Space elevator vs Rotovator

(E.R.) wrote in message
. com...

Nice essay, Vince. No, I mean that. Healthy debate is a _good_
thing.

:-) Thanks.

Agreed, 24k Shuttle flights is unfeasable. The Highlift scheme
requires 6 Shuttle trips, or an equal number of Delta 4/3 flights.

The design we are working on bootstraps from 20,000 lbs plus
the empty second stage of a Zenit. So this is like 1/18th
the initial mass Highlift systems.

"And this beaming power is a futeristic concept that makes it seem
like tethers are not practical today"

There is a design for the beaming laser (free electron type) on the
table today - I think I've read that the company is ready to build,
they lack customers.

It is still a futuristic concept where it is hard to say how much
development it is going to take (years or dollars), or how well it
will really work. SDI has billions and I don't think they have
a laser anywhere near the power at that distance that these guys
need.

"If it takes 15 days to climb, you have a radiation risk. If a
solar partical event (aka solar flare) happens during this time
the passengers could be in danger."

I agree with you. An SE might not be the best method to ship
people - but cargo doesn't care how much radiation it gets.
Perhaps the best method to ship people up is OSP or rotovator,
then a quick shuttle elsewhere.

I think the big market over the next 20 years is tourism. So if it
is not good for that, I don't think it is much use really.

But the SE will be much more expensive than the rotovator, so
why even use it for cargo?

-- Vince

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~
Vincent Cate Space Tether Enthusiast
http://spacetethers.com/
Anguilla, East Caribbean http://offshore.ai/vince
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~

You have to take life as it happens, but you should try to make it
happen the way you want to take it. - German Proverb

(Vincent Cate) wrote in message om...
(E.R.) wrote in message
. com...

There is a design for the beaming laser (free electron type) on the
table today - I think I've read that the company is ready to build,
they lack customers.

It is still a futuristic concept where it is hard to say how much
development it is going to take (years or dollars), or how well it
will really work. SDI has billions and I don't think they have
a laser anywhere near the power at that distance that these guys
need.


From the NIAC report -
http://www.isr.us/Downloads/niac_pdf/chapter4.html

"A complete power beaming system with 200 kW of power is the aim of
Compower, a private company [Bennett, 2000] (see figure 4.1). The
laser power will come from a 200 kW freeelectron laser (FEL) which
University of California - Berkeley will be supplying for a fixed
price of $120M."

I recall one participant at the 2nd SE conference claiming the FEL was
designed, and was waiting for a buyer. This implies it has been
tested in the lab, but I've no details on that.



I agree with you. An SE might not be the best method to ship
people - but cargo doesn't care how much radiation it gets.
Perhaps the best method to ship people up is OSP or rotovator,
then a quick shuttle elsewhere.

I think the big market over the next 20 years is tourism. So if it
is not good for that, I don't think it is much use really.

I've seen reports that differ in opinion. It might be pointed out
that your tourists will need supplies ...

But the SE will be much more expensive than the rotovator, so
why even use it for cargo?

An SE might be cheaper to operate than a tether. An SE should be able
to deliver cargo to orbit with less shock and damage than a tether,
allowing more fragile satellites to be built.

I'm not claiming an SE is the ultimate solution. It should be a cog
in the ground to orbit infrastructure, however.

As an aside - an SE can be used to make .. more SEs. And long
tethers.

(E.R.) wrote in message . com...
From the NIAC report -
http://www.isr.us/Downloads/niac_pdf/chapter4.html

"A complete power beaming system with 200 kW of power is the aim of
Compower, a private company [Bennett, 2000] (see figure 4.1). The
laser power will come from a 200 kW freeelectron laser (FEL) which
University of California - Berkeley will be supplying for a fixed
price of $120M."

I recall one participant at the 2nd SE conference claiming the FEL was
designed, and was waiting for a buyer. This implies it has been
tested in the lab, but I've no details on that.

Claiming it has been designed and wanting a buyer does really imply it
has been built and tested. Aerospace guys usually design, get money,
then build.

I've seen reports that differ in opinion. It might be pointed out
that your tourists will need supplies ...

It all depends on what cost/lb to orbit you think we will have.
With a rotovator I think the costs can be low enough for tourists.

The supplies may not be much if you are growing food in space.
Even if you just bring up the nutrients for a hydroponic farm
and only recycle the water and CO2, it does not take much at all.

As an aside - an SE can be used to make .. more SEs. And long
tethers.

Of course a rotovator can be used to make more rotovators.

-- Vince

Getting bulk stuff cheaply into orbit via "rotovator" seems like only
half the equation, as for re-obtaining said stuff once it's in orbit,
without being pulverized by the same and/or without wasting energy, is
a difficult task. Surviving the radiation of space needs mass, not
just anywhere sort of mass but, of the sorts of mass that can be
surrounding your butt, if you get my drift.

Your rotovator could certainly help fling tonnes of stuff into GSO,
perhaps magnetically gathered such into a manageable clump, where a
relatively sophisticated spacecraft could safely gather it up and stow
said mass within voids surrounding their craft. Obviously, some of
that mass could include solid fuel elements, as well as modules
intended for the mission of the collectively assembled spacecraft.
Though it'll take far more complications as well as nearly a week
longer for just the initial GSO station keeping to take affect, rather
than of the supposedly manned spacecraft going for the moon-L1, thus
more space radiation exposure as well as more energy resources
utilized, thus more CO2 for Earth.

Instead of focusing upon a rather spendy ESE, or even the cheap
rotovator, how about reconsidering as a compromise upon a LSE, that
could have been initially developed and deployed a decade ago?

If the moon is mostly of basalt, as it perhaps should be, then of
whatever bulk is required for sustaining humans in space, whether
that's of simply mass for spacecraft shielding (abating radiation as
well as improving impact resistance) or of EMPD propulsion fuel
considerations, I believe this substance is in fact available from the
moon, and of affordably accommodating such within the LSE-CM/ISS is
perhaps just the ticket, as in right here and now, not of some
horrifically spendy day decades from now and solely dependent upon
those CNT fibers taking the heat as well as the radiation as well as
whatever other solar flak, not to forget about the year after year of
dodging a few hundred thousand other not so insignificant objects in
it's path (add up the total ESE tether surface exposure and do the
math).

We can get ourselves to/from the moon rather quickly these days, thus
a timeline of potentially lethal exposure to the mostly solar
radiation has become somewhat limited, and thereby survivable within
minimal shielding, as in terms of hours to perhaps a few days worth,
unless of course you've got 341 g/cm of something surrounding your
butt, as then you can tolerate some extended mission related travel
time without having all of your DNA/RNA chopped into bits by various
TBI worthy radiation issues, that's not even to mention significant
erosion if not through-holes as a result of your impacting with a
grain of sand, of which without sufficient shielding density is
exactly where life as we know it becomes downright difficult, and/or
subsequently where your own immune system proceeds to further
irradicate yourself from within, whereas I believe there are known
limits to what having banked bone marrow can achieve.

I've learned that sending technology efficient robotic missions off
into a lunar orbit is apparently a whole lot easier if not more energy
efficient than establishing most any Earth GSO, of which I suppose
that includes the likes of Earth L2 or L1, as those positions being
more complicated and more energy and/or time consuming in order to
establish, whereas as sending robotics off to visit a LSE-CM/ISS is
not only efficiently doable but highly beneficial, especially once
docked and/or snagged by the LSE-CM/ISS robotics and/or crew, as this
is obviously where the final mission configuration outfitting could
take place, as well as applied shielding of mostly moon dirt and/or
basalt rock, and whatever refuel.

What we can't seem to afford to deliver directly into space from
Earth, at least not without creating great amounts of global warming
CO2 for Earth, is that of any sufficient mass of radiation shielding,
and/or of just offering sufficient physical shield density for
surviving micro impacts that are more than a wee bit testy issues for
human space flights, along with there being anything leftover for the
likes of spare fuel, beer and pizza. Eventually, decades from now,
after spending perhaps trillions, the ESE(s) will most likely become
capable of accommodating those deliveries of such mass. Though most
any ESE should be more efficient than rockets, the overall process
still offers a significant CO2 impact for Earth, not to mention an
ongoing maintenance, defense of and logistics fiasco along with a list
of "what if's" that should keep all of us on our toes.

This latest ESE/LSE report/argument needs a whole lot of work, as well
as it could use your input plus lots more expertise, as well as
medications on my behalf. Within this delivery, I'm discussing or at
least attempting to convey upon the pro/con issues of the ESE/LSE,
though obviously I'm thoroughly confused and disorientated as usual,
as I can actually foresee others and even myself being snookered
again, just like those grand old Apollo cold-war days, along with all
the dog wagging on steroids, plus all of that being so nicely packaged
into the sorts of top notch NASA/NOVA produced and/or moderated
infomercials that'll knock your socks off.

Since I'm no good at telling my stories, I may have to get myself back
into this one, polish it up and otherwise continue to share in
whatever I've learned, as well as sharing whatever warm and fuzzy
favor returning that I can think of, as I'm certain of those opposing
or silently playing along, or perhaps they're pretending at their
playing "hide and seek" because, in reality these folks may actually
be dumber than dumb (that's merely arrogance without being smart
enough for realizing it), but obviously those folks would otherwise
expect nothing less from my perspective. So, I'll keep trying to
oblige.

I've accomplished this effort as yet another of my poor deliveries on
the PRO/CON issues of the ESE/LSE. Have yourself a look-see, a few
laughs at the expense of humanity, then give me some of that "all
knowing" feedback and even flak if that's all you've got. Of course,
what's mostly in need are specific numbers, of doable "what ifs" and
of whatever inventions you can devise upon, applicable for either the
ESE or LSE. Actually the ESE needs a whole lot more help and of
trillions more of your hard earned money than my LSE, but I'll
certainly take whatever you've got, even if it's just ESE leftovers.
PRO/CON ESE/LSE: http://guthvenus.tripod.com/gv-ese-lse.htm


Regards, Brad Guth / IEIS~GASA / the discovery of other LIFE on Venus
Besides way too many other topics, here's other ongoing LSE UPDATES:
Basalt tether update: http://guthvenus.tripod.com/gv-lse-gpa.htm
http://guthvenus.tripod.com/gv-cm-ccm-01.htm
http://guthvenus.tripod.com/gv-edwards-se.htm
http://guthvenus.tripod.com/gv-se-flywheels.htm
http://guthvenus.tripod.com/gv-cm-ccm-elevator.htm