Once and for all...are humans or robots better for Mars?

On Jan 20, 10:46*pm, "Sea Wasp (Ryk E. Spoor)"
wrote:

*and "space-hardening" things
gets vastly harder to do the more complex the gadget is. At least until
they get to, say, purely photonic computers or something of that
nature).

There's always redundancy instead of/in addition to hardening. I
work on a little chip with 100 processing elements in a memory/
communications matrix. That's 100 CPUs on one chip. There are four
of them circling the Earth on ISS right now as part of MISSE7.

Schemes such as dividing the CPUs into teams of four and having them
watch each other for errors, are a possibility for redundancy instead
of hardening. Most radiation-caused failures are soft failures (a
bit get changed by an energetic particle) rather than hard failures
(the chip is actually permanently damaged).

On Jan 21, 12:44*am, Fred J. McCall wrote:

As funny as that sounds, it's actually at least somewhat the truth. My
generation grew up during Mercury, Gemini, and Apollo. *A lot of us
became scientists and engineers. *Manned exploration ended and now
we're trying to find some way to overcome a shortage of engineers and
scientists as my generation retires.

Even a blind man could figure it out...

Even a blind man would realize that there is no shortage of scientists
and engineers in the USA. That's FUD spread by corporations to push
their program of H1B visas and off shoring. If there's such a
shortage of scientists and engineers in the USA why are so many of
them working at hardware stores?

On Jan 21, 6:54*am, "Sea Wasp (Ryk E. Spoor)"
wrote:
On 1/21/11 3:18 AM, Mike Dworetsky wrote:

Building new nuclear power plants would fill part of the gap for
electricity. But they are slow to construct

* * * * Don't HAVE to be slow, comparatively speaking. There's nothing
inherently harder about building a nuke plant than building a coal
plant. And you can make many smaller nukes for local areas -- Toshiba
has one design that's meant for a moderate-sized town and lasts 20-30 years.

The electricity from those small pop-them-in-the-ground nukes are
*expensive*; about four to eight times as expensive as a conventional
nuke. Their electricity costs something like $.40/KWHr while the
(USA) national average is ~$.11/KWHr at the consumer's circuit
panel. A conventional nuke can produce electricity well under $.12/
KWHr. At least, the South Texas Nuclear Project does.

As with so many things, there are economies of scale.

..

US corporations are overcoming a shortage of engineers by off-shoring as
much engineering as possible. *I hear this story repeatedly from just
about every engineer I talk to.

Jeff
--

they might as well since they are ofshoring production and customer
phone support.

will the last american manufacturer worker please turn off the lights
and lock the gate before applying for unemployment............

Absolutely. *And the most efficient way to do this would be by having a
geologist in a space suit, or a geologist very close to an unmanned
vehicle so it can be efficiently tele-operated. *The time delay of radio
signals from the Earth to Mars and back makes tele-operation extremely
difficult and time consuming, as the Mars rover missions have shown.

Jeff

really what difference does speed make? have the geologist controlling
multiple rovers at different locations.

in the down time of the speed of light, the geologist is commanding
another rover to do something else.

and do robotic science on site but have sample returns for futher
investigation, perhaps on ISS.

to minimize contamination of mars based life to our earth

On 1/21/11 8:29 AM, Sylvia Else wrote:
On 21/01/2011 11:54 PM, Sea Wasp (Ryk E. Spoor) wrote:
On 1/21/11 3:18 AM, Mike Dworetsky wrote:
Michael Gordge wrote:
On Jan 21, 7:33 am, "Mike Dworetsky"
wrote:

but by
comparison to other sorts of projects relatively little is being
spent on this ultimate solution to the energy crisis.

Where's the energy crisis and why and how is it an energy crisis?

MG

If you want to be more specific, it's also a pollution/byproduct crisis.
The big demand is for clean energy, without CO2 contributing to global
warming and without consumption of fossil fuels which have value as a
source of chemicals for industrial uses such as plastics.

There is plenty of coal, for now, though it is a comparatively dirty
fuel. But oil is increasingly scarce or controlled by people you may not
like very much. It is hard to run your car or truck on coal. If oil is
plentiful, why is it considered worthwhile drilling in deep water to get
it? And why is it costing around $100/bbl?

Building new nuclear power plants would fill part of the gap for
electricity. But they are slow to construct

Don't HAVE to be slow, comparatively speaking. There's nothing
inherently harder about building a nuke plant than building a coal
plant. And you can make many smaller nukes for local areas -- Toshiba
has one design that's meant for a moderate-sized town and lasts 20-30
years.


and subject to political
popularity contests. Electricity consumption is growing fast in
industrialized countries. It will get worse as electric cars come into
use.

If you convert everyone to electric, it would become almost impossible;
you'd have to double the grid's carrying capacity and, more importantly,
you'd need MUCH higher capacity lines for anywhere that was going to try
to charge such vehicles quickly.

Well, we know how do do those. Finding batteries that are capable of
being charged quickly is a different matter.

That's one hurdle. Doubling the carrying capacity of the grid, and
bringing megawatt-load capable lines to either individual houses or
hundred-megawatt load-capable lines to "electric filling stations"
across the country? THAT will be expensive, on the Manned Space Program
To Mars Plus Bailout level of expensive.


But fusion power could be used in other ways, such as producing hydrogen
by electrolysis (or by some more direct mechanism involving heat), and
the hydrogen could then be used as the fuel.

Fun though the idea is, the Hydrogen Fuel Economy is looking like a
stupider idea every day I look at it. The infrastructure to carry,
store, and transfer the stuff safely doesn't exist, so you've got
another hundreds of billions to trillions of dollars expenditure involved.

Instead, use the power to synthesize the energy carriers that we
ALREADY USE: Liquid hydrocarbons. It may be somewhat less efficient, but
you save IMMENSE amounts by using the same cars, same filling stations,
same generators, same EVERYTHING... and if you synthesize it from things
like water and atmospheric CO2, it becomes carbon-neutral and
environmentally friendly.


All I am really pointing out is that very little is being spent on
research into ways of making fusion practical, in comparison to many
other things. Fusion holds the promise of producing energy with no
pollution or long-lived radioactive by-products.

I was under the impression that any reasonable fusion reaction (i.e. not
using difficult-to-obtain isotopes of something) would produce enough
neutrons to make PLENTY of the structure radioactive.

That's not much, in the scheme of things.

Not significantly better than a fission reactor, though, and fission we
know how to make NOW.
--
Sea Wasp
/^\
;;;
Website: http://www.grandcentralarena.com Blog:
http://seawasp.livejournal.com

On 1/21/11 11:50 AM, trag wrote:
On Jan 21, 6:54 am, "Sea Wasp (Ryk E. Spoor)"
wrote:
On 1/21/11 3:18 AM, Mike Dworetsky wrote:

Building new nuclear power plants would fill part of the gap for
electricity. But they are slow to construct

Don't HAVE to be slow, comparatively speaking. There's nothing
inherently harder about building a nuke plant than building a coal
plant. And you can make many smaller nukes for local areas -- Toshiba
has one design that's meant for a moderate-sized town and lasts 20-30 years.

The electricity from those small pop-them-in-the-ground nukes are
*expensive*; about four to eight times as expensive as a conventional
nuke. Their electricity costs something like $.40/KWHr while the
(USA) national average is ~$.11/KWHr at the consumer's circuit
panel. A conventional nuke can produce electricity well under $.12/
KWHr. At least, the South Texas Nuclear Project does.

As with so many things, there are economies of scale.

Yes. If Toshiba or others were making a hundred of them a year rather
than one every year or two, the price would drop.

--
Sea Wasp
/^\
;;;
Website: http://www.grandcentralarena.com Blog:
http://seawasp.livejournal.com

In article , David Mitchell writes:
On 21/01/11 12:54, Sea Wasp (Ryk E. Spoor) wrote:

I was under the impression that any reasonable fusion reaction (i.e. not
using difficult-to-obtain isotopes of something) would produce enough
neutrons to make PLENTY of the structure radioactive.

Boron fusion doesn't produce neutrons, just nice, clean Helium and
electrons, and there's plenty of boron about.

I never heard of boron fusion before I read your post, but it does
appear to be a real thing. However, I'm less than clear on something:
how does splitting boron into three helium qualify as "fusion"? Sure
sounds like "fission" to me, although with much lighter elements than
we typically associate with fission.

--
Michael F. Stemper
#include Standard_Disclaimer
The FAQ for rec.arts.sf.written is at:
http://www.leepers.us/evelyn/faqs/sf-written
Please read it before posting.

: (Michael Stemper)
: I never heard of boron fusion before I read your post, but it does
: appear to be a real thing. However, I'm less than clear on something:
: how does splitting boron into three helium qualify as "fusion"? Sure
: sounds like "fission" to me, although with much lighter elements than
: we typically associate with fission.

It's called fusion rather than fission largely because you aren't spitting
a boron nucleus into three helium nuclei (which would be hard, since there
aren't enough nucleons in a boron atom to make up 3 helium atoms), but
rather fusing a proton and a boron nucleus, yielding three helium atoms.
If all you did was split atoms lighter than iron, you can't get energy
out of it. Mushing the proton and the boron together is the only thing
that lets you get energy out of it. Hence, calling it fusion.

Of course, there are quite severe problems with proton-boron fusion,
which make it unlikely to persevere.


Wayne Throop http://sheol.org/throopw

On Jan 21, 3:00*am, "Norm D. Plumber" wrote:
(Derek Lyons) wrote:
Howard Brazee wrote:

On Thu, 20 Jan 2011 11:16:17 -0800 (PST), Ilya2 wrote:

Yes, it is "hogwash" in the sense that Apollo 13 did not stop the
program or even came close to stopping it, but the answer to your
question -- because it was Cold War. Demonstrating US technological
superiority over USSR was a specific, identifiable goal. No such goal
exists today.

Actually such a goal *does* exist today - for countries such as China
and India.

Except their goal is "proving we are a Real Spacefaring Nation by
doing what Real Spacefaring Nations have done in the past".

D.

Difficult to say what China's goal is with respect to a space program.

Not really. Having a space program proves that they have missiles
that can strike anywhere on the planet.