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SSTO's would have made possible Arthur C. Clarke's vision of 2001.



 
 
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  #1  
Old December 8th 11, 11:19 AM posted to rec.arts.sf.science,sci.space.policy,sci.astro,sci.physics,sci.space.history
Robert Clark
external usenet poster
 
Posts: 1,150
Default SSTO's would have made possible Arthur C. Clarke's vision of 2001.

Just saw this article on The Space Review discussing a recently
discovered copy of a 1963 TV interview with Arthur C. Clarke:

The perils of spaceflight prediction.
by Jeff Foust
Monday, December 5, 2011
http://thespacereview.com/article/1981/1

In the interview Clarke gives some predictions of the future of space
exploration. From the standpoint of the beginnings of human
spaceflight, he suggests a manned Mars mission within 25 years, which
would have been by 1988, and Moon bases by the end of the 20th
century.
This turned out to be too optimistic. But as I argued below, this
could indeed have been technically and even financially feasible: if
it had been recognized that reusable SSTO's are possible and in fact
aren't even really hard, we would have had routine, private
spaceflight by the 1970s.
Such wide spread, frequent launches using reusable spacecraft would
have cut the costs to space by two orders of magnitude, at least. This
would then have made the costs of lunar bases and manned Mars missions
well within the affordability range.
The important point is that the required high efficiency engines and
lightweight stages for SSTO's already exist and have for decades. All
that is required is to marry the two together. An expendable test SSTO
could be produced, like, tomorrow. Just this one simple, cheap test
would finally make clear the fact that routine spaceflight is already
doable.


Bob Clark

================================================== ==========
Newsgroups: sci.space.policy, sci.astro, sci.physics,
sci.space.history, rec.arts.sf.science
From: Robert Clark
Date: Mon, 4 Jul 2011 09:28:30 -0700 (PDT)
Subject: SSTO's would have made possible Arthur C. Clarke's vision of
2001.

Space Travel: The Path to Human Immortality?
Space exploration might just be the key to human beings surviving
mass
genocide, ecocide or omnicide.
July 24, 2009
"On December 31st, 1999, National Public Radio interviewed the
futurist and science fiction genius Arthur C. Clarke. Since the
author
had forecast so many of the 20th Century's most fundamental
developments, the NPR correspondent asked Clarke if anything had
happened in the preceding 100 years that he never could have
anticipated. 'Yes, absolutely,' Clarke replied, without a moment's
hesitation. 'The one thing I never would have expected is that, after
centuries of wonder and imagination and aspiration, we would have
gone
to the moon ... and then stopped.'"
http://www.alternet.org/news/141518/...n_immortality/

I remember thinking when I first saw 2001 as a teenager and could
appreciate it more, I thought it was way too optimistic. We could
never have huge rotating space stations and passenger flights to
orbit
and Moon bases and nuclear-powered interplanetary ships by then.
That's what I thought and probably most people familiar with the
space
program thought that. And I think I recall Clarke saying once that
the
year 2001 was selected as more a rhetorical, artistic flourish rather
than being a prediction, 2001 being the year of the turn of the
millennium (no, it was NOT in the year 2000.)
However, I've now come to the conclusion those could indeed have been
possible by 2001. I don't mean the alien monolith or the intelligent
computer, but the spaceflights shown in the film.
It all comes down to SSTO's. As I argued previously [1] these could
have led and WILL lead to the price to orbit coming down to the $100
per kilo range. The required lightweight stages existed since the
60's
and 70's for kerosene with the Atlas and Delta stages, and for
hydrogen with the Saturn V upper stages. And the high efficiency
engines from sea level to vacuum have existed since the 70's with the
NK-33 for kerosene, and with the SSME for hydrogen.
The kerosene SSTO's could be smaller and cheaper and would make
possible small orbital craft in the price range of business jets, at
a
few tens of millions of dollars. These would be able to carry a few
number of passengers/crew, say of the size of the Dragon capsule. But
in analogy with history of aircraft these would soon be followed by
large passenger craft.
However, the NK-33 was of Russian design, while the required
lightweight stages were of American design. But the 70's was the time
of detente, with the Apollo-Soyuz mission. With both sides realizing
that collaboration would lead to routine passenger spaceflight, it is
conceivable that they could have come together to make possible
commercial spaceflight.
There is also the fact that for the hydrogen fueled SSTO's, the
Americans had both the required lightweight stages and high
efficiency
engines, though these SSTO's would have been larger and more
expensive. So it would have been advantageous for the Russians to
share their engine if the American's shared their lightweight stages.
For the space station, many have soured on the idea because of the
ISS
with the huge cost overruns. But Bigelow is planning on "space
hotels"
derived from NASA's Transhab[2] concept. These provide large living
space at lightweight. At $100 per kilo launch costs we could form
large space stations from the Transhabs linked together in modular
fashion, financed purely from the tourism interests. Remember the low
price to orbit allows many average citizens to pay for the cost to
LEO.
The Transhab was developed in the late 90's so it might be
questionable that the space station could be built from them by 2001.
But remember in the film the space station was in the process of
being
built. Also, with large numbers of passengers traveling to space it
seems likely that inflatable modules would have been thought of
earlier to house the large number of tourists who might want a longer
stay.
For the extensive Moon base, judging from the Apollo missions it
might
be thought any flight to the Moon would be hugely expensive. However,
Robert Heinlein once said: once you get to LEO you're half way to
anywhere in the Solar System. This is due to the delta-V requirements
for getting out of the Earth's gravitational compared to reaching
escape velocity.
It is important to note then SSTO's have the capability once refueled
in orbit to travel to the Moon, land, and return to Earth on that one
fuel load. Because of this there would be a large market for
passenger
service to the Moon as well. So there would be a commercial
justification for Bigelow's Transhab motels to also be transported to
the Moon [3].
Initially the propellant for the fuel depots would have to be lofted
from Earth. But we recently found there was water in the permanently
shadowed craters on the Moon [4]. Use of this for propellant would
reduce the cost to make the flights from LEO to the Moon since the
delta-V needed to bring the propellant to LEO from the lunar surface
is so much less than that needed to bring it from the Earth's surface
to LEO.
This lunar derived propellant could also be placed in depots in lunar
orbit and at the Lagrange points. This would make easier flights to
the asteroids and the planets. The flights to the asteroids would be
especially important for commercial purposes because it is estimated
even a small sized asteroid could have trillions of dollars worth of
valuable minerals [5]. The availability of such resources would make
it financially profitable to develop large bases on the Moon for the
sake of the propellant.
Another possible resource was recently discovered on the Moon:
uranium
[6]. Though further analysis showed the surface abundance to be much
less than in Earth mines, it may be that there are localized
concentrations just as there are on Earth. Indeed this appears to be
the case with some heavy metals such as silver and possibly gold that
appear to be concentrated in some polar craters on the Moon [7].
So even if the uranium is not as abundant as in Earth mines, it may
be
sufficient to be used for nuclear-powered spacecraft. Then we
wouldn't
have the problem of large amounts of nuclear material being lofted on
rockets on Earth. The physics and engineering of nuclear powered
rockets have been understood since the 60's [8]. The main impediment
has been the opposition to launching large amounts of radioactive
material from Earth into orbit above Earth. Then we very well could
have had nuclear-powered spacecraft launching from the Moon for
interplanetary missions, especially when you consider the financial
incentive provided by minerals in the asteroids of the asteroid belt.

Bob Clark

1.)Newsgroups: sci.space.policy, sci.astro, sci.physics,
sci.space.history
From: Robert Clark
Date: Sat, 25 Jun 2011 21:36:07 -0700 (PDT)
Subject: A kerosene-fueled X-33 as a single stage to orbit
vehicle.
http://groups.google.com/group/sci.s...5ca2dc05?hl=en

2.)TransHab.
http://en.wikipedia.org/wiki/TransHab

3.)Private Moon Bases a Hot Idea for Space Pioneer.
by Leonard David, SPACE.com's Space Insider Columnist
Date: 14 April 2010 Time: 02:23 PM ET
http://www.space.com/8217-private-mo...e-pioneer.html

4.)Mining the Moon's Water: Q & A with Shackleton Energy's Bill
Stone.
by Mike Wall, SPACE.com Senior WriterDate: 13 January 2011 Time:
03:57
PM ET
http://www.space.com/10619-mining-mo...ne-110114.html

5.)Riches in the Sky: The Promise of Asteroid Mining.
Mark Whittington, Nov 15, 2005
http://voices.yahoo.com/riches-sky-p...ning-8776.html

6.)Uranium could be mined on the Moon.
Uranium could one day be mined on the Moon after a Japanese
spacecraft
discovered the element on its surface.
By Julian Ryall in Tokyo 4:58PM BST 01 Jul 2009
http://www.telegraph.co.uk/science/s...-the-Moon.html

7.)Silver, Gold, Mercury and Water Found in Moon Crater Soil by
LCROSS
Project.
Catherine Dagger, Oct 22, 2010
http://voices.yahoo.com/silver-gold-...36.html?cat=15

8.)NERVA.
http://en.wikipedia.org/wiki/NERVA
================================================== ===================
http://groups.google.com/group/rec.a...594d36b?hl=en#
  #2  
Old December 8th 11, 03:39 PM posted to sci.space.policy
Jim Davis
external usenet poster
 
Posts: 420
Default SSTO's would have made possible Arthur C. Clarke's vision of 2001.

Robert Clark wrote:

...that reusable SSTO's are possible...


In the future very probably, but certainly not in 2011.

...and in fact
aren't even really hard...


That's just utter cluelessness.

Jim Davis





  #3  
Old December 10th 11, 04:58 PM posted to rec.arts.sf.science,sci.space.policy,sci.astro,sci.physics,sci.space.history
Robert Clark
external usenet poster
 
Posts: 1,150
Default SSTO's would have made possible Arthur C. Clarke's vision of 2001.

On Dec 8, 9:39*am, Jim Davis wrote:
Robert Clark wrote:
...that reusable SSTO's are possible...


In the future very probably, but certainly not in 2011.

...and in fact
aren't even really hard...


That's just utter cluelessness.

Jim Davis


Take a Falcon 9 first stage, which has a mass ratio better than 20 to
1, equivalently a propellant fraction better than 95%, and swap out
the low efficiency Merlins for high efficiency engine[s] such as the
RD-180, which has a vacuum Isp 338 s.
Run the rocket equation. You'll see it can reach orbit with
significant payload as an expendable vehicle. The payload is so high
in fact that with reasonable estimates for reentry/landing systems you
can still carry useful payload with a reusable version.

Bob Clark
  #4  
Old December 10th 11, 06:44 PM posted to rec.arts.sf.science,sci.space.policy,sci.astro,sci.physics,sci.space.history
Robert Clark
external usenet poster
 
Posts: 1,150
Default SSTO's would have made possible Arthur C. Clarke's vision of 2001.

On Dec 8, 5:19*am, Robert Clark wrote:
* Just saw this article on The Space Review discussing a recently
discovered copy of a 1963 TV interview with Arthur C. Clarke:

The perils of spaceflight prediction.
by Jeff Foust
Monday, December 5, 2011http://thespacereview.com/article/1981/1

*In the interview Clarke gives some predictions of the future of space
exploration. From the standpoint of the beginnings of human
spaceflight, he suggests a manned Mars mission within 25 years, which
would have been by 1988, and Moon bases by the end of the 20th
century.
*This turned out to be too optimistic. But as I argued below, this
could indeed have been technically and even financially feasible: if
it had been recognized that reusable SSTO's are possible and in fact
aren't even really hard, we would have had routine, private
spaceflight by the 1970s.
*Such wide spread, frequent launches using reusable spacecraft would
have cut the costs to space by two orders of magnitude, at least. This
would then have made the costs of lunar bases and manned Mars missions
well within the affordability range.
*The important point is that the required high efficiency engines and
lightweight stages for SSTO's already exist and have for decades. All
that is required is to marry the two together. An expendable test SSTO
could be produced, like, tomorrow. Just this one simple, cheap test
would finally make clear the fact that routine spaceflight is already
doable.


Nice article here about Elon Musk and his dedication on getting
the Falcon 9 to be a fully reusable, if not single stage, system:

1 visionary + 3 launchers + 1,500 employees = ?
Is SpaceX changing the rocket equation?
By Andrew Chaikin
http://www.airspacemag.com/space-exp...tml?c=y&page=1


Bob Clark

  #5  
Old December 10th 11, 06:59 PM posted to sci.space.policy
Jim Davis
external usenet poster
 
Posts: 420
Default SSTO's would have made possible Arthur C. Clarke's vision of 2001.

Robert Clark wrote:

Take a Falcon 9 first stage, which has a mass ratio better than
20 to 1, equivalently a propellant fraction better than 95%, and
swap out the low efficiency Merlins for high efficiency
engine[s] such as the RD-180, which has a vacuum Isp 338 s.


If you swap out the Merlins for RD-180s the mass ratio of the stage
will drop.

The payload is so high
in fact that with reasonable estimates for reentry/landing
systems you can still carry useful payload with a reusable
version.


Nonsense. The payload will be barely over 1% of GLOW and just over
18% of dry weight. The recovery systems will eat up all the payload
and more.

Your "reasonable estimates" are based on wishful thinking.

Jim Davis

  #6  
Old December 11th 11, 01:46 AM posted to rec.arts.sf.science,sci.space.policy,sci.astro,sci.physics,sci.space.history
Robert Clark
external usenet poster
 
Posts: 1,150
Default SSTO's would have made possible Arthur C. Clarke's vision of 2001.

On Dec 10, 12:59*pm, Jim Davis wrote:
Robert Clark wrote:
Take a Falcon 9 first stage, which has a mass ratio better than
20 to 1, equivalently a propellant fraction better than 95%, and
swap out the low efficiency Merlins for high efficiency
engine[s] such as the RD-180, which has a vacuum Isp 338 s.


If you swap out the Merlins for RD-180s the mass ratio of the stage
will drop.


To what? And what will then be the delta-V of the expendable version?

Bob Clark
  #7  
Old December 12th 11, 02:29 PM posted to rec.arts.sf.science,sci.space.policy,sci.astro,sci.physics,sci.space.history
Jeff Findley[_2_]
external usenet poster
 
Posts: 1,388
Default SSTO's would have made possible Arthur C. Clarke's vision of 2001.

In article cf5bafb7-ad45-496f-9c91-8a4d109944a5
@d17g2000yql.googlegroups.com, says...

On Dec 8, 9:39*am, Jim Davis wrote:
Robert Clark wrote:
...that reusable SSTO's are possible...


In the future very probably, but certainly not in 2011.

...and in fact
aren't even really hard...


That's just utter cluelessness.


Take a Falcon 9 first stage, which has a mass ratio better than 20 to
1, equivalently a propellant fraction better than 95%, and swap out
the low efficiency Merlins for high efficiency engine[s] such as the
RD-180, which has a vacuum Isp 338 s.
Run the rocket equation. You'll see it can reach orbit with
significant payload as an expendable vehicle. The payload is so high
in fact that with reasonable estimates for reentry/landing systems you
can still carry useful payload with a reusable version.


Sane reusable launch vehicles have never been developed because no one
has seriously tried.

And before anyone mentions it, the X-33 debacle wasn't a serious
attempt. NASA picked *the* most technically challenging proposal and
proceeded to run it into the ground. It was their chance to play with
new tech. Actually flying X-33 appeared to be a secondary or tertiary
goal to NASA.

It also didn't help that the contractor had a vested interest in the
"business as usual" approach to launch vehicles. They sold themselves
as "new space" with a long history of successful innovation, and some
"black tech" they couldn't openly talk about, but they failed miserably
in the execution of the program.

It's my opinion that sane reusable launch vehicles won't come from NASA
or the traditional US aerospace contractors.

Jeff
--
" Ares 1 is a prime example of the fact that NASA just can't get it
up anymore... and when they can, it doesn't stay up long. "
- tinker
  #8  
Old December 12th 11, 03:51 PM posted to rec.arts.sf.science,sci.space.policy,sci.astro,sci.physics,sci.space.history
Robert Clark
external usenet poster
 
Posts: 1,150
Default SSTO's would have made possible Arthur C. Clarke's vision of 2001.

wrote:
In article cf5bafb7-ad45-496f-9c91-8a4d109944a5
@d17g2000yql.googlegroups.com, says...

On Dec 8, 9:39*am, Jim Davis wrote:
Robert Clark wrote:
...that reusable SSTO's are possible...


In the future very probably, but certainly not in 2011.


...and in fact
aren't even really hard...


That's just utter cluelessness.


*Take a Falcon 9 first stage, which has a mass ratio better than 20 to
1, equivalently a propellant fraction better than 95%, and swap out
the low efficiency Merlins for high efficiency engine[s] such as the
RD-180, which has a vacuum Isp 338 s.
*Run the rocket equation. You'll see it can reach orbit with
significant payload as an expendable vehicle. The payload is so high
in fact that with reasonable estimates for reentry/landing systems you
can still carry useful payload with a reusable version.


Sane reusable launch vehicles have never been developed because no one
has seriously tried.

And before anyone mentions it, the X-33 debacle wasn't a serious
attempt. *NASA picked *the* most technically challenging proposal and
proceeded to run it into the ground. *It was their chance to play with
new tech. *Actually flying X-33 appeared to be a secondary or tertiary
goal to NASA.

It also didn't help that the contractor had a vested interest in the
"business as usual" approach to launch vehicles. *They sold themselves
as "new space" with a long history of successful innovation, and some
"black tech" they couldn't openly talk about, but they failed miserably
in the execution of the program.

It's my opinion that sane reusable launch vehicles won't come from NASA
or the traditional US aerospace contractors.

Jeff


Good points. Here's a nice article that expresses the idea that
routine space flight is only going to be achieved when the development
of such vehicles is privately financed:

OCTOBER 20, 2011 AT 6:48 PM
Elon Musk and the forgotten word.
http://behindtheblack.com/behind-the...forgotten-word

The most important achievement of SpaceX may turn out to be they
showed in stark terms that privately financed spacecraft, both the
launchers and the crew capsules, can be developed for 1/10th the cost
of government financed ones.


Bob Clark
 




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