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Towards routine, reusable space launch.

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  Towards routine, reusable space launch. "Robert Clark" <rgregoryclark@gmSPAMBLOCKail.com> - 2018-06-07 16:24 -0400
    Re: Towards routine, reusable space launch. "Robert Clark" <rgregoryclark@gmSPAMBLOCKail.com> - 2018-06-07 16:47 -0400
    Re: Towards routine, reusable space launch. Fred J. McCall <fjmccall@gmail.com> - 2018-06-07 23:24 -0700
    Re: Towards routine, reusable space launch. Doc O'Leary  <droleary@2017usenet1.subsume.com> - 2018-06-08 13:10 +0000
      Re: Towards routine, reusable space launch. Sergio <invalid@invalid.com> - 2018-06-08 08:31 -0500
      Re: Towards routine, reusable space launch. Fred J. McCall <fjmccall@gmail.com> - 2018-06-08 20:47 -0700
        Re: Towards routine, reusable space launch. Doc O'Leary  <droleary@2017usenet1.subsume.com> - 2018-06-09 17:19 +0000
          Re: Towards routine, reusable space launch. Jeff Findley <jfindley@cinci.nospam.rr.com> - 2018-06-09 16:02 -0400
            Re: Towards routine, reusable space launch. Doc O'Leary  <droleary@2017usenet1.subsume.com> - 2018-06-11 03:16 +0000
              Re: Towards routine, reusable space launch. Sergio <invalid@invalid.com> - 2018-06-10 23:19 -0500
              Re: Towards routine, reusable space launch. Thomas Koenig <tkoenig@netcologne.de> - 2018-06-11 05:25 +0000
              Re: Towards routine, reusable space launch. Fred J. McCall <fjmccall@gmail.com> - 2018-06-11 04:00 -0700
              Re: Towards routine, reusable space launch. Jeff Findley <jfindley@cinci.nospam.rr.com> - 2018-06-11 07:49 -0400
      Re: Towards routine, reusable space launch. Greg Goss <gossg@gossg.org> - 2018-06-09 09:34 -0600
        Re: Towards routine, reusable space launch. Jeff Findley <jfindley@cinci.nospam.rr.com> - 2018-06-09 15:56 -0400
    Re: Towards routine, reusable space launch. "Robert Clark" <rgregoryclark@gmSPAMBLOCKail.com> - 2018-06-08 18:06 -0400

#689363 — Towards routine, reusable space launch.

Several companies are proposing satellite megaconstellations that would 
require hundreds to thousands of communications satellites. This may finally 
provide the impetus to produce reusable launchers.

Proponents of reusable launchers such as SpaceX have argued by producing 
them the costs of launch will be reduced which will drive an increase in the 
market that will pay for their development. However, the OldSpace companies 
have maintained the market for launch is not enough to justify the expense 
of developing reusable launchers. But without reusability the price for 
launch is too high to generate a large market. So we have a "chicken or the 
egg" type problem.

But the hundreds to perhaps thousands of launches required for the new 
megaconstellations may finally provide the necessary market. The NewSpace 
companies SpaceX and Blue Origin are already committed to reusability. But 
in a surprise the OldSpace company Arianespace while previously discounting 
the viability of reusable launchers has announced they will transition to 
reusable launchers also, citing the impending market provided by the 
megaconstellation satellites.

Here's a discussion of a fast route to reusable launchers for ArianeSpace 
that could lead to a manned launcher as well:

A half-size Ariane for manned spaceflight.
https://exoscientist.blogspot.com/2014/11/a-half-size-ariane-for-manned.html

   Bob Clark

------------------------------------------------------------------
Single-stage-to-orbit was already shown possible 50 years ago
with the Titan II first stage.
In fact, contrary to popular belief SSTO's are actually easy.
Just use the most efficient engines and stages at the same time,
and the result will automatically be SSTO.
Blog: Http://Exoscientist.blogspot.com
------------------------------------------------------------------ 

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#689375

=========================================================
"Robert Clark"  wrote in message news:pfc49a$gv2$1@dont-email.me...

Here's a discussion of a fast route to reusable launchers for ArianeSpace
that could lead to a manned launcher as well:

A half-size Ariane for manned spaceflight.
https://exoscientist.blogspot.com/2014/11/a-half-size-ariane-for-manned.html

===========================================================

Sorry, that link should have been:

Half-size Ariane core stage for a reusable launcher.
http://exoscientist.blogspot.com/2018/06/half-size-ariane-core-stage-for.html

  Bob Clark


------------------------------------------------------------------
Single-stage-to-orbit was already shown possible 50 years ago
with the Titan II first stage.
In fact, contrary to popular belief SSTO's are actually easy.
Just use the most efficient engines and stages at the same time,
and the result will automatically be SSTO.
Blog: Http://Exoscientist.blogspot.com
------------------------------------------------------------------ 

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#689432

"Robert Clark" <rgregoryclark@gmSPAMBLOCKail.com> wrote on Thu, 7 Jun
2018 16:24:06 -0400:

>Several companies are proposing satellite megaconstellations that would 
>require hundreds to thousands of communications satellites. This may finally 
>provide the impetus to produce reusable launchers.
>
>Proponents of reusable launchers such as SpaceX have argued by producing 
>them the costs of launch will be reduced which will drive an increase in the 
>market that will pay for their development. However, the OldSpace companies 
>have maintained the market for launch is not enough to justify the expense 
>of developing reusable launchers. But without reusability the price for 
>launch is too high to generate a large market. So we have a "chicken or the 
>egg" type problem.
>

A big driver is that the cost of launching tends to drive the cost of
what you launch.  If you're going to have to spend $200 million to get
your payload on station, you're going to spend a lot of money making
your payload large, reliable, and capable so that you're not wasting
that money.  That drives the cost of your payload up.

Cut the cost of launching to 30% of that and suddenly launching
cheaper and less capable payloads becomes practical.  The problem is
that nobody really knows what the elasticity of demand is for
launches.


-- 
"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

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#689459

For your reference, records indicate that 
"Robert Clark" <rgregoryclark@gmSPAMBLOCKail.com> wrote:

> Several companies are proposing satellite megaconstellations that would 
> require hundreds to thousands of communications satellites. This may finally 
> provide the impetus to produce reusable launchers.

What are the actual numbers when it comes to savings from a reusable 
rocket?  It’d also be interesting to know how new technologies might 
impact the economics of launching items into space (including just making 
disposable launch vehicles much cheaper).  Once you start to contemplate 
the need for multiple daily launches, even recovering boosters to reuse 
them seems like a slow and labor-intensive process.  On the path to a 
space elevator, it seems like there should be many more ways to reach 
escape velocity that do a better job than what Musk is doing today.

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

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#689463

On 6/8/2018 8:10 AM, Doc O'Leary wrote:
> On the path to a 
> space elevator, it seems like there should be many more ways to reach 
> escape velocity that do a better job than what Musk is doing today.

space elevator - ever do any calculations on that ? like lift power
required, mechanical loads, electrical losses, how to aim, ....

It is simply a mechanical constraint on launching a rocket, like the
rail gun, seems like a nice idea until you try to build one. (navy has
discontinued rail gun)

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#689598

Doc O'Leary  <droleary@2017usenet1.subsume.com> wrote on Fri, 8 Jun
2018 13:10:48 -0000 (UTC):

>For your reference, records indicate that 
>"Robert Clark" <rgregoryclark@gmSPAMBLOCKail.com> wrote:
>>
>> Several companies are proposing satellite megaconstellations that would 
>> require hundreds to thousands of communications satellites. This may finally 
>> provide the impetus to produce reusable launchers.
>>
>
>What are the actual numbers when it comes to savings from a reusable 
>rocket?  
>

That depends on a lot of things.

>
>It’d also be interesting to know how new technologies might 
>impact the economics of launching items into space (including just making 
>disposable launch vehicles much cheaper).  
>

Real reuse will always be cheaper.  If you can make disposable launch
vehicles much cheaper, the same technologies allow making reusable
launch vehicles much cheaper.

>
>Once you start to contemplate 
>the need for multiple daily launches, even recovering boosters to reuse 
>them seems like a slow and labor-intensive process.  
>

But orders of magnitude faster than throwing them away and building a
new one.

>
>On the path to a 
>space elevator, it seems like there should be many more ways to reach 
>escape velocity that do a better job than what Musk is doing today.
>

You've discovered a good supply of unobtainium, have you?  Otherwise,
rockets are your man for getting stuff to orbit for the foreseeable
future.


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

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#689678

For your reference, records indicate that 
Fred J. McCall <fjmccall@gmail.com> wrote:

> Doc O'Leary  <droleary@2017usenet1.subsume.com> wrote on Fri, 8 Jun
> 2018 13:10:48 -0000 (UTC):
> 
> >What are the actual numbers when it comes to savings from a reusable 
> >rocket?  
> >
> 
> That depends on a lot of things.

Well, sure, but it always helps to have some data to work with before 
beginning an optimization process.  Best/worst cases or averages or 
whatever.  What the savings is related to the total cost of the launch 
is going to be guiding factor on how much effort it makes sense to 
expend to re-use different parts of the system.

> >It’d also be interesting to know how new technologies might 
> >impact the economics of launching items into space (including just making 
> >disposable launch vehicles much cheaper).  
> >
> 
> Real reuse will always be cheaper.  If you can make disposable launch
> vehicles much cheaper, the same technologies allow making reusable
> launch vehicles much cheaper.

That is non-obvious.  Ideally, I would think a “zero waste” system 
would be cheapest; every kg of mass that gets sent up either stays up 
(doing something useful) or was the fuel.  All this booster landing 
(and subsequent refurbishing for relaunch) we’re seeing, while cool, 
is definitely *not* the most efficient use of resources.

> >Once you start to contemplate 
> >the need for multiple daily launches, even recovering boosters to reuse 
> >them seems like a slow and labor-intensive process.  
> >
> 
> But orders of magnitude faster than throwing them away and building a
> new one.

But that’s still assuming old technologies rather than new ones.  You 
don’t “throw away” a space elevator.  Nor a mag-lev cannon.  I’m not 
sure how viable a high-altitude balloon launch would be, but it may 
also be cheaper than traditional first-stage rockets.

> >On the path to a 
> >space elevator, it seems like there should be many more ways to reach 
> >escape velocity that do a better job than what Musk is doing today.
> >
> 
> You've discovered a good supply of unobtainium, have you?  Otherwise,
> rockets are your man for getting stuff to orbit for the foreseeable
> future.

It’s always a good idea to noodle around with other technologies, no 
matter how impossible they appear to be today.  Because, yes, rockets 
are the way to get to orbit, but I’m most interested in the 
*unforeseeable* future that has humans on other planets around other 
stars.  Just being satisfied with rockets is not going to make that 
happen.

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

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#689707

In article <pfh27b$ghr$1@dont-email.me>, droleary@
2017usenet1.subsume.com says...
> 
> For your reference, records indicate that 
> Fred J. McCall <fjmccall@gmail.com> wrote:
> 
> > Doc O'Leary  <droleary@2017usenet1.subsume.com> wrote on Fri, 8 Jun
> > 2018 13:10:48 -0000 (UTC):
> > 
> > >What are the actual numbers when it comes to savings from a reusable 
> > >rocket?  
> > >
> > 
> > That depends on a lot of things.
> 
> Well, sure, but it always helps to have some data to work with before 
> beginning an optimization process.  Best/worst cases or averages or 
> whatever.  What the savings is related to the total cost of the launch 
> is going to be guiding factor on how much effort it makes sense to 
> expend to re-use different parts of the system.
> 
> > >It?d also be interesting to know how new technologies might 
> > >impact the economics of launching items into space (including just making 
> > >disposable launch vehicles much cheaper).  
> > >
> > 
> > Real reuse will always be cheaper.  If you can make disposable launch
> > vehicles much cheaper, the same technologies allow making reusable
> > launch vehicles much cheaper.
> 
> That is non-obvious.  Ideally, I would think a ?zero waste? system 
> would be cheapest; every kg of mass that gets sent up either stays up 
> (doing something useful) or was the fuel.  All this booster landing 
> (and subsequent refurbishing for relaunch) we?re seeing, while cool, 
> is definitely *not* the most efficient use of resources.

Falcon 9 is the "first generation" reuse for SpaceX.  For "zero waste", 
you'll have to wait for their "second generation" which will be BFR/BFS.   
 
> > >Once you start to contemplate 
> > >the need for multiple daily launches, even recovering boosters to reuse 
> > >them seems like a slow and labor-intensive process.  
> > >
> > 
> > But orders of magnitude faster than throwing them away and building a
> > new one.
> 
> But that?s still assuming old technologies rather than new ones.  You 
> don?t ?throw away? a space elevator.  Nor a mag-lev cannon.  I?m not 
> sure how viable a high-altitude balloon launch would be, but it may 
> also be cheaper than traditional first-stage rockets.

High altitude balloon launch is a tad risky and only gains you a bit of 
altitude and zero velocity.  Not worth the complexity and cost, IMHO.
 
> > >On the path to a 
> > >space elevator, it seems like there should be many more ways to reach 
> > >escape velocity that do a better job than what Musk is doing today.
> > >
> > 
> > You've discovered a good supply of unobtainium, have you?  Otherwise,
> > rockets are your man for getting stuff to orbit for the foreseeable
> > future.
> 
> It?s always a good idea to noodle around with other technologies, no 
> matter how impossible they appear to be today.  Because, yes, rockets 
> are the way to get to orbit, but I?m most interested in the 
> *unforeseeable* future that has humans on other planets around other 
> stars.  Just being satisfied with rockets is not going to make that 
> happen.

Sure, but SpaceX has proven that you can reduce costs dramatically by 
using existing technology and introducing reuse of as many components as 
possible.  They're getting close to catching fairings and they have some 
ideas for second stage reuse too.  That would be very close to "zero 
waste" with Falcon, if they can get to that point.

BFR/BFS is planned to be "zero waste" from the very beginning.  Fully 
reusable TSTO with "gas and go" like operations. 

Also don't count out Blue Origin.  They're off to a slow start, but have 
a very reliable funding source in Jeff Bezos ($1 billion a year).

Besides, how you going to get those space elevator bits into orbit?  
That's right, conventional (hopefully reusable) launch vehicles. 

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.

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#689966

For your reference, records indicate that 
Jeff Findley <jfindley@cinci.nospam.rr.com> wrote:

> High altitude balloon launch is a tad risky and only gains you a bit of 
> altitude and zero velocity.  Not worth the complexity and cost, IMHO.

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).

> BFR/BFS is planned to be "zero waste" from the very beginning.  Fully 
> reusable TSTO with "gas and go" like operations. 

But that’s not the true “zero waste” I was talking about.  Any resources 
that you’re sending up *and* down, along with any fuels you burn to do it 
safely, is a waste.  It may be a necessary waste for the current launch 
technologies, so it’s good to minimize it, but I still say it’s a good 
idea to think about ways to shoot stuff into space that doesn’t involve a 
lot of heavy stuff coming back to Earth.

> Also don't count out Blue Origin.  They're off to a slow start, but have 
> a very reliable funding source in Jeff Bezos ($1 billion a year).

I’m not counting them out, but when the topic is cost/efficiency, the 
basic question is still how much energy is being expended to get each 
kg into orbit.  So long as the idea is still to send a lot of 
supporting (non-fuel) heavy stuff up only to have most of it come back 
down, there are wastes that a new technology can come in and improve 
upon.

> Besides, how you going to get those space elevator bits into orbit?  
> That's right, conventional (hopefully reusable) launch vehicles. 

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.

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

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#689968

On 6/10/2018 10:16 PM, Doc O'Leary wrote:
> For your reference, records indicate that 
> Jeff Findley <jfindley@cinci.nospam.rr.com> wrote:

> 
> 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.  



A space elevator is not possible in reality.  It is a running joke in
engineering land.

	calculate the mechanical loads.

	calculate the weight of copper cables, and the mechanical cables

	calculate the weight of the tower, and estimate the sizes of tower
sections to support the weight at different levels

	estimate the weight of the electric motor 150 HP

  going to use a counterweight ?


just ballpark it,  assume 0.1 m/sec and 2000 # weight of cargo, and
100,000 foot high.

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#689972

Doc O'Leary <droleary@2017usenet1.subsume.com> schrieb:

> I’m not counting them out, but when the topic is cost/efficiency, the 
> basic question is still how much energy is being expended to get each 
> kg into orbit.

At the moment, not at all.  Ballpark calculation:

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.

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#689981

Doc O'Leary  <droleary@2017usenet1.subsume.com> wrote on Mon, 11 Jun
2018 03:16:38 -0000 (UTC):

>For your reference, records indicate that 
>Jeff Findley <jfindley@cinci.nospam.rr.com> wrote:
>>
>> High altitude balloon launch is a tad risky and only gains you a bit of 
>> altitude and zero velocity.  Not worth the complexity and cost, IMHO.
>>
>
>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?

>
>>
>> BFR/BFS is planned to be "zero waste" from the very beginning.  Fully 
>> reusable TSTO with "gas and go" like operations. 
>>
>
>But that’s not the true “zero waste” I was talking about.  Any resources 
>that you’re sending up *and* down, along with any fuels you burn to do it 
>safely, is a waste.  It may be a necessary waste for the current launch 
>technologies, so it’s good to minimize it, but I still say it’s a good 
>idea to think about ways to shoot stuff into space that doesn’t involve a 
>lot of heavy stuff coming back to Earth.
>

Well, let us know if you think of one that doesn't require unobtainium
or payloads to take tens of thousands of gravities on launch.

>
>>
>> Also don't count out Blue Origin.  They're off to a slow start, but have 
>> a very reliable funding source in Jeff Bezos ($1 billion a year).
>>
>
>I’m not counting them out, but when the topic is cost/efficiency, the 
>basic question is still how much energy is being expended to get each 
>kg into orbit.  So long as the idea is still to send a lot of 
>supporting (non-fuel) heavy stuff up only to have most of it come back 
>down, there are wastes that a new technology can come in and improve 
>upon.
>

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

>
>>
>> Besides, how you going to get those space elevator bits into orbit?  
>> That's right, conventional (hopefully reusable) launch vehicles. 
>>
>
>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.


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

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#689982

In article <pfkpim$sa0$1@dont-email.me>, droleary@
2017usenet1.subsume.com says...
> For your reference, records indicate that 
> Jeff Findley <jfindley@cinci.nospam.rr.com> wrote:
> 
> > High altitude balloon launch is a tad risky and only gains you a bit of 
> > altitude and zero velocity.  Not worth the complexity and cost, IMHO.
> 
> 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).

Balloon launch isn't worth the trades which have to be made, IMHO.
 
> > BFR/BFS is planned to be "zero waste" from the very beginning.  Fully 
> > reusable TSTO with "gas and go" like operations. 
> 
> But that?s not the true ?zero waste? I was talking about.  Any resources 
> that you?re sending up *and* down, along with any fuels you burn to do it 
> safely, is a waste.  It may be a necessary waste for the current launch 
> technologies, so it?s good to minimize it, but I still say it?s a good 
> idea to think about ways to shoot stuff into space that doesn?t involve a 
> lot of heavy stuff coming back to Earth.
 
By your definition, a passenger carrying aircraft is "waste" because it 
flies from one destination to another while carrying passengers.  But 
that sort of "waste" is absolutely not a metric to optimize.  Passengers 
are buying the cheapest ticket for the flight that gets them to their 
destination.  They don't give a rat's ass about the "waste" of the 
actual aircraft having to fly there and back.

Back to space launch.  We're nowhere near the minimum cost per kg 
payload to orbit with chemical launch vehicles.  Propellant costs are 
currently less than 1% of launch costs, even for SpaceX.  

Any "waste" of propellant that allows full reuse of hardware is 
currently worth the investment.  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.

When faced with an optimization problem, you look for the biggest "bang 
for the buck" bits to optimize.  Propellant "waste" is *not* that, not 
by a couple orders of magnitude.  Also, your launch hardware is a 
precious commodity, so it makes all the sense in the world to recover it 
and use it multiple times, just like a passenger carrying jet aircraft.

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.

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#689653

Doc O'Leary  <droleary@2017usenet1.subsume.com> wrote:

>For your reference, records indicate that 
>"Robert Clark" <rgregoryclark@gmSPAMBLOCKail.com> wrote:
>
>> Several companies are proposing satellite megaconstellations that would 
>> require hundreds to thousands of communications satellites. This may finally 
>> provide the impetus to produce reusable launchers.
>
>What are the actual numbers when it comes to savings from a reusable 
>rocket?  It’d also be interesting to know how new technologies might 
>impact the economics of launching items into space (including just making 
>disposable launch vehicles much cheaper).  Once you start to contemplate 
>the need for multiple daily launches, even recovering boosters to reuse 
>them seems like a slow and labor-intensive process.  On the path to a 
>space elevator, it seems like there should be many more ways to reach 
>escape velocity that do a better job than what Musk is doing today.

"Recovering" them?  In Musk's version, they land themselves near the
re-assembly plant.
-- 
We are geeks.  Resistance is voltage over current.

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#689705

In article <fo2adqFki2aU1@mid.individual.net>, gossg@gossg.org says...
> 
> Doc O'Leary  <droleary@2017usenet1.subsume.com> wrote:
> 
> >For your reference, records indicate that 
> >"Robert Clark" <rgregoryclark@gmSPAMBLOCKail.com> wrote:
> >
> >> Several companies are proposing satellite megaconstellations that would 
> >> require hundreds to thousands of communications satellites. This may finally 
> >> provide the impetus to produce reusable launchers.
> >
> >What are the actual numbers when it comes to savings from a reusable 
> >rocket?  It?d also be interesting to know how new technologies might 
> >impact the economics of launching items into space (including just making 
> >disposable launch vehicles much cheaper).  Once you start to contemplate 
> >the need for multiple daily launches, even recovering boosters to reuse 
> >them seems like a slow and labor-intensive process.  On the path to a 
> >space elevator, it seems like there should be many more ways to reach 
> >escape velocity that do a better job than what Musk is doing today.
> 
> "Recovering" them?  In Musk's version, they land themselves near the
> re-assembly plant.

News this week of SpaceX proposing new KSC facilities for Block 5 
boosters.  My guess is they won't be shipping them back to California 
until they're ready for refurbishment.  If they ever get to that point.

Jeff
-- 
All opinions posted by me on Usenet News are mine, and mine alone.  
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#689564

In that discussion I forgot the key point. The most important factor in 
regards to cost is not the development cost.
The key cost factor is what they would charge per flight for a reusable 
launcher. Robert Zubrin made this point insightfully in one of his books. He 
recounts that he made the argument for reusable launchers in his former job 
with one of the big launch companies.

He argued that they could cut the cost of launch by an order of magnitude. 
The company execs responded: why would we do that? Their view was their 
revenue would then be slashed by a factor of ten. They were assuming the 
market would still be the same but they would be getting one-tenth the 
revenue.

So the OldSpace companies were acting quite rationally in a business sense 
in discounting reusability. They were saying the market was not enough to 
make it advantageous to them.

But if there were a large market then they would make more money making more 
launchers at the lower price. That is, the price would be reduced by a 
factor of ten but the number of launches would be increased by more than a 
factor of ten.

Also, the importance of the large market and lowered prices for satellite 
launches extends beyond that of just the satellite market. By making 
launches at such reduced prices, that increases the possible market for 
passenger flights to space. So the impending megaconstellation launches may 
also bring to fruition the long desired routine passenger flights to space.

Bob Clark


------------------------------------------------------------------
Single-stage-to-orbit was already shown possible 50 years ago
with the Titan II first stage.
In fact, contrary to popular belief SSTO's are actually easy.
Just use the most efficient engines and stages at the same time,
and the result will automatically be SSTO.
Blog: Http://Exoscientist.blogspot.com
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