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

[input~2]

Review of the 6 objects catalogued by USSTRATCOM:

Object A (possibly Dragon)
epoch Oct 8, 0354UTC: 203 x 326 km x 51.65°
epoch Oct 9, 0356UTC: 311 x 329 km x 51.64°

Object B
epoch Oct 8, 0342UTC: 203 x 323 km x 51.65°
epoch Oct 9, 0345UTC: 166 x 306 km x 51.64°

Object C
epoch Oct 8, 0353UTC: 174 x 314 km x 51.66°
epoch Oct 8, 2313UTC: 170 x 296 km x 51.65°

Object D
epoch Oct 8, 0342UTC: 202 x 321 km x 51.65°
epoch Oct 9, 0345UTC: 187 x 274 km x 51.66°

Object E
epoch Oct 8, 0342UTC: 202 x 326 km x 51.67°
epoch Oct 8, 2148UTC: 200 x 319 km x 51.65°

Object F
epoch Oct 8, 0353UTC: 171 x 344 km x 51.63°
epoch Oct 9, 0344UTC: 186 x 264 km x 51.64°

[FinalFrontier]

I wonder why we don't have 34 pages of rampant speculation on that other launch vehicle failure we had in the past week? (Delta IVM - GPSII-F3)

I suppose the obvious answer would be:

A. It didn't evolve an apparent small explosion easily seen on footage.
B. Not as high profile a mission, for obvious reasons.

[ugordan]

I wonder why we don't have 34 pages of rampant speculation on that other launch vehicle failure we had in the past week? (Delta IVM - GPSII-F3)

There was no failure in that case as the vehicle had a huge performance margin to burn off.

[Maverick]

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/

Thanks Chris. I kinda lost my way with all these massive threads. It's a good sign this is a really busy site, but I prefer staying with the news site and awesome L2 most of the time.

[woods170]

I wonder why we don't have 34 pages of rampant speculation on that other launch vehicle failure we had in the past week? (Delta IVM - GPSII-F3)

I suppose the obvious answer would be:

A. It didn't evolve an apparent small explosion easily seen on footage.
B. Not as high profile a mission, for obvious reasons.

Correct, yet the 'anomoly' in RL-10 is just as worrying to me as the 'anomaly' in Merlin-1C. Merlin-1C is relative new-comer. RL-10 has been around for ages. The Delta-IV flight got lucky with the performance margin they had.

[woods170]

I wonder why we don't have 34 pages of rampant speculation on that other launch vehicle failure we had in the past week? (Delta IVM - GPSII-F3)

There was no failure in that case as the vehicle had a huge performance margin to burn off.

Assuming that it was fully tanked.

[kevin-rf]

I wonder why we don't have 34 pages of rampant speculation on that other launch vehicle failure we had in the past week? (Delta IVM - GPSII-F3)

Shhh... I've been secretly enjoying the high SNR of posts on that thread. I do wonder if we are seeing an RL-10 Nozzle that did not fully deploy or seal properly.

[Juggernaut]

is there someone who knows if duration of 2nd stage burn was nominal?

[Maciej Olesinski]

is there someone who knows if duration of 2nd stage burn was nominal?

From what i understand it was nominal and could deliver satelites to their orbit but because of ISS safty window this was aborted. Correct me if im wrong guyz

[ugordan]

I wonder why we don't have 34 pages of rampant speculation on that other launch vehicle failure we had in the past week? (Delta IVM - GPSII-F3)

There was no failure in that case as the vehicle had a huge performance margin to burn off.

Assuming that it was fully tanked.

Why wouldn't it be? To lower the performance margin? Makes no sense.

[ugordan]

is there someone who knows if duration of 2nd stage burn was nominal?

It was longer. I worked out a roughly 15 second increase in 2nd stage burn duration alone over the published nominal burn time. Think about it, if it didn't burn longer, there would have been propellant left for the Orbcomm delivery.

[Juggernaut]

is there someone who knows if duration of 2nd stage burn was nominal?

From what i understand it was nominal and could deliver satelites to their orbit but because of ISS safty window this was aborted. Correct me if im wrong guyz

this means the compensation to the engine#1 failure was charged only to 1st stage with longer burn and no off-nominal amount of fuel was used during the 1st burn of 2nd stage... this lead to conclude that new ascent profile computed after failure exceeded in forecast the window (time and position) expected for raise the orbit before Orbcomm's separation.

[john smith 19]

In terms the general public can understand:
This is a video of a tank bursting.
<youtube link removed>
edit : spelling

Tank rupture tests are *designed* to look lame.
Water is incompressible (an any pressure <1000s of atm's) so it *transmits* applied force to the structure.

Gases *store* applied force as a pressure rise *until* the structure fails, releasing the force in a pulse. Think aerosol can in a fire.
Actually since we seem to be dealing with an implosion I believe an electric kettle boiling dry might convey the right feeling.

[modemeagle]

is there someone who knows if duration of 2nd stage burn was nominal?

It was longer. I worked out a roughly 15 second increase in 2nd stage burn duration alone over the published nominal burn time. Think about it, if it didn't burn longer, there would have been propellant left for the Orbcomm delivery.

Using the NASA video for times I found the following with burn times:

SI NOMINAL: 3:03
SI ACTUAL: 3:21
EXTENDED BURN TIME: 0:18

SII NOMINAL: 5:59
SII ACTUAL: 6:12
EXTENDED BURN TIME: 0:13

[robertross]

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/

So enjoyable to read an article as accurate as possible (up to this moment), without clouding it with speculation until all the facts are in. Very good job Chris.

[robertross]

Sorry Guckyfan I believe Merlin uses a pintle injector:

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

S

Indeed it does.

[Jim]

I wonder why we don't have 34 pages of rampant speculation on that other launch vehicle failure we had in the past week? (Delta IVM - GPSII-F3)

There was no failure in that case as the vehicle had a huge performance margin to burn off.

Assuming that it was fully tanked.

launch vehicles are always fully tanked.

[Jim]

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

Launch vehicles are always fully tanked

[john smith 19]

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

*if* this is a correct description of the root cause that suggests a)test procedure failure (test procedures not an accurate test of the real flight stresses) b) Mfg fault that made this dome *much* closer to its failure limits after test than normal. c) Unique environment that stressed hardware in ways *never* seen before.

a) Would be very worrying. It would imply that that all *previous* Merlin 1c flights have just been lucky. I find that *very* hard to believe.

b) Depends on the exact location of the failure on the part and how it's mfg in the first place. Usual options are machining from solid ("hogging out"), casting and forging. Casting *historically* has had issues with flaws in the casting (gas bubbles, inert occlusions) but is very good for high volume complex parts if the volume is there, which it might be with 10 engines a vehicle and a desire to launch a lot of vehicles.

A classic failure mode for rocket engines has been where a connector is *welded* onto the main component. Connector holds, pipe holds, weld fails.

Does anyone know how Spacex are making this part at present?
They seem to like integrating as much as possible and I could definitely see them doing what Armadillo do and machining the fluid connectors *directly* into any component that needs them. A bit more CNC time saves a *lot* of trouble in Xray and dye penetration later.

c) would be pretty worrying as well, given this is expected to be the start of a *routine* flight profile and as others have said this F9 was quite a long way from its nominal performance limits (far enough that people were happy to manifest a secondary payload). OTOH that would raise another question.

Why didn't the *other* engines (either the 4 corners or all) see this condition also?

BTW Would a fuel dome fracture also imply that the propellant mix was going O2 rich and causing a temperature spike causing *possible* chamber and nozzle burn through *if* it lasted long enough?

I think it would but I'm guessing the computer was well into shutting it down by then.

Let's keep in mind a few things.

*despite* a serious mishap the primary payload is still on course for ISS.

I believe (but cannot confirm) had Dragon had a crew on board they would be unharmed by the experience.

Had NASA flight rules been less restrictive it is *probable* Orbcomms payload could have reacted its planned orbit. NASA is however responsible for a $1Bn+ asset so is justifiably cautious in this area.

The GNC door opened on *schedule* and perhaps Spacex might consider fine tuning their emergency information handling to get that sort of news out more promptly, along with any other key events like solar panel deployment.

[Juggernaut]

is there someone who knows if duration of 2nd stage burn was nominal?

It was longer. I worked out a roughly 15 second increase in 2nd stage burn duration alone over the published nominal burn time. Think about it, if it didn't burn longer, there would have been propellant left for the Orbcomm delivery.

ok then it was consumed more propellant than expected.
However it could have been also not only a problem of propellant available but also suitability of time/position for orbit raising, CAM and de-orbiting of 2nd stage following the Orbcomm delivery.