LIVE: SpaceX Falcon 9/Dragon CRS-2 (SpX-2) LAUNCH and FD-1 UPDATES

[AJA]

None of this freezing oxidiser would happen if they stirred the tanks.

Oh wait.. Yeah. Let's never do that again.

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E - Without a perigee raise burn, Dragon might re-enter in a day or two.

[meekGee]

could it be humidity in the He supply?   

[Chris Bergin]

Sunday most likely for docking rather than Saturday.

I'll bet you 10 English pounds sterling it won't be Saturday

[Star One]

Sunday most likely for docking rather than Saturday.

I'll bet you 10 English pounds sterling it won't be Saturday

That's a pretty safe bet.

[antonioe]

No Euros, eh?

[R7]

Frozen NTO? -11C at Florida?

[Star One]

No Euros, eh?

I say old boy what are these Euros you speak of.

[Chris Bergin]

Well done everyone. Was nice to be able to sit back for once and watch about five of you banging away with the transcription

So I've updated the launch article:
http://www.nasaspaceflight.com/2013/03/spacex-milestone-falcon9-launch-dragon-crs2/

And I'll start writing the next article tonight as good L2 info's starting to arrive now.

[russianhalo117]

Any thoughts on what would cause 3 out of 4 to fail? That sounds like a systematic error.

AFAIK, Helium tank serves all 8 tanks via separate lines. Blockage likely occurred in one of the main lines valves before the lines split off to there assigned tanks.

[Space Pete]

So it sounds to me like the biggest hurdle - clearing the helium line to the oxidizer tank in order to pressurize it - has already been overcome. It doesn't sound like there is any good reason why the remaining thruster pods shouldn't come online now.

[IRobot]

Musk: Pod 1 has 5 thrusters; pod 4 has 4.

So that confirms the pods are numbered by rotation. Pod 1 complements 3 and pod 2 complements 4.
Each complement can easily de-orbit.

[mmeijeri]

None of this freezing oxidiser would happen if they stirred the tanks.

Why would they need to stir the tank if it is well-insulated and perhaps heated? And how could it cause an explosion with storable oxidiser?

I wonder if the fuel / oxidiser lines have insulation and heaters, as on the Shuttle.

[corrodedNut]

Musk: Pod 1 has 5 thrusters; pod 4 has 4.

Yeah, sounds like "pods" 2 and 4 are "quads", and "pods" 1 and 3 are "quints".

Even numbered "pods" have an even number of Dracos, and vice versa.

[Star One]

Well done everyone. Was nice to be able to sit back for once and watch about five of you banging away with the transcription

So I've updated the launch article:
http://www.nasaspaceflight.com/2013/03/spacex-milestone-falcon9-launch-dragon-crs2/

And I'll start writing the next article tonight as good L2 info's starting to arrive now.

Was actually quite good doing racing along with that teleconference.

[simonbp]

Was this the only Falcon to have flown through heavy clouds? I wonder if there was some thermal issue on ascent that cause the systemic failure of the check valves...

[AJA]

wait - the He sure as hell didn't freeze.
If the oxidizer froze, how did this prevent the tank from pressurizing?
I can see how it prevented oxidizer from reaching downstream towards the thruste...  Maybe the pressure sensor is downstream from the tank?  this makes little sense.

I can only think of some 'wetting' of the inside of the ox tank near the diaphragm/valve interface with the He tanks. Or even simple thermal contraction and tightening of the same - beyond what was expected, because the whole tank wasn't exposed to the kind of nominal thermal warming that was expected. This is horribly speculative though.

[mdo]

... In terms of phase angle the two spacecraft currently approach each other at a rate of about 7.8 deg/hour or 185 deg/day (in terms of revs/day: ISS 16.04, Dragon 15.52).

Shouldn't these be reversed?  ISS - 15.52 revs/day, and Dragon 16.04?  Otherwise, how is Dragon overtaking ISS?

Yes, thanks for spotting; original post corrected.

[IRobot]

None of this freezing oxidiser would happen if they stirred the tanks.

Why would they need to stir the tank if it is well-insulated and perhaps heated? And how could it cause an explosion with storable oxidiser?

I wonder if the fuel / oxidiser lines have insulation and heaters, as on the Shuttle.

I think that was an Apollo 13 joke, but not sure

[Kabloona]

None of this freezing oxidiser would happen if they stirred the tanks.

Why would they need to stir the tank if it is well-insulated and perhaps heated? And how could it cause an explosion with storable oxidiser?

I wonder if the fuel / oxidiser lines have insulation and heaters, as on the Shuttle.

Towards end of presser, Elon said ox tanks are at 70F, so freezing seems unlikely. Stuck check valve(s) more likely (IMO).

[Star One]

Was this the only Falcon to have flown through heavy clouds? I wonder if there was some thermal issue on ascent that cause the systemic failure of the check valves...

Something to check for the upgraded Falcon?