A Space & astronomy forum. SpaceBanter.com

Go Back   Home » SpaceBanter.com forum » Space Science » Policy
Site Map Home Authors List Search Today's Posts Mark Forums Read Web Partners

Were liquid boosters on Shuttle ever realistic?



 
 
Thread Tools Display Modes
  #31  
Old October 28th 17, 08:38 PM posted to sci.space.policy
Jeff Findley[_6_]
external usenet poster
 
Posts: 2,307
Default Were liquid boosters on Shuttle ever realistic?

In article m,
says...

On 2017-10-27 18:49, Greg (Strider) Moore wrote:

Actually delivers? They've done 15 flights this year and expect at least 4
more (I'm not counting Heavy as I expect that will slip).


What percentage were re-used stage 1s ?


Google it. It's worth a Google.

SpaceX is basically at the "prototype" stage for reflying stages. It
hasn't delivered yet on high rate and quick turn around of reflying stages.


So what? They're doing better at turning around recovered first stages
to be re-flown faster than any of the competition (none of them are
doing this for their orbital launchers). They're also cheaper than just
about anyone else (for LEO and GTO payloads). So, who cares how long it
takes to turn around a Block 3 or Block 4?

Just because everyone has confidence that it will deliver, it doesn't
mean that it has delivered.


The Block 5 has improvements to the design to help with reuse. SpaceX
will only get better at this while the competition (aside from Blue
Origin, who's still working on the BE-4 engine for New Glenn) are not
even trying to reuse anything.

Also not clear what percentage of landings might cause more than a
easily replaced broken leg (compressed crush zone). Say, for sake of
discussion, only 50% of stages can be reflown, this could change SpaceX
plans to wind down Falcon 9 production to start BFR production because
they would need higher stock of new Falcon 9s to cope with fact they
aren't recyling 100% of stages.


The crush core is more likely to be used up on high energy launches. In
the future, these will be flown on Falcon Heavy, so that the side
boosters will land on concrete pads at Cape Canaveral and only the core
booster stage will need to land on the barge (with more fuel margin than
a Falcon 9 would have had). So this will get better with time.

So there needs to be more empirical data on landings, refurbishements
before SpaceX would know for sure how thing will pan out.


Bull****. They're already saving money by reusing recovered first
stages. That's what counts. Customers are already switching to flights
with reused first stages because they can get their payloads into orbit
faster than if they wait for a new first stage to be built. Getting
your satellite in orbit faster means it generates revenue sooner.

or it could be that even with the hard landings, the stages are far from
having any structural damage and fixing legs is the only repair needed,
so it become more of a 1 and 0 (either it lands and can be re-used
easily, or goes kaboom on landing).


This is more likely. That's why there is crush core inside the legs.
It's expendable. It's like an energy absorbing bumper on a car. A
"fender bender" destroys the bumper cover and the energy absorbing
material in the bumper, but saves the rest of the car from structural
damage. So, those leaning first stages on barges means the crush core
did its job.

And while "going kaboom" on landing hasn't happened in a while, is this
just stroke of luck, or has SpaceX realy gotten their software to work
reliably enough to conclude that "kabooms" won't happen again? How many
more landings before such a conclusion can be made?


There is always risk. There are no guarantees in life.

Jeff
--
All opinions posted by me on Usenet News are mine, and mine alone.
These posts do not reflect the opinions of my family, friends,
employer, or any organization that I am a member of.
  #33  
Old October 29th 17, 02:47 AM posted to sci.space.policy
Fred J. McCall[_3_]
external usenet poster
 
Posts: 10,018
Default Were liquid boosters on Shuttle ever realistic?

JF Mezei wrote:

On 2017-10-27 18:49, Greg (Strider) Moore wrote:

Actually delivers? They've done 15 flights this year and expect at least 4
more (I'm not counting Heavy as I expect that will slip).


What percentage were re-used stage 1s ?


Enough to service all customers asking for them.


Consider commercial aircraft. There is a huge difference between
building the couple of prototypes to do flight tests and going into
production and ramping up production. The prototypes get a lot more
"manual" work to get things to fit/work. But to go into production all
those production glitches need to be fixed otherwise they can't ramp up
production since each plane takes too long to assemble.


The 'used' boosters are the same as the new ones, so all the
'prototype' **** was done long ago. There is very little 'automated
assembly' in aerospace in general and even less when it comes to
rocket boosters.


SpaceX is basically at the "prototype" stage for reflying stages. It
hasn't delivered yet on high rate and quick turn around of reflying stages.


Name a customer who has asked for a 'used' stage and hasn't gotten
one. You don't fly payloads worth hundreds of millions of dollars on
'prototypes', you nitwit.


Just because everyone has confidence that it will deliver, it doesn't
mean that it has delivered.


Also not clear what percentage of landings might cause more than a
easily replaced broken leg (compressed crush zone). Say, for sake of
discussion, only 50% of stages can be reflown, this could change SpaceX
plans to wind down Falcon 9 production to start BFR production because
they would need higher stock of new Falcon 9s to cope with fact they
aren't recyling 100% of stages.


Say, for sake of discussion, that each used stage must be bathed in
magic pixie dust produced by rainbow unicorn farts. It makes about as
much sense as what you're saying. A compressed crush zone is NOT a
"broken leg". This has been explained to you repeatedly, but in true
Mayfly fashion it doesn't seem to stick in your brain for more than a
very short time. Let me try again. The emergency crush core on
Falcon 9 landing legs is there for when the landing is so 'hot' that
the leg would take damage from the impact. In this case, the crush
core, well, crushes and absorbs all that energy. The leg itself is
unlikely to take damage unless the entire crush core is expended,
which has NEVER happened. The crush core is a cartridge that is
designed to be easily inspected, removed, and replaced as needed.

Just what else do you think is being 'damaged' in your 50% 'for
discussion' catastrophic damage rate?


So there needs to be more empirical data on landings, refurbishements
before SpaceX would know for sure how thing will pan out.


You will never think there is enough 'empirical data' to draw a
conclusion because you insist on nitwittery.


or it could be that even with the hard landings, the stages are far from
having any structural damage and fixing legs is the only repair needed,
so it become more of a 1 and 0 (either it lands and can be re-used
easily, or goes kaboom on landing).


Which is where it's at. Just what 'structural damage' do you think
can occur when the energy absorbing crush core hasn't been fully
crushed?


And while "going kaboom" on landing hasn't happened in a while, is this
just stroke of luck, or has SpaceX realy gotten their software to work
reliably enough to conclude that "kabooms" won't happen again? How many
more landings before such a conclusion can be made?


It's rocketry, you nitwit. A 'kaboom' is always possible. Musk said
(back at the beginning of 2016) that he expected about a 70% success
rate with recovery in 2016 (actual rate was 63% and one more success
would have taken it to 75%) when recovery was still billed as
'experimental' and 90% in 2017 (so far it's 100%) when recovery is
considered 'production'. Developmental tests of the capability were
performed in 2014-2015, including both water landings and some barge
attempts. Experimental test was conducted in 2016. 'Production' use
started at the beginning of 2017. Success rate through experimental
test and production use is 19 attempts for 14 successes (just under
74%) with all the failures occurring during the experimental test
phase. That's a pretty damned good record when it comes to rocket
testing.

Musk seems to think he has enough data to declare it 'production use'
starting at the beginning of this year. I believe him before I belief
**** you pull out of your ass.


--
"Some people get lost in thought because it's such unfamiliar
territory."
--G. Behn
  #34  
Old October 29th 17, 02:58 AM posted to sci.space.policy
Fred J. McCall[_3_]
external usenet poster
 
Posts: 10,018
Default Were liquid boosters on Shuttle ever realistic?

JF Mezei wrote:

On 2017-10-27 18:52, Fred J. McCall wrote:

You try far too hard to muddy things up.


And some cheer lead too much for SpaceX.

Just because SpaceX has great image and people have confidence it will
deliver on what it promises does not mean that it has already delivered.


OK, I was being polite. Now I will be less so. You're a ****ing
idiot who is ignorant of the facts and can't retain them when they are
given to you. After two years of developmental test (2014-2015) Musk
predicted the success rates for both experimental test (2016 - 70%
predicted vs 63% achieved; one more success would have been 75%) and
operational use (2017 - 90% predicted vs 100% achieved so far) with
pretty astonishing accuracy. You don't do that on "not enough data"
and if it was 'just lucky guesses' he should be buying lottery tickets
to fund SpaceX. That's not cheerleading. That's the bloody facts,
which you seem to be immune to.

SpaceX declared landing the first stage 'operational' as of this year
and has started commercially offering reflown boosters as an option
(first commercial launch in March of this year). Again, that's the
FACTS, you ignorant assclown.


--
"Ignorance is preferable to error, and he is less remote from the
truth who believes nothing than he who believes what is wrong."
-- Thomas Jefferson
  #35  
Old October 29th 17, 07:37 AM posted to sci.space.policy
Niklas Holsti
external usenet poster
 
Posts: 168
Default Were liquid boosters on Shuttle ever realistic?

On 17-10-29 05:32 , JF Mezei wrote:
On 2017-10-28 21:58, Fred J. McCall wrote:

SpaceX declared landing the first stage 'operational' as of this year
and has started commercially offering reflown boosters as an option
(first commercial launch in March of this year). Again, that's the
FACTS, you ignorant assclown.



So you are stating that reflying 1 stage proves that they can quickly
turn around stages and offer high frequency launch of reflown stages?


According to Wikipedia
(https://en.wikipedia.org/wiki/Falcon_9#Notable_flights, heading
"Relaunch of previously-flown first stages") there have so far been
*three* reflights of Falcon 9 boosters, not one. All successful, and all
relanded the booster, again.

--
Niklas Holsti
Tidorum Ltd
niklas holsti tidorum fi
. @ .
  #36  
Old October 29th 17, 04:02 PM posted to sci.space.policy
Greg \(Strider\) Moore
external usenet poster
 
Posts: 752
Default Were liquid boosters on Shuttle ever realistic?

"JF Mezei" wrote in message
eb.com...

On 2017-10-28 21:47, Fred J. McCall wrote:

Musk seems to think he has enough data to declare it 'production use'
starting at the beginning of this year. I believe him before I belief
**** you pull out of your ass.



Am not debating that they can do it. And yes, they are selling launches
on refurb stages. But as I recall, they've only have 1 launch so far on
a refurb stage. All those sales are for future launches. When those
happen, then SpaceX will have demonstrated it can deliver on turning
around landed stages quickly enough to meet customer demand.


You really need to learn to use Google. There are 3 reflights so far, and 2
more scheduled. So that's about 2% of the flights.
Iridium has bought 2 more flights (for next year) on used boosters
(ironically these won't be recovered).

And if Heavy takes off this year, that's 2 more boosters that will be
reflown this year. If not, next year.


Until then, it is cheer leading to state that they have proven it.

And the day may come where a launch on refurb stage will be sold at a
premium since it pretty much eliminates the 0-day defects on a totally
new stage.

Just because the future is extremely promising doesn't mean SpaceX has
already demonstrated it.


--
Greg D. Moore http://greenmountainsoftware.wordpress.com/
CEO QuiCR: Quick, Crowdsourced Responses. http://www.quicr.net
IT Disaster Response -
https://www.amazon.com/Disaster-Resp...dp/1484221834/

  #37  
Old October 29th 17, 04:07 PM posted to sci.space.policy
Greg \(Strider\) Moore
external usenet poster
 
Posts: 752
Default Were liquid boosters on Shuttle ever realistic?

"JF Mezei" wrote in message
web.com...

On 2017-10-29 02:37, Niklas Holsti wrote:

According to Wikipedia
(https://en.wikipedia.org/wiki/Falcon_9#Notable_flights, heading
"Relaunch of previously-flown first stages") there have so far been
*three* reflights of Falcon 9 boosters, not one. All successful, and all
relanded the booster, again.


Thank for clarification.

Stll not the 15 or so flight another poster claimed.


No one claimed 15 REflights. We've been pointing out 15 flights, with 4
more definitely planned. That's a higher rate than pretty much anyone
booster.
This for a system that's still relatively new. Oh and Boeing moved an X-37B
flight to Falcon 9 off of one of their own ULA boosters.

And they've shown an ability to reschedule payloads as things change. If
nothing else, the ability to stack and destack in under 2 weeks (I think
it's actually just a few days) is a huge improvement over existing
launchers.


They note that the the first reflight resulted in the booster, despite
landing fine, was retired. I would assume SpaceX wants to figure out how
many times boosters can be re-used, and retiring after only 2 launches
isn't that great.


Sure it is. First it's historical. Secondly you move in incremental steps.

But this is another example of being too early to draw conclusions on
just how reusable they will be.


No, you keep making assumptions about what most of us think.


--
Greg D. Moore http://greenmountainsoftware.wordpress.com/
CEO QuiCR: Quick, Crowdsourced Responses. http://www.quicr.net
IT Disaster Response -
https://www.amazon.com/Disaster-Resp...dp/1484221834/

  #38  
Old October 29th 17, 04:15 PM posted to sci.space.policy
Greg \(Strider\) Moore
external usenet poster
 
Posts: 752
Default Were liquid boosters on Shuttle ever realistic?

"JF Mezei" wrote in message
web.com...

On 2017-10-28 15:38, Jeff Findley wrote:

So what? They're doing better at turning around recovered first stages
to be re-flown faster than any of the competition


The only "re-use" competition is the Shuttle and it wasn't a commercial
endeavour.

Landing a just launched stage doesn't save any money. It costs money.

Launching a payload with a re-used stage 1 is what saves you money.


The Block 5 has improvements to the design to help with reuse.


One could infer that those improvements are a sign that the current
Falcon 9 is harder to re-use as the cheer leaders say it is.


No, this is how engineering is done. Incremental steps as you learn more.


SpaceX
will only get better at this while the competition (aside from Blue
Origin, who's still working on the BE-4 engine for New Glenn) are not
even trying to reuse anything.


The argument isn't whether SpaceX is ahead or other or not. The mere
fact that they have demonstrated they can land a stage, and have re-used
at least 1 stage means they are way ahead of anyone else.

But that doesn't mean that they have proven that they can already
quickly turn around every landed Falcon 9.

They've demonstrated the concept, they've demonstrated they can land
stages, they have demonstrated they can refly at least 1 stage. But
havent yet demonstrated they can have short turn around between landing
pad and launch pad such that it allows high launch rate OF RE-USED STAGES.

Just because it is very likely that they will be able to turn these
around quickly doesn't translate to them having demonstrated it.

Just because there are improvements coming that will make future refurb
even easier doesn't mean that they have demonstrated it already.



The crush core is more likely to be used up on high energy launches.


On a commecial aircraft, after a hard landing, the aircraft is put "off
line" for inspections. So I would assume that if a crush core gets used
up fully, the stage may require more time to be certified for reflight.


I am not questioning the huge game changing advantage SpaceX has in
having developped re-usable stages. Am not questioning that they have
proven they can land stages and re-use at least 1.

What they haven't proven yet is the ability to ramp up refurbishement to
do quick turn around from landing pad to launch pad. It's too early for
them to have demonstrated it.


Give them time. But I was curious.
Booster 1035 will have reflown in less than 6 months.
Looking at the list, right now it looks like 6 months on average.
That's similar to the first few flights of the shuttle.

But, Musk's goal is to do a reflight within 24 hours. I suspect he'll do it
within the next year or two, if only as a demonstration.

I suspect we'll see 1-2 weeks between reflights down the road.


--
Greg D. Moore http://greenmountainsoftware.wordpress.com/
CEO QuiCR: Quick, Crowdsourced Responses. http://www.quicr.net
IT Disaster Response -
https://www.amazon.com/Disaster-Resp...dp/1484221834/

  #39  
Old October 29th 17, 04:23 PM posted to sci.space.policy
Fred J. McCall[_3_]
external usenet poster
 
Posts: 10,018
Default Were liquid boosters on Shuttle ever realistic?

JF Mezei wrote:

On 2017-10-28 15:38, Jeff Findley wrote:

So what? They're doing better at turning around recovered first stages
to be re-flown faster than any of the competition


The only "re-use" competition is the Shuttle and it wasn't a commercial
endeavour.

Landing a just launched stage doesn't save any money. It costs money.

Launching a payload with a re-used stage 1 is what saves you money.


But SpaceX is going to the trouble to land them, so presumably they
think they're going to save money.



The Block 5 has improvements to the design to help with reuse.


One could infer that those improvements are a sign that the current
Falcon 9 is harder to re-use as the cheer leaders say it is.


One could infer that if one was an idiot. Sane people with actual
working brains would infer that the current Falcon 9 is harder to
re-use than they would like it to be, which is something entirely
different than what you said.



SpaceX
will only get better at this while the competition (aside from Blue
Origin, who's still working on the BE-4 engine for New Glenn) are not
even trying to reuse anything.


The argument isn't whether SpaceX is ahead or other or not. The mere
fact that they have demonstrated they can land a stage, and have re-used
at least 1 stage means they are way ahead of anyone else.


I'm surprised you remember this, Mayfly.


But that doesn't mean that they have proven that they can already
quickly turn around every landed Falcon 9.


But that would certainly be the way to bet. This will never be
'proven' to your satisfaction, because there will always be more
stages to turn around.


They've demonstrated the concept, they've demonstrated they can land
stages, they have demonstrated they can refly at least 1 stage. But
havent yet demonstrated they can have short turn around between landing
pad and launch pad such that it allows high launch rate OF RE-USED STAGES.


Nor do they need to. You seem quite confused about how this 'needs'
to work to be viable. Turn around doesn't need to be particularly
"short term". It just needs to be cheaper than manufacturing a new
one, which is pretty much a given. If my total launch rate is 17
launches per year and I have 34 'used' stages in stock, I can take as
long as a year to 'turn' them and still meet launch schedules. Not
that it will take that long. You could completely disassemble,
inspect, and reassemble the stage in much less time than that.


Just because it is very likely that they will be able to turn these
around quickly doesn't translate to them having demonstrated it.

Just because there are improvements coming that will make future refurb
even easier doesn't mean that they have demonstrated it already.


They will never 'demonstrate' it to your satisfaction, nor do they
need to.



The crush core is more likely to be used up on high energy launches.


On a commecial aircraft, after a hard landing, the aircraft is put "off
line" for inspections. So I would assume that if a crush core gets used
up fully, the stage may require more time to be certified for reflight.


I would certainly expect so, BUT THAT HAS NEVER HAPPENED IN THE ENTIRE
HISTORY OF FALCON 9.


I am not questioning the huge game changing advantage SpaceX has in
having developped re-usable stages. Am not questioning that they have
proven they can land stages and re-use at least 1.

What they haven't proven yet is the ability to ramp up refurbishement to
do quick turn around from landing pad to launch pad. It's too early for
them to have demonstrated it.


They don't need to do it. That's not the point of the exercise.
Nobody is talking about refueling a stage after it lands and reusing
it immediately for any Falcon rocket. Unless you think the cost of
landing, reconditioning, and reusing a stage is more than the cost of
a new stage (and if you do you're a Falcon idiot), SpaceX has proven
everything it needs to prove.


--
"Some people get lost in thought because it's such unfamiliar
territory."
--G. Behn
  #40  
Old October 29th 17, 04:30 PM posted to sci.space.policy
Fred J. McCall[_3_]
external usenet poster
 
Posts: 10,018
Default Were liquid boosters on Shuttle ever realistic?

JF Mezei wrote:

On 2017-10-28 21:47, Fred J. McCall wrote:

Musk seems to think he has enough data to declare it 'production use'
starting at the beginning of this year. I believe him before I belief
**** you pull out of your ass.


Am not debating that they can do it. And yes, they are selling launches
on refurb stages. But as I recall, they've only have 1 launch so far on
a refurb stage. All those sales are for future launches. When those
happen, then SpaceX will have demonstrated it can deliver on turning
around landed stages quickly enough to meet customer demand.


They just started selling flights on 'refurb stages' this year. Even
at the high launch rate that SpaceX has, just how many opportunities
do you think there are to refly stages? And what, in your mind,
drives how fast they must turn them? They have almost a year's worth
of 'used' stages in stock. You'd like to have a few more than that on
hand in case something goes wrong with a launch or booster recovery,
but that allows the better part of a year to refurb a stage and still
be 'fast enough' and that's pretty much a no brainer. I say 'pretty
much', because you don't seem to get it.


Until then, it is cheer leading to state that they have proven it.


Bull****.


And the day may come where a launch on refurb stage will be sold at a
premium since it pretty much eliminates the 0-day defects on a totally
new stage.


Unlikely, since that sort of kills the whole thing. The idea is LOWER
COST TO ORBIT, not higher.


Just because the future is extremely promising doesn't mean SpaceX has
already demonstrated it.


Except, of course, they pretty much have.


--
"Some people get lost in thought because it's such unfamiliar
territory."
--G. Behn
 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Are rotating stations realistic ? John Doe Space Station 2 May 19th 10 10:15 AM
"Boeing To Study Liquid Fly Back Shuttle Boosters For NASA" gaetanomarano Policy 19 November 27th 07 06:59 AM
shuttle, tank and boosters on its crawler Rich Space Shuttle 37 September 11th 06 09:09 AM
Shuttle Liquid Fly-Back Booster to save money, improve safety(flashback) Bob Wilson Space Shuttle 0 July 16th 06 02:12 AM
Space Shuttle Boosters and Launch Pad Revell Model Kit on eBay TB Space Shuttle 2 February 1st 05 08:00 AM


All times are GMT +1. The time now is 12:36 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 SpaceBanter.com.
The comments are property of their posters.