SpaceX Falcon 9/Dragon CRS SpX-1 MISSION GENERAL DISCUSSION

[pippin]

Could. But SpaceX said otherwise.

[Juggernaut]

Could. But SpaceX said otherwise.

as far as i know, at the moment SpaceX did not say anything about Orbcomm delivery. we know about it from Orbcomm's press release

[MP99]

But since there is only one (?) flight of Merlin 1C left, and then SpaceX transitions to the very different Merlin 1D, the failure has come at about the worst time in that version's manufacturing cycle.  SpaceX has a few hard decisions to make going forward (in my view).  While unlikely, they might wish to transition earlier to the F9v1.1 than they had planned...but that creates it own set of problems.  Tough call and I wish them the best.

I could see SpX-2 going up on v1.1.

If that happens, who'll give me odds on 9 "special offer" F1's appearing on the sales page to, use up those M1Cs? ;-)

cheers, Martin

[kevin-rf]

A "Fuel dome fracture" implies a crack in the fuel component rather than an explosion and (at least at first) no flying fragments.

Not entirely true, the structure (weakened by what ever caused it) caused the Fuel Dome to fail suddenly releasing the pressure in the combustion chamber, dumping gasses (Fuel/Lox) from the fuel dome and combustion chamber into the stream (then igniting), over pressurizing the panels exterior to the engine, and dropping the lower half of the engine (at least the nozzle). That is clear from the video's.

There is a fair amount of very accurate words in the SpaceX releases that describe what happen in such detail that you can walk away thinking the failure was not an energetic event. I would be willing to bet that everything south of the fuel dome was already gone when the "pressure drop" was noted and the engine began closing valves and shutting down the turbo pumps.

btw. Does the fuel being released and then igniting count as a BLEVE?

[Chandonn]

... and for all those people yelling "EXPLOSION!", this is why several of us were saying "stop jumping to conclusions and wait for an official statement"...

[pippin]

Could. But SpaceX said otherwise.

as far as i know, at the moment SpaceX did not say anything about Orbcomm delivery. we know about it from Orbcomm's press release

http://www.nasaspaceflight.com/2012/10/dragon-iss-spacex-review-falcon-9-ascent-issues/

Please be aware that Chris doesn't write articles based on rumors or speculation. If he writes a low fuel condition was the cause, he has sources for that (in this case also mentioned on L2).

No need for further speculation.

[MKremer]

There is a fair amount of very accurate words in the SpaceX releases that describe what happen in such detail that you can walk away thinking the failure was not an energetic event. I would be willing to bet that everything south of the fuel dome was already gone when the "pressure drop" was noted and the engine began closing valves and shutting down the turbo pumps.

If that were the case, why would SpX say they still had engine sensor data after the 'event'?

[ugordan]

... and for all those people yelling "EXPLOSION!", this is why several of us were saying "stop jumping to conclusions and wait for an official statement"...

Call it an explosion, propellant leak, chamber rupture, Engine Pressure Release (TM), whatever - it's irrelevant. What is relevant is that this was a major engine anomaly and calling it by some other name does not diminish the seriousness of it. Do you expect us to silently watch and wait for any official updates, in a general discussion thread? If so, you don't seem to have noticed how this forum generally works...

[MP99]

I don't have any details about the engine but the walls are likely fairly thin, perhaps only a few millimeters thick.  There are many failure modes, from burn-though, stress cracking, etc., that generally require analysis of the post-failure hardware to determine.  That may not be possible in this case.

It occurs to me that M1D is reported with a much higher T/W than M1C, presumably on the basis that they learned from M1C where they needed plenty of margin and where they had been unnecessarily conservative.

I wonder if this failure might lead them to re-consider some of those calculations?

cheers, Martin

[WHAP]

Does anyone know if the Falcon 9 took off fully fueled? 

Launch vehicles are always fully tanked

Not true. 

[Cherokee43v6]

But since there is only one (?) flight of Merlin 1C left, and then SpaceX transitions to the very different Merlin 1D, the failure has come at about the worst time in that version's manufacturing cycle.  SpaceX has a few hard decisions to make going forward (in my view).  While unlikely, they might wish to transition earlier to the F9v1.1 than they had planned...but that creates it own set of problems.  Tough call and I wish them the best.

I could see SpX-2 going up on v1.1.

If that happens, who'll give me odds on 9 "special offer" F1's appearing on the sales page to, use up those M1Cs? ;-)

cheers, Martin

Amusing thought but unlikely.  Considering the costs involved in restarting the line, producing Falcon 1s, marketing to sell the flights.  From a business perspective it would be more cost effective to strip the excess engines of common parts to feed back into the manufacturing line and scrap the non-common parts.

Alternatively the engines could be retasked to their grasshopper/reusable test program.

Of course, all of this assumes that the company doesn't decide to just eat the risk, since even with the problem the launcher still achieved a successful primary mission.

[Juggernaut]

Could. But SpaceX said otherwise.

as far as i know, at the moment SpaceX did not say anything about Orbcomm delivery. we know about it from Orbcomm's press release

http://www.nasaspaceflight.com/2012/10/dragon-iss-spacex-review-falcon-9-ascent-issues/

Please be aware that Chris doesn't write articles based on rumors or speculation. If he writes a low fuel condition was the cause, he has sources for that (in this case also mentioned on L2).

No need for further speculation.

I am not speculating.
I was just answering the previous post saying that even if you have all the fuel available at the start of 2nd stage burning, the flight strategy depends also on the orbital parameters you have at that time, which has changed wrt the nominal one.

Having said that, then i was already satisfied with answer on 2nd stage burn duration which was longer than nominal. this implies an over-consumption of 2nd stage fuel with consequential revision of budget for following maneuvers (orbit raise, pointing, CAM, etc..)

[Cherokee43v6]

I haven't had time to dredge the discussions but I do have a question that perhaps has been lost amidst the engine failure discussion.

Considering that F9/Dragon is supposed to be capable of carrying approx 4000 lbs uphill, is there a reason it only carried approx 1000 lbs on this flight?  Bulky but light supplies?  Conservative build up to max?

[guckyfan]

Sorry Guckyfan I believe Merlin uses a pintle injector:

http://en.wikipedia.org/wiki/Pintle_injector

S

Indeed it does.

Correct, I said it is a very different engine.

However the separation fuel dome - injector - combustion chamber is still true and it shows the point that fuel in the fuel dome is not ignited.

[JBF]

I haven't had time to dredge the discussions but I do have a question that perhaps has been lost amidst the engine failure discussion.

Considering that F9/Dragon is supposed to be capable of carrying approx 4000 lbs uphill, is there a reason it only carried approx 1000 lbs on this flight?  Bulky but light supplies?  Conservative build up to max?

If I remember correctly packaging weight was the same as the equipment weight, so I'd bet on space limited.  The opening video should be interesting.

[jcm]

I haven't had time to dredge the discussions but I do have a question that perhaps has been lost amidst the engine failure discussion.

Considering that F9/Dragon is supposed to be capable of carrying approx 4000 lbs uphill, is there a reason it only carried approx 1000 lbs on this flight?  Bulky but light supplies?  Conservative build up to max?

If I remember correctly packaging weight was the same as the equipment weight, so I'd bet on space limited.  The opening video should be interesting.

The press kit implies packaging is about 10 percent of equipment -
Up cargo 454 kg, including 54 kg packaging
Down cargo 905 kg, including 146 kg packaging
unless I am reading it wrong...

[kevin-rf]

If that were the case, why would SpX say they still had engine sensor data after the 'event'?

Everything important is north of the Fuel Dome. The Valves, the Turbo pumps, the electronics, many of the sensors, ect. There are sensors south of the Fuel Dome, and SpaceX has not said if they lost them, but I would wager they did.

[Prober]

Article on the latest. Held as long as I could to let things settle and get a better picture of status.

http://www.nasaspaceflight.com/2012/10/dragon-iss-spacex-review-falcon-9-ascent-issues/

excellent sum up of the real events.   Think I'll send a link to one of my local news stations so they get the story right.

[Chandonn]

... and for all those people yelling "EXPLOSION!", this is why several of us were saying "stop jumping to conclusions and wait for an official statement"...

Call it an explosion, propellant leak, chamber rupture, Engine Pressure Release (TM), whatever - it's irrelevant. What is relevant is that this was a major engine anomaly and calling it by some other name does not diminish the seriousness of it. Do you expect us to silently watch and wait for any official updates, in a general discussion thread? If so, you don't seem to have noticed how this forum generally works...

Speculation and discussion is one thing.  Excessive arm-waving is another.

[Danderman]

I haven't had time to dredge the discussions but I do have a question that perhaps has been lost amidst the engine failure discussion.

Considering that F9/Dragon is supposed to be capable of carrying approx 4000 lbs uphill, is there a reason it only carried approx 1000 lbs on this flight?  Bulky but light supplies?  Conservative build up to max?

If I remember correctly packaging weight was the same as the equipment weight, so I'd bet on space limited.  The opening video should be interesting.

Since the F9 1.1 launched Dragon will have the same volume constraints at the current Dragon, the implication from your statement is that payload mass will not increase once F9 1.1 is introduced.