Author Topic: Fairing reuse  (Read 590173 times)

Offline Jim

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Re: Fairing reuse
« Reply #580 on: 02/24/2017 02:06 AM »

As for when did SpaceX start thinking about fairing recovery - I don't know, and neither do you.  It's clearly not the final design, but whether they were built more robustly to enable even initial experimentation - we simply can't tell.  But probably earlier than a year ago...


The fairing design predates the first launch

Why would that support your case?

because nothing supports yours and the fairing supports the payload and that it why it is heavy.  There is no other US fairing that can support a payload in the same manner without major redesign.
« Last Edit: 02/24/2017 02:07 AM by Jim »

Offline meekGee

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Re: Fairing reuse
« Reply #581 on: 02/24/2017 02:08 AM »

As for when did SpaceX start thinking about fairing recovery - I don't know, and neither do you.  It's clearly not the final design, but whether they were built more robustly to enable even initial experimentation - we simply can't tell.  But probably earlier than a year ago...


The fairing design predates the first launch

Why would that support your case?

because nothing supports yours and the fairing supports the payload and that it why it is heavy.  There is no other US fairing that can support a payload.
What I asked was why would the fact that the fairing design is old support your assertion.  You brought it up, not me.
« Last Edit: 02/24/2017 03:30 AM by meekGee »
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Offline Jim

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Re: Fairing reuse
« Reply #582 on: 02/24/2017 02:08 AM »
....

Also shines new light on the payload restrictions of about 10 T to the current payload. It was speculated that FH can not bring heavy payloads to LEO because the adapter is not capable to hold heavy loads. Maybe the adapter is not the limitation.. Maybe it's the fairing.

It will be interesting to see what the maximum payload will be for the FH when vertically integrated at LC-39A

if it happens at all.

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Re: Fairing reuse
« Reply #583 on: 02/24/2017 11:50 AM »
....

Also shines new light on the payload restrictions of about 10 T to the current payload. It was speculated that FH can not bring heavy payloads to LEO because the adapter is not capable to hold heavy loads. Maybe the adapter is not the limitation.. Maybe it's the fairing.

It will be interesting to see what the maximum payload will be for the FH when vertically integrated at LC-39A

if it happens at all.

True. The primary customer for FH would be heavy GTO sats. These are not so heavy to exceed the GTO capacity of FH. So there would be no reason to update to vertical integration or new fairings that support heavier loads. Time will tell if SpaceX wants to launch heavy LEO payloads like bigelow modules and national security payloads.

Offline watermod

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Re: Fairing reuse
« Reply #584 on: 02/24/2017 12:59 PM »
If it can be made/machined to size this new material (metal foam) might make a great next-gen faring.
http://www.foxnews.com/tech/2017/02/23/this-foam-stops-bullets-cold-and-pulverizes-them-to-dust.html

Offline Doesitfloat

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Re: Fairing reuse
« Reply #585 on: 02/24/2017 03:04 PM »
This theory hasn't been mentioned yet so:
Spacex fairing are heavier because they use a less expensive but lower strength carbon fiber. The high strength aerospace carbon fiber is double to triple the cost of a utility strength fiber. In addition to ensure the higher strength the resin system is also more expensive. ( Resin system + manufacturing system)
Simply to get an equivalent strength out of lower strength fiber  there must be more... hence heavier.
But Cheaper

Offline ennisj

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Re: Fairing reuse
« Reply #586 on: 02/24/2017 07:15 PM »
One other thing I haven't seen mentioned is that SpaceX uses a pneumatic system for fairing separation; everyone else (to my knowledge) uses pyrotechnics.

I can't imaging why that would double the weight though. But it is another difference.

Offline AAPSkylab

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Re: Fairing reuse
« Reply #587 on: 02/24/2017 07:34 PM »
This theory hasn't been mentioned yet so:
Spacex fairing are heavier because they use a less expensive but lower strength carbon fiber. The high strength aerospace carbon fiber is double to triple the cost of a utility strength fiber. In addition to ensure the higher strength the resin system is also more expensive. ( Resin system + manufacturing system)
Simply to get an equivalent strength out of lower strength fiber  there must be more... hence heavier.
But Cheaper

Is this cheaper construction known as fact or is it speculation?

If this is true, could this mean that their intent is to research and develop fairing recovery and reuse while using this less expensive construction method.  After they succeed (if possible) then they could transfer their recovery tech to a more expensive but lighter construction method.  This way the recovery tech might not be a weight penalty and the ability to recover and reuse would mitigate the increased cost of construction.

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Re: Fairing reuse
« Reply #588 on: 02/24/2017 08:02 PM »
I like the idea that they built a cheap but heavy fairing .... knowing that eventually they would reengineer it with more expensive but lighter materials... more expensive ONCE, yes,  but since now it's recoverable (the mass savings is used for whatever the recovery mechanism is), actually LESS expensive iff they mostly get it back.

they were thinking ahead.

People focus on SpaceX changing plans but they miss that they also have been taking the long view here for a long time.

Also I don't see the need for a lot of heat shielding (said upthread a lot).... These have very low density so terminal velocity is low.
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Offline cscott

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Re: Fairing reuse
« Reply #589 on: 02/24/2017 11:28 PM »
I don't see any evidence they are using anything other than current state-of-the-art aerospace composites for the fairing.  Let's not pile speculation on speculation.

Offline Lee Jay

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Re: Fairing reuse
« Reply #590 on: 02/25/2017 12:20 AM »
I like the idea that they built a cheap but heavy fairing ....

What makes you think it's cheap?  Elon said it was "millions of dollars", which is quite a lot for a structure this size.

Offline JamesH65

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Re: Fairing reuse
« Reply #591 on: 02/25/2017 05:24 PM »
I don't see any evidence they are using anything other than current state-of-the-art aerospace composites for the fairing.  Let's not pile speculation on speculation.

Of course, there is no evidence they are using state of the art aerospace composites either...unless you want to assume/speculate that they are....;-)

Offline cscott

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Re: Fairing reuse
« Reply #592 on: 02/25/2017 06:27 PM »
We know the original manufacturer of the fairings was doing current aerospace grade work.  You can speculate that SpaceX simplified or complexified things after they brought manufacturing in-house, but until they do a major fairing redesign Occam's razor would state they are still using something close to standard manufacturing practice for composites.

And SpaceX disclaims any craziness:
Quote
. The fairing is 13.1 meters (43 feet) high and 5.2 meters (17 feet) wide. It consists of an aluminum honeycomb core with carbon-fiber face sheets fabricated in two half-shells.
http://www.spacex.com/news/2013/04/12/fairing

Note: when I say "state-of-the-art" I mean, same as any other current manufacturer would use.  I'm not claiming super secret sauce or unicorn novelty.
« Last Edit: 02/25/2017 06:31 PM by cscott »

Offline Robotbeat

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Re: Fairing reuse
« Reply #593 on: 02/25/2017 06:33 PM »
Toray makes the best carbon fiber, bar none. They got a monopoly on the best stuff. But it's very, very difficult to get ahold of it if you aren't Boeing. You need an agreement with them, which SpaceX only recently got. Safe to say SpaceX has not been using Toray in the past.
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Offline DOCinCT

Re: Fairing reuse
« Reply #594 on: 02/25/2017 08:47 PM »
Even though the fairing is somewhat constrained in terms of usable volume there are spaces available not normally assigned to payload as shown in the hatched area in the picture. If they went the parachute route, the spaces by the PAF seem most useful.
(Note:the heavy PAF can handle payloads up to 24,000 lb, far short of the FH throw wgt.)

Offline Jim

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Re: Fairing reuse
« Reply #595 on: 02/25/2017 11:23 PM »
Fairing 2.0 will be a little different and slightly larger

Offline Jcc

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Re: Fairing reuse
« Reply #596 on: 02/25/2017 11:31 PM »
Fairing 2.0 will be a little different and slightly larger

Do you have a source (and if so, please tell)?

Offline cscott

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Re: Fairing reuse
« Reply #597 on: 02/26/2017 12:43 AM »
Jim is a source.

Offline meekGee

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Re: Fairing reuse
« Reply #598 on: 02/26/2017 12:50 AM »
It'll be interesting to see how much it will weigh...

Though the principle of "performance loss for reusability" still applies.
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Offline envy887

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Re: Fairing reuse
« Reply #599 on: 02/26/2017 01:16 AM »
Any idea when this will be flying? Only on Heavy or on F9 also?

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