Author Topic: SpaceX F9 : Zuma : January 7/8, 2018, CCAFS : DISCUSSION  (Read 786451 times)

Offline Lars-J

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Re: SpaceX F9 : Zuma : January 7/8, 2018, CCAFS : DISCUSSION
« Reply #820 on: 01/09/2018 05:25 am »
What do we make of the pretty pictures from Sudan?  (See here and here.)  Is this expected F9 S2 behavior?  Has it been seen before?
This seems like a key question.  I was surprised to see spinning, but others claimed this was normal.  I'm skeptical.  The only time I recall seeing a second stage spin like this (viewed from the ground) was during the very first Falcon 9 launch, when the second stage lost roll control.

 - Ed kyle

Wouldn't the LOX venting naturally result in spinning?
No.  Typically, venting is done symmetrically to prevent unwanted rolls, yaws, etc.  On the other hand, they might purposefully put the stage into a spin for reentries. 

 - Ed Kyle

Yes, and this is post re-entry burn, so there is no longer any need for maintaining a proper attitude.

Offline RoboGoofers

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Re: SpaceX F9 : Zuma : January 7/8, 2018, CCAFS : DISCUSSION
« Reply #821 on: 01/09/2018 05:26 am »
Even if symmetric, they might spin a bit to even out variances.

Offline the_other_Doug

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Re: SpaceX F9 : Zuma : January 7/8, 2018, CCAFS : DISCUSSION
« Reply #822 on: 01/09/2018 05:30 am »
What do we make of the pretty pictures from Sudan?  (See here and here.)  Is this expected F9 S2 behavior?  Has it been seen before?
This seems like a key question.  I was surprised to see spinning, but others claimed this was normal.  I'm skeptical.  The only time I recall seeing a second stage spin like this (viewed from the ground) was during the very first Falcon 9 launch, when the second stage lost roll control.

 - Ed kyle

Wouldn't the LOX venting naturally result in spinning?
No.  Typically, venting is done symmetrically to prevent unwanted rolls, yaws, etc.  On the other hand, they might purposefully put the stage into a spin for reentries. 

 - Ed Kyle

Yes, and this is post re-entry burn, so there is no longer any need for maintaining a proper attitude.

I'm assuming that, seeing as the S2 seems to have de-orbited successfully, that it would not have been able to get into the proper attitude for its de-orbit burn if it had lost roll control before payload sep had been attempted...?

Of course, that would have been glaringly obvious to SpaceX's "first look at the data" which led them to announce that the Falcon operated nominally.  And since one of SpaceX's virtues is that they always own up to their failures, one way or another, I can't see them lying about that kind of thing...
-Doug  (With my shield, not yet upon it)

Offline AC in NC

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Re: SpaceX F9 : Zuma : January 7/8, 2018, CCAFS : DISCUSSION
« Reply #823 on: 01/09/2018 05:32 am »
What I want to know is what officials would intentionally leak classified information like that and risk jail time. The only plausible explanations I know is that they weren't actually given classified information (and thus are perhaps making a guess) or that they're deliberately being misleading, therefore not leaking classified information.

Leaking classified information is practically a job requirement for "officials".  Risking jail time is only for some low-level submariner with some stray photographs they forgot about.

Offline the_other_Doug

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Re: SpaceX F9 : Zuma : January 7/8, 2018, CCAFS : DISCUSSION
« Reply #824 on: 01/09/2018 05:34 am »
What I want to know is what officials would intentionally leak classified information like that and risk jail time. The only plausible explanations I know is that they weren't actually given classified information (and thus are perhaps making a guess) or that they're deliberately being misleading, therefore not leaking classified information.

Leaking classified information is practically a job requirement for "officials".  Risking jail time is only for some low-level submariner with some stray photographs they forgot about.

Everyone knows the fastest way to get classified information leaked is to brief the Congressional leadership about it.  Party makes no difference, it's been this way for at least the 62 years I've been on the planet, and probably for a good century before that...
-Doug  (With my shield, not yet upon it)

Offline meekGee

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Re: SpaceX F9 : Zuma : January 7/8, 2018, CCAFS : DISCUSSION
« Reply #825 on: 01/09/2018 05:48 am »
Notice that all of the reports about failure to separate use the anonymous-passive "is assumed" phrasing.

"Assumed"?  By whom?  Who assumed?  The reporter?  A Reddit poster?

I'd like to see a report that says "XXX is assuming that the payload failed to separate from S2", for some credible value of XXX - before I even consider the report worth more than exactly zero.
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Offline IanH84

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Re: SpaceX F9 : Zuma : January 7/8, 2018, CCAFS : DISCUSSION
« Reply #826 on: 01/09/2018 05:49 am »
It could be that SpaceX *insisted* on a Northrop Grumman payload adapter if they wouldn't be able to confirm successful separation due to it being classified.

I don't know what the standard practice is with classified payloads. Seems to me if you're the classified payload, you would want the upper stage to be able to confirm separation (via contact switches at the sep plane) as a pre-condition before doing C/CAM and de-orbit, otherwise you risk splashing the payload prematurely in case of failed separation.

You don't have to release any information publicly about separation, but wouldn't you at least want the upper stage to be able to detect proper separation and not de-orbit prematurely in case separation failed?

Sure.  But since we've been told on many, many occasions that SpaceX does not *ever* send control inputs to the Falcons in-flight, *and* since they (supposedly) had no telemetry from the other side of the PAM for any confirmations of anything, seeing as SpaceX was not allowed to see any of the payload's telemetry (again per a lot of speculation here), then it's at least possible that the S2 literally could not be told to alter its pre-programmed sequence.

And, if all SpaceX could see on their telemetry was that the sep signal had been sent, they may not even have had a clue that the payload had not, in fact, separated.  Especially if they were not allowed to access any payload-viewing cameras -- which, to be honest, since SpaceX didn't build the PAM, there might not even have been one.  Or, if there were, it could have been something that could not communicate in any way back to SpaceX.

One last minor nit -- fairing separation confirmation on the SpaceX webcast came something like three minutes after the fact.  Any possibility that this could have been somehow related to the reported separation failure?  After all, the fairing is electrically connected to S2 through the PAM, right?  So, if the PAM was not relaying signals properly, maybe the fairing sep indicators acting up could be related to the failure of the sep signal to reach the payload?

Or maybe the Black Control Center that took over monitoring S2 after MECO and staging just didn't have good communications lines back to the webcast people... there's just no way to know.
On the US Launch Report video, fairing separation is visible

Offline zubenelgenubi

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Re: SpaceX F9 : Zuma : January 7/8, 2018, CCAFS : DISCUSSION
« Reply #827 on: 01/09/2018 06:06 am »
Marco Langbroek notes in New Zuma orbit estimates
Quote
The sightings of the Falcon 9 upper stage from the Zuma launch venting fuel over East Africa some 2h 15m after launch, suggests that Zuma might be in a higher orbit than in my pre-launch estimate. Rather than ~400 km it might be ~900-1000 km.
<snip>
If correct, this means Zuma might become observable in the N hemisphere about a week from now.
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Offline nacnud

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Re: SpaceX F9 : Zuma : January 7/8, 2018, CCAFS : DISCUSSION
« Reply #828 on: 01/09/2018 06:16 am »
On the US Launch Report video, fairing separation is visible


At 3:24?

Offline Rangertech1

I'm curious why there wasn't mention of a failed solar panel deployment. "Dead on orbit" is an indicator. Maybe I'm too old and forgot that some engineer invented the impossible to fail solar panel?
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Offline Kabloona

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Re: SpaceX F9 : Zuma : January 7/8, 2018, CCAFS : DISCUSSION
« Reply #830 on: 01/09/2018 06:29 am »
On the US Launch Report video, fairing separation is visible


At 3:24?

Looks like 3:24 is indeed the time the fairing comes off. We can hear the announcer right then saying "fairing separation any second now..."
« Last Edit: 01/09/2018 06:34 am by Kabloona »

Offline Ben the Space Brit

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Re: SpaceX F9 : Zuma : January 7/8, 2018, CCAFS : DISCUSSION
« Reply #831 on: 01/09/2018 06:43 am »
So, just throwing this out there: What if the speculation about a hypersonic re-entry test vehicle is true? If so, then the 'LEO target orbit' was misinformation and everything went as planned.

Zuma separated nominally after the upper stage completed putting it on its suborbital trajectory towards the Pacific Test Range (hence the independently-measured shorter-than-normal upper stage burn). The upper stage then fired a braking burn so it would come down well away from Zuma and not interfere with the vehicle tracking during EDL. The STRATCOM trace (USA 280?) was Zuma on its sub-orbital hop towards the area around Kwaljalein Atoll. Purely by coincidence, the faster Zuma reached its re-entry interface at the same time as the upper stage. Someone mentioned this to someone, hence the 're-entered with the upper stage' rumour.

DARPA would never tell anyone about the results of what would clearly have to be a large, expensive and sensitive bit of equipment so we'll never know whether this possibility is true.
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Offline FinalFrontier

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Re: SpaceX F9 : Zuma : January 7/8, 2018, CCAFS : DISCUSSION
« Reply #832 on: 01/09/2018 07:01 am »
FWIW here. NBC is reporting spacecraft loss due to failure to separate from the second stage. They are also reporting the vehicle fell into the sea, which is making me question the entire report because I am not sure the second stage has even re entered yet. Do we know whether it has or not?

To me this is a critical point here. If the failure was separation related it could be the fault of SpaceX. If the spacecraft separated but then failed to work it's not their fault. Big distinction here.

NBC report: https://www.nbcnews.com/science/space/u-s-spy-satellite-believed-destroyed-after-launch-officials-say-n835976
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Offline docmordrid

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Re: SpaceX F9 : Zuma : January 7/8, 2018, CCAFS : DISCUSSION
« Reply #833 on: 01/09/2018 07:08 am »
FWIW here.
>
To me this is a critical point here. If the failure was separation related it could be the fault of SpaceX.
>
NBC report: https://www.nbcnews.com/science/space/u-s-spy-satellite-believed-destroyed-after-launch-officials-say-n835976

Not if the payload adapter failed. It  was provided by Northrop-Grumman,  not SpaceX.
« Last Edit: 01/09/2018 07:10 am by docmordrid »
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Offline FinalFrontier

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Re: SpaceX F9 : Zuma : January 7/8, 2018, CCAFS : DISCUSSION
« Reply #834 on: 01/09/2018 07:19 am »
FWIW here.
>
To me this is a critical point here. If the failure was separation related it could be the fault of SpaceX.
>
NBC report: https://www.nbcnews.com/science/space/u-s-spy-satellite-believed-destroyed-after-launch-officials-say-n835976

Not if the payload adapter failed. It  was provided by Northrop-Grumman,  not SpaceX.

Was just about to post again regarding this. Here's the thing, I had heard prior to launch that SpaceX never even actually processed this spacecraft, they were just sent the vehicle and the payload adapter possibly with the fairing already on.

What extent did SpaceX have in processing, and is there any chance a problem with the adapter could be related to attachment to the second stage?

From what the most reliable sources have said the only thing we have is "Falcon 9 performed nominally" which would tend to suggest the failure was with the adapter or the spacecraft and SpaceX is not liable.

I know they probably won't comment about this but it's really a big deal. If this bird was really as expensive as rumor suggests then liability for the failure is huge because it determines who has to pay for it.
« Last Edit: 01/09/2018 07:20 am by FinalFrontier »
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Offline yokem55

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Re: SpaceX F9 : Zuma : January 7/8, 2018, CCAFS : DISCUSSION
« Reply #835 on: 01/09/2018 07:23 am »
FWIW here.
>
To me this is a critical point here. If the failure was separation related it could be the fault of SpaceX.
>
NBC report: https://www.nbcnews.com/science/space/u-s-spy-satellite-believed-destroyed-after-launch-officials-say-n835976

Not if the payload adapter failed. It  was provided by Northrop-Grumman,  not SpaceX.

Was just about to post again regarding this. Here's the thing, I had heard prior to launch that SpaceX never even actually processed this spacecraft, they were just sent the vehicle and the payload adapter possibly with the fairing already on.

What extent did SpaceX have in processing, and is there any chance a problem with the adapter could be related to attachment to the second stage?

From what the most reliable sources have said the only thing we have is "Falcon 9 performed nominally" which would tend to suggest the failure was with the adapter or the spacecraft and SpaceX is not liable.

I know they probably won't comment about this but it's really a big deal. If this bird was really as expensive as rumor suggests then liability for the failure is huge because it determines who has to pay for it.
Liability for loss of the payload is strictly the customer's. That is why commercial folks buy insurance policies to cover launch mishaps. The government always self insures thier payloads, and NG, as large as they are, would likely have self insured it as well.

Offline jimbowman

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Re: SpaceX F9 : Zuma : January 7/8, 2018, CCAFS : DISCUSSION
« Reply #836 on: 01/09/2018 07:24 am »
I know they probably won't comment about this but it's really a big deal. If this bird was really as expensive as rumor suggests then liability for the failure is huge because it determines who has to pay for it.

U.S taxpayers

Online Steven Pietrobon

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Re: SpaceX F9 : Zuma : January 7/8, 2018, CCAFS : DISCUSSION
« Reply #837 on: 01/09/2018 07:29 am »
Here are screen grabs of the fairing separation. Note that the vehicle is moving to the right from the perspective of the viewer. We can clearly see a fairing separate from the top. However, the bottom fairing appears as a bright blob right next to the exhaust. Not sure if this is due to the viewing angle.
« Last Edit: 01/10/2018 07:34 am by Steven Pietrobon »
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Offline FinalFrontier

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Re: SpaceX F9 : Zuma : January 7/8, 2018, CCAFS : DISCUSSION
« Reply #838 on: 01/09/2018 07:30 am »
FWIW here.
>
To me this is a critical point here. If the failure was separation related it could be the fault of SpaceX.
>
NBC report: https://www.nbcnews.com/science/space/u-s-spy-satellite-believed-destroyed-after-launch-officials-say-n835976

Not if the payload adapter failed. It  was provided by Northrop-Grumman,  not SpaceX.

Was just about to post again regarding this. Here's the thing, I had heard prior to launch that SpaceX never even actually processed this spacecraft, they were just sent the vehicle and the payload adapter possibly with the fairing already on.

What extent did SpaceX have in processing, and is there any chance a problem with the adapter could be related to attachment to the second stage?

From what the most reliable sources have said the only thing we have is "Falcon 9 performed nominally" which would tend to suggest the failure was with the adapter or the spacecraft and SpaceX is not liable.

I know they probably won't comment about this but it's really a big deal. If this bird was really as expensive as rumor suggests then liability for the failure is huge because it determines who has to pay for it.
Liability for loss of the payload is strictly the customer's. That is why commercial folks buy insurance policies to cover launch mishaps. The government always self insures thier payloads, and NG, as large as they are, would likely have self insured it as well.

Still a big deal because if it's the fault of SpaceX it will affect their ability to get future government payloads.

But, given the fact they have not stood down flows for other missions it doesn't seem like it was their hardware.

Interestingly, WSJ/bloomberg, two of the most ill repute publications around, are both contradicting everyone else and saying the second stage itself failed. That is where most of the conflicting rumors are coming from.
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Offline docmordrid

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Re: SpaceX F9 : Zuma : January 7/8, 2018, CCAFS : DISCUSSION
« Reply #839 on: 01/09/2018 07:39 am »
Most other such stories referenced Andy Pasztor's WSJ/Dow Jones story, so I'd give them a lower demerit count. Slightly.
« Last Edit: 01/09/2018 07:41 am by docmordrid »
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