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Vision of the three Rs: Regular, Reliable and Reusable



 
 
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  #21  
Old February 17th 07, 07:54 PM posted to sci.space.policy
Eric Chomko
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Posts: 2,630
Default Vision of the three Rs: Regular, Reliable and Reusable


Fred J. McCall wrote:
h (Rand Simberg) wrote:

:On Sat, 17 Feb 2007 00:28:54 GMT, in a place far, far away,
(Derek Lyons) made the phosphor on my monitor glow
:in such a way as to indicate that:
:
:Set up a water depot in LEO, and guarantee to purchase at least 1000
:tons/year from the lowest bidder to actually deliver, but with a price
:cap set initially just barely within reach of current launchers. Then
:lower the price cap each year for ten years, to drive continual progress.
:
:In other words - pork and handouts.
:
:No, handouts are when you give the money with no service provided.
:
:Buying something for which demand exists (beyond a future handwaving
:one) amounts to the same thing - giving away money in exchange for
:token services.
:
:Huh?
:
:That should have been 'for which no demand exists'.
:
:But demand can be easily created. Water in space is useful.

And yet every space station that ever was has a problem getting rid of
the stuff.

Hint: You don't try to 'create demand'. You service the ones that
exist and let the new ones come as they will.


Create might be to direct a word but there is nothing wrong with
demand being created out of byproducts of research. Think of the
ARPAnet turned Internet and how the latter has been an economic boon.
Surely the ARPAnet wasn't created to create a demand as it were. But
as a byproduct or research no one can argue that the Internet hasn't
been worthy of service.

Same could be said of spaceflight. Hopefully with all the launches,
the building of ISS and further exploration we stumble upon an actual
economic demand for space.

Eric


--
"The reasonable man adapts himself to the world; the unreasonable
man persists in trying to adapt the world to himself. Therefore,
all progress depends on the unreasonable man."
--George Bernard Shaw


  #22  
Old February 17th 07, 08:23 PM posted to sci.space.policy
Henry Spencer
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Posts: 2,170
Default Vision of the three Rs: Regular, Reliable and Reusable

In article .com,
Totorkon wrote:
Just as important will be the electrolysis and liquification
hardware. Cooling and storing H2 and O should be easier given the
temperature of space and vacuum for the thermous effect.


Actually, electrolyzing water is not a very good way to get fuel.

Electrolysis is *grossly* energy-intensive; a kilowatt-*year* of energy
electrolyzes only about a ton of water.

Moreover, dealing with the results is not that easy, especially for LH2,
which needs active refrigeration at all times -- a headache not only for a
fuel depot, but for its customers. (There are people who claim that LH2
could be kept liquid with passive cooling, but that's a rather ambitious
claim. LOX is much easier.) And both LOX and LH2 probably need active
refrigeration to cool and liquify them in the first place -- passive
cooling doesn't work very well for getting rid of large amounts of heat
at low temperatures, because the radiator areas become enormous.

It is almost certainly preferable to just launch LOX and kerosene (or
perhaps some lighter hydrocarbon, like chilled propane). The one big
advantage of hydrogen is that it's *light*, but if you're picking it up
in orbit, that no longer matters very much.
--
spsystems.net is temporarily off the air; | Henry Spencer
mail to henry at zoo.utoronto.ca instead. |
  #23  
Old February 17th 07, 08:38 PM posted to sci.space.policy
Henry Spencer
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Posts: 2,170
Default Vision of the three Rs: Regular, Reliable and Reusable

In article ,
Fred J. McCall wrote:
Hint: You don't try to 'create demand'. You service the ones that
exist and let the new ones come as they will.
--
"The reasonable man adapts himself to the world; the unreasonable
man persists in trying to adapt the world to himself. Therefore,
all progress depends on the unreasonable man."
--George Bernard Shaw


Interesting juxtaposition of text and signature quote there, Fred.

The big changes -- and hence the big chances to get rich or do good --
come not from servicing existing markets, but from servicing markets which
*don't* already exist and have to be built along with your business. On
FedEx's first day, a fleet of over a dozen aircraft carried a grand total
of six packages. Aiming at a hypothetical market is a risky thing to do,
but the payoff can be huge.
--
spsystems.net is temporarily off the air; | Henry Spencer
mail to henry at zoo.utoronto.ca instead. |
  #24  
Old February 17th 07, 10:08 PM posted to sci.space.policy
Fred J. McCall
external usenet poster
 
Posts: 5,736
Default Vision of the three Rs: Regular, Reliable and Reusable

(Henry Spencer) wrote:

:In article ,
:Fred J. McCall wrote:
:Hint: You don't try to 'create demand'. You service the ones that
:exist and let the new ones come as they will.
:--
:"The reasonable man adapts himself to the world; the unreasonable
: man persists in trying to adapt the world to himself. Therefore,
: all progress depends on the unreasonable man."
: --George Bernard Shaw
:
:Interesting juxtaposition of text and signature quote there, Fred.
:
:The big changes -- and hence the big chances to get rich or do good --
:come not from servicing existing markets, but from servicing markets which
:*don't* already exist and have to be built along with your business. On
:FedEx's first day, a fleet of over a dozen aircraft carried a grand total
f six packages. Aiming at a hypothetical market is a risky thing to do,
:but the payoff can be huge.

True, but there is a difference between recognizing an unserved market
demand and serving it and trying to 'create' market demand for an
arbitrary service. The latter is what was being suggested.

--
"The reasonable man adapts himself to the world; the unreasonable
man persists in trying to adapt the world to himself. Therefore,
all progress depends on the unreasonable man."
--George Bernard Shaw
  #25  
Old February 18th 07, 03:45 AM posted to sci.space.policy
Totorkon
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Posts: 183
Default Vision of the three Rs: Regular, Reliable and Reusable

On Feb 17, 11:23 am, (Henry Spencer) wrote:
In article .com,

Totorkon wrote:
Just as important will be the electrolysis and liquification
hardware. Cooling and storing H2 and O should be easier given the
temperature of space and vacuum for the thermous effect.


Actually, electrolyzing water is not a very good way to get fuel.

Electrolysis is *grossly* energy-intensive; a kilowatt-*year* of energy
electrolyzes only about a ton of water.


I will have to google this subject again. I thought that a kg of
water represented about two Kwh of thermal energy, enough to split
about three tons per Kwyr at 75% efficiency. A single 138 m^2 solar
'blanket' on the ISS generates 16 Kwh. Of course the collector would
have to be near geosynchronous altitude for 24 hours of sun, or be in
a polar orbit, which would further limit its usefulness.

Moreover, dealing with the results is not that easy, especially for LH2,
which needs active refrigeration at all times -- a headache not only for a
fuel depot, but for its customers. (There are people who claim that LH2
could be kept liquid with passive cooling, but that's a rather ambitious
claim. LOX is much easier.) And both LOX and LH2 probably need active
refrigeration to cool and liquify them in the first place -- passive
cooling doesn't work very well for getting rid of large amounts of heat
at low temperatures, because the radiator areas become enormous.


Zubrin has plans to land a tank of LH2 on mars to react with CO2,
guess that might not be a great idea given the time of transit.

It is almost certainly preferable to just launch LOX and kerosene (or
perhaps some lighter hydrocarbon, like chilled propane). The one big
advantage of hydrogen is that it's *light*, but if you're picking it up
in orbit, that no longer matters very much.
--
spsystems.net is temporarily off the air; | Henry Spencer
mail to henry at zoo.utoronto.ca instead. |


Truth can be a bitter medicine, but it is the only cure for a foolish
notion. Thankyou for the dose, Doctor Spencer.

  #26  
Old February 18th 07, 05:58 AM posted to sci.space.policy
Totorkon
external usenet poster
 
Posts: 183
Default Vision of the three Rs: Regular, Reliable and Reusable

On Feb 17, 11:23 am, (Henry Spencer) wrote:
In article .com,

Totorkon wrote:
Just as important will be the electrolysis and liquification
hardware. Cooling and storing H2 and O should be easier given the
temperature of space and vacuum for the thermous effect.


Actually, electrolyzing water is not a very good way to get fuel.

Electrolysis is *grossly* energy-intensive; a kilowatt-*year* of energy
electrolyzes only about a ton of water.

Moreover, dealing with the results is not that easy, especially for LH2,
which needs active refrigeration at all times -- a headache not only for a
fuel depot, but for its customers. (There are people who claim that LH2
could be kept liquid with passive cooling, but that's a rather ambitious
claim. LOX is much easier.) And both LOX and LH2 probably need active
refrigeration to cool and liquify them in the first place -- passive
cooling doesn't work very well for getting rid of large amounts of heat
at low temperatures, because the radiator areas become enormous.

It is almost certainly preferable to just launch LOX and kerosene (or
perhaps some lighter hydrocarbon, like chilled propane). The one big
advantage of hydrogen is that it's *light*, but if you're picking it up
in orbit, that no longer matters very much.
--
spsystems.net is temporarily off the air; | Henry Spencer
mail to henry at zoo.utoronto.ca instead. |


I see my mistake. I read that 1kg of H2 generates about 30 thermal
Kwh, which would correspond to about 9kg of water.

If you were in charge of the space program, with a gaurenteed budget
of say 20 or 30 billion per year, how would you spend it?

  #27  
Old February 18th 07, 07:40 AM posted to sci.space.policy
kT
external usenet poster
 
Posts: 5,032
Default Vision of the three Rs: Regular, Reliable and Reusable

Totorkon wrote:
On Feb 17, 11:23 am, (Henry Spencer) wrote:
In article .com,

Totorkon wrote:
Just as important will be the electrolysis and liquification
hardware. Cooling and storing H2 and O should be easier given the
temperature of space and vacuum for the thermous effect.

Actually, electrolyzing water is not a very good way to get fuel.

Electrolysis is *grossly* energy-intensive; a kilowatt-*year* of energy
electrolyzes only about a ton of water.

Moreover, dealing with the results is not that easy, especially for LH2,
which needs active refrigeration at all times -- a headache not only for a
fuel depot, but for its customers. (There are people who claim that LH2
could be kept liquid with passive cooling, but that's a rather ambitious
claim. LOX is much easier.) And both LOX and LH2 probably need active
refrigeration to cool and liquify them in the first place -- passive
cooling doesn't work very well for getting rid of large amounts of heat
at low temperatures, because the radiator areas become enormous.

It is almost certainly preferable to just launch LOX and kerosene (or
perhaps some lighter hydrocarbon, like chilled propane). The one big
advantage of hydrogen is that it's *light*, but if you're picking it up
in orbit, that no longer matters very much.
--
spsystems.net is temporarily off the air; | Henry Spencer
mail to henry at zoo.utoronto.ca instead. |


I see my mistake. I read that 1kg of H2 generates about 30 thermal
Kwh, which would correspond to about 9kg of water.

If you were in charge of the space program, with a gaurenteed budget
of say 20 or 30 billion per year, how would you spend it?


You realize of course that you are discussing rocket science with an
elderly senile has been, right?

--
Get A Free Orbiter Space Flight Simulator :
http://orbit.medphys.ucl.ac.uk/orbit.html
  #28  
Old February 18th 07, 09:01 AM posted to sci.space.policy
Totorkon
external usenet poster
 
Posts: 183
Default Vision of the three Rs: Regular, Reliable and Reusable

On Feb 17, 10:40 pm, kT wrote:
Totorkon wrote:
On Feb 17, 11:23 am, (Henry Spencer) wrote:
In article .com,


Totorkon wrote:
Just as important will be the electrolysis and liquification
hardware. Cooling and storing H2 and O should be easier given the
temperature of space and vacuum for the thermous effect.
Actually, electrolyzing water is not a very good way to get fuel.


Electrolysis is *grossly* energy-intensive; a kilowatt-*year* of energy
electrolyzes only about a ton of water.


Moreover, dealing with the results is not that easy, especially for LH2,
which needs active refrigeration at all times -- a headache not only for a
fuel depot, but for its customers. (There are people who claim that LH2
could be kept liquid with passive cooling, but that's a rather ambitious
claim. LOX is much easier.) And both LOX and LH2 probably need active
refrigeration to cool and liquify them in the first place -- passive
cooling doesn't work very well for getting rid of large amounts of heat
at low temperatures, because the radiator areas become enormous.


It is almost certainly preferable to just launch LOX and kerosene (or
perhaps some lighter hydrocarbon, like chilled propane). The one big
advantage of hydrogen is that it's *light*, but if you're picking it up
in orbit, that no longer matters very much.
--
spsystems.net is temporarily off the air; | Henry Spencer
mail to henry at zoo.utoronto.ca instead. |


I see my mistake. I read that 1kg of H2 generates about 30 thermal
Kwh, which would correspond to about 9kg of water.


If you were in charge of the space program, with a gaurenteed budget
of say 20 or 30 billion per year, how would you spend it?


You realize of course that you are discussing rocket science with an
elderly senile has been, right?

--
Get A Free Orbiter Space Flight Simulator :http://orbit.medphys.ucl.ac.uk/orbit.html- Hide quoted text -

- Show quoted text -


Henry's point about the difficulty of liquifying hydrogen makes sense,
on earth it takes close to 40% of the energy inherent in the H2 to
liquify. In space as the temperature drops, an exponetially larger
radiating area is required to drop it further.
I get a bit more than a ton of H2&O per Kwyr, but electrolysis is
notoriously inefficient.
I think he would get an argument from Zubrin about the ease of keeping
H2 liquid in space.
I would argue that the process of recovering water from a pole of the
moon, or from phobos, and then generating propellants is so important,
and the establishment of regular access to orbit is so fundamental,
that developing these capabilities is a worthier goal than putting
people on the moon again.

  #29  
Old February 18th 07, 09:17 AM posted to sci.space.policy
kT
external usenet poster
 
Posts: 5,032
Default Vision of the three Rs: Regular, Reliable and Reusable

Totorkon wrote:
On Feb 17, 10:40 pm, kT wrote:
Totorkon wrote:
On Feb 17, 11:23 am, (Henry Spencer) wrote:
In article .com,
Totorkon wrote:
Just as important will be the electrolysis and liquification
hardware. Cooling and storing H2 and O should be easier given the
temperature of space and vacuum for the thermous effect.
Actually, electrolyzing water is not a very good way to get fuel.
Electrolysis is *grossly* energy-intensive; a kilowatt-*year* of energy
electrolyzes only about a ton of water.
Moreover, dealing with the results is not that easy, especially for LH2,
which needs active refrigeration at all times -- a headache not only for a
fuel depot, but for its customers. (There are people who claim that LH2
could be kept liquid with passive cooling, but that's a rather ambitious
claim. LOX is much easier.) And both LOX and LH2 probably need active
refrigeration to cool and liquify them in the first place -- passive
cooling doesn't work very well for getting rid of large amounts of heat
at low temperatures, because the radiator areas become enormous.
It is almost certainly preferable to just launch LOX and kerosene (or
perhaps some lighter hydrocarbon, like chilled propane). The one big
advantage of hydrogen is that it's *light*, but if you're picking it up
in orbit, that no longer matters very much.
--
spsystems.net is temporarily off the air; | Henry Spencer
mail to henry at zoo.utoronto.ca instead. |
I see my mistake. I read that 1kg of H2 generates about 30 thermal
Kwh, which would correspond to about 9kg of water.
If you were in charge of the space program, with a gaurenteed budget
of say 20 or 30 billion per year, how would you spend it?

You realize of course that you are discussing rocket science with an
elderly senile has been, right?

--
Get A Free Orbiter Space Flight Simulator :http://orbit.medphys.ucl.ac.uk/orbit.html- Hide quoted text -

- Show quoted text -


Henry's point about the difficulty of liquifying hydrogen makes sense,
on earth it takes close to 40% of the energy inherent in the H2 to
liquify.


When launching from the Earth, fuel costs are insignificant compared to
the cost of the launcher, engines and payloads, so energy for fuel
manufacture, and the costs of the fuel itself, is irrelevant.

When you come up with a launch scheme where fuel costs are important,
please let us all know about it, as soon as you possibly can.

In space as the temperature drops, an exponetially larger
radiating area is required to drop it further.


You realize you are talking to a condensed matter physicist, right?

I get a bit more than a ton of H2&O per Kwyr, but electrolysis is
notoriously inefficient.


That's a myth. Electrolysis is one of the most efficient operations
imaginable, almost, but not quite, as efficient as rocket engines.

We are talking about attainable efficiency in the mid 90s. I just don't
know where people get crackpot ideas that electrolysis is inefficient.

I think he would get an argument from Zubrin about the ease of keeping
H2 liquid in space.


In space we have solar power. Clearly reaction engines aren't necessary.

I would argue that the process of recovering water from a pole of the
moon, or from phobos, and then generating propellants is so important,
and the establishment of regular access to orbit is so fundamental,
that developing these capabilities is a worthier goal than putting
people on the moon again.


I agree. However, most of it can be automated, and reaction engines
aren't necessary for automated operations, when you have solar power,
and especially with very low microgravity of small moons and asteroids.

Reaction engines are only really necessary for Earth to LEO, and clearly
hydrogen wins. Plus, there are added advantages that Henry never speaks
of, being the corrupt old school ******* that he is. For instance -
water and oxygen for breathing, drinking, growing plants, and hydrogen
being the lightest element (molecule) for solar powered acceleration.

Any intensive research and development into solar conversion and
hydrogen manipulation will easily pay for itself in commerce, the
commerce necessary to solve real problems right here on Earth

--
Get A Free Orbiter Space Flight Simulator :
http://orbit.medphys.ucl.ac.uk/orbit.html
  #30  
Old February 18th 07, 11:36 PM posted to sci.space.policy
Sylvia Else
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Posts: 1,063
Default Vision of the three Rs: Regular, Reliable and Reusable

kT wrote:


We are talking about attainable efficiency in the mid 90s. I just don't
know where people get crackpot ideas that electrolysis is inefficient.


People equate large energy inputs with inefficiency. Only those with
some scientific background will know that they should be comparing the
actual energy input with the theoretical minimum.

Sylvia.
 




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