X-Message-Number: 28355
Date: Sat, 26 Aug 2006 22:22:29 -0400
From: Keith Henson <>
Subject: Nanotech, space elevator and wealth

In order for cryonics to work, our society has to stay together and produce 
LN2 at reasonable cost till the singularity or something close to it.

Exactly how long that will take is unknown, but a matter of 1-3 decades 
will probably bracket it.  The world's society has serious problem which 
are made worse by the anticipation of bad times a-coming.

I wrote an article on the connection between good economic times and a lack 
of war that was published in a reviewed journal,


And a slightly longer version of the article is on line.


This has made me rather sensitive to the indirect effects of peak oil and 
global warming.

One way both can be solved is power satellites (from the late 70s).  That's 
darn close to impossible to do with rockets, but mechanical powered space 
elevators (if nanotubes are strong enough) make them amazingly 
economical.  And working on them would make the future brighter and less 
likely to have wars.

Here is a bit of a write up.

2000 tonne per day space elevator
Abstract Text

Even the most optimistic carbon nanotube materials will require some taper 
to build a space elevator. Tapered cables are difficult to drive 
mechanically, leading to complex systems of electrically powered climbers 
and lasers to deliver energy to the climbers. This leads to slow transit 
and replication times.

This paper proposes the design of a moving, non-tapered space elevator 
cable threaded through a system of pulleys that increase the number of 
supporting strands as the space elevator approaches geostationary orbit 
(GEO). The number of pulley stations and the length of the cable will 
depend on the performance of the cable--projected materials have cable 
lengths of 50-500 times the distance to GEO.

The proposed design is particularly suited to rapid buildup. The up cable 
goes beyond GEO before winding back down. New cable attached to the 
existing one at the bottom reinforces the elevator from the top. This 
design also makes cloning the elevator simple.

Cables can move much faster than climbers, perhaps as fast as 1500 km/hr, 
reducing transit time to a day and replication time to 50-500 days. Maximum 
velocity is uncertain because part of the cable in the earth's atmosphere 
and subject to aerodynamic forces. This design also makes cable degradation 
due to molecular oxygen less of a problem since any part of the cable is 
only briefly exposed and the entire cable can be inspected and replaced as 

The paper analyzes a mature system able to lift 2000 metric tons per day to 
GEO. The mechanical power requirement is about a Gw (for scale the aircraft 
carrier Enterprise is rated at 0.21 Gw). Five Gw power satellites (at 
2kg/kW) would mass 10,000 metric tons each, allowing a mature space 
elevator to transport parts for more than 50 power satellites a year. At 5 
Gw-days to lift the parts, the lift energy would be paid back in one day of 
operation of a 5 Gw power satellite.

The obvious effects of building scores of 5 Gw power satellites a year on 
such matters as reducing energy costs and carbon emissions are briefly 


(Photo of model. The cable on the left side of the photograph goes to the 
top, stress being transferred to the other cables through the pulley stations.)


If anyone wants to be involved, working on it, investing, etc, send me a note.

Keith Henson

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