Author Topic: F9 Block 5 Updates and Discussion  (Read 323675 times)

Online smoliarm

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Re: F9 Block 5 Updates and Discussion
« Reply #660 on: 05/07/2018 11:33 am »
...
Seems way more than necessary if those are rivets.
...

Yes, for me too it looks more than necessary.
Although I saw such things, but pretty far from aerospace field.
I worked in Far North with geologists, and they had very similar patterns (with "pimps") on all shelves in the field toolboxes. They explained it was an anti-freezing trick. Because if you put metal tool onto a plain metal shelf - then even a tiny water drop (from condensate) will freeze and glue the tool DEAD to the shelf. As for the "pimped" shelf, it takes MUCH more water to do this nasty thing.

So my guess - this pattern is to limit the direct contact of the leg with the booster body.
What's the reason for that? I don't know :)

Offline zhangmdev

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Re: F9 Block 5 Updates and Discussion
« Reply #661 on: 05/07/2018 12:04 pm »
But those parts do not touch the core body. And I don't think the fuel tank is cold enough to cause freezing problem. My guess is vortex generation, but usually there are dimples not bumps.

Offline 2008rlctx

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Re: F9 Block 5 Updates and Discussion
« Reply #662 on: 05/07/2018 12:10 pm »
what do you guys make of this? it looks like some sort of stiffing piece attached to the outside of the main leg structure. is that metal or just more carbon fiber? are those rivets?

Sure look like rivets. Looks too small for trying to affect airflow.

So if they are rivets, then it must be a way to attached a metal piece to a composite one?

At the speeds this thing flies, I wouldn't discount these bumps affecting airflow. I've seen cars with miniscule bumps on mirrors that seem they couldn't do anything, but manufacturers have invested money in tooling to put little bumps there... So why not here?
I agree it's unlikely these are rivets and more likely something molded into or onto the carbon fiber to affect airflow or the other suggestion above, maybe affecting water/ice formation.

Online RotoSequence

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Re: F9 Block 5 Updates and Discussion
« Reply #663 on: 05/07/2018 12:35 pm »
Rockets don't usually spend enough time in atmosphere during flight for smaller protrusions to be worth eliminating.

Whatever they're connecting, with that many fasteners, those parts are rather thoroughly joined.

Offline pospa

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Re: F9 Block 5 Updates and Discussion
« Reply #664 on: 05/07/2018 01:44 pm »
...My guess is vortex generation, but usually there are dimples not bumps.

Agree, I gues they are turbulators at the trailing edge of the unfolded leg to mitigate laminar airflow during stage decelaration and landing.

Offline robert_d

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Re: F9 Block 5 Updates and Discussion
« Reply #665 on: 05/07/2018 02:51 pm »
I just wanted to compliment SpaceX on the way they have handled this current "glitch" in the static fire. I  am putting it here because it seems to be another example of how hard they have worked to make the new block 5 something special. It seems their whole philosophy of operation is somehow complimentary to Blue Origin's "Step by step, ferociously". SpaceX's would be something like "Run as fast as you can, carefully". They seem to have learned from the prior failures, and, looking towards crewed flights on the block 5, check everything conceivable. They take full advantage of the more powerful computational/sensor landscape available to identify issues and resolve them. May they never get complacent. 

Offline Coastal Ron

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Re: F9 Block 5 Updates and Discussion
« Reply #666 on: 05/07/2018 02:57 pm »
...My guess is vortex generation, but usually there are dimples not bumps.

Agree, I gues they are turbulators at the trailing edge of the unfolded leg to mitigate laminar airflow during stage decelaration and landing.

Except if you look at the picture you'll see that the whole area is not streamlined - there are ridges and valleys right next to this long strip of bumps, which leads me to believe that they really don't care about airflow in this area. I think these are more likely mechanical connections.
If we don't continuously lower the cost to access space, how are we ever going to afford to expand humanity out into space?

Online Johnnyhinbos

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Re: F9 Block 5 Updates and Discussion
« Reply #667 on: 05/07/2018 03:41 pm »
I’m pretty sure those are rivets connecting the carbon fiber leg “fairing” to a stiffener made out of another material. This would run from hinge point down to contact point.
« Last Edit: 05/07/2018 03:42 pm by Johnnyhinbos »
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Online RDMM2081

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Re: F9 Block 5 Updates and Discussion
« Reply #668 on: 05/07/2018 05:21 pm »
"Run as fast as you can, carefully"

Made my morning!  I agree with the opinion that this is likely not a "showstopper" type issue they are working, but rather something in the "overabundance of caution" category.  I also think we are about to witness the birth of steamrollerV2 when Banghabandu goes up.  I am prepared to be shocked by the pace, and still expecting to be shocked by how shocked I end up being.

Offline Jim

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Re: F9 Block 5 Updates and Discussion
« Reply #669 on: 05/07/2018 06:07 pm »
I just wanted to compliment SpaceX on the way they have handled this current "glitch" in the static fire. I  am putting it here because it seems to be another example of how hard they have worked to make the new block 5 something special. It seems their whole philosophy of operation is somehow complimentary to Blue Origin's "Step by step, ferociously". SpaceX's would be something like "Run as fast as you can, carefully". They seem to have learned from the prior failures, and, looking towards crewed flights on the block 5, check everything conceivable. They take full advantage of the more powerful computational/sensor landscape available to identify issues and resolve them. May they never get complacent. 

Why is this any different than any other vehicle or contractors?  This is nothing out of the ordinary.

Online LouScheffer

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Re: F9 Block 5 Updates and Discussion
« Reply #670 on: 05/07/2018 08:18 pm »
I just wanted to compliment SpaceX on the way they have handled this current "glitch" in the static fire. I  am putting it here because it seems to be another example of how hard they have worked to make the new block 5 something special. It seems their whole philosophy of operation is somehow complimentary to Blue Origin's "Step by step, ferociously". SpaceX's would be something like "Run as fast as you can, carefully". They seem to have learned from the prior failures, and, looking towards crewed flights on the block 5, check everything conceivable. They take full advantage of the more powerful computational/sensor landscape available to identify issues and resolve them. May they never get complacent. 

Why is this any different than any other vehicle or contractors?  This is nothing out of the ordinary.

I agree with Jim that this is nothing unusual for other contractors.  What poster is getting at, I think, is that you might expect a company that is always trying new things (fairing recovery, launching heavy, new block build, all introduced this half year) might also suffer from "go fever".  But in this case they seem to be quite conservative, whereas it's hard to imagine them holding a launch if they found a problem with the fairing recovery hardware.  In theory it's just common sense to handle production and experimentall stuff appropriately, but common sense is not as common as you might think.

Online docmordrid

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Re: F9 Block 5 Updates and Discussion
« Reply #671 on: 05/07/2018 08:43 pm »
"Run as fast as you can, carefully"

Made my morning! 
>

Mine too! BTW,

"Quantum potes fugere sedulo"

Anyone want to design them a crest? ;)

DM

Offline joek

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Re: F9 Block 5 Updates and Discussion
« Reply #672 on: 05/07/2018 08:44 pm »
Why is this any different than any other vehicle or contractors?  This is nothing out of the ordinary.

What is different and out of the ordinary is the apparent ability to maintain a high level of prudence-caution while also maintaining a high level of change-innovation.

Offline Rabidpanda

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Re: F9 Block 5 Updates and Discussion
« Reply #673 on: 05/07/2018 10:01 pm »
Why is this any different than any other vehicle or contractors?  This is nothing out of the ordinary.

What is different and out of the ordinary is the apparent ability to maintain a high level of prudence-caution while also maintaining a high level of change-innovation.

Are there any examples of companies in the aerospace world that don’t (generally) maintain a high level of prudence and caution?

What makes you think what SpaceX is doing here is out of the ordinary for them or any similar company?

Every action by SpaceX doesn’t have to be some crazy new approach that will revolutionize the industry. I think it’s more meaningful to save the praise for the things that are actually revolutionary (reusing F9 boosters, etc).

Offline Kabloona

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Re: F9 Block 5 Updates and Discussion
« Reply #674 on: 05/08/2018 12:43 am »
I’m pretty sure those are rivets connecting the carbon fiber leg “fairing” to a stiffener made out of another material. This would run from hinge point down to contact point.

I'd agree that they're fasteners, but what you're calling a stiffener I'd guess is more like a metal doubler that, along with the fasteners, acts to clamp the two composite pieces (outer and inner faces) of the leg together. Carbon fiber is already so stiff that the leg cross-section should be more than strong enough without stiffeners, and the relative narrowness of that strip, just wide enough to carry the bearing stress of the fastener heads, makes me think it's for that purpose.

Probably SpaceX came up with a more efficient manufacturing process for the legs, one that requires some assembly but makes the composite parts easier to fabricate.

Quote
Theoretically, all composites could be adhesively bonded. However, many manufacturers avoid adhesive bonds where joints undergo large amounts of stress; thus, fasteners are still specified for many joints. Also, some structures and components are so large that they preclude the use of the special lay-up tooling and curing equipment needed for most adhesive applications, making fasteners cost-effective for such cases.

http://www.machinedesign.com/basics-design/joining-composites
« Last Edit: 05/08/2018 01:26 am by Kabloona »

Offline ZachF

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Re: F9 Block 5 Updates and Discussion
« Reply #675 on: 05/08/2018 01:39 am »
"Run as fast as you can, carefully"

Made my morning! 
>

Mine too! BTW,

"Quantum potes fugere sedulo"

Anyone want to design them a crest? ;)

Something like this?
artist, so take opinions expressed above with a well-rendered grain of salt...
https://www.instagram.com/artzf/

Online Johnnyhinbos

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Re: F9 Block 5 Updates and Discussion
« Reply #676 on: 05/08/2018 01:45 am »
I’m pretty sure those are rivets connecting the carbon fiber leg “fairing” to a stiffener made out of another material. This would run from hinge point down to contact point.

I'd agree that they're fasteners, but what you're calling a stiffener I'd guess is more like a metal doubler that, along with the fasteners, acts to clamp the two composite pieces (outer and inner faces) of the leg together. Carbon fiber is already so stiff that the leg cross-section should be more than strong enough without stiffeners, and the relative narrowness of that strip, just wide enough to carry the bearing stress of the fastener heads, makes me think it's for that purpose.

Probably SpaceX came up with a more efficient manufacturing process for the legs, one that requires some assembly but makes the composite parts easier to fabricate.

Quote
Theoretically, all composites could be adhesively bonded. However, many manufacturers avoid adhesive bonds where joints undergo large amounts of stress; thus, fasteners are still specified for many joints. Also, some structures and components are so large that they preclude the use of the special lay-up tooling and curing equipment needed for most adhesive applications, making fasteners cost-effective for such cases.

http://www.machinedesign.com/basics-design/joining-composites
Good point. It’ll be interesting to see these legs unfolded...
John Hanzl. Author, action / adventure www.johnhanzl.com

Online docmordrid

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Re: F9 Block 5 Updates and Discussion
« Reply #677 on: 05/08/2018 01:59 am »


"Run as fast as you can, carefully"

Made my morning! 
>

Mine too! BTW,

"Quantum potes fugere sedulo"

Anyone want to design them a crest? ;)

Something like this?

Perfect
DM

Online intrepidpursuit

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Re: F9 Block 5 Updates and Discussion
« Reply #678 on: 05/08/2018 04:39 am »
I’m pretty sure those are rivets connecting the carbon fiber leg “fairing” to a stiffener made out of another material. This would run from hinge point down to contact point.

I'd agree that they're fasteners, but what you're calling a stiffener I'd guess is more like a metal doubler that, along with the fasteners, acts to clamp the two composite pieces (outer and inner faces) of the leg together. Carbon fiber is already so stiff that the leg cross-section should be more than strong enough without stiffeners, and the relative narrowness of that strip, just wide enough to carry the bearing stress of the fastener heads, makes me think it's for that purpose.

Probably SpaceX came up with a more efficient manufacturing process for the legs, one that requires some assembly but makes the composite parts easier to fabricate.

Quote
Theoretically, all composites could be adhesively bonded. However, many manufacturers avoid adhesive bonds where joints undergo large amounts of stress; thus, fasteners are still specified for many joints. Also, some structures and components are so large that they preclude the use of the special lay-up tooling and curing equipment needed for most adhesive applications, making fasteners cost-effective for such cases.

http://www.machinedesign.com/basics-design/joining-composites

It may also be a tool for refurbishment. Say the legs are wearing at the edges due to flames and aerodynamics so they put a separate piece of carbon fiber there that is replaceable.

Bonding carbon fiber to metal is difficult and often causes more problems than it solves. I can't imagine a flat piece of metal like that adding stiffness to the contoured carbon fiber there and the color implies it is all the same material. It could well be for joining, but bonding two chunks of carbon fiber together is generally pretty trivial compared to fastening them. The only reason I can think of to fasten it is to make it removable.

Offline strax

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Re: F9 Block 5 Updates and Discussion
« Reply #679 on: 05/08/2018 06:54 am »


"Run as fast as you can, carefully"

Made my morning! 
>

Mine too! BTW,

"Quantum potes fugere sedulo"

Anyone want to design them a crest? ;)

Something like this?

Perfect

Nah...

This is better: ardet nec consumitur, burned (but) not destroyed. And a phoenix as picture.

Think of all those burned S1's.

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