Author Topic: SpaceX Falcon Heavy Discussion (Thread 6)  (Read 56344 times)

Offline dorkmo

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Re: SpaceX Falcon Heavy Discussion (Thread 6)
« Reply #40 on: 06/27/2017 11:35 PM »
It is looking like SpaceX will have about a month of downtown between the upcoming Intelsat launch and CRS-12. Is it possible that some of the FH upgrades could be completed during that time?

Id guess they could if they ran three shifts a day.

Offline CyndyC

Re: SpaceX Falcon Heavy Discussion (Thread 6)
« Reply #41 on: 06/27/2017 11:48 PM »
..... back when they thought it would be easy to fasten three Falcon first stages side by side.  Since then much has changed.

Exactly why I came over here, after the grid fin discussion in the Iridium thread, and wondering how tightly the cores could be secured with those [and the legs] inbetween. So a look at http://www.spacex.com/falcon-heavy says and shows bars are connecting the cores only at the top of each first stage and at the bottom near the legs. The Falcon 9 has been flown without that extra stabilization at the top and bottom of the first stage, so the vibration loads have been much more evenly distributed. Now it appears the vibration loads will be much more concentrated somewhere near the middle. Would that be a routine engineering calculation, or something they may be risking?

In contrast to my reasoning last night, there is more counterintuitive reasoning to also consider, related to the fact that brick buildings are less stable in tornadoes and high winds than buildings of more flexible materials, such as wood & vinyl. So maybe the greater risk is where the stages have extra stabilization and less flexibility. Personally I'll be opting for the former consideration. It's going to make me nervous there won't be a connecting rod across the middle. I'm guessing that might have been a subject of debate earlier in the development process.
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Offline LouScheffer

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Re: SpaceX Falcon Heavy Discussion (Thread 6)
« Reply #42 on: 06/28/2017 12:03 AM »
Now it appears the vibration loads will be much more concentrated somewhere near the middle. Would that be a routine engineering calculation, or something they may be risking?

 It's going to make me nervous there won't be a connecting rod across the middle. I'm guessing that might have been a subject of debate earlier in the development process.
Structural analysis is pretty routine by rocket science standards.   Back in the 1960s, NASA saw a bunch of companies each developing their own analysis software, and supported the development of NASTRAN, which has been used and enhanced for more than a half century. 

Unlike combustion analysis or computational aerodynamics, analysis of modes of vibration is a pretty mature field.  Of course you can still make mistakes, but of all the reasons the FH might fail, lack of connecting rods in the middle of stack is pretty low on the list.

Offline Herb Schaltegger

Re: SpaceX Falcon Heavy Discussion (Thread 6)
« Reply #43 on: 06/28/2017 01:10 AM »
Now it appears the vibration loads will be much more concentrated somewhere near the middle. Would that be a routine engineering calculation, or something they may be risking?

 It's going to make me nervous there won't be a connecting rod across the middle. I'm guessing that might have been a subject of debate earlier in the development process.
Structural analysis is pretty routine by rocket science standards.   Back in the 1960s, NASA saw a bunch of companies each developing their own analysis software, and supported the development of NASTRAN, which has been used and enhanced for more than a half century. 

Unlike combustion analysis or computational aerodynamics, analysis of modes of vibration is a pretty mature field.  Of course you can still make mistakes, but of all the reasons the FH might fail, lack of connecting rods in the middle of stack is pretty low on the list.

As far as I'm aware, pretty much no boosters for any operational launcher from any nation have ever had more than two connection points. Further, in each case, the load is generally carried by one of the two (either top or bottom), not both.

In short, two connection points is fine. If you can't adequately secure the boosters to the core with two cross-members, then you don't have any business trying to design multi-core rockets.
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Offline IanThePineapple

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Re: SpaceX Falcon Heavy Discussion (Thread 6)
« Reply #44 on: 07/05/2017 06:23 PM »
Random question: Is it known what will happen to 1027 (the FH Core STA)? Will it be scrapped or be converted to a normal FH core?
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Offline Kabloona

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Re: SpaceX Falcon Heavy Discussion (Thread 6)
« Reply #45 on: 07/05/2017 10:19 PM »
Now it appears the vibration loads will be much more concentrated somewhere near the middle. Would that be a routine engineering calculation, or something they may be risking?

 It's going to make me nervous there won't be a connecting rod across the middle. I'm guessing that might have been a subject of debate earlier in the development process.
Structural analysis is pretty routine by rocket science standards.   Back in the 1960s, NASA saw a bunch of companies each developing their own analysis software, and supported the development of NASTRAN, which has been used and enhanced for more than a half century. 

Unlike combustion analysis or computational aerodynamics, analysis of modes of vibration is a pretty mature field.  Of course you can still make mistakes, but of all the reasons the FH might fail, lack of connecting rods in the middle of stack is pretty low on the list.

As far as I'm aware, pretty much no boosters for any operational launcher from any nation have ever had more than two connection points. Further, in each case, the load is generally carried by one of the two (either top or bottom), not both.

In short, two connection points is fine. If you can't adequately secure the boosters to the core with two cross-members, then you don't have any business trying to design multi-core rockets.

Reminds me of a structural analyst at Lockheed Martin who was fond of quoting one of his college professors:
"Big beams carry large loads."


Offline MoDyna

Re: SpaceX Falcon Heavy Discussion (Thread 6)
« Reply #46 on: 07/11/2017 09:40 PM »
I was really intrigued a few years back when SpaceX was describing what the FH would have in the way of "gee-wiz" technology, like for instance the "cross-core propellant feed". I gather that this will not be on the FH that flies later this year. Has this been dropped for good, or will it be a later upgrade?

Online philw1776

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Re: SpaceX Falcon Heavy Discussion (Thread 6)
« Reply #47 on: 07/11/2017 09:49 PM »
Abandoned for good as complexities exceeded performance value.  The standard FH is already rated more powerful than the powerpoint crossfeed FH with its left and right cores and its plumbing weight and reliability decrease.

Read the SpaceX Falcon Heavy Discussion (Thread 6) here.
« Last Edit: 07/11/2017 09:50 PM by philw1776 »
ďWhen it looks more like an alien dreadnought, thatís when you know youíve won.Ē

Offline Roy_H

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Re: SpaceX Falcon Heavy Discussion (Thread 6)
« Reply #48 on: 07/12/2017 12:05 AM »
Random question: Is it known what will happen to 1027 (the FH Core STA)? Will it be scrapped or be converted to a normal FH core?

Excuse my ignorance, but what are you talking about. What is STA?
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Offline gongora

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Re: SpaceX Falcon Heavy Discussion (Thread 6)
« Reply #49 on: 07/12/2017 12:16 AM »
Random question: Is it known what will happen to 1027 (the FH Core STA)? Will it be scrapped or be converted to a normal FH core?

Excuse my ignorance, but what are you talking about. What is STA?

Structural Test Article.

Offline rpapo

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Re: SpaceX Falcon Heavy Discussion (Thread 6)
« Reply #50 on: 07/12/2017 10:34 AM »
Random question: Is it known what will happen to 1027 (the FH Core STA)? Will it be scrapped or be converted to a normal FH core?

Excuse my ignorance, but what are you talking about. What is STA?

Structural Test Article.
This is why Elon hates acronyms.
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Online GORDAP

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Re: SpaceX Falcon Heavy Discussion (Thread 6)
« Reply #51 on: 07/12/2017 10:57 AM »
Random question: Is it known what will happen to 1027 (the FH Core STA)? Will it be scrapped or be converted to a normal FH core?

Excuse my ignorance, but what are you talking about. What is STA?

Structural Test Article.
This is why Elon hates acronyms.

I specifically hate TLAs  (Three Letter Acronyms).  :-)


Offline vanoord

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Re: SpaceX Falcon Heavy Discussion (Thread 6)
« Reply #52 on: 07/12/2017 11:41 AM »
Random question: Is it known what will happen to 1027 (the FH Core STA)? Will it be scrapped or be converted to a normal FH core?

Apparently last seen at McGregor in October.

Similarly random questions:

There have been references to an FH booster core STA being constructed as well - but there hasn't been a gap in the core serial numbers that it would fit into: does / did it exist?

Online envy887

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Re: SpaceX Falcon Heavy Discussion (Thread 6)
« Reply #53 on: 07/12/2017 01:18 PM »
I was really intrigued a few years back when SpaceX was describing what the FH would have in the way of "gee-wiz" technology, like for instance the "cross-core propellant feed". I gather that this will not be on the FH that flies later this year. Has this been dropped for good, or will it be a later upgrade?

I don't think there's a left and a right; aren't the boosters are the same part rotated around the long axis of the core (rotational symmetry rather than mirrored symmetry)?

Either way, crossfeed is gone for good.

Offline wannamoonbase

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Re: SpaceX Falcon Heavy Discussion (Thread 6)
« Reply #54 on: 07/12/2017 01:42 PM »
I was really intrigued a few years back when SpaceX was describing what the FH would have in the way of "gee-wiz" technology, like for instance the "cross-core propellant feed". I gather that this will not be on the FH that flies later this year. Has this been dropped for good, or will it be a later upgrade?

I don't think there's a left and a right; aren't the boosters are the same part rotated around the long axis of the core (rotational symmetry rather than mirrored symmetry)?

Either way, crossfeed is gone for good.

I believe that is correct.  The side boosters are identical and could change sides between launches.

Crossfeed is exciting but given EM's comments and the SpaceX aversion to complexity it makes sense to get FH flying (Edit: to launch those large CommSats) and move onto a single core SFR.
« Last Edit: 07/12/2017 02:19 PM by wannamoonbase »
Excited to be finally into the first Falcon Heavy flow, we are getting so close!

Offline JasonAW3

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Re: SpaceX Falcon Heavy Discussion (Thread 6)
« Reply #55 on: 07/12/2017 02:09 PM »
Random question: Is it known what will happen to 1027 (the FH Core STA)? Will it be scrapped or be converted to a normal FH core?

Excuse my ignorance, but what are you talking about. What is STA?

Structural Test Article.
This is why Elon hates acronyms.

That is one reason I like Elon.
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Offline abaddon

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Re: SpaceX Falcon Heavy Discussion (Thread 6)
« Reply #56 on: 07/12/2017 02:33 PM »
There have been references to an FH booster core STA being constructed as well - but there hasn't been a gap in the core serial numbers that it would fit into: does / did it exist?
Since they're converting previously flown F9's into FH boosters, it would make sense if they simply converted a booster into an STA.  Why not test something similar to what you're going to fly?  And they have Block 3 cores to spare...

OTOH, since they are converting cores to boosters, that would suggest they are structurally identical, and maybe don't need structural testing at all.
« Last Edit: 07/12/2017 02:34 PM by abaddon »

Offline old_sellsword

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Re: SpaceX Falcon Heavy Discussion (Thread 6)
« Reply #57 on: 07/12/2017 03:10 PM »
Random question: Is it known what will happen to 1027 (the FH Core STA)? Will it be scrapped or be converted to a normal FH core?

Apparently last seen at McGregor in October.

Similarly random questions:

There have been references to an FH booster core STA being constructed as well - but there hasn't been a gap in the core serial numbers that it would fit into: does / did it exist?

Unless it didnít get a serial number, it doesnít exist as a standalone STA. My theory is that they used 1023 as soon as they got its new FH side booster octaweb installed, then they shipped it back to Hawthorne for completion after testing.

Offline vanoord

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Re: SpaceX Falcon Heavy Discussion (Thread 6)
« Reply #58 on: 07/13/2017 08:22 AM »
Unless it didnít get a serial number, it doesnít exist as a standalone STA. My theory is that they used 1023 as soon as they got its new FH side booster octaweb installed, then they shipped it back to Hawthorne for completion after testing.

My suspicion would also be that it never existed.

Offline catdlr

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Re: SpaceX Falcon Heavy Discussion (Thread 6)
« Reply #59 on: 07/17/2017 03:54 AM »
A new generation of giant rockets is about to blast off

Quote
Itís been 44 years since the mighty Saturn V last thundered skyward from a launch pad at Kennedy Space Center in Florida. The towering rocket, generating enough power to lift 269,000 pounds into orbit, had been the workhorse of the Apollo moon missions.

Later this year, SpaceX plans to launch its most powerful rocket yet from the same pad. The long-awaited Falcon Heavy is key to the Hawthorne companyís plans to ramp up its defense business, send tourists around the moon and launch its first uncrewed mission to Mars.

But unlike the Saturn V, the Falcon Heavy will have plenty of competition.

http://www.latimes.com/business/la-fi-heavy-lift-rockets-20170716-htmlstory.html
Tony De La Rosa

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