The first human mars mission?

Sander Vesik wrote:
George William Herbert wrote:
Sander Vesik wrote:
In situ resources? Hahahahaha. And just how were you planning to test it
works?

Have you read Zubrin's books or refereed publications on Mars Direct?

A test program including both subscale tests and then sending an
unmanned return vehicle 2 years ahead of the crew, to manufacture
its return fuel before the crew leave Earth, are both planned.
If the first return vehicle fails to successfully manufacture its
return fuel for any reason, you don't send the crew until the
second ERV has landed and manufactured *its* fuel, etc.

Note that earlier in the thread, a sample return mission was mooted
(not by me) as going to cost more or less as much as the manned
mission anyways and thus not worth it... Which at least appears to
rule that scenario out.

It's not going to cost more or less as much as a
manned mission; the numbers I have seen are mostly in
the $1-2 billion range, though $5b has been whispered
on really bad days. This is not theoretical; It's
been on NASA's long term Mars exploration planning
since they got serious about Mars in the middle of
the 90s. It was likely to fly in 07 or 09 until
we lost the two missions in one year, and the
plans all got screwed up.

I missed that earlier comment. I don't know who said
it but it does not reflect either the estimated costs of
a sample return by the teams doing long range planning
to do one nor does it reflect the scientific priorities
and planning process, which has sample return as a major
midterm goal for the program.


-george william herbert

Henry Spencer wrote:

In article ,
Robert =?ISO-8859-1?Q?Kitzm=FCller?=
wrote:
On the other hand, mars means a big deal to the public, and the public
would care who would set her or his foot down there first.

I see no sign of this.

Maybe it is just this way in Europe, but any mention of space in the
general media is bent towards mars (eg: new propulsion concept makes
marstrip possible).

has already been one successful launcher startup without outright
government backing -- Pegasus development was privately funded, by
OSC and Hercules --
and I think there is reasonable hope for more.

Pegasus got most of its contracts from NASA, US armed forces and the
like.

Quite true. So did most of the early US airlines, which got started on
Air Mail contracts. There's nothing particularly wrong with that.

Whose NB-52 was it the first Pegasus-vehicles launched from? This is
another indication, that while it might have used private money, OSC
as an organisation had close ties to NASA.

Robert Kitzmueller

Side note: Thomas, typing in 200 character lines is annoying.
Please use standard screen widths.

Thomas Lee Elifritz wrote:
George William Herbert wrote:
Thomas Lee Elifritz wrote:
George William Herbert wrote:
[...]
Then you are setting your photo interpretation skills and
analysis above that of, oh, for example all the professional
planetary science photo interpreters who have been working
for their entire careers on this problem.

You mean the same Malin and Edgett who first claimed that there
was no water on the surface of Mars, [...]

Elifritz CV in planetary science:
-0-

Malin CV in planetary science:
see 20 pubs listed below

Elifritz confidence level 1 demonstrated credibility 0
Malin confidence level 0.5 demonstrated credibility 1.0

You lose. You may be right, but you are not right for
demonstrably well founded reasons, and that's just as
bad as being wrong.

Let me see if I got your reasoning straight. Malin built a
great camera, took a lot of pictures, published a lot of peer
reviewed papers, but was demonstrably wrong in his
interpretation of the images, therefore his credibility in
photointerpretation should be higher than Elifritz (that's me),
who built no camera, published no papers, but was
demonstrably correct in his photointerpretation of the results
(i.e. - his pre Odyssey claim that water exists on the surface of Mars).

It gets even more interesting, you claim that Elifritz (that's me),
who was demonstrably right in his prediction of the existence
of Martian water (post MGS, MOLA, pre
Odyssey) was right for the wrong reasons (i.e. - he published
no peer reviewed papers) therefore his prediction is wrong
about its general underground extant and
distribution..

Yes.

Let us refer to... oh, I don't know, the Face on Mars.

People see all sorts of things in the low bits in data.
Some of it is true, some of it is wishful thinking.

We know now that the Cydonia 'face' is a pile of rocks.
We know that because we got significantly better resolution
imagery of the region, and stuff some people thought they
saw in the low bits of the Viking data turned out to be
noise and misdirection and random stuff.

Malin is thinking ahead to things like subsurface radar
sensors tuned to look for water, 10 cm and better future
imagers for the Mars surface, etc. The opinions he's
put out on the Water question, and a number of others
(along with the rest of the Mars Science community) have
been tempered by experience, deep education, and an awareness
that in many cases better data is needed to make more sure
answers on a lot of questions.

What are the odds that the surface features you interpret
as water signs look significantly different at much higher
resolution, and/or that the subsurface radar work shows
something different?

They are significant. Because that has happened every
time we send new sensors to Mars, or any other planet.
Not with every single thing, for sure, but many topics
have changed interpretation with new sensor results,
and many unpredicted new things are seen as well.

Malin knows that, because he's been there and done that
and knows it really well.

You appear to believe that the current data set is golden
and the last word we'll ever find or need.

I think Malin's approach is a lot smarter and more accurate,
over time.

You don't understand the geology,
physics, or photointerpretation well enough to be that
sure, and worse yet you don't understand that you don't
know it.

But I apparently have an demonstrated ability to see frozen
groundwater in the Mars surface morphology, and I am able to
visualize plausible climatological scenarios for its
geological evolution and distribution.

At worst, that makes me a dilettante.

Lots of people think they see signs of frozen groundwater,
and climatalogical scenarios for the groundwater have been
pervasive in serious Mars science since Viking.

It is entirely possible, however, that the signs you are
so sure must be and only could be water, will turn out to
be something else on closer examination, and that it looking
like frozen water sign is due to side effects of the scale
of the imagery we're getting from the current missions,
not intrinsic accurate data.

This is a variation on the 'even a stopped clock is right twice
a day' theme. Are you right because you're right, or are you
right because the evolving accuracy of the data set just
coincidentally agrees with you right now, but may not tomorrow?

Not understanding that problem is why you're wrong,
and why Malin's got more credibility than you do.


-george william herbert

In article ,
Robert =?ISO-8859-1?Q?Kitzm=FCller?= wrote:
On the other hand, mars means a big deal to the public, and the public
would care who would set her or his foot down there first.
I see no sign of this.

Maybe it is just this way in Europe, but any mention of space in the
general media is bent towards mars (eg: new propulsion concept makes
marstrip possible).

It's the easiest explanatory hook to hang something like that on, yes.
That means it's something the public is familiar with, not that it's
something they *care* about.

Whose NB-52 was it the first Pegasus-vehicles launched from?

NASA's... and OSC paid for its services.

This is
another indication, that while it might have used private money, OSC
as an organisation had close ties to NASA.

Oh, there's no question that OSC had plenty of informal ties to NASA and
the military. I'm told there was some NASA involvement in the aerodynamic
work, and there's the non-trivial matter of DARPA contracting for some
launches at a time when Pegasus was still a paper design. But this is a
far cry from getting large amounts of government development funding.
--
MOST launched 1015 EDT 30 June, separated 1046, | Henry Spencer
first ground-station pass 1651, all nominal! |

Henry Spencer wrote:

In article ,
Dick Morris wrote:
The Mars Direct scenario uses only the Mars atmosphere for propellant
production, so it wouldn't be terribly difficult to test the prototype
hardware in a vacuum chamber with a simulated Mars atmosphere.

The biggest question is whether it will work with Mars dust in the air
it's pulling in. That's a little more difficult to simulate, since we
don't *know* the exact composition and characteristics of the dust.

Zubrin addressed the dust issue in TCFM, as I recall. His approach was
to liquify the CO2 under pressure and then purify it by distillation, so
that any dust in the air would remain in the solution. We don't know
the exact composition of the dust - presumably a mixture of silicates
with perhaps some salts - but the process suggested by Zubrin should
work with almost any dust composition. Atmospheric dust might be a
problem during one of the periodic dust storms, but it would be
advisable not to land during one of those in any event. It won't take
very long to react the initial seed hydrogen after landing, and we can
proceed at a more leisurely pace after that, shutting down the process
if a dust storm should occur.

It would be highly desirable to put at least a small-scale test of the
process on an earlier unmanned lander. (And that exact idea has been
proposed for other reasons.)

It would. The proposed Mars Sample Return mission would also give us
some fairly precise data on the kinds of atmospheric dust compositions
we could expect to occur.

--
MOST launched 1015 EDT 30 June, separated 1046, | Henry Spencer
first ground-station pass 1651, all nominal! |

McLean1382 wrote:

Dick Morris writes:

I was reading a paper in "The Case for Mars VI" last week which put it
at about 1/3 of the total estimated program cost. That's a non-trivial
cost item, but there are additional indirect effects. The high cost of
Earth-to-orbit transportation with expendable launchers leads to the
traditional obsession for minimizing the mass placed into orbit, which
drives development costs up across the board.

Depends on which iteration of the reference mission you look at. Another
version projects earth-to-orbit systems as 25% of the cost.

Even with LEO transit costs a couple of orders of magnitude less, you are still
going to have strong incentives to minimize mass. Getting from LEO to Mars and
back still requires a lot of delta v, even with aerobraking. And the need for
extreme reliability will drive up development costs in any case.

There will still be an incentive, though not to the extreme that NASA
carries it. An excessive focus on mass minimization drives up
development costs through endless trade studies to determine the
absolute best (miminum mass) concepts, extremely detailed analyses to
precisely characterize each part's operating environment amd
reliability, plus the agressive weight-reduction campaigns that seem to
be inevitable when a too-aggressive dry mass target has been selected
and the hardware ends up over-weight. That process also degrades
reliability by limiting redundancy and safety factors. Design the
entire mission with comfortable safety margins from the start and
development cost goes down while reliability goes up. (To obtain an
acceptable level of mission reliability it will still be necessary to
carry a significant quantity of spares for the higher-failure-rate
items.)

(Above all, we should never, never, EVER design a mission based on
technology advances that are ASSUMED will be available by the time
development is complete. If the technology advances do not materialize
on time, then virtually the entire development team will be sitting
around playing computer solitair or surfing the net while technology
catches up, or the program will require a very expensive redesign.
NEVER use an operational program as a device to "push the technology".
NASA has shot itself in the head doing exactly that for the last 30
years: Shuttle, ISS, NASP, SEI, X-33, SLI.)

The real barrier to the Mars Reference MIssion isn't so much the cost estimate,
but the reasonable fear of cost overruns, and the danger of these is probably
greatest on the TMI stage, TEI stage, landers, an ascent stage. We've built
HLVs, and have engines, tanks and strap-ons in production that are reasonably
well suited. The other vehicles are much more like estimating the cost of the
LM before it was built.

I would say that the cost estimates alone are quite sufficient as a
barrier, but if we design the ENTIRE mission with comfortable margins,
then the probability of cost overruns will be greatly reduced. That
will increase the IMLEO significantly, other factors being equal, but
that will not be a substantial cost item with low-cost Earth-to-orbit
transportation.

McLean

Dick Morris writes:

Henry Spencer wrote:

In article ,
Dick Morris wrote:
The Mars Direct scenario uses only the Mars atmosphere for propellant
production, so it wouldn't be terribly difficult to test the prototype
hardware in a vacuum chamber with a simulated Mars atmosphere.

The biggest question is whether it will work with Mars dust in the air
it's pulling in. That's a little more difficult to simulate, since we
don't *know* the exact composition and characteristics of the dust.

Zubrin addressed the dust issue in TCFM, as I recall. His approach was
to liquify the CO2 under pressure and then purify it by distillation, so
that any dust in the air would remain in the solution.

But there's still that pesky "liquify the CO2 under pressure" bit, which
requires refrigerators and compressors, with the moving parts and the
sliding seals, *before* you get rid of the dust. That machinery can
still get torn up if we underestimate the dust problem.


--
*John Schilling * "Anything worth doing, *
*Member:AIAA,NRA,ACLU,SAS,LP * is worth doing for money" *
*Chief Scientist & General Partner * -13th Rule of Acquisition *
*White Elephant Research, LLC * "There is no substitute *
* for success" *
*661-951-9107 or 661-275-6795 * -58th Rule of Acquisition *

John Schilling wrote:
But there's still that pesky "liquify the CO2 under pressure" bit, which
requires refrigerators and compressors, with the moving parts and the
sliding seals, *before* you get rid of the dust. That machinery can
still get torn up if we underestimate the dust problem.

Well.... if you liquefy at ambient pressure at the top
of a column, then off the bottom, on one side,
have the fractional distillation chamber, then you
might get away with not having any exposed seals
or moving parts prior to the stage past the fractional
distillation.

I don't have the relevant CO2 thermodynamics in front
of me at the moment however, so I have no idea whether
it works at 4 millibars and reasonable temps or not.


-george william herbert

George William Herbert wrote:

John Schilling wrote:


But there's still that pesky "liquify the CO2 under pressure" bit, which
requires refrigerators and compressors, with the moving parts and the
sliding seals, *before* you get rid of the dust. That machinery can
still get torn up if we underestimate the dust problem.



Well.... if you liquefy at ambient pressure at the top
of a column, then off the bottom, on one side,
have the fractional distillation chamber, then you
might get away with not having any exposed seals
or moving parts prior to the stage past the fractional
distillation.

I don't have the relevant CO2 thermodynamics in front
of me at the moment however, so I have no idea whether
it works at 4 millibars and reasonable temps or not.


I think I don't understand what you are saying here. What
do you mean by liquefy at ambient pressure? CO2 can't be
liquid at martian ambient pressure.

Alain Fournier

(George William Herbert) :

John Schilling wrote:
But there's still that pesky "liquify the CO2 under pressure" bit, which
requires refrigerators and compressors, with the moving parts and the
sliding seals, *before* you get rid of the dust. That machinery can
still get torn up if we underestimate the dust problem.

Well.... if you liquefy at ambient pressure at the top
of a column, then off the bottom, on one side,
have the fractional distillation chamber, then you
might get away with not having any exposed seals
or moving parts prior to the stage past the fractional
distillation.

I don't have the relevant CO2 thermodynamics in front
of me at the moment however, so I have no idea whether
it works at 4 millibars and reasonable temps or not.

I don't think so, remember 'DRY ICE'? If you just lower the temperature you
get solid CO2. You do need to pressurize at a higher temp to get a liquid.

Earl Colby Pottinger

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