[ExI] Power sats and the industrial development of space

[painlord2k at libero.it]

Il 24/03/2009 8.05, Jeff Davis ha scritto:
> On Mon, Mar 23, 2009 at 5:46 PM, Tom Nowell<nebathenemi at yahoo.co.uk>  wrote:
>> Jeff, whenever we've asked Mr Henson why he favours massive earth-launch as soon as possible, he's always pointed to the time taken to set up lunar mining or asteroid mining facilities, and how they'd probably add a significant amount to start-up costs. Keith is of the opinion we need solar power satellites in 10-15 years, which means getting the whole project under way NOW.
>
> Yes, but he's also said that the space elevator isn't happening, and
> orion, though apparently feasible, has a BIG public relations problem.
> And laser launch is notional, with zero infrastructure.  So we're
> left with proven conventional launch methods.  Big uns.  Lotsa big
> uns.

Well, if what Brian Wang wrote is correct, there are the technology to 
build  fiber of 9-10 GPa now/few months, with the real possibility to 
move to industrial production in few years.

We need not less than 50-60 GPa for a non-tapered cable for the SE and, 
IIRC, 30 GPa for a realistic tapered one.

Given that carbon nanotubes have strenght from 70 to 200 GPa, there is 
space to big improvements. But with only 10 GPa we would be able to 
built a SkyHook (not so good as a SE but better than nothing).

And to be precise, we could not be able to build a SE for the Earth with 
10 GPa but, for the Moon and Mars, 10 GPA would be good enough. As 
usual, different problems, different technologic solutions.
But, given the pace of progress, it is not so improbable that we have 
materials with more than 50 GPa between 2014 and 2019.
At that point, we could be perfectly able to build the SE and after this 
the SPS very faster and have it done before than using rocket launches 
with the current technology and starting now.

I think Mr. Henson is a bit too much worried about Peak Oil and what 
think could do to our civilization. His react like the man that knowing 
that the near river will probably flood his house start digging and 
building a dam moving the earth with a shovel and don't think that could 
do it better building a wheelbarrow to move the earth. He is captived in 
the "There is no time, I/We/Them must act immediately or the sky will 
fall" mindset.

Mirco