is there.
It's an Air Force Base.  I'm sure there are strict restrictions on photographers in civilian news copters.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: glennfish on 09/02/2016 04:07 PM
Two things bother me greatly.

1.  The onset speed of the detonation.
2.  The trajectory of that "thingee" that flies over the plume apparently from the strongback.


I've looked closely at that "thingee" flying straight up from the strongback, stepping forwards and backwards in the video fame by frame several times. One thing I noticed is that if you assume that it originated at an elevation at or above where the explosion seems to be centered, and if you try to visually extrapolate the reverse-trajectory while stepping the video backwards, it seems like that part must have been launched a few frames after the initial explosion began (i.e. running backwards it seems it would reach it's expected starting point before the shrinking fireball disappears).  That might indicate that it was launched from some part on the strongback due to pressure buildup from the original explosion coming from a point on the rocket to the left and possibly a bit below.

Of course my technique is very inaccurate and I could be wrong about the timing of the trajectory but that's what it looks like to me.

If you make the following assumption, do you come to the same conclusion?

1.  The vertical component is < 50% of the total velocity
2.  The horizontal component towards the camera and left is > 50% of the total velocity.

Yes, whether or not I'm right or wrong, I don't see how the horizontal component matters at all.

It would rise more slowly which would give a perception of a later instantiation while the horizontal component wouldn't be as obvious.  Just an idea.  I'll have to duplicate what you did to have a real opinion.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: meekGee on 09/02/2016 04:09 PM
I previously said the initial explosion was fast and energetic.

However it is not IMO energetic enough to fit a total bulkhead failure.

I think in that case you'd get violent mixing of LOX and RP1 in large quantities, and then when it ignites, you'd get one HELL of an explosion, one that wouldn't leave the fairing intact like that.

It was indeed fast, but it was also relatively small. Just enough to cause the rest of the rocket to fail slowly.

So still I think something failed in the rocket, caused a fuel air or fuel gox mix to form, and then something else (what?) Ignited it.

Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: mme on 09/02/2016 04:13 PM
The LOX dome in the common bulkhead impinges the RP-1 tank, is that correct?

Bolded red here (side view): < Payload ] ( LOX ) RP1) |< M-vac

So it would take an RP-1 overpressurization (or LOX depress) to invert the dome. Right?

My own pet theory is that an RP-1 overpress inverted the bulkhead, overpressing the LOX tank and splitting the two at the now-weakened bulkhead. Hot twisted bulkhead metal ignited the mixing propellants.

Still, given the energy, it's difficult to imagine how the payload wasn't propelled upwards with the pressure from the LOX if the tank split circumferentially. Sort of like how STS-51L's ET was propelled forward when the aft LH2 dome split off.

This is a key indication that the initial explosion was external to the tank.

A detonation inside the tank would be vastly more energetic than the pressure from a COPV failure -- which itself would have sufficient energy to launch the payload upwards.  It just sat there...

External explosion compromises the second stage tankage, fuel/lox waterfalls onto pad below, lower stage detonates, and finally, payload comes tumbling down.
Even if the explosion was ignited outside the rocket a failure of the rocket could still be the source of the oxygen/rp-1.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: vanoord on 09/02/2016 04:23 PM
Posting from my phone, so apologies for this not being the most readable.

That second pic there shows that there is a bit of a "cradle" on the strong back right about where the intertank is, if I'm looking at it right.  This perks my interest and goes along with something else I've been wondering.  Watching the video, my mind sees relative motion between the rocket and strong back (very small probably nothing).  I've been thinking this was a trick of how far away the camera is etc.  But what if it isn't?  What if there was some relative motion there?  Could this "cradle" have actually punctured the skin of the rocket?  Does anyone know the wind speeds, it looked like a relatively stiff breeze from looking at the vent gasses (not really a good judge of things).  I'm sure there are wind constraints even for a static test right?

I honestly think I'm crazy on this theory, but thought I'd throw it out to be debunked here.

The cradle is in pretty much the exact place the explosion started.

Probably correlation, not causation.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Lee Jay on 09/02/2016 04:24 PM
How about this.

Let's say there was a small, maybe pin-hole leak in the RP-1 fueling umbilical, and during fueling it sprayed the top of the strongback with RP1.  Kerosene evaporates slowly so it can hang around for a while.

It looks like there's a GOX stream near the strongback.  See the arrow below.  That spot seems to correspond to the initiation location as determined by the diffraction spikes.

What if that GOX stream and the hypothetical slowly-evaporating RP-1 from the hypothetical leak finally got to sufficient concentrations, just due to just the right (or wrong) wind conditions that it could ignite into a fuel-air explosion given an ignition source?  That small-ish explosion ruptures the tanks, and everything falls, burning on the way down.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: chuck34 on 09/02/2016 04:38 PM
Posting from my phone, so apologies for this not being the most readable.

That second pic there shows that there is a bit of a "cradle" on the strong back right about where the intertank is, if I'm looking at it right.  This perks my interest and goes along with something else I've been wondering.  Watching the video, my mind sees relative motion between the rocket and strong back (very small probably nothing).  I've been thinking this was a trick of how far away the camera is etc.  But what if it isn't?  What if there was some relative motion there?  Could this "cradle" have actually punctured the skin of the rocket?  Does anyone know the wind speeds, it looked like a relatively stiff breeze from looking at the vent gasses (not really a good judge of things).  I'm sure there are wind constraints even for a static test right?

I honestly think I'm crazy on this theory, but thought I'd throw it out to be debunked here.

The cradle is in pretty much the exact place the explosion started.

Probably correlation, not causation.

Yes, that's where the explosion appears to start, thus my question.

Clearly correlation is not causation, but merely stating a trite old saying doesn't rule it out either. 

What are the wind constraints for a static fire?  Is there something that guaruntees there can be no relative motion between the rocket and strongback in that location?  The skin wouldn't even necessarily need to be punctured either, a big enough dent could cause the tanks to buckle under pressure too.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Jim on 09/02/2016 04:44 PM
There are clamps that hold the vehicle near the fairing that prevents relative motion
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Rocket Science on 09/02/2016 04:49 PM
If the concentration and pressures are high enough of the RP-1/LOX you could have a spontaneous ignition...
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Asmegin on 09/02/2016 04:50 PM
User Squeazle (https://www.reddit.com/user/Squeazle) on reddit, claiming to be with the CCAFS FD, posted a few things re: pad status. Goes without saying that his information cannot be confirmed, but his post history does seem to back up his position.

Quote
While I am not an official spokesperson for either Cape Canaveral Air Force Station Fire Department or Kennedy Space Center Fire Department, I am a member of CCAFS FD and was on scene at yesterday's anomaly and was involved with the eventual extinguishment of the remaining fires. I can confirm that NO personnel from either side were injured or airlifted from the scene. The Air Force's Explosive Ordinance Disposal team preceded closely in front of fire crews and did a superb job clearing a path for us to follow and approach the pad.

(On how bad the pad was damaged) Quite. Granted, I'm not in construction or an engineer but it seems like it will be months before the pad is usable. Dozens of pressurized vessels and tanks were destroyed including 5-6 pressurized rail cars. The gantry itself, while still standing appears to be a total loss, as may be a lightening arrest tower at the corner of the pad. Several buildings located on or near the pad are either destroyed or severely damaged. There's no power at the moment and I can tell you from first-hand experience that the water mains and hydrants are compromised. Debris made it as far as pad 39A, which is quite a distance. They'll be finding pieces of it in the surrounding woods and beach line for years, just as they've found pieces of 1997's Delta II mishap as recently as a year or two ago. I have loads of pictures and video, including the initial walk-down of the pad with Fire, EOD, SpaceX, and AF investigators, and know people who have posted them to social media but without SpaceX' and the Air Force's expressed permission, I'm wary of posting them.

I'm fairly certain I saw a rocket motor, or at least it's nozzle, directly under the gantry on top of the pad and a black composite tank that looked fairly intact off in the field, but that's about all that was recognizable.

The hangar actually doesn't appear damaged but I'm sitting on the opposite side of the pad right now and can't see it close up. As for concrete, I'm not sure yet but plumbing and piping leading into/out of the pad definitely is.

(on debris flying to 39A) It does seem unlikely that it would travel that distance but a contingent of EOD was dispatched to 39A for report of debris.
When I have a better handle on permissions, I'll post some. They're pretty interesting.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: gadgetmind on 09/02/2016 04:52 PM
When you're dealing with a high oxygen content you don't even need a spark. Scuba tanks need oxygen safe cleaning for even mild oxygen enrichment as oil/grease can combust spontaneously, as can other materials.

I'm certain these risks are fully understood by all concerned, and that all materials including seals and lubricants are oxygen safe, but this is a "don't trust anything" investigation, and an ignition source not being present doesn't rule anything out.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: cro-magnon gramps on 09/02/2016 04:53 PM
I did a cursory search back to page 12, and no one had posted this... off of twitter, picked it up yesterday. The creator put the fire ball and the Dragon Abort vid together and sort of proved that Dragon would escape with plenty of margin... I hedged my comment, because I know that there may be purists who will knock his effort...


https://twitter.com/StateMachines/status/771535425328459780
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: Patchouli on 09/02/2016 04:53 PM

Yes, passive air cooling and I was not 100% certain if they did a air/GN2 change-over for the PLF purge.

Somewhat crazy theory but what if AMOS-6 itself had a propellant leak wouldn't that fill the fairing with flammable gas which could have leaked outside and found an ignition source or just reacted with O2 from the LOX tank venting?

I did a cursory search back to page 12, and no one had posted this... off of twitter, picked it up yesterday. The creator put the fire ball and the Dragon Abort vid together and sort of proved that Dragon would escape with plenty of margin... I hedged my comment, because I know that there may be purists who will knock his effort...


https://twitter.com/StateMachines/status/771535425328459780

At least we now know at least one crew vehicle's LAS should be up to the task of escaping a worst case failure.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: John Alan on 09/02/2016 04:54 PM
User Squeazle (https://www.reddit.com/user/Squeazle) on reddit, claiming to be with the CCAFS FD, posted a few things re: pad status. Goes without saying that his information cannot be confirmed, but his post history does seem to back up his position.

Quote
While I am not an official spokesperson for either Cape Canaveral Air Force Station Fire Department or Kennedy Space Center Fire Department, I am a member of CCAFS FD and was on scene at yesterday's anomaly and was involved with the eventual extinguishment of the remaining fires. I can confirm that NO personnel from either side were injured or airlifted from the scene. The Air Force's Explosive Ordinance Disposal team preceded closely in front of fire crews and did a superb job clearing a path for us to follow and approach the pad.

(On how bad the pad was damaged) Quite. Granted, I'm not in construction or an engineer but it seems like it will be months before the pad is usable. Dozens of pressurized vessels and tanks were destroyed including 5-6 pressurized rail cars. The gantry itself, while still standing appears to be a total loss, as may be a lightening arrest tower at the corner of the pad. Several buildings located on or near the pad are either destroyed or severely damaged. There's no power at the moment and I can tell you from first-hand experience that the water mains and hydrants are compromised. Debris made it as far as pad 39A, which is quite a distance. They'll be finding pieces of it in the surrounding woods and beach line for years, just as they've found pieces of 1997's Delta II mishap as recently as a year or two ago. I have loads of pictures and video, including the initial walk-down of the pad with Fire, EOD, SpaceX, and AF investigators, and know people who have posted them to social media but without SpaceX' and the Air Force's expressed permission, I'm wary of posting them.

I'm fairly certain I saw a rocket motor, or at least it's nozzle, directly under the gantry on top of the pad and a black composite tank that looked fairly intact off in the field, but that's about all that was recognizable.

The hangar actually doesn't appear damaged but I'm sitting on the opposite side of the pad right now and can't see it close up. As for concrete, I'm not sure yet but plumbing and piping leading into/out of the pad definitely is.

(on debris flying to 39A) It does seem unlikely that it would travel that distance but a contingent of EOD was dispatched to 39A for report of debris.
When I have a better handle on permissions, I'll post some. They're pretty interesting.

I'm thinking history will show JCSAT-16 as the last rocket launched from SLC-40.... it's done...  :'(  :(
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: envy887 on 09/02/2016 04:56 PM
How about this.

Let's say there was a small, maybe pin-hole leak in the RP-1 fueling umbilical, and during fueling it sprayed the top of the strongback with RP1.  Kerosene evaporates slowly so it can hang around for a while.

It looks like there's a GOX stream near the strongback.  See the arrow below.  That spot seems to correspond to the initiation location as determined by the diffraction spikes.

What if that GOX stream and the hypothetical slowly-evaporating RP-1 from the hypothetical leak finally got to sufficient concentrations, just due to just the right (or wrong) wind conditions that it could ignite into a fuel-air explosion given an ignition source?  That small-ish explosion ruptures the tanks, and everything falls, burning on the way down.

This would fit what we know so far, except that the RP-1 umbilical is about 4 meters directly below where your arrow is pointed. That seems like a long way for a stream of liquid fuel to go, and the wind would quickly dissapate vapors or small droplets.
Title: Re: SpaceX Falcon 9 - AMOS-6 - (Pad Failure) - DISCUSSION THREAD
Post by: vanoord on 09/02/2016 04:57 PM
Yes, that's where the explosion appears to start, thus my question.

Clearly correlation is not causation, but merely stating a trite old saying doesn't rule it out either. 

What are the wind constraints for a static fire?  Is there something that guaruntees there can be no relative motion between the rocket and strongback in that location?  The skin wouldn't even necessarily need to be punctured either, a big enough dent could cause the tanks to buckle under pressure too.

I've overlaid an image from immediately before the explosion over one a couple of minutes after it.

It shows the strongback buckled at pretty much the point you're referring to, which could be interpreted as it being damaged by the initial explosion and subsequently failing there.

However, it looks like the buckling of the strongback was caused by it taking the weight of the payload and was twisted as it fell - but it still failed at the same point.

 I've marked that point on a clean image of the top of the vehicle (with a Dragon) and the construction of the strongback is different at that point.

It looks like it has what I woul