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#1340
by
mn
on 24 Jan, 2018 15:36
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What "usual starting sequence"? This is the first static fire of the stack on the pad...
"The usual starting sequence [of a single stick F9]". Of course it doesn't have a commonality but it's the only thing we have to compare against and it leads to some conclusions (as the other poster stated (para-quoted): "There is some reason for SX to have chosen a different start)
Restating outloud the circumstances that lead to this thread of discussion:
1) A F9 can handle the startup stresses of all engines starting simultaneously (eg: the usual startup sequence)
2) FH has staggered startup which it's reasonable to presume is for some physical reason rather than simply caution.
3) The FH cores are reasonably independent with respect to thrust but perhaps varyingly less so due to other "forces" (eg: acoustic, pressure, vibration, ...)
4) We're interested in knowing if there's a FH System reason for the stagger and what that might be or whether it's simply the total systemic shock of such an ignition to the Pad, GSE, Trench, etc... or whether it's simply prudence
Why do we need to guess when we have what was explicitly reported by Chris G
Due to thrust torque (a thrust-induced rotation) scenario that could destroy or severely damage the octawebs at the base of each Falcon core that house the Merlin 1D engines, the Falcon Heavy’s 27 engines will not be lit simultaneously like the Falcon 9 engines
https://www.nasaspaceflight.com/2017/11/spacex-aims-december-launch-falcon-heavy/
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#1341
by
AC in NC
on 24 Jan, 2018 15:49
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Why do we need to guess when we have what was explicitly reported by Chris G
That's a separate question. Observationally, I would respond: "Because that's what we do".
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#1342
by
allio
on 24 Jan, 2018 16:07
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#1343
by
the_other_Doug
on 24 Jan, 2018 16:25
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SpaceX ended up with dissimilar cores too, right?
The center core is unique, the side cores are not. (And are close enough to regular F9 boosters that they could be converted). AIUI all DIV Heavy cores are different from regular DIV cores.
Also AIUI, Atlas V Heavy would not have required any unique cores. So FH falls in-between the two, but falling much closer to the AV Heavy than the DIV Heavy in that regard.
It's my understanding that the F9 Block 5 stages will all be capable of use in any of the three positions in an FH stack. It all has to do with the octaweb design, which is what will be standard across all Block 5 cores.
That will make putting a Heavy together a lot easier, I would imagine...
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#1344
by
StuffOfInterest
on 24 Jan, 2018 16:28
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It's my understanding that the F9 Block 5 stages will all be capable of use in any of the three positions in an FH stack. It all has to do with the octaweb design, which is what will be standard across all Block 5 cores.
That's a bit surprising. I would imagine that the reinforcements in the center core add a not insignificant amount of weight. That would make it less than ideas to use on the side boosters and single stick launchers. I guess, being on the first stage, there is less of a penalty at play.
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#1345
by
dglow
on 24 Jan, 2018 16:31
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Firing! Woooo!
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#1346
by
Marsin2010
on 24 Jan, 2018 16:31
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A good looking burn. I counted a full 12 seconds.
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#1347
by
PahTo
on 24 Jan, 2018 16:32
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Appears to have worked! The rocket is still there and the engines have shut down (apparently after a full duration test)!
Woot!
Thanks Steven and ChrisG and NSF!
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#1348
by
AC in NC
on 24 Jan, 2018 16:33
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Who's going to wash the water tower?
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#1349
by
cppetrie
on 24 Jan, 2018 16:34
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That plume was amazing to see!
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#1350
by
ZachS09
on 24 Jan, 2018 16:34
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With the static fire having taken place, I'd estimate that the Falcon Heavy will launch on February 7th, which is exactly two weeks (14 days) from today.
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#1351
by
M.E.T.
on 24 Jan, 2018 16:34
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Great. So I miss it by a couple of minutes and it seems the periscope thing doesn't allow you to rewind. So where do I get to see a replay?
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#1352
by
dglow
on 24 Jan, 2018 16:37
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Great. So I miss it by a couple of minutes and it seems the periscope thing doesn't allow you to rewind. So where do I get to see a replay?
Check YouTube in a few minutes?
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#1353
by
eeergo
on 24 Jan, 2018 16:38
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#1354
by
JBF
on 24 Jan, 2018 16:38
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I hope someone had a good audio recording rig out there.
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#1355
by
M.E.T.
on 24 Jan, 2018 16:38
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Great. So I miss it by a couple of minutes and it seems the periscope thing doesn't allow you to rewind. So where do I get to see a replay?
Check YouTube in a few minutes?
Haha. Already there. Nothing yet. Here I wait for weeks for this moment, but when your three year old needs your attention NOW, there is no arguing.
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#1356
by
garcianc
on 24 Jan, 2018 16:40
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#1357
by
GeneBelcher
on 24 Jan, 2018 16:41
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#1358
by
ugordan
on 24 Jan, 2018 16:44
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If we go by the rumble alone, it sounded shorter than 12 seconds, more like 8-ish. Unlike the Fliorida Today stream, Chris_G was downstream from the flame trench so had a good "bang" once that initial overpressure arrived.
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#1359
by
old_sellsword
on 24 Jan, 2018 16:44
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SpaceX ended up with dissimilar cores too, right?
The center core is unique, the side cores are not. (And are close enough to regular F9 boosters that they could be converted). AIUI all DIV Heavy cores are different from regular DIV cores.
Also AIUI, Atlas V Heavy would not have required any unique cores. So FH falls in-between the two, but falling much closer to the AV Heavy than the DIV Heavy in that regard.
It's my understanding that the F9 Block 5 stages will all be capable of use in any of the three positions in an FH stack. It all has to do with the octaweb design, which is what will be standard across all Block 5 cores.
That will make putting a Heavy together a lot easier, I would imagine...
From what we know, center cores are significantly different than side boosters. But side boosters will double as single sticks.
