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Towards routine, reusable space launch.



 
 
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  #11  
Old June 11th 18, 08:02 PM posted to sci.astro,sci.physics,sci.space.policy
Sergio
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Posts: 37
Default Towards routine, reusable space launch.

On 6/11/2018 11:36 AM, Thomas Koenig wrote:
Jeff Findley schrieb:

By your definition, a passenger carrying aircraft is "waste" because it
flies from one destination to another while carrying passengers.


Of course.

Firing passengers from large-caliber guns generates much less waste,
obviously, and should be the preferred solution :-)


perhaps the passengers should walk.
  #12  
Old June 11th 18, 10:23 PM posted to sci.astro,sci.physics,sci.space.policy
benj
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Posts: 5
Default Towards routine, reusable space launch.

On 6/11/2018 3:02 PM, Sergio wrote:
On 6/11/2018 11:36 AM, Thomas Koenig wrote:
Jeff Findley schrieb:

By your definition, a passenger carrying aircraft is "waste" because it
flies from one destination to another while carrying passengers.


Of course.

Firing passengers from large-caliber guns generates much less waste,
obviously, and should be the preferred solution :-)


perhaps the passengers should walk.

Correct me if I'm wrong, Sergio, But then they would be
"pedestrians" rather than passengers, right?
  #13  
Old June 11th 18, 11:18 PM posted to sci.space.policy,sci.physics,sci.astro,rec.arts.sf.science
Doc O'Leary[_3_]
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Posts: 13
Default Towards routine, reusable space launch.

For your reference, records indicate that
Thomas Koenig wrote:

An older version of a Falcon 9 reportedly had 488 tons of total
fuel, 147 of it RP-1 (a modified kerosene). Liquid oxygen is
quite cheap, and if we give RP-1 a cost of 1 dollar per kg,
we probably are in the right ballpark. So, around 150 000 Dollar
per launch.

This is _very_ low compared to all the other costs. A launch
cost around 50 to 60 million dollars now, if I remember the
figures right.


That’s just the problem: you’re only accounting for the cost of the fuel, whereas I would consider large parts of “all the other costs” as inherently part of the efficiency equation. After all, if we found a way to eliminate the boosters entirely, the savings is obviously not just from the decrease in fuel.

--
"Also . . . I can kill you with my brain."
River Tam, Trash, Firefly


  #14  
Old June 11th 18, 11:35 PM posted to sci.space.policy,sci.physics,sci.astro,rec.arts.sf.science
Doc O'Leary[_3_]
external usenet poster
 
Posts: 13
Default Towards routine, reusable space launch.

For your reference, records indicate that
Fred J. McCall wrote:

Doc O'Leary wrote on Mon, 11 Jun
2018 03:16:38 -0000 (UTC):

Like I said, it might not *currently* be viable, but as an alternative
technology it brings new sets of trade-offs to the table such that a few
tweaks here and there might make it viable for certain kinds of launches
(e.g., “bulky” items that are hard to make aerodynamically efficient
benefit from starting at the highest possible altitude).


And just what such items do we send to space?


Chicken and egg. The fact is that we *do* sometimes have to
elaborately engineer spacecraft in order to make them small enough to
fit into a nose cone or payload bay of a rocket. A different launch
vehicle/process might allow us more flexibility when it comes to
approaching those very real problems.

We're constrained by the real world. Magic materials are right out.


Straw man. All I’m saying is that it’s foolish to completely discount
new technologies simply because they’re not the rockets you know so
well from the past.

Hope for bigger things. I fully believe that, for a society to be
advanced enough to make a space elevator project realistic, it’s value
would be more incremental than revolutionary. Rockets are the best we
have right now, but we’re stuffed if that’s the best we can do.


Just why are we 'stuffed'? Be specific.


Because rockets have only taken humans as far as the Moon, but we
haven’t gone to the Moon in decades, and we’ll likely see all the
people who *have* been to the Moon dead before we ever return there.
*Maybe* the promise of a Mars colony is achievable with rockets, but
probably not in the lifetime of anyone walking on Earth today. And
even in 1000 lifetimes, rockets aren’t going to take us to explore
another planet around another star.

--
"Also . . . I can kill you with my brain."
River Tam, Trash, Firefly


  #15  
Old June 11th 18, 11:50 PM posted to sci.space.policy,sci.physics,sci.astro,rec.arts.sf.science
Doc O'Leary[_3_]
external usenet poster
 
Posts: 13
Default Towards routine, reusable space launch.

For your reference, records indicate that
Jeff Findley wrote:

Balloon launch isn't worth the trades which have to be made, IMHO.


Certainly not today, no, or people would be doing it. But as I keep
saying, new technologies keep popping up all the time that might make
it viable in the future, at least for a few use cases.

By your definition, a passenger carrying aircraft is "waste" because it
flies from one destination to another while carrying passengers.


Yes; that is true by any definition. Just because it’s (arguably) the
least wasteful mode of transportation we currently have says nothing
about how we might travel in the future.

They don't give a rat's ass about the "waste" of the
actual aircraft having to fly there and back.


That same logic could have been used regarding ship or train travel
prior to the airplane’s dominance. The point being that they *will*
care as soon as a new technology comes along that allows more
efficient travel. What that might be in reality is unknown, but
clearly something like teleportation or Futurama-style tubes are
sci-fi ways of moving just the bits that need to be moved from one
location to another.

When your hardware costs more than two
orders of magnitude more than your propellant does, it makes a hell of a
lot of sense to "expend" a bit of propellant to get your expensive
hardware back intact.


Yes. And I’m just wondering why you can’t just take the next step and
admit that eliminating that expensive hardware *completely* would
represent a cost saving of two orders of magnitude! You wrote it, but
it’s like you weren’t really thinking about what your words actually
meant.

--
"Also . . . I can kill you with my brain."
River Tam, Trash, Firefly


  #16  
Old June 12th 18, 02:38 AM posted to rec.arts.sf.science,sci.astro,sci.physics,sci.space.policy
Greg Goss
external usenet poster
 
Posts: 169
Default Towards routine, reusable space launch.

Thomas Koenig wrote:

Jeff Findley schrieb:

By your definition, a passenger carrying aircraft is "waste" because it
flies from one destination to another while carrying passengers.


Of course.

Firing passengers from large-caliber guns generates much less waste,
obviously, and should be the preferred solution :-)


Bobble tech doesn't bother with the guns. Just encapsulate then blow
a nuke nearby.
--
We are geeks. Resistance is voltage over current.
  #17  
Old June 12th 18, 03:20 AM posted to sci.astro,sci.physics,sci.space.policy
Sergio
external usenet poster
 
Posts: 37
Default Towards routine, reusable space launch.

On 6/11/2018 4:23 PM, benj wrote:
On 6/11/2018 3:02 PM, Sergio wrote:
On 6/11/2018 11:36 AM, Thomas Koenig wrote:
Jeff Findley schrieb:

By your definition, a passenger carrying aircraft is "waste" because it
flies from one destination to another while carrying passengers.

Of course.

Firing passengers from large-caliber guns generates much less waste,
obviously, and should be the preferred solution :-)


perhaps the passengers should walk.

Correct me if I'm wrong, Sergio, But then they would be
"pedestrians" rather than passengers, right?


you are right, again.
Unless you consider them as "shoe" passengers, ugh.

or if they were bundled together, like a tour group
  #18  
Old June 12th 18, 04:52 AM posted to sci.space.policy,sci.physics,sci.astro,rec.arts.sf.science
Fred J. McCall[_3_]
external usenet poster
 
Posts: 10,018
Default Towards routine, reusable space launch.

Doc O'Leary wrote on Mon, 11 Jun
2018 22:18:30 -0000 (UTC):

For your reference, records indicate that
Thomas Koenig wrote:

An older version of a Falcon 9 reportedly had 488 tons of total
fuel, 147 of it RP-1 (a modified kerosene). Liquid oxygen is
quite cheap, and if we give RP-1 a cost of 1 dollar per kg,
we probably are in the right ballpark. So, around 150 000 Dollar
per launch.

This is _very_ low compared to all the other costs. A launch
cost around 50 to 60 million dollars now, if I remember the
figures right.


Thats just the problem: youre only accounting for the cost of the fuel, whereas I would consider large parts of all the other costs as inherently part of the efficiency equation. After all, if we found a way to eliminate the boosters entirely, the savings is obviously not just from the decrease in fuel.


Yes, if you postulate the existence of magic everything gets much
easier.


--
"Some people get lost in thought because it's such unfamiliar
territory."
--G. Behn
  #19  
Old June 12th 18, 04:58 AM posted to sci.space.policy,sci.physics,sci.astro,rec.arts.sf.science
Fred J. McCall[_3_]
external usenet poster
 
Posts: 10,018
Default Towards routine, reusable space launch.

Doc O'Leary wrote on Mon, 11 Jun
2018 22:35:20 -0000 (UTC):

For your reference, records indicate that
Fred J. McCall wrote:

Doc O'Leary wrote on Mon, 11 Jun
2018 03:16:38 -0000 (UTC):

Like I said, it might not *currently* be viable, but as an alternative
technology it brings new sets of trade-offs to the table such that a few
tweaks here and there might make it viable for certain kinds of launches
(e.g., ?bulky? items that are hard to make aerodynamically efficient
benefit from starting at the highest possible altitude).


And just what such items do we send to space?


Chicken and egg. The fact is that we *do* sometimes have to
elaborately engineer spacecraft in order to make them small enough to
fit into a nose cone or payload bay of a rocket.


Head and ass. Cite for such payloads? Be specific. You're posting
into a 'sci' newsgroup. Handwavium is not sufficient.


A different launch
vehicle/process might allow us more flexibility when it comes to
approaching those very real problems.


What 'very real problems' would those be?



We're constrained by the real world. Magic materials are right out.


Straw man. All Im saying is that its foolish to completely discount
new technologies simply because theyre not the rockets you know so
well from the past.


Go look up what 'straw man' means. It manifestly does NOT mean
pointing out reality. Cite some of these 'new technologies' and what
it takes for them to work. Be specific. You're crossposting into a
'sci' newsgroup. Handwavium is not sufficient.

Hope for bigger things. I fully believe that, for a society to be
advanced enough to make a space elevator project realistic, it?s value
would be more incremental than revolutionary. Rockets are the best we
have right now, but we?re stuffed if that?s the best we can do.


Just why are we 'stuffed'? Be specific.


Because rockets have only taken humans as far as the Moon, but we
havent gone to the Moon in decades, and well likely see all the
people who *have* been to the Moon dead before we ever return there.
*Maybe* the promise of a Mars colony is achievable with rockets, but
probably not in the lifetime of anyone walking on Earth today. And
even in 1000 lifetimes, rockets arent going to take us to explore
another planet around another star.


So, not 'stuffed' at all, then. As I thought. What do you propose to
replace rockets with, other than 'magic'?


--
"Some people get lost in thought because it's such unfamiliar
territory."
--G. Behn
  #20  
Old June 12th 18, 05:03 AM posted to sci.space.policy,sci.physics,sci.astro,rec.arts.sf.science
Fred J. McCall[_3_]
external usenet poster
 
Posts: 10,018
Default Towards routine, reusable space launch.

Doc O'Leary wrote on Mon, 11 Jun
2018 22:50:22 -0000 (UTC):

For your reference, records indicate that
Jeff Findley wrote:

Balloon launch isn't worth the trades which have to be made, IMHO.


Certainly not today, no, or people would be doing it. But as I keep
saying, new technologies keep popping up all the time that might make
it viable in the future, at least for a few use cases.


Certainly not tomorrow or the next day, either. Just what are these
magical "new technologies" that keep "popping up all the time"?



By your definition, a passenger carrying aircraft is "waste" because it
flies from one destination to another while carrying passengers.


Yes; that is true by any definition. Just because its (arguably) the
least wasteful mode of transportation we currently have says nothing
about how we might travel in the future.


If you want to talk about "how we might travel in the future", you
need to come up with some suggestions (that aren't PFM).



They don't give a rat's ass about the "waste" of the
actual aircraft having to fly there and back.


That same logic could have been used regarding ship or train travel
prior to the airplanes dominance.


Nope. Ships and trains went 'there and back', too. Logic really
isn't your strong suit, is it?


The point being that they *will*
care as soon as a new technology comes along that allows more
efficient travel. What that might be in reality is unknown, but
clearly something like teleportation or Futurama-style tubes are
sci-fi ways of moving just the bits that need to be moved from one
location to another.


In other words, you're postulating some unspecified 'magic'. You're
posting into the wrong newsgroup. See the 'sci' at the front? That
means SCIENCE. That means you can't just wave your arms and fly to
the Moon. You have to actually put forward the scientific basis for
why you can do so.



When your hardware costs more than two
orders of magnitude more than your propellant does, it makes a hell of a
lot of sense to "expend" a bit of propellant to get your expensive
hardware back intact.


Yes. And Im just wondering why you cant just take the next step and
admit that eliminating that expensive hardware *completely* would
represent a cost saving of two orders of magnitude! You wrote it, but
its like you werent really thinking about what your words actually
meant.


Because this is a SCIENCE newsgroup, you ****! Yes, magic would be
nice. We don't have it and never will. Get over it.


--
"Ordinarily he is insane. But he has lucid moments when he is
only stupid."
-- Heinrich Heine
 




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