Mars 2014 - One Way

Henry Spencer wrote:
There is room for some doubt (unless you're Zubrin) about issues like the
problems of handling dusty Martian air and the energy requirements of the
complete system. Serious engineering uncertainties do remain, and only
Mars-surface tests can definitively settle whether current ideas about
solving them would actually work. But any flat declaration that the whole
concept is "infeasible" rests on hidden assumptions.

Zubrin is fairly optimistic about Martian ISRU, but in
many ways he is justifiably so. The only reasonably
likely issues with the concept are, as you say, dust
and perhaps efficiency. Both of those are problems of
degree though, and can be solved directly with "over-"
engineering. One of the great elements of Zubrin's
plan is that it doesn't put the lives of the crew into
danger based on the success or failure of ISRU. The
crew doesn't leave Earth until their return craft on
Mars is fueled. And realistically the return vehicle's
fueling can be made fairly bullet proof based on data
from robotic ISRU testing missions. It is, in my
opinion, the best plan around, although it is by no
means perfect nor impossible to improve upon.

(Henry Spencer) :

There is room for some doubt (unless you're Zubrin) about issues like the
problems of handling dusty Martian air and the energy requirements of the
complete system.

But these are things that can be tested on Earth before you send it there.
Verses using moon of unknown elements as fuel.

the ISS,
The orbit is all wrong for Moon or Mars missions!

No, that's a misconception, based on oversimplified notions of orbital
dynamics. The only thing *badly* wrong with the ISS orbit as an assembly
site is that it's relatively expensive to get to,

That is infact what I meant., I am aware that once assembled even a polar or
retrograde orbit can still get you to moon with very little diffirence in the
fuel/DeltaV required.

If you want a *good* assembly site, using existing launchers, the thing to
do is to put in a couple of Zenit or Atlas V pads at Kourou, and assemble
in an equatorial orbit.

a refueling stop at Phobos,

We have no probes on Mar's moons, what does he plan to use there as fuel
that we know is there?

It is likely -- not certain -- that a substantial fraction of the mass of
Phobos is either water ice, or water-rich organic gunk like the Tagish Lake
meteorite. Confirmation of this definitely would be useful...

The ice is the most likely explaination but when you are in orbit of Mars
that is no time to find out that you are wrong and there is something new and
diffirent way to get the same long distance measurements.

Earl Colby Pottinger

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The only objection I've seen which had a ring of truth aboout it was
about particulate size and filtration. I think was a physicist friend
who was wonderingh if you could adequately filter out dust matter from
the the air before processing, or even post processing over a sustained
period of time without human intervention.

I've done work on chemical plant where our "clean" water source had
significant impurities and it was a pretty intensive job keeping the
filters working but I'm not clear if the Martian atmosphere is that
dusty.

It is something that needs to be tested over time.

Dave

I am not entirely sure why you'd bother having to mine Phobos
for your orbital mission fuel anyways. GEO to Phobos and back
on one tankload of ion fuel is within reasonable design parameters,
and I have a whole set of mission architectures I worked up for
Mars missions starting with manned Phobos missions and building
a base there for teleoperation of surface rovers, ramping up
through eventually staging a lander out of the Phobos base.


-george william herbert


I can think of one reason to mine Phobos. Hauling all that fuel up to Low Earth
orbit, 270 tons of it, is bound to be expensive, it would be much cheaper if
you could find an extraterrestrial source of hydrogen. One such source might
possibly be Phobos. The initial mission will of course have to be fueled from
Earth. The Ship uses up some of its fuel to get to Phobos, it has enough to get
back to Earth, but it mines some more for the landers and for then Next Mars
mission after that. If there is no hydrogen on Phobos, the ship can safely
return to Earth Orbit with that fuel which remains, otherwise it can fill its
tanks again from phobos, fuel the tanks of its landers so they can land and
take off again. The Interplanetary ship now has enough fuel for the trip to
Earth and back to Mars for the next mission. The astronauts of the next mission
will have to mine Phobos for the return trip, but this time they already know
that Phobos has fuel.

Tom

In article ,
Earl Colby Pottinger wrote:
There is room for some doubt (unless you're Zubrin) about issues like the
problems of handling dusty Martian air and the energy requirements of the
complete system.

But these are things that can be tested on Earth before you send it there.
Verses using moon of unknown elements as fuel.

Unfortunately, the properties of Martian airborne dust are equally
unknown, in fact more so, which makes simulating it rather problematic.
And details of local conditions can influence energy efficiency
substantially.

This is not, in any case, a hard problem to solve: a small unmanned
lander with a scaled-down fuel plant will answer most of the questions
adequately. (This is Chemical Engineering 101: you always build and
operate a pilot plant before signing off on the plans for a production
plant. The design is as close to a production plant as possible, and it's
operated like a production plant too, but it's smaller.)

...The only thing *badly* wrong with the ISS orbit as an assembly
site is that it's relatively expensive to get to,

That is infact what I meant.

But as I said -- in a part you snipped out -- that's not very important,
because launch costs are not a major part of the price tag and (say)
doubling them is not a big problem.

(What *is* potentially a nuisance is the requirement to subdivide things
into smaller pieces. But even that's manageable, if it's not pushed to
extremes, as this case wouldn't.)

It is likely -- not certain -- that a substantial fraction of the mass of
Phobos is either water ice, or water-rich organic gunk...

The ice is the most likely explaination but when you are in orbit of Mars
that is no time to find out that you are wrong and there is something new and
diffirent way to get the same long distance measurements.

Depends on whether you have a backup plan... which you should. Not
necessarily one that completes the whole mission, but one that gets
you home.

In any case, this is what precursor missions are for. If there's a
question that has to be resolved, you resolve it.
--
"Think outside the box -- the box isn't our friend." | Henry Spencer
-- George Herbert |

George William Herbert wrote:

I am not entirely sure why you'd bother having to mine Phobos
for your orbital mission fuel anyways. GEO to Phobos and back
on one tankload of ion fuel is within reasonable design parameters,
and I have a whole set of mission architectures I worked up for
Mars missions starting with manned Phobos missions and building
a base there for teleoperation of surface rovers, ramping up
through eventually staging a lander out of the Phobos base.

I'd love to see those. Would you consider putting them online at retro.com?



-george william herbert




--
Hop David
http://clowder.net/hop/index.html

In article ,
Cris Fitch wrote:

One way to Mars is the right way to go. And it may be fatal for some
of the colonists - just consider early colonies in the Americas.

I bet some people would argue it will fatal for all of them,
eventually.

I wouldn't be especially surprised if all of the early colonists
experienced premature death by Terrestrial standards, from accidents,
unanticipated toxicities, osteoporosis and so on. How acceptable this is
PR wise will probably depend on how premature the deaths are (ten years
off life expectacy might be ok but forty, not so much) and how they are
presented to the people funding the effort (which may not be governments).
--
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http://www.marryanamerican.ca
http://www.livejournal.com/users/james_nicoll

Tkalbfus1 wrote:
I am not entirely sure why you'd bother having to mine Phobos
for your orbital mission fuel anyways. GEO to Phobos and back
on one tankload of ion fuel is within reasonable design parameters,
and I have a whole set of mission architectures I worked up for
Mars missions starting with manned Phobos missions and building
a base there for teleoperation of surface rovers, ramping up
through eventually staging a lander out of the Phobos base.


-george william herbert



I can think of one reason to mine Phobos. Hauling all that fuel up to Low Earth
orbit, 270 tons of it, is bound to be expensive, it would be much cheaper if
you could find an extraterrestrial source of hydrogen. One such source might
possibly be Phobos. The initial mission will of course have to be fueled from
Earth. The Ship uses up some of its fuel to get to Phobos, it has enough to get
back to Earth, but it mines some more for the landers and for then Next Mars
mission after that. If there is no hydrogen on Phobos, the ship can safely
return to Earth Orbit with that fuel which remains, otherwise it can fill its
tanks again from phobos, fuel the tanks of its landers so they can land and
take off again. The Interplanetary ship now has enough fuel for the trip to
Earth and back to Mars for the next mission. The astronauts of the next mission
will have to mine Phobos for the return trip, but this time they already know
that Phobos has fuel.

Tom

And the same could be said for Deimos, it seems to me.

--
Hop David
http://clowder.net/hop/index.html

:

The only objection I've seen which had a ring of truth aboout it was
about particulate size and filtration. I think was a physicist friend
who was wonderingh if you could adequately filter out dust matter from
the the air before processing, or even post processing over a sustained
period of time without human intervention.

I've done work on chemical plant where our "clean" water source had
significant impurities and it was a pretty intensive job keeping the
filters working but I'm not clear if the Martian atmosphere is that
dusty.

It is something that needs to be tested over time.

Yes it can be that dusty, Mars has sand storms that can last months at a
time. And the sunset clearly show that there is still lots of dust in the
air at other times.

Earl Colby Pottinger

--
I make public email sent to me! Hydrogen Peroxide Rockets, OpenBeos,
SerialTransfer 3.0, RAMDISK, BoatBuilding, DIY TabletPC. What happened to
the time? http://webhome.idirect.com/~earlcp

Cris Fitch wrote:

[...]
The faster the colony becomes semi self-sufficient the more likely
it will hold on and survive. Spare parts are a problem since your
resupply from the Earth has such a nasty delay. Thus machine tools
and raw feedstock are very important. One problem is that much of
this technology on Earth is associated with large industrial scale
production. Initial Mars production will likely be in small batches.
Think of a small glass making machine, a small iron smelter, etc.

If I'm a colonist on Mars, I don't just want duct tape - I want the
means to make my own duct tape.

That's simple: just take some canvas and some eggwhite, or mayvbe
flour&water, and slap the stuff on. You could probably make small batches
of suitable organic molecules for a better adhesive in a rather compact
lab. And a certain number of spare parts could be built by the computer
"printing" prototyping machines, which may already be out of their first
generation. Such machines would, however, probably be too inefficient for
producing large numbers of identical parts.

And if the place is iron oxide rich, then maybe you'd use local materials
for the sintering stock.

/dps

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