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

[garidan]

Why don't they use pop corn as packaging ? It would turn packaging into valuable payload ... 

[Zed_Noir]

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...

The Dragon is carrying 905 kg/1995 lbs of packaged cargo to the ISS according to the SpaceX press kit on page 10. Actual up cargo mass is 400 kg/ 882 lbs.

Not included in the up cargo mass is the ice cream loaded on the morning of the launch. 

The Dragon will carry 905 kg/1995 lbs of packaged cargo down from the ISS according to the SpaceX press kit on page 12. Actual down cargo mass is 759 kg/1673 lbs.

[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.

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.

Ok I was wrong, 882lb of cargo, 119lbs of packaging.  I think expectations of a full load every trip would be a mistake.

[john smith 19]

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.

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

I think you need to check the details. Engine design separates the fuel and the oxidizer as long as possible. So *unless* that rupture carries on into the LOX distribution level below it you're looking at high pressure liquid fuel.

So more like the video of the water pressure test of the tank earlier on.

OTOH if the RP1 was at *boiling* temperature (at the injection pressure) you've got the basis of a BLEVE. RP1 is used as a coolant in the 1st stage engines but does it get to its 800psi boiling point?

As the fuel dumps out of the fuel dome the fuel going to the injector falls and you could definitely have a (brief) O2 rich burn. I speculated it might last long enough to start burning through the CC or nozzle wall but I doubt it.

The question now becomes what is the root cause of the fracture?

Any idea how the fuel dome is mfg?

[subzero788]

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.

You're forgetting about unpressurised cargo in the trunk, of which there was none on this flight.

[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?

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.

Ok I was wrong, 882lb of cargo, 119lbs of packaging.  I think expectations of a full load every trip would be a mistake.

I agree, however they appear to be carrying 1/4 of capacity.  In fact it sounds like they're carrying less than they did on the COTS 2/3 flight.  That is what made me curious as to what factors were involved.

[Robotbeat]

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.

They haven't put any unpressurized payload on, yet.

[Prober]

"the fairing ruptured...due to the engine pressure release..." so they already know it wasn't aero loads that broke the fairing loose, it was "engine pressure release," which I'm not sure how to interpret...a turbopump self-destructing, or

"engine pressure release" sounds synonymous to "explosion" to me. Maybe it wasn't a catastrophic explosion, but it definitely went out with a bang.

Think about it, if you were SpaceX, would you want to say that one of your engines "exploded"?

We're going to have six pages of discussion about the definition of "explosion" now...

In my opinion, mission-wise, a second stage restart failure, if that turns out to be the case, is more significant to potential SpaceX customers than the first stage engine shutdown, because a restart issue would be a flat out launch failure.

 - Ed Kyle

your saying SpaceX needs to add an RCS system to the 2nd stage to do the Orbital type mission?

[TrueBlueWitt]

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.

Ok I was wrong, 882lb of cargo, 119lbs of packaging.  I think expectations of a full load every trip would be a mistake.

I agree, however they appear to be carrying 1/4 of capacity.  In fact it sounds like they're carrying less than they did on the COTS 2/3 flight.  That is what made me curious as to what factors were involved.

Yet for this flight they are using the full central stack of racks which weren't even installed for COTS 2/3...

[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?

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.

Ok I was wrong, 882lb of cargo, 119lbs of packaging.  I think expectations of a full load every trip would be a mistake.

I agree, however they appear to be carrying 1/4 of capacity.  In fact it sounds like they're carrying less than they did on the COTS 2/3 flight.  That is what made me curious as to what factors were involved.

Yet for this flight they are using the full central stack of racks which weren't even installed for COTS 2/3...

Which would lend credence to 'bulky but light'.

[Robotbeat]

"the fairing ruptured...due to the engine pressure release..." so they already know it wasn't aero loads that broke the fairing loose, it was "engine pressure release," which I'm not sure how to interpret...a turbopump self-destructing, or

"engine pressure release" sounds synonymous to "explosion" to me. Maybe it wasn't a catastrophic explosion, but it definitely went out with a bang.

Think about it, if you were SpaceX, would you want to say that one of your engines "exploded"?

We're going to have six pages of discussion about the definition of "explosion" now...

In my opinion, mission-wise, a second stage restart failure, if that turns out to be the case, is more significant to potential SpaceX customers than the first stage engine shutdown, because a restart issue would be a flat out launch failure.

 - Ed Kyle

your saying SpaceX needs to add an RCS system to the 2nd stage to do the Orbital type mission?

No, it wouldn't be needed. Also, Ed didn't know (and is actually wrong in this case).

Ed, your definition of launch failure is pretty silly. If people used your definition as an industry standard, then no one would ever want to launch secondaries because it'd cause too much of a risk of the whole flight being labeled a failure. A bunch of performance would be just left on the table for the sole reason of avoiding the label of full "failure." Not only that, but even the Orbcomm spacecraft is still usable for its most important primary purpose, which is checking out that the spacecraft works as planned in orbit. I don't think the "partial failure" of the Shuttle's two engine-out events should be counted as launch failures, nor do I think the recent Delta IV anomaly should be counted as a launch failure, nor do I think the one Atlas V underperformance should be counted as a launch failure. They were underperforming missions that left the primary mission successful according to the customer, and that's what matters.

I would say a reasonable definition of a full launch failure is one which would cause the crew of a manned vehicle to do an abort and leave the launch vehicle early and not enter a useful orbit, since that is partially what people use these statistics for (i.e. calculating launch vehicle safety). Clearly that wasn't the case in this flight.

When people think of a launch failure, they think of this:


They don't think of slight underperformance as a full launch failure.


Also, Ed, your figures for Merlin Vac (based on Merlin 1D) thrust are out of date and much too low. The M1D-based Merlin Vac can do at least 80 tons of thrust, versus 45 you estimated here: http://www.spacelaunchreport.com/falcon9.html

[system9]

The part that frustrates me is in my video:


The official announcement clearly states that all 9 Merlin engines are performing normally.

This is obviously totally inaccurate. I think in 2012 it is reasonable to expect information to be accurate ~45 seconds after the engine event they announce something that could have jeopardized people's safety. I'm all for NASA and SpaceX. Hell, I flew down from Chicago to support and watch the launch but I expect that communications out to the launch site to be accurate.  We literally had debris flying overhead and knew nothing about it.

[meekGee]

Why don't they use pop corn as packaging ? It would turn packaging into valuable payload ... 

Hard to get the butter off of everything later, zero-g and all.

[jcm]

   
I would say a reasonable definition of a full launch failure is one which would cause the crew of a manned vehicle to do an abort and leave the launch vehicle early and not enter a useful orbit, since that is partially what people use these statistics for (i.e. calculating launch vehicle safety). Clearly that wasn't the case in this flight.

When people think of a launch failure, they think of this:


They don't think of slight underperformance as a full launch failure.

 

Well, it depends on who 'they' are. Not everyone is focussed on the manned case. This particular case is a grey area - how much underperformance is 'slight'? When a Proton upper stage strands its payload in LEO rather than GTO, that's counted as a full failure.

Is it fair to say that Falcon 9 has a 100 percent success rate after 4 flights? I think that is rather generous. 75 percent, per Ed's rule? That does seem harsh.  96 percent, by my rule? I feel that's reasonable.

[Cherokee43v6]

Why don't they use pop corn as packaging ? It would turn packaging into valuable payload ... 

Hard to get the butter off of everything later, zero-g and all.

Dunno... I think that problem can be licked :p

[Robotbeat]

   
I would say a reasonable definition of a full launch failure is one which would cause the crew of a manned vehicle to do an abort and leave the launch vehicle early and not enter a useful orbit, since that is partially what people use these statistics for (i.e. calculating launch vehicle safety). Clearly that wasn't the case in this flight.

When people think of a launch failure, they think of this:


They don't think of slight underperformance as a full launch failure.

 

Well, it depends on who 'they' are. Not everyone is focussed on the manned case. This particular case is a grey area - how much underperformance is 'slight'? When a Proton upper stage strands its payload in LEO rather than GTO, that's counted as a full failure.

Is it fair to say that Falcon 9 has a 100 percent success rate after 4 flights? I think that is rather generous. 75 percent, per Ed's rule? That does seem harsh.  96 percent, by my rule? I feel that's reasonable.

If you're a customer thinking about launching on some launch vehicle, I think you should look at primary payload success separate from secondary payload success. In that case, currently it is 100% (within, say, half a launch either way) for primary missions and much less than that for secondary (you might even want to count the failure of relight on Falcon 9 flight 1 in that case... though, of course, that was clearly a development flight).

[yg1968]

The part that frustrates me is in my video:


The official announcement clearly states that all 9 Merlin engines are performing normally.

This is obviously totally inaccurate. I think in 2012 it is reasonable to expect information to be accurate ~45 seconds after the engine event they announce something that could have jeopardized people's safety. I'm all for NASA and SpaceX. Hell, I flew down from Chicago to support and watch the launch but I expect that communications out to the launch site to be accurate.  We literally had debris flying overhead and knew nothing about it.

I think that this was a description from the PAO. Anybody that knew what was happenning wouldn't have said that.

[ugordan]

The official announcement clearly states that all 9 Merlin engines are performing normally.

The "official" announcement is the NASA PAO who read out scripted event sequences throughout the count. It was not the SpaceX propulsion console guy who was notable for not announcing nominal performance.

This is obviously totally inaccurate. I think in 2012 it is reasonable to expect information to be accurate ~45 seconds after the engine event they announce something that could have jeopardized people's safety. I'm all for NASA and SpaceX. Hell, I flew down from Chicago to support and watch the launch but I expect that communications out to the launch site to be accurate.  We literally had debris flying overhead and knew nothing about it.

You gotta be kidding me. You were nowhere near the flight path of the vehicle. Don't worry about flying debris, the USAF range safety guy in charge of the Big Red Button doesn't listen to NASA PAO (or SpaceX flight console guys for that matter).

If you're that paranoid about "debris flying overhead", I suggest you don't go near a Delta II launch...

[edfishel]

JCM ..
I agree with your formulation. I'm approaching this question as a journalist who has followed space news for decades and as the general public would understand the question.  The purpose of this flight was to deliver supplies to the ISS and, as of now, SpaceX is well on its way to doing that.  The ORBCOMM prototype satellite was, at best, a side show in the eyes of the public. Your 96% seems fair.

[system9]

The official announcement clearly states that all 9 Merlin engines are performing normally.

The "official" announcement is the NASA PAO who read out scripted event sequences throughout the count. It was not the SpaceX propulsion console guy who was notable for not announcing nominal performance.

This is obviously totally inaccurate. I think in 2012 it is reasonable to expect information to be accurate ~45 seconds after the engine event they announce something that could have jeopardized people's safety. I'm all for NASA and SpaceX. Hell, I flew down from Chicago to support and watch the launch but I expect that communications out to the launch site to be accurate.  We literally had debris flying overhead and knew nothing about it.

You gotta be kidding me. You were nowhere near the flight path of the vehicle. Don't worry about flying debris, the USAF range safety guy in charge of the Big Red Button doesn't listen to NASA PAO (or SpaceX flight console guys for that matter).

If you're that paranoid about "debris flying overhead", I suggest you don't go near a Delta II launch...

Thank you for your insight and trajectory calculations of unplanned exploded\ejected debris.