Author Topic: SpaceX Falcon 9 (F9-S1-0024) Reuse Testing Coverage  (Read 104995 times)

Offline Lar

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Re: SpaceX Falcon 9 (F9-0024-S1) Reuse Testing Coverage
« Reply #120 on: 08/02/2016 04:01 am »
That's fair enough.  I'm no metals expert, but presumably (amongst other things) SpX have to test this/a stage's tankage to destruction to determine how many re-flights they can safely do.. or is there some way to determine this categorically without filling and emptying repeatedly until that final RUD?

Has Elon ever said how many re-flights the stages are designed to handle?  There must be some limit on it..
 
I would think that at this point 10 tests would be enough. Maybe the tank might last considerably longer, but 10 at 70% gets to a very low residual. In a year or so they can run another stage 100 times.

Testing to a RUD seems like a bad idea.
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Offline AC in NC

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Re: SpaceX Falcon 9 (F9-0024-S1) Reuse Testing Coverage
« Reply #121 on: 08/02/2016 04:10 am »
I would think that at this point 10 tests would be enough. Maybe the tank might last considerably longer, but 10 at 70% gets to a very low residual. In a year or so they can run another stage 100 times.

Testing to a RUD seems like a bad idea.

How about running 10 tests ahead of the most reused stage in inventory?

Offline Elmar Moelzer

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Re: SpaceX Falcon 9 (F9-0024-S1) Reuse Testing Coverage
« Reply #122 on: 08/02/2016 04:48 am »
I thought that Musk mentioned that they expect stages can be reused dozens of times and at least 10 or more times without major refurbishment. I might be remembering this wrong, though.

Offline CameronD

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Re: SpaceX Falcon 9 (F9-0024-S1) Reuse Testing Coverage
« Reply #123 on: 08/02/2016 05:30 am »
I thought that Musk mentioned that they expect stages can be reused dozens of times and at least 10 or more times without major refurbishment. I might be remembering this wrong, though.

I agree testing to RUD is a bad idea, but how many times do they cycle cryogenics into the tanks?  AFAIK, it's at least three (WDR, Static Fire, Launch) probably more, so that could imply the tanks are designed to handle at least 30 cycles. ...but what about compression/expansion stress-loads on the stage during transport, lifting, ascent and landing? That has to be taken into account also.

My point is this: SpX know they can build a cryo-tank stage that can survive being tested, transported, launched, landed, transported and re-tested like nothing else in history, but can it do it all over again? ..and again??  ..and again?? Expendable stages don't need to, but these ones do - 'dozens of times'.  EELV designers are probably yelling "you've over-designed it!" and it will be interesting to see how long they last in practice, but I sure wouldn't want my payload on Flight Just-One-Too-Many ...
 
Just my $0.005 worth.
« Last Edit: 08/02/2016 05:36 am by CameronD »
With sufficient thrust, pigs fly just fine - however, this is not necessarily a good idea. It is hard to be sure where they are
going to land, and it could be dangerous sitting under them as they fly overhead.

Offline JamesH65

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Re: SpaceX Falcon 9 (F9-0024-S1) Reuse Testing Coverage
« Reply #124 on: 08/02/2016 10:03 am »
Although 'cheap' these test still cost a hat load of cash, $200k minimum.So doing lots of tests will start getting expensive, so they just need enough to give the desired number of 9's reliability.

Offline wannamoonbase

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Re: SpaceX Falcon 9 (F9-0024-S1) Reuse Testing Coverage
« Reply #125 on: 08/02/2016 01:17 pm »
Although 'cheap' these test still cost a hat load of cash, $200k minimum.So doing lots of tests will start getting expensive, so they just need enough to give the desired number of 9's reliability.

Agreed, and perhaps, enough to make the engineers and insurance companies happy.  Likely there will be tests in the future as well on other returned stages after they've flown 2,3,4 times etc. 

Test data compared to flight data and see how things perform over time and confidence builds.

Also, I think the quote of $200K for fuel was pre Full Thrust and densification.  I don't know the cost, but I it's small.  The cost of pad hardware is one thing, but the cost of cooling the RP1 and LOx can't be ignored.
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Offline rsdavis9

Re: SpaceX Falcon 9 (F9-0024-S1) Reuse Testing Coverage
« Reply #126 on: 08/02/2016 01:38 pm »
They need to do like 3+ tests now and then wait till they have a booster flown multiple times and do the same 3+ whatever static firing. The loads during flight are not the same as static. Doing static fires until destruction doesn't make a lot of sense at this point.
With ELV best efficiency was the paradigm. The new paradigm is reusable, good enough, and commonality of design.
Same engines. Design once. Same vehicle. Design once. Reusable. Build once.

Online ZachS09

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Re: SpaceX Falcon 9 (F9-0024-S1) Reuse Testing Coverage
« Reply #127 on: 08/02/2016 03:42 pm »
I thought they were to do at least ten tests beforehand.
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Offline Kansan52

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Re: SpaceX Falcon 9 (F9-0024-S1) Reuse Testing Coverage
« Reply #128 on: 08/02/2016 04:43 pm »
I thought they were to do at least ten tests beforehand.

If memory serves, that was stated earlier. Also memory says nothing from SX to say that has changed.

The test stand is being cleared to test a new core. Expectation/speculation is that more reuse testing will resume soon.

Offline The Roadie

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Re: SpaceX Falcon 9 (F9-0024-S1) Reuse Testing Coverage
« Reply #129 on: 08/02/2016 06:14 pm »
JCSAT 14 returned stage (fuselage 024) removed from McGregor test stand this morning.

Reported in the Facebook group by member Keith Wallace.
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Offline The Roadie

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Re: SpaceX Falcon 9 (F9-0024-S1) Reuse Testing Coverage
« Reply #130 on: 08/03/2016 02:38 am »
And in under 8 hours, 029/AMOS6 is erect on the stand! Also reported with a photo by FB Keith Wallace.

https://www.facebook.com/groups/spacexgroup/permalink/10154447379276318/
"A human being should be able to...plan an invasion..conn a ship..solve equations, analyze a new problem..program a computer, cook a tasty meal.."-RAH

Offline Dante80

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Re: SpaceX Falcon 9 (F9-0024-S1) Reuse Testing Coverage
« Reply #131 on: 08/03/2016 05:53 am »
And in under 8 hours, 029/AMOS6 is erect on the stand! Also reported with a photo by FB Keith Wallace.

https://www.facebook.com/groups/spacexgroup/permalink/10154447379276318/

That was pretty fast! Lets see when they light this..

Offline John Alan

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Re: SpaceX Falcon 9 (F9-0024-S1) Reuse Testing Coverage
« Reply #132 on: 08/03/2016 08:14 am »
Speculation...
My guess is 72 hour (3 day) tak times is the S1 test rate goal of SpaceX...
Time a fresh stage rolls onto the property... till it rolls off property as a tested item...
2 a week... 100 a year... across this one test stand... if need be...

My guess is 29 is done by Friday... but ships only when needed...
24 back on and fired 3 more times before next Friday...

 ;)

Offline LouScheffer

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Re: SpaceX Falcon 9 (F9-S1-0024) Reuse Testing Coverage
« Reply #133 on: 08/08/2016 01:42 pm »
There were three tests. They took Sunday off. And today. And now the crane is back over the stage, per Keith Wallace on FB https://www.facebook.com/groups/spacexgroup/permalink/10154444636826318/

Presumably this means 029 arrived and has priority on the stand to support AMOS6.
Maybe three tests in a row is all they can run, limited perhaps by sub-cooled oxygen supply.   It could be that they have storage for 3x a single booster, in preparation for FH testing.  Refrigeration equipment is expensive, and a full booster load per day would be plenty under normal circumstances, meaning they could not keep up with multiple full duration firings in quick succession.  Speculation, of course, but it could explain why they ran three tests in  a row, then stopped.

Offline 411rocket

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Re: SpaceX Falcon 9 (F9-S1-0024) Reuse Testing Coverage
« Reply #134 on: 08/08/2016 06:57 pm »
There were three tests. They took Sunday off. And today. And now the crane is back over the stage, per Keith Wallace on FB https://www.facebook.com/groups/spacexgroup/permalink/10154444636826318/

Presumably this means 029 arrived and has priority on the stand to support AMOS6.
Maybe three tests in a row is all they can run, limited perhaps by sub-cooled oxygen supply.   It could be that they have storage for 3x a single booster, in preparation for FH testing.  Refrigeration equipment is expensive, and a full booster load per day would be plenty under normal circumstances, meaning they could not keep up with multiple full duration firings in quick succession.  Speculation, of course, but it could explain why they ran three tests in  a row, then stopped.

Looks like you missed the write up, published on Aug 4th.  :o

https://www.nasaspaceflight.com/2016/08/spacex-falcon-9-preparation-jcsat-16-amos-6/

Offline Kabloona

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Re: SpaceX Falcon 9 (F9-0024-S1) Reuse Testing Coverage
« Reply #135 on: 08/10/2016 12:52 am »
I thought they were to do at least ten tests beforehand.

More on the number of test fires from Gwynne Shotwell:

Quote
As part of that work, SpaceX is test-firing one of the Falcon 9 stages it successfully landed, from the May launch of the JCSAT-14 satellite, at its McGregor, Texas, test site. That stage has already completed some full-duration static test firings. “We’re going to run as many tests on this stage as we can pull off,” she said. “Hopefully we’ll get more than four, and maybe eight to ten of these, before we go ahead and refly.”

http://spacenews.com/spacex-offers-large-rockets-for-small-satellites/

« Last Edit: 08/10/2016 01:07 am by Kabloona »

Offline LouScheffer

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Re: SpaceX Falcon 9 (F9-S1-0024) Reuse Testing Coverage
« Reply #136 on: 08/10/2016 01:59 am »
There were three tests. They took Sunday off. And today. And now the crane is back over the stage, per Keith Wallace on FB https://www.facebook.com/groups/spacexgroup/permalink/10154444636826318/

Presumably this means 029 arrived and has priority on the stand to support AMOS6.
Maybe three tests in a row is all they can run, limited perhaps by sub-cooled oxygen supply.   It could be that they have storage for 3x a single booster, in preparation for FH testing.  Refrigeration equipment is expensive, and a full booster load per day would be plenty under normal circumstances, meaning they could not keep up with multiple full duration firings in quick succession.  Speculation, of course, but it could explain why they ran three tests in  a row, then stopped.

Looks like you missed the write up, published on Aug 4th.  :o

https://www.nasaspaceflight.com/2016/08/spacex-falcon-9-preparation-jcsat-16-amos-6/
It's clear they needed to clear the stand for the new core.  But there were two idle days between the final re-test and removing the used booster from the stand.  Given that they demonstrated two tests per day, why did they not continue to 5 (or even 7) firings as long as they were set up for it?  Surely that would have been a lot easier than dismounting, then re-mounting the booster.   That's why I speculate they ran out of some supply, and sub-cooled LOX is a likely suspect.

Offline 411rocket

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Re: SpaceX Falcon 9 (F9-S1-0024) Reuse Testing Coverage
« Reply #137 on: 08/10/2016 02:25 am »
It's clear they needed to clear the stand for the new core.  But there were two idle days between the final re-test and removing the used booster from the stand.  Given that they demonstrated two tests per day, why did they not continue to 5 (or even 7) firings as long as they were set up for it?  Surely that would have been a lot easier than dismounting, then re-mounting the booster.   That's why I speculate they ran out of some supply, and sub-cooled LOX is a likely suspect.

There was the open house for the locals too, including whatever setup & teardown required. This is in addition to the Prop supplies, as you had stated. I think that there was only 1 firing per day, for 3 days though, from what I had been reading.
« Last Edit: 08/10/2016 04:46 am by Lar »

Offline deruch

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Re: SpaceX Falcon 9 (F9-S1-0024) Reuse Testing Coverage
« Reply #138 on: 08/10/2016 06:48 pm »
It's clear they needed to clear the stand for the new core.  But there were two idle days between the final re-test and removing the used booster from the stand.  Given that they demonstrated two tests per day, why did they not continue to 5 (or even 7) firings as long as they were set up for it?  Surely that would have been a lot easier than dismounting, then re-mounting the booster.   That's why I speculate they ran out of some supply, and sub-cooled LOX is a likely suspect.

I agree that this represents the most likely suspect but don't discount other considerations like staff availability/rotation or test stand maintenance/re-checking, etc.  It might not be related to the booster at all.
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Offline kaiser

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Re: SpaceX Falcon 9 (F9-S1-0024) Reuse Testing Coverage
« Reply #139 on: 08/12/2016 03:30 am »
It's clear they needed to clear the stand for the new core.  But there were two idle days between the final re-test and removing the used booster from the stand.  Given that they demonstrated two tests per day, why did they not continue to 5 (or even 7) firings as long as they were set up for it?  Surely that would have been a lot easier than dismounting, then re-mounting the booster.   That's why I speculate they ran out of some supply, and sub-cooled LOX is a likely suspect.

There was the open house for the locals too, including whatever setup & teardown required. This is in addition to the Prop supplies, as you had stated. I think that there was only 1 firing per day, for 3 days though, from what I had been reading.

Well that, and you are also in uncharted testing territory.  You don't know all of the post boost-back failure modes that could be lurking, an from the previous tests no doubt they have a ton of data to analyze and look for trends, etc.  You risk a RUD everytime you do it and damaging the stand.  If you have a paying customer needing that stand shortly, you don't want to push it too far.  You just re-fired 3 times, might be worth it to do an inspection and let through the items that that stand is on the critical path for rather than continue to increase the probability of a RUD on the stand and potentially delay a half dozen launches or so.
« Last Edit: 08/12/2016 03:33 am by kaiser »

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