Re: The Moon

From: william mook (william.mook_at_mokindustries.com)
Date: 10/11/04 

Date: 10 Oct 2004 22:58:47 -0700

"Scott Hedrick" <dinehnm@yahoo.com> wrote in message news:<0D1ad.66918$DV3.28036@bignews5.bellsouth.net>...
> "warrenb" <warren@southhighlands.com> wrote in message
> news:41687a2d$1@dnews.tpgi.com.au...
> > It makes more sense/cheaper to live on the bottom of the ocean, or build a
> > biosphere in the desert
>
> OK, let's see your numbers. Have you done the math to support this claim, or
> are you talking out of your Haller?

Well, for space travel, what you're paying for is momentum. So we're
talking cost of momentum. As the cost of momentum drops we can
project more for a given amount of money. This means we can do more
for a given amount of money. I propose that space based resources
will displace Earth based resources because space based assets will
deliver more stuff at lower price than terrestrial competitors.

Here's a typical launcher;

http://www.astronautix.com/lvs/pro8k82k.htm

A reasonably priced rocket these days is the Russian Proton rocket.
It costs $50 million and puts up about 19,760 kg into a 186 km orbit.
Speed of the payload is about 7.6 km/sec. Momentum then is mass times
speed so;

    7,600 x 19,760 = 150,176,000 kg m/sec

and the cost is $50 million, so the cost per momentum today for
rockets is 3 kg m/sec per dollar. Or $0.33 per kg m/sec.

With this capability we can put up small satellites that can process
information and provide a global information network.

http://www.astronautix.com/craft/echo.htm

In the 1950s and 60s the US orbited a pressurized mylar balloon that
was 30 m in diameter and massed 66kg. Since mass scales with area of
balloons, and the gas mass was not the largest component, we can say
that a 19,760 kg balloon would be 519 m in diameter. Built as an
inflatable concentrator this system would generate 115 MW of laser or
maser energy. At $50 million this is $0.50 per watt. Nearly
economic.

A fully reusable unpiloted vehicle might drop costs another factor of
ten, depending on launch rate.

Such a system would deliver solar pumped lasers to orbit at a cost of
$0.05 per watt. Definitely economic.

Once we have lasers of sufficient size and at appropriate costs, we
can imagine laser sustained detonation rockets with the laser beams
powered conventionally which might drop costs a factor of 100. Laser
rockets with laser beams powered by sunlight captured on the ground
might drop costs a factor of 1,000 - and space based capture of
sunlight to power laser beams might drop laser rocket costs by a
factor of 10,000. Nuclear pulse rockets have already been shown to be
capable of cost reductions by a factor of 10,000 or more from chemical
rockets. So;

   Expendable Launch Vehicles - $330.00 per kg km/sec
   Reusable Launch Vehicles - $33.00 per kg km/sec
   First Generation Laser - $3.30 per kg km/sec
   Second Generation Laser - $0.33 per kg km/sec
   Third Generation Laser - $0.03 per kg km/sec
   Nuclear Pulse Rocket - $0.003 per kg km/sec

As the costs for momentum drop the rockets get bigger and faster and
we have the following benefits;

  ICBM - End of global warfare - 1950
  Satellite - Global Communication - 1960
  Power Satellite - Global Energy - 1970*Proposed
  Asteroid Capture - Global Manufacturing - 1968*Proposed
  Suborbital ballistic delivery -
  Low cost orbital travel -
  Space Homes -

Relevant Pages

  • Re: The Moon
    ... Well, for space travel, what you're paying for is momentum. ... As the cost of momentum drops we can ... rockets is 3 kg m/sec per dollar. ... can imagine laser sustained detonation rockets with the laser beams ...
    (sci.space.shuttle)
  • Re: The Moon
    ... Well, for space travel, what you're paying for is momentum. ... As the cost of momentum drops we can ... rockets is 3 kg m/sec per dollar. ... can imagine laser sustained detonation rockets with the laser beams ...
    (sci.space.policy)
  • Re: The Moon
    ... > Well, for space travel, what you're paying for is momentum. ... As the cost of momentum drops we can ... > can imagine laser sustained detonation rockets with the laser beams ...
    (sci.space.history)
  • Re: The Moon
    ... > Well, for space travel, what you're paying for is momentum. ... As the cost of momentum drops we can ... > can imagine laser sustained detonation rockets with the laser beams ...
    (sci.space.policy)
  • Re: The Moon
    ... > Well, for space travel, what you're paying for is momentum. ... As the cost of momentum drops we can ... > can imagine laser sustained detonation rockets with the laser beams ...
    (sci.space.shuttle)