Re: Is it this easy to live on Mars?

Your 1.95 kw per person in America is not all-inclusive, as in not by
a long shot, that is unless you're including those in graves.

~ BG


On Sep 25, 5:04 pm, Willie.Moo...@xxxxxxxxx wrote:
On Sep 24, 11:57 pm, BradGuth <bradg...@xxxxxxxxx> wrote:



On Sep 24, 8:14 pm, Willie.Moo...@xxxxxxxxx wrote:

On Sep 22, 8:58 pm, BradGuth <bradg...@xxxxxxxxx> wrote:

Sustaining a human biological life that’s active and kicking in
Antarctica requires upwards of roughly 8~10 kw.h/day

Yet they spend LESS than 6 watts per day gathering oxygen from the air
- You are making my point for me dumbass! haha - the amount of energy
needed to obtain oxygen is as nothing compared to other likely costs -
which was my freaking point. sheez! .

Yet, I wonder about the accuracy of your figures - living in
Antarctica with a 101.3 kpa air pressure is very different than living
on Mars with a 0.6 kpa air pressure. Heat transfer due to convection
for example is likely to be less than 1% than on Earth - so dumping
heat to the thin atmosphere is likely to be a problem.

A more accurate comparable would be our experience of the Apollo
journeys. Here we have a crew of 3 spending 8 days or more on a
journey to the moon and return to Earth. There are three important
electrical systems, the Command Module, the Service Module and the
Lunar Module

http://en.wikipedia.org/wiki/Apollo_spacecraft#Specifications_2http:/....

This includes;
Command Module 20 kWh - batteries
Service Module 6.3 kW power - 670 kWh - fuel cells
Ascent Module 2.6 kWh - batteries
Descent Module 13.2 kWh - batteries

It loows like there's 2.1 kW per person would last for 4.4 days on the
fuel cells. Adding all the kWh together for all the systems -
obtains .705.8 kWh - dividing by 6.3 kW obtains 4.66 days. This
suggests that average power is far less than peak power - about half -
to give a 9 day capability using ALL systems. This is 3 kW per
AVERAGE - which is 1 kW per person - which is 1/10th the figure you
suggest.

On the moon, there is a total of 15.8 kWh and over 48 hours that
averages 330 watts for two people. That's 165 watts per person.

This implies that a solar panels that is 20 sq meters is needed to
sustain a person on Mars at 1 kW per person, and 3.3 sq meters is
needed to sustain a person at the 165 watts per person - and both of
these is far larger than 6 watts - which suggests that oxygen,
nitrogen and water are not going to be a problem for Mars explorers.

unless you plan
on losing weight,

Why? A person consumes about a ton of stuff per year. Most of that
is oxygen and water. With oxygen and water supplied from Mars'
atmosphere, this means only 160 kg (352 lbs) of freeze dried food is
needed for each person per year. So, for a two year journey only 320
kg is needed in freeze dried food

plus energy for whatever’s the technology and
habitat or work related machinery and space/area heating,

Have you done a heat transfer equation for a carbon dioxide atmosphere
at 0.6 kpa? I think shedding heat in the sun will be the problem -
but I can't tell for sure until I've done the work. Have you? If so,
please share it.

whereas you
might as well figure upon providing of food and other energy that’s
worth at least 24 kw.h/day, up to as much as 100 kw.h/day if

???? 70 grams of proteins per day add up to 25 kg per year. Similar
quantities of fats and 310 grams of carbohydrates per day add up to
160 kg per year per person. A total less than 350 kg per person for
the entire mission - providing water and oxygen is obtained on Mars.

significant technology and/or surface transporters are involved.

What the hell are you talking about? Nothing could be further from
the truth.

That’s a lot of food and fuel,

You make no sense.

especially considering that all the O2
and h2o is essentially free for the taking,

That's the point - molecular sieve and a small amount of energy
derived from solar panels provides all the oxygen and water and
nitrogen desired.

whereas on Mars it’s
anything but directly available or much less free,

That's the point of my post. 6 watts per day is needed to get
oxygen. Less power gets nitrogen and water. This is far smaller than
even the lunar module surface power levels.

and the on-again
off-again weather on Mars can make Antarctica seem like a Sunday walk
in the park,

I think you have not considered that Mars will be easier than the
lunar surface, and that the lunar surface was easier than
Antarctica.

worse yet is that Mars offers essentially zilch worth of
local energy in order to process or create much of anything.

What rot - the solar constant at mars is 700 watts per sq m. At 40%
conversion efficiency 280 watts per sq m solar panels are easily
achievable. With 20% insolation that's 56 watts continuous per sq
meter. So, 3.3 sq meters is sufficient to meet the needs of each
person on the surface indefinitely. With only 480 grams of freeze
dried food per day supplemented with water extracted from Mars air at
very little energy.
.

So, I do not quite see how an active individual human life on Mars can
be artificially sustained for much less than 5 kw/hr, or an all-
inclusive 120 kw.h/day

You're saying it takes 5,000 watts per person - when we have actual
experience of people on the moon existing at 165 watts per person -
and I've shown that all the oxygen and nitrogen and water desired can
be obtained at less than 10 watts per person. A solar panels of 3.3
sq meters 1.82 m on a side - supplies this indefinitely. This masses
only 20 kg or less.

unless they are hibernating underground, of
which staying extensively underground may become a requirement of
protecting our frail human DNA.

You haven't done a heat balance equiation.

A fully active human expedition on
the surface of Mars that’s including physical labor might even tip the
all-inclusive energy scale at 10 kw.h or 240 kw.h/day,

No it won't. You don't know what the hell you're talking about - not
in the least.

of which a
mobile 50+ kw nuclear reactor shouldn’t have any trouble keeping up
with the demands of up to 10 individuals.

9 kg of water is decomposed into 1 kg of hydrogen and 8 kg of oxygen
using 210 megajoules at typical efficiencies. 50 kilowatt electrical
power plant produces .4,320 megajoules of energy in a 24 hour period
This is enough energy to reduce 20.5 kg of hydrogen and 164.6 kg of
oxygen per day. This is a total of 185.1 kg of propellant per day.
Spending 180 days on mars this is enough to produce .33.3 metric tons
of rocket fuel. Sending a reactor and a stage 2.15 years prior to
landing another stage with people, allows the produciton of 143.2
metric tons of propellant. This allows the return 37.4 metric tons of
payload back to Earth using these propellants.

Instead of a nuclear reactor a 1,000 sq meter panel array consisting
of 330 panels each 4ft x 8ft unfolded from a z-folded arrangement and
massing 2.5 metric tons measuring 8 ft x 8 ft x 11 ft - extending
1,320 ft long strip 8 ft wide when extended. This produces 92,400
watts peak.

Once again, the notions of us humans surviving on Mars is at least
technically doable,

Far easier than you suggest.

as long as our frail DNA and mobile reactor holds
out,

Rot - we have had this discussion. 8 millirads per day is
survivable. 22 millirads per day in interplanetary space equally so.

Keep telling that one to TRW,

Please provide a pointer to the TRW data. 500 rad per day seems a bit
high.

Please understand even if what you say is correct,about the 500+ rad
per day that figure is the level of radiation in the center of the van
allen radiation belt. That level is not seen in interplanetary
space.

Raytheon and a good dozen other members
of DARPA.

You like to mention the Defense Advanced Researxh Projecxts Agency in
many many inappropriate contexts. Why is that? They tell you an SBIR
proposal you sent was infeasible for something? lol.

and they essentially hunker down each night or take significant
ground cover whenever there’s too much cosmic or solar radiation to
deal with.

You are confusing and confabulating several diverse ideas here - yes
we will have to sheild ourselves from solar storms. No radiation is
not a show stopper.

The point is we can reduce our supply chain dramatically by including
solar panels and molecular sieves in our invenstory of stuff to take
to mars.

I'll accept 5 kw/human as technically doable. You go first.

Well you are good at quoting figures, not so good at backing them
up.

The USA is the most energy intense nation on Earth with the highest
energy use per capita and the largest industrial infrastructure in
place.

Each citizen uses energy at 1.95 kW - and this figure includes the
electrical consumption of every business every machine every
industrial process that's electrically driven. haha - at the consumer
level, an all electrric house with heat pump, regrigeration,
airconditioning, all electrical appliances hot water heater you name
it - totals less than 1 kW average use rate - per FAMILY! Which
includes mom dad and 2.3 kids. That's less than 250 watts and more
than 200 watts per person.

Now this is suspiciously close to the 165 watts per person experienced
by the LM astronauts while on the surface of the moon.

So, if this doesn't suggest something is amiss - I don't know what
does.

Like I said Apollo LM used 165 watts per person and with modern
electronics ...

read more »

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