Author Topic: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION  (Read 634446 times)

Online Galactic Penguin SST


Given that the majority of new rocket designs experience a catastrophic loss of vehicle in the first few launches, spacex has been doing pretty well.

Hopefully SpaceX went through that phase with Falcon 1.

I was going to ask this: Was the core engine on F-1 flight 1 a Merlin-1C? If so, then we're looking at two failures in about 40 or so units flown.

Nope, F1 flights 1 and 2 used the Merlin-1A. Flight 3 was the first flight with the regen nozzle (Merlin-1C).
Astronomy & spaceflight geek penguin. In a relationship w/ Space Shuttle Discovery. Current Priority: Chasing the Chinese Spaceflight Wonder Egg & A Certain Chinese Mars Rover

Offline Fivey

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Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #481 on: 10/08/2012 09:28 am »
*If* this was a RUD event for engine 1 - Would this be the first time a LV has survived an "engine RUD" and still delivered the payload successfully?

I'm wondering about that too.  Did we witness an historic first tonight?

http://www.spacenews.com/civil/spacex-acknowledges-falcon-engine-anomaly-during-latest-launch.html

Note dates

Offline guckyfan

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Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #482 on: 10/08/2012 09:41 am »
I have looked at the frames before that "explosion" one by one.

There were dark streaks in the exhaust well before that event. As dark indicates unburnt kerosene, does that indicate the shutdown was already initiated? In that case might the debris be really only the shirt that was torn loose by pressure change of shutdown?

Could this be a possible explanation of what we see?

Edit: Can somebody please explain the meaning of RUD event?
« Last Edit: 10/08/2012 09:46 am by guckyfan »

Offline Maciej Olesinski

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Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #483 on: 10/08/2012 09:49 am »
Edit: Can somebody please explain the meaning of RUD event?

Rapid Unscheduled Disassembly (explosion)

Offline guckyfan

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Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #484 on: 10/08/2012 09:51 am »

Rapid Unscheduled Disassembly (explosion)


 :)

Thanks

Edit corrected quote
« Last Edit: 10/08/2012 09:52 am by guckyfan »

Offline alexterrell

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Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #485 on: 10/08/2012 10:17 am »
I think it's too early to call this a win for SpaceX.
Anything but a perfect record is not a win for a launch company with so few launches under their belt.

Given that the majority of new rocket designs experience a catastrophic loss of vehicle in the first few launches, spacex has been doing pretty well.
I suppose with any other launcher this would have led to LOM.

There have now been two launches (excluding the Falcon 1 launches) and the engine failure is 1 in 18 (give or take and ignoring changes to the engine design). Would F9 survive two engines failing? The chances of that are about 1 in 360 (without doing the full statistics), which is borderline acceptable for a manned launcher (assuming the launch escape system works 90% of the time).

That said, if good telemetary has been received, SpaceX can make the engine more reliable. They might also have better data to extrapolate the effect of 2 engines exploding (or RUD - must remember that one).

Is Orbcomm confirmed orbited yet?
« Last Edit: 10/08/2012 10:20 am by alexterrell »

Offline john smith 19

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Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #486 on: 10/08/2012 10:36 am »
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.
« Last Edit: 10/08/2012 10:45 am by john smith 19 »
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Offline mr. mark

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Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #487 on: 10/08/2012 10:36 am »
I'm wondering if moving forward with Merlin 1d production is the the answer. We've heard that the design is more straight forward.

Offline peter-b

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Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #488 on: 10/08/2012 10:39 am »
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.

I'm not sure that debris would get far enough into the supersonic airflow to impinge on the Dragon, but okay.
Research Scientist (Sensors), Sharp Laboratories of Europe, UK

Offline Bogeyman

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Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #489 on: 10/08/2012 10:44 am »
Could the fragment seen on the launch screenshot be part of the engine shroud?:

http://imageshack.us/photo/my-images/38/falcon9triebwerksfehler.jpg/

Offline Lol

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Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #490 on: 10/08/2012 10:46 am »

There have now been two launches (excluding the Falcon 1 launches) and the engine failure is 1 in 18 (give or take and ignoring changes to the engine design). Would F9 survive two engines failing? The chances of that are about 1 in 360 (without doing the full statistics), which is borderline acceptable for a manned launcher (assuming the launch escape system works 90% of the time).

There have been 4 successful launches of Falcon 9.
So 40 Merlin 1C flown there.

There was 3 launches of Falcon 1 with Merlin 1C. In each launch engine performed nominally.

So out of 43 Merlin 1C flown to this date, 42 performed good.

How you came up with one out of 18 failure rate is above me.

EDIT: Besides, do not forget that Falcon 9 could tolerate 2 engines failures. Probably not in early stages of the flight(first few dozens seconds), but if second engine fail after one minute or so that should be no biggie too.
« Last Edit: 10/08/2012 10:53 am by Lol »

Offline john smith 19

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Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #491 on: 10/08/2012 10:48 am »
I'm not sure that debris would get far enough into the supersonic airflow to impinge on the Dragon, but okay.
What people are worried about and what they *should* be worried about are not always the same  :)
MCT ITS BFR SS. The worlds first Methane fueled FFSC engined CFRP SS structure A380 sized aerospaceplane tail sitter capable of Earth & Mars atmospheric flight.First flight to Mars by end of 2022 TBC. Forward looking statements. T&C apply. "Extraordinary claims require extraordinary proof" R. Simberg."Competitve" means cheaper ¬cheap SCramjet proposed 1956. First +ve thrust 2004. US R&D spend to date > $10Bn. #deployed designs. Zero.

Offline ugordan

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Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #492 on: 10/08/2012 10:49 am »
Could the fragment seen on the launch screenshot be part of the engine shroud?:

http://imageshack.us/photo/my-images/38/falcon9triebwerksfehler.jpg/

That's why I think too. Onboard video shows outlines of 2 engine fairings and engine #1 fairing definitely looks missing/modified. Each fairing is made of two pieces and you can see the split line in your image, the debris piece is consistent with the upper panel of the fairing.

Offline boinc

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Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #493 on: 10/08/2012 10:51 am »
Could the fragment seen on the launch screenshot be part of the engine shroud?:

http://imageshack.us/photo/my-images/38/falcon9triebwerksfehler.jpg/

There is definetly some debris coming out there. Will this engine failure have any impact on future operations?

Offline ugordan

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Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #494 on: 10/08/2012 10:54 am »
Will this engine failure have any impact on future operations?

Of course it will. It's only logical to assume the vehicle is grounded until anomaly investigation is performed and corrective actions identified/implemented.

Offline boinc

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Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #495 on: 10/08/2012 11:01 am »
Will this engine failure have any impact on future operations?

Of course it will. It's only logical to assume the vehicle is grounded until anomaly investigation is performed and corrective actions identified/implemented.

On the second look it seems like the engine cover rather crashed into the engine. The boardcomputer detected that and shut the engine down.

Offline Lol

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Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #496 on: 10/08/2012 11:03 am »
Will this engine failure have any impact on future operations?

Of course it will. It's only logical to assume the vehicle is grounded until anomaly investigation is performed and corrective actions identified/implemented.

With next launch scheduled for January next year, there is no reason to believe that investigation and corrective measures wont be done by that time. 

Offline ugordan

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Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #497 on: 10/08/2012 11:08 am »
On the second look it seems like the engine cover rather crashed into the engine. The boardcomputer detected that and shut the engine down.

Or something blew off the lower fairing panel and then the upper part just collapsed with no support and under aerodynamic load.

With next launch scheduled for January next year, there is no reason to believe that investigation and corrective measures wont be done by that time. 

There is no particularly good reason to think that it will be done by then, either. Why do you assume root cause analysis and corrective action will be as trivial as that?

Offline alexterrell

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Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #498 on: 10/08/2012 11:11 am »

There have been 4 successful launches of Falcon 9.
So 40 Merlin 1C flown there.

There was 3 launches of Falcon 1 with Merlin 1C. In each launch engine performed nominally.

So out of 43 Merlin 1C flown to this date, 42 performed good.

How you came up with one out of 18 failure rate is above me.

EDIT: Besides, do not forget that Falcon 9 could tolerate 2 engines failures. Probably not in early stages of the flight(first few dozens seconds), but if second engine fail after one minute or so that should be no biggie too.
Sorry about that (must stop posting before thinking).

On the basis of this the statistical chances of multiple engine failure leading to LOM are tiny.

Next step is to identify a failure which could knock out all engines, including an analysis of how well the correction software (and hardware) performed (it appears to have done its job). Could one engine failure plus a computing failure lead to LOM.

SpaceX would I'm sure love to get their hands on the engine shielding for the neighbouring engines. Did it contain all the damage - or were neighbouring engines lucky to survice (saved by the bell)? Did they get some high resolution pictures? Or will they be able to recover this stage?

What happened when the engine failed to the vehicle flight path. Was there a shock to the system which might damage other equipment? I assume they have accelerometer telemetary to measure just that.

Lots of analysis to do but this failure does demonstrate the safety of the rocket.

Offline mr. mark

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Re: SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION
« Reply #499 on: 10/08/2012 11:15 am »
Basically the B-17 of the US space fleet.

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