Author Topic: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION  (Read 629958 times)

Offline mmeijeri

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Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #600 on: 10/08/2012 05:28 pm »
Lucky that they had performance margin on this flight

And even that "luck" may be cold comfort if it is true that the Orbcomm satellites were delivered to the wrong orbit and if the Dragon's GNC door is jammed shut. That would mean the mission was a total failure. I had expected something to go wrong sooner or later, but nothing this bad, it's really disappointing.

It goes to show how wrong people are to call the ELC a subsidy. There's a reason the DoD pays good money for assured access to space.

It also shows how important it is to have a steady stream of cheap cargo, especially if nothing important depends on it as it does in this case. We could have had many propellant flights this year if the right choices had been made. It would have been the perfect payload to get the last bugs out of a launch system and to build up a reliability record. It's no big deal if a propellant flight is lost.
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Offline Go4TLI

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Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #601 on: 10/08/2012 05:30 pm »
1. There are likely a host of scenarios where it could have ended differently and performance relative to other potential payloads could be a factor in the future. 

2. There could be other engines with similar issues (if and when the problem is discovered) that need correcting.  It could be a process issue, which goes beyond that specific serial number or even engine design.
1. says who? we still have no factual info on what happened.
2. a lot of ifs.

Today was a bad day for SpaceX. We'll know soon hopefully whether luck or good engineering saved their bacon today.

1.  True with respect to knowing precisely what happened.  But an engine appears to have exploded based on known evidence now.  If you think that scenario always will end well you are fooling yourself. 

2.  "Ifs" are based on the fact that this is speculation because as you said we do not know the precise cause.  These "ifs" however are based on engineering knowledge of space hardware and common sense best practices.

Offline JBF

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Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #602 on: 10/08/2012 05:31 pm »
Lucky that they had performance margin on this flight

And even that "luck" may be cold comfort if it is true that the Orbcomm satellites were delivered to the wrong orbit and if the Dragon's GNC door is jammed shut. That would mean the mission was a total failure. I had expected something to go wrong sooner or later, but nothing this bad, it's really disappointing.

It goes to show how wrong people are to call the ELC a subsidy. There's a reason the DoD pays good money for assured access to space.

It also shows how important it is to have a steady stream of cheap cargo, especially if nothing important depends on it as it does in this case. We could have had many propellant flights this year if the right choices had been made. It would have been the perfect payload to get the last bugs out of a launch system and to build up a reliability record. It's no big deal if a propellant flight is lost.

Heh nice doom and gloom scenario you have here. The most likely reason for no information is that they want to be able to present all the facts.
"In principle, rocket engines are simple, but thatís the last place rocket engines are ever simple." Jeff Bezos

Offline PreferToLurk

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Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #603 on: 10/08/2012 05:32 pm »
Mainstream media have ended their silence on the RUD, SpaceX better hurry up and put out a statement or risk losing control of the narrative. 

http://arstechnica.com/science/2012/10/that-smooth-spacex-launch-turns-out-one-of-the-engines-exploded/

That is now the top headline in the google news coverage of the launch.

Offline edkyle99

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Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #604 on: 10/08/2012 05:33 pm »
The fact that the vehicle continued to orbit is indeed a good thing.  The appearance of a possible engine explosion is not a good thing and I concur with Jim they got "lucky".

I'm not sure just yet what I think I'm seeing in the video.  It might just be an engine shutdown, which if you go back and look at the older Merlin 1C static test videos has a certain violence of its own.  This happened at altitude, which can enhance plume effects, etc.  On the other hand, fragments of something are visible after the shutdown.  These might be structural, but are just as likely to be ice or insulation.

Hopefully SpaceX will be able to fill in the blanks.

 - Ed Kyle

Offline thydusk666

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Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #605 on: 10/08/2012 05:33 pm »
Is there a backup plan in case the GNC door cannot be opened?
Would it be technically possible to perform an autonomous docking?

Offline Ronsmytheiii

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Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #606 on: 10/08/2012 05:33 pm »
if it is true that the Orbcomm satellites were delivered to the wrong orbit and if the Dragon's GNC door is jammed shut.

I dont think anyone of repute is suggesting this at this time.  Remember that SpaceX is busy with a bunch of things from the first stage issue, orbcomm ect.  The PAO plays to the "science is cool" crowd and probably is not doing a step-by step update.  Lts not jump to conclusions based on a lack of updates.
« Last Edit: 10/08/2012 05:33 pm by Ronsmytheiii »

Offline Garrett

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Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #607 on: 10/08/2012 05:34 pm »

But saying they got lucky is unsubstantiated, unless of course you have inside info (that quick!?), which is unfair on the rest of us :P


Lucky that they had performance margin on this flight
Ah, that's beyond what I know. I had the understanding that F9 had engine out capability, i.e. it always has "performance margin" for such events. Is that not the case?
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Offline Jim

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Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #608 on: 10/08/2012 05:34 pm »
Is there a backup plan in case the GNC door cannot be opened?
Would it be technically possible to perform an autonomous docking?

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Offline Lars_J

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Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #609 on: 10/08/2012 05:39 pm »
Lucky that they had performance margin on this flight

And even that "luck" may be cold comfort if it is true that the Orbcomm satellites were delivered to the wrong orbit and if the Dragon's GNC door is jammed shut. That would mean the mission was a total failure. I had expected something to go wrong sooner or later, but nothing this bad, it's really disappointing.

::) Going a bit overboard, eh? If nothing else, engine-out capability of the F9 has gone from theory to FACT. (even if it comes out of the performance margin, which existed in this flight)

It also shows how important it is to have a steady stream of cheap cargo, especially if nothing important depends on it as it does in this case. We could have had many propellant flights this year if the right choices had been made. It would have been the perfect payload to get the last bugs out of a launch system and to build up a reliability record. It's no big deal if a propellant flight is lost.

No worries, I'm sure you would still be there saying "I had expected something to go wrong sooner or later, but nothing this bad, it's really disappointing" if this had occurred in a hypothetical 4th propellant delivery flight. You don't see the contradiction in your two paragraphs?
« Last Edit: 10/08/2012 05:41 pm by Lars_J »

Offline DMeader

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Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #610 on: 10/08/2012 05:39 pm »
Is there a backup plan in case the GNC door cannot be opened?
Would it be technically possible to perform an autonomous docking?

CBM-equipped vehicles don't "dock", they are "berthed". The vehicle alone can't do that, it needs done by the arm, which needs the grapple fixture exposed, hence the need for the door to open.

Offline Bugfix

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Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #611 on: 10/08/2012 05:41 pm »
Wasn't there a NOTAM for the Pacific for yesterday, in case they had to deorbit the Dragon shortly after launch? And if the GNC door didn't open, wouldn't this be such a case? Or can Dragon not initiate the deorbit burn without the GNC door open?

Offline Prober

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Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #612 on: 10/08/2012 05:44 pm »
It obviously *looked* pretty serious and Spacex confirm early engine shutdown.

I'll note that concerns about aerodynamic forces shredding the engine nozzle tend to be about the engine at *sea* level, not when the engine, or rather the nozzle on it reaches (or exceeds) its designed altitude. On that basis the idea that the engine was starting to spin down (smoky exhaust suggesting unburnt RP1) and the unbalenced aero forces tearing the nozzle off seem unlikely.

If it was a full on RUD event this could be Spacex's *finest* hour.

Engine is not just shut down early, it's *destroyed* (if correct).
Primary mission goes to completion.
Secondary mission also appears to have successfully been carried out.

As others have asked, has a mission *ever* survived that much damage and still succeeded?

No LOM, No LOV and I suspect (but cannot prove) had it been a crewed Dragon no LOC (I can imagine ways to kill the crew which leave the capsule intact but I can't believe they would not be picked up in design or test).

I also suspect ISS crew will be taking a *very* detailed look over the whole of Dragon looking for damage before they commit to berthing.

The key issues are design flaw Vs fabrication flaw and how to correct and/or detect it.

No doubt a lot of telemetry is being chewed through right now and I hope NASA don't get cold feet over Dragon and CRS. while shocking I believe the results will be of *huge* benefit to the programme.

Wrong, this is not a finest hour.  They just got lucky.  A performance critical mission would not have the same out come.

agree, they got luckey twice IMHO, last mission something funky with their tank pressurization.   This mission they seem to have fixed that issue.

I did notice another item kinda strange.  Was wondering if this was the tank that long ago had "welding issues" ?   

Something wierd I also noticed in some of the Pics.   Some of the vertical lighting makes the LV look all pure white.   While in some other pics the engine section looks like its been out in the sun for a few years (kinda yellow).  Makes the whole LV look like it was parts of several reassembled for this mission.   Another key give away is the SpaceX letters on the bottom and nothing on the tank above....its kinda strange.


« Last Edit: 10/08/2012 05:54 pm by Prober »
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Offline craigcocca

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Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #613 on: 10/08/2012 05:45 pm »
We can stop the speculation now. The GNC door opened as planned last night, per SpaceX (posted on SFN at 1:35pm ET)
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Offline mmeijeri

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Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #614 on: 10/08/2012 05:49 pm »
::) Going a bit overboard, eh? If nothing else, engine-out capability of the F9 has gone from theory to FACT. (even if it comes out of the performance margin, which existed in this flight)

That's only a silver lining, it's still very bad news overall.

Quote
No worries, I'm sure you would still be there saying "I had expected something to go wrong sooner or later, but nothing this bad, it's really disappointing" if this had occurred in a hypothetical 4th propellant delivery flight. You don't see the contradiction in your two paragraphs?

No, I wouldn't because there would be very little riding on it. No prospective customers to scare off, no funding in danger of drying up, no ISS resupply in jeopardy. I'd be saying "this is why these flights are so useful".
Pro-tip: you don't have to be a jerk if someone doesn't agree with your theories

Offline mmeijeri

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Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #615 on: 10/08/2012 05:50 pm »
We can stop the speculation now. The GNC door opened as planned last night, per SpaceX (posted on SFN at 1:35pm ET)

Thank goodness. Any official word on the Orbcomm satellites?
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Offline JohnFornaro

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Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #616 on: 10/08/2012 05:50 pm »
"Falcon 9 detected an anomaly on one of the nine engines and shut it down," Musk wrote in an email to Spaceflight Now. "As designed, the flight computer then recomputed a new ascent profile in realtime to reach the target orbit, which is why the burn times were a bit longer."

Totally excellent recovery.  Scary that it happened.

"rapid unscheduled disassembly"

Most American families with small children experience this every Christmas.  Not sure what all the fuss is about.

Basically the B-17 of the US space fleet.

A tough, airplane, among my favorites.

"normalization of deviance"

You talkin' to me???

Awaiting on further input from Snappy Comeback Department.

If you don't like armchair engineering, you should get off the internet.

+1

Quote
I really think the agora needs to recalibrate what normalization of deviance means with SpaceX.  SpaceX will not take months or years to stand down like NASA would.  SpaceX will evaluate the risks, Pareto the causes, control the most likely ones and move on.  SpaceX will not correct the things that it finds to be low likelihood, unlike NASA.  It's a difference in culture that customers need to be aware of.

+1 more.

Plus, sincere thanks for the new (for me) term Pareto, which is exactly how one must work in the real world.

Learn something new every day.

Still starting your car with a lead acid battery charged by an alternator are you? Got jumper cables in your trunk?

Great [edited] snappy comeback, except for this question, which left me scratching my head.  At least I'm not cranking the engine by hand...

Oh, and welcome to the forum.

What he said.  This is probably the best forum, but hey, there I go expressing an opinion not based on hard, factual data.

Great flight so far.  Hope the landing goes well.  Enjoy your ice cream up there.
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Offline titanmiller

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Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #617 on: 10/08/2012 05:52 pm »
From the Ars article :

Quote
Approximately one minute and 19 seconds into last nightís launch, the Falcon 9 rocket detected an anomaly on one first stage engine. Initial data suggests that one of the rocketís nine Merlin engines, Engine 1, lost pressure suddenly and an engine shutdown command was issued immediately. We know the engine did not explode, because we continued to receive data from it. Our review indicates that the fairing that protects the engine from aerodynamic loads ruptured due to the engine pressure release, and that none of Falcon 9ís other eight engines were impacted by this event.

As designed, the flight computer then recomputed a new ascent profile in real time to ensure Dragonís entry into orbit for subsequent rendezvous and berthing with the ISS. This was achieved, and there was no effect on Dragon or the cargo resupply mission.

Falcon 9 did exactly what it was designed to do. Like the Saturn V, which experienced engine loss on two flights, Falcon 9 is designed to handle an engine out situation and still complete its mission.

http://arstechnica.com/science/2012/10/that-smooth-spacex-launch-turns-out-one-of-the-engines-exploded/
« Last Edit: 10/08/2012 05:53 pm by titanmiller »

Offline Mongo62

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Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #618 on: 10/08/2012 05:53 pm »
From SpaceX:

Quote
Approximately one minute and 19 seconds into last nightís launch, the Falcon 9 rocket detected an anomaly on one first stage engine. Initial data suggests that one of the rocketís nine Merlin engines, Engine 1, lost pressure suddenly and an engine shutdown command was issued immediately. We know the engine did not explode, because we continued to receive data from it. Our review indicates that the fairing that protects the engine from aerodynamic loads ruptured due to the engine pressure release, and that none of Falcon 9ís other eight engines were impacted by this event.

As designed, the flight computer then recomputed a new ascent profile in real time to ensure Dragonís entry into orbit for subsequent rendezvous and berthing with the ISS. This was achieved, and there was no effect on Dragon or the cargo resupply mission.

Falcon 9 did exactly what it was designed to do. Like the Saturn V, which experienced engine loss on two flights, Falcon 9 is designed to handle an engine out situation and still complete its mission.

So I am guessing that unplanned sideways jetting exhaust impacted the adjacent fairing, which broke apart.  This would presumably be the large objects seen falling from the base of the first stage.  It would seem that the engine did NOT explode, but instead developed a "leak".
« Last Edit: 10/08/2012 05:58 pm by Mongo62 »

Offline mmeijeri

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Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #619 on: 10/08/2012 05:54 pm »
Heh nice doom and gloom scenario you have here. The most likely reason for no information is that they want to be able to present all the facts.

I wasn't saying the mission was a total failure, just that it could turn out to be a total failure. I'm really relieved the GNC door rumour was wrong, and I hope the Orbcomm one is too. The mission could still turn out to be a total success, though one with a very worrying anomaly. However, even now for all we know it could still end in total failure. Let's not count our Dragons before they hatch.
Pro-tip: you don't have to be a jerk if someone doesn't agree with your theories

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