[mdlug-discuss] [mdlug] Automotive technical info wanted (only slightly off topic)

[allen]

Ingles, Raymond wrote:
>  Stick 'em in space:
>
>  http://en.wikipedia.org/wiki/Solar_power_satellite
>
>  And use nuclear rockets to get thousands of tons of equipment to space
> cheaply (note: non-radioactive exhaust):
>
>  http://www.nuclearspace.com/a_liberty_ship.htm
>
>  (The good tech stuff starts ~section 6.)
>
>  And with launch techniques like that, we can start doing bigger things
> in space (like space-based industry and manufacturing). Maybe some
> space-based Orions (no fallout onto Earth) or even this little gem:
>
>  http://www.npl.washington.edu/AV/altvw56.html
>
>  Note that the space-based solar power generators don't *have* to be
> photovoltaic (although those are getting more efficient all the time).
> You could use mirrors to concentrate light on a 'hot spot' and use
> steam or whatever.
>
>  Sincerely,
>
>  Ray Ingles                                   (313) 227-231
I remember NERVA and Project Orion back from when they were still new 
but the problem of nuclear hysteria is still real although ebbing. I 
think it'll take a while yet before the grip of the nuclear hysterics 
relaxes to the point that nuclear launch vehicles won't generate 
tsunamis of, well, hysteria.

There are also lots of bureaucratic elbow-jogglers who'd want to have 
their permission obtained before they'd forgo the demagogic 
possibilities of a nuclear launch vehicle. There are even legitimate 
concerns that would have to be addressed incrementally.

Problem is, the two vehicles in the linked articles are big solutions to 
big problems that trouble no one. That's been NASA's problem all along, 
the problems the agency exists to solve aren't of much interest to all 
but a very small element of society.

The military needs its intelligence-gathering, com and nav satellites. 
The civilian sector needs communication satellites, weather and nav. 
Once you've exhausted that list about all that's left is scientific 
inquiry and scientific funding dollars are the subject of vigorous 
competition: fund the Space Shuttle or the Superconducting Supercollider 
or the National Ignition Facility?

How do you convince anyone to build a factory to build economical launch 
vehicles if the demand is so inconsistent and specialized? If you can't 
build those economical launch vehicles then you've got a boutique market 
which is inherently specialized which means expensive launch vehicles. 
Classic chicken-and-egg problem.

Further muddying the waters is the whole romantic "to go where no man 
has gone before" mythology. The cold fact of the matter is that the Age 
of Exploration was driven by the lust for filthy profits as was most 
exploration. To the bulk of the human race there's not much reason to do 
something if it doesn't do you some good and the good that's come out of 
space exploration hasn't been all that obvious to most people.

What's necessary to kick-start space industry is a business that 
provides a self-evidently worthwhile service, doesn't demand gigantic 
up-front investments, can be expanded incrementally and it wouldn't hurt 
if it conferred some status on various involved parties.

Richard Branson's Virgin Galactic startup may put all those pieces together.

He's got dibs on the follow-on to Burt Rutan's Starship One and White 
Knight One and he's building a "space port" in New Mexico. Since hauling 
people was where Branson got his start, it's something he already knows 
about and there might be a business in hauling people around the globe. 
At least Branson seems to think there is.

For what it's worth, I agree with him.

There are people who can afford to go almost wherever they want, like 
the International Space Station, so there'll be a novelty market. There 
are also people for whom the money is inconsequential but the cachet, 
and time, isn't. Paris Hilton, when she gets out of the slam, might 
think nothing of rocketing over to Paris for breakfast and Tokyo for the 
night life all in the same day. Finally, there are people whose presence 
is worth the price of a ticket.

If the business works you've got a legitimate business to expand into. 
Hauling six people at a time makes money so hauling twenty at a time 
makes sense and sets the stage of Starship Three which is, I think, 
orbit-capable. Now you've got reliable, economically-viable LEO 
capability which means all sorts of otherwise ridiculous ideas become 
workable and the chicken-and-egg problem is solved.

The reason I think power sats, if they ever fly, will be made with PV 
arrays is that the manufacturing/assembly process is much more amenable 
to autonomous manufacture. For the PV array you need, mostly, solar 
cells and a structural framework. Most of what's left would be a 
relatively small part of the overall structure. Stuff like power 
transmission on the sat, power conversion and antenna array and some 
sort of stabilization system.

With solar thermal you're looking at an impressive plumbing job, lots of 
moving parts, specialized hardware that most likely couldn't be 
manufactured autonomously and would have to be hauled up from Earth, 
working fluids, etc. All that means lots of on-site personnel and all 
the support they need. Given certain assumptions PV just looks more doable.

This is longer then I intended. Probably boredom waiting around for the 
Nobel Prize committee to drive up in their van and Ed McMahon to jump 
out and award me a medal. Oh, wait!

Allen