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#900
by
deruch
on 08 Jan, 2018 21:53
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If we see FH go back into the hanger we'll know the Zuma mishap was a vehicle issue.
Or we'll "know" that they finished testing what they wanted to, or that there's an issue with the FH vehicle, or a problem with pad GSE, or that weather has changed and is precluding their planned testing.....
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#901
by
mme
on 08 Jan, 2018 21:57
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If we see FH go back into the hanger we'll know the Zuma mishap was a vehicle issue.
Or we'll "know" that they finished testing what they wanted to, or that there's an issue with the FH vehicle, or a problem with pad GSE, or that weather has changed and is precluding their planned testing.....
Thanks. Epistemological sloppiness drives me nuts (even though I am not immune to it myself.)
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#902
by
Kansan52
on 08 Jan, 2018 21:59
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Has EM stopped lowering expectations with FH?
Anyone posting odds on clearing the tower? Completing the mission?
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#903
by
Roy_H
on 08 Jan, 2018 22:03
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#904
by
Kansan52
on 08 Jan, 2018 22:05
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#905
by
Ben the Space Brit
on 08 Jan, 2018 22:07
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The 'mission' is basically to clear a series of milestones and thus I don't think that you can really talk about 'mission success' beyond 'getting the upper stage into LEO parking orbit'. Everything else is very much 'learning experience' and, optimistically 'Hey! It worked!'
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#906
by
Surfdaddy
on 08 Jan, 2018 22:40
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So when might we expect to see a (first) static fire?
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#907
by
Okie_Steve
on 08 Jan, 2018 23:25
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<snip>
beyond 'getting the upper stage into LEO parking orbit'
I think I might add "in one piece" to that list
Edit: fix botched quote
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#908
by
Lars-J
on 08 Jan, 2018 23:26
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So when might we expect to see a (first) static fire?
I think I might add "in one piece" to that ...
??
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#909
by
Craig_VG
on 08 Jan, 2018 23:43
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#910
by
Inoeth
on 09 Jan, 2018 02:45
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So as also reported in the update thread, FH is going verticle- or probably already is by now as the tweet is now an hour old...
https://twitter.com/SpaceflightNow/status/950558453520584704Great sign for a Static Fire on Wednesday. It does however make me wonder what they'll be doing tomorrow with FH then- continued fit-tests, perhaps a WDR of some sort... probably too optimistic of me to think that they'll do the SF tomorrow instead of wednesday but perhaps SpaceX is looking for some more positive PR right now...
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#911
by
Steven Pietrobon
on 09 Jan, 2018 02:54
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Even the hold down firing test will be pretty exciting. If27 engines are starting up with 0.2secs between each pair that alone will last close to 3 secs between the first and the last pair igniting.
Formula is T*(N-M)/M = 0.2*(27-2)/2 = 2.5 seconds where T is time between engine starts, N is total number of engines and M is number of engines that are igniting at a time. Equation ignores effects of N not dividing M!
Update: If we assume the sequence is 2-2-2-2-1-2-2-2-2-1-2-2-2-2-1 then formula is T*(R*trunc(N/M+1)-1) = 0.12*(3*trunc(9/2+1)-1) = 0.12*(3*5-1) = 1.68 seconds. Have
T = 0.12 s (time between engine starts)
R = 3 (number of cores)
N = 9 (number of engines per core)
M = 2 (number of engines between engine start)
trunc() rounds down to nearest integer
Update 2: If we assume the sequence is 2-2-2-2-2-2-2-2-2-2-2-2-2-1 then formula is T*trunc(R*N/M) = 0.12*13 = = 1.56 seconds.
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#912
by
TheFallen
on 09 Jan, 2018 04:33
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If we see FH go back into the hanger we'll know the Zuma mishap was a vehicle issue.
The FH is right where we want it to be as of this moment
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#913
by
the_other_Doug
on 09 Jan, 2018 05:21
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If we see FH go back into the hanger we'll know the Zuma mishap was a vehicle issue.
Perhaps you're right... I entirely missed the info about the possible Zuma issue... tho the fact that they rolled out the FH this morning many, many hours after the launch makes me guess that whatever issue Zuma is having, it's not SpaceX's fault.
Not to put too fine a point on it, but -- if Zuma had a payload separation failure, even if it was SpaceX's fault (which I don't believe), how could that possibly impact this FH test flight? The payload adapter and payload are, from what we can tell, permanently mated to the second stage. There seems to be no plan whatsoever to even attempt a payload separation.
So, the Zuma "issue" just
can't impact this FH flight. Perhaps it may impact the GovSat launch, but no way could it impact FH...
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#914
by
Robotbeat
on 09 Jan, 2018 05:24
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If we see FH go back into the hanger we'll know the Zuma mishap was a vehicle issue.
Perhaps you're right... I entirely missed the info about the possible Zuma issue... tho the fact that they rolled out the FH this morning many, many hours after the launch makes me guess that whatever issue Zuma is having, it's not SpaceX's fault.
Not to put too fine a point on it, but -- if Zuma had a payload separation failure, even if it was SpaceX's fault (which I don't believe), how could that possibly impact this FH test flight? The payload adapter and payload are, from what we can tell, permanently mated to the second stage. There seems to be no plan whatsoever to even attempt a payload separation.
So, the Zuma "issue" just can't impact this FH flight. Perhaps it may impact the GovSat launch, but no way could it impact FH...
That's not quite true. If there's a failure of SpaceX's mission assurance protocol that leads to some failure, then they would likely halt all launches to figure out what contributed to that failure and why the normal procedures (which goes beyond just one system) didn't catch the problem.
But this isn't SpaceX's failure, so it's irrelevant.
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#915
by
groundbound
on 09 Jan, 2018 05:31
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But this isn't SpaceX's failure, so it's irrelevant.
We have no certainty of that, just a lot of circumstantial evidence that points in that general direction.
Uninterrupted continuation of FH preparations probably amounts to one more shred of circumstantial evidence.
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#916
by
Robotbeat
on 09 Jan, 2018 05:45
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But this isn't SpaceX's failure, so it's irrelevant.
We have no certainty of that, just a lot of circumstantial evidence that points in that general direction.
...
We have direct statement by SpaceX saying the Falcon 9 performed nominally. That's more than just circumstantial.
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#917
by
clongton
on 09 Jan, 2018 10:54
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Much and more has been made of the complexity of lighting twenty seven engines.
Every time Soyuz launches it ignites 20 main engines and 12 verniers - 32 engines all ignited for liftoff.
It's not like a cluster this size is anything new.
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#918
by
eeergo
on 09 Jan, 2018 11:01
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Much and more has been made of the complexity of lighting twenty seven engines.
Every time Soyuz launches it ignites 20 main engines and 12 verniers - 32 engines all ignited for liftoff.
It's not like a cluster this size is anything new.
No, Soyuz's engines are clustered nozzles and combustion chambers with a single engine turbomachinery. Each side block has a single engine with four main nozzles and two verniers (RD-107 and derivatives), and the center block A has a single engine with four main nozzles and four verniers (RD-108 and derivatives).
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#919
by
nacnud
on 09 Jan, 2018 11:15
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Every time Soyuz launches it ignites 20 main engines and 12 verniers - 32 engines all ignited for liftoff...
Soyuz ground lights five engines with, in total, 32 nozzles. I suppose you could call it 32 ignition events? Still only five engines though.
) and tweeted out and sent to all reaches of the planet via Pony Express, smoke signals and carrier pigeons. 