Author Topic: SpaceX Falcon 9 - Iridium NEXT Flight 1 DISCUSSION (Jan. 14 2017)  (Read 336253 times)

Online FutureSpaceTourist

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That call out was regarding Launch Complex, Youtube Technical webcast 33:31
https://www.youtube.com/watch?v=7WimRhydggo?t=2010

Ah, ok thanks. I was going on this:

T+14 minutes. Think I heard "No indications of fire on ASDS".

I guess Steven didn't quite pickup what they were referring to.

Offline Hauerg

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Didn't see any comment on this so I thought I'd ask.

Watching the launch yesterday I noticed the number 29 on the lower part of the rocket, just above the octoweb. Does anyone know what that number is? The 29th rocket?

It is booster 1029. However this was the 30th Falcon 9 launch (F9-030). I assume the reason that the booster s/n is lower than the flight number is because they changed the s/n syntax with the introduction of Block 2.
Do you count the September explosion as a launch (attempt)?
I do not. (For me the Iridium-1 flight was flight #29, 28 of those were successful.) 
Nor do SpaceX, ot his booster should have been at LEAST #30.

Online rsdavis9

On the tech webcast shortly after s2 startup they say "mvac pu is active". Did I here that correctly? what is mvac pu?
With ELV best efficiency was the paradigm. The new paradigm is reusable, good enough, and commonality of design.
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Offline edkyle99

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Do you count the September explosion as a launch (attempt)?
I do not. (For me the Iridium-1 flight was flight #29, 28 of those were successful.) 
Nor do SpaceX, ot his booster should have been at LEAST #30.
Stage numbers can get shuffled around, and we don't know for certain if a different nomenclature wasn't  used for earlier stages.  See this reddit for a summary of what is known.
https://www.reddit.com/r/spacex/wiki/cores

As stage reflights begin, the stage numbering will become even more confusing.  Hopefully SpaceX will keep numbering them as this one was numbered, but it would be nice to know the second stage numbers as well.

 - Ed Kyle
« Last Edit: 01/15/2017 03:18 PM by edkyle99 »

Offline HMXHMX

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On the tech webcast shortly after s2 startup they say "mvac pu is active". Did I here that correctly? what is mvac pu?

Propellant Utilization, presumably.  Adjusts mixture ratio for more complete propellant consumption.

Offline old_sellsword

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Do you count the September explosion as a launch (attempt)?
I do not. (For me the Iridium-1 flight was flight #29, 28 of those were successful.) 
Nor do SpaceX, ot his booster should have been at LEAST #30.

I count it as a launch attempt, and so does SpaceX actually. They called Amos-6 F9-029 and Iridium-1 F9-030. The number 29 painted on the booster was not the flight number, it was the booster's serial number (1029). These are very important to distinguish.

As I stated earlier, the booster serial numbers are smaller than the number of flights due to reasons the public doesn't know. The only way it makes sense to me is if Block 1 (v1.0) cores had s/n in the format B0001 and then when Block 2 started production they switched to B1001.
« Last Edit: 01/16/2017 05:18 AM by old_sellsword »

Offline Brian45

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thanks for the clarification. Does that mean we'll see the "29" again on the launch pad at some future date (assuming the re-use this core)?

I don't recall seeing this number label on previous launches. Was it just the camera angle?

Offline edkyle99

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I count it as a launch attempt, and so does SpaceX actually.
I know this is all semantics, but F9-29 was not an actual launch attempt as I'm sure you are aware.  It was an assembled vehicle that was destroyed in a ground test.  Such things have happened before (the first Atlas-Able, for example, Thor 103, a Soyuz or two, the Centaur stage of AC-68, etc, among a number of such incidents.)  If you count F9-29 as a "launch", you need to also count these others.  That list gets confusing pretty fast.  Was the exploded S-IVB-503 stage a "launch"?  Was "Discoverer Zero" a "launch?

 - Ed Kyle
« Last Edit: 01/15/2017 03:31 PM by edkyle99 »

Offline old_sellsword

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thanks for the clarification. Does that mean we'll see the "29" again on the launch pad at some future date (assuming the re-use this core)?

I don't recall seeing this number label on previous launches. Was it just the camera angle?

This is first painted number we've seen, and all cores after this one should have a painted serial number too. Although we don't know if they've gone back and painted numbers on the old ones (ie. CRS-8) as well.

I know this is all semantics, but F9-29 was not an actual launch attempt as I'm sure you are aware.

You're right, I used poor phrasing there. I was more noting that SpaceX isn't going to reuse the F9-029 mission designation.
« Last Edit: 01/15/2017 03:29 PM by old_sellsword »

Offline gongora

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If you think of them as missions instead of flights then leaving AMOS-6 as mission 29 is quite reasonable.

Offline Johnnyhinbos

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This is first painted number we've seen...

Don't think that's true. There's been photos of returned stages in the HIF with legs removed that had an ID #. The number was much (much) smaller and IIRC, was obscured when the leg was folded up.

I was pretty stoked to see such large numbers, in multiple locations, and in plain sight at launch time. Was a definite move towards giving individual cores a pronounced identity - something not surprising now that they will have both histories and futures...
John Hanzl. Author, action / adventure www.johnhanzl.com

Offline Bob Shaw

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MVAC is presumably 'Merlin Vacuum (Engine)'

PU could be a variety of things.

Offline old_sellsword

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This is first painted number we've seen...

Don't think that's true. There's been photos of returned stages in the HIF with legs removed that had an ID #. The number was much (much) smaller and IIRC, was obscured when the leg was folded up.

Can you point me to some of those pictures? I'd love to see them.

Offline Brian45

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Johnnyhinbos - you hit the nail on the head - I thought the number was an indicator of SpaceX's tracking of Stage 1s in a very public way. Hope to see ol' 29 on the stand many times!!

Offline DanielW

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I would bet that stage serial numbers are 0 indexed.

Offline old_sellsword

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I would bet that stage serial numbers are 0 indexed.

It's way more complicated than that, because you'd have to account for all the cores like Grasshopper, F9R Dev 1&2, FH STAs, etc.

Offline kch

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On the tech webcast shortly after s2 startup they say "mvac pu is active". Did I here that correctly? what is mvac pu?

MVAC is presumably 'Merlin Vacuum (Engine)'

Makes sense -- that's what it usually means, especially in that context.  :)



PU could be a variety of things.


Propellant Utilization, presumably.  Adjusts mixture ratio for more complete propellant consumption.

Offline Johnnyhinbos

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This is first painted number we've seen...

Don't think that's true. There's been photos of returned stages in the HIF with legs removed that had an ID #. The number was much (much) smaller and IIRC, was obscured when the leg was folded up.

Can you point me to some of those pictures? I'd love to see them.
Wish I could - finding reference photos through Tapatalk is untenable. Perhaps this evening I'll try the desktop version and try to track one down unless someone else can (happily) ninja me...
John Hanzl. Author, action / adventure www.johnhanzl.com

Offline Jarnis

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My old workhorse computer got so excited it crashed and rebooted back up with 15 seconds to launch... :o  Just what I needed, more nail-biting...

What is this non-redundant mission critical computer system?!?! :D

(here I had two computers running one stream each, plus TV running youtube smartTV app running the hosted cast as well... The only non-redundant parts were the switch and the system running the firewall)

Offline Space Ghost 1962

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I would bet that stage serial numbers are 0 indexed.
Believe they are "1"  indexed, e.g. first, second, third, und so weiter.

The significance of this launch is that SX can field a finished Falcon 9 system where all the parts work on a major mission, flown under AF/FAA supervision. That means missions can continue now working down a manifest.

Prior to this they had lost that confidence due to an obvious, unanticipated failure when no expectation of such was present. Why this was so bad wasn't just due to the loss of the mission/payload/vehicle, but more so because they clearly did not understand that they were under risk of such.

After having convinced all that they did.

The problem with SX (or others) aerospace agile development is that, in contrast to ULA (or others) system engineering is that these lapses are themselves excessively costly to all, and simply cannot be overlooked as many might. And where an engine anomaly (e.g. OA6) might bring things close to the edge of margin, during the same period lapses for SX have meant multiple lost missions.

For SX just flying does not mean they have reached parity with ULA/others - they need to be able to do "agile development" at comparable not excessive cost.

And its not just SX here that are affected by this - all other providers will be competing more with SX, and thus must be more "agile" to do so, otherwise they won't be competitive. They risk the same as SX in doing so.

SX is behind on FH. They also have a pad to rebuild. And another version of F9 to field, likely with 3 COPV's of improved design.

Those that want to wish away the problem will be disappointed. SX needs to have carbon fiber subcooled LOX tanks of radically excessive performance by current standards. Plus more.


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