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tahanson43206 wrote:

For kbd512 re #240

SearchTerm:Power double for safety and quality of life  kbd512 Post #240

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I agree that the idea of denying a crew a proper shower for two years is pure 1500's.   However, there ** was ** a time when no European took a bath.

Perhaps that ancient practice still continues in some regions.

(th)

France, I would suspect :-)  All that over-expensive perfume has got to covering something awful!  And then there's the garlic to consider :-)

I nominate that Louis's mission should be carried out by French, who are used to that sort of thing.

NB.  Joking of course :-)  A French crew would bring a nuclear reactor with them and would have plenty of hot water.  The lack of bathing would be strictly voluntary.

Scott Manley seem to think that the successful manned missions to the ISS had a strong influence on NASA. It built a partnership of success. And is an indicator that moving forward, SpaceX and NASA will partner the Mars missions.

He also seems to think there will be protests from the National Team, LockMart, Orbital/Grumman, and howls from BO.

The helicopter flew today!

https://spacenews.com/ingenuity-perform … t-on-mars/

louis wrote:

I'd forgotten about this. It does seem that my original thought, that you could capture CO and oxygen from the atmosphere   and have a ready made energy store when humans landed a couple of years later is not so crazy and could work. Whether it's worth going to that trouble compared with just loading 30 tons of methane and oxygen on a Starship is another matter. I guess boil off over two months might be an issue?

If I read this correctly, Louis is suggesting the capture of CO and O2 already in the atmosphere on Mars.

It could be done, but it is no trivial undertaking.  The Martian atmosphere is 95% CO2, 2% Argon, 2.8% Nitrogen, 0.174% O2 and 0.0747% CO.  For this to work, you must first separate the CO2 from the other gases.  The CO2 in the Martian atmosphere is close to its triple point temperature, so relatively little compressor work would be needed to increase its density relative to the other components.  The remaining gases would be 40% Argon, 56% N2, 3.48% O2 and 1.49% CO, by volume.  The CO would be about 1% by mass.  On this basis, the calorific value of the non-CO2 content of the Martian atmosphere is about 100KJ/kg ( CO heat of combustion is 10MJ/kg).  At 1bar, the mixture would have volumetric energy density of 150KJ/m3.  At 300bar, it would be 45MJ/m3.  Because the CO and O2 are present in low concentration, you could probably store the mixture in a single tank, without risk of explosion.  To burn it, you would may need to pass it through a heated catalyst bed, as the concentration of fuel and oxidiser is too low to support flaming combustion, even under extreme compression.

In terms of total work output, one needs to compress 19kg of CO2 for every 1kg of stored gas mixture, which would release 100KJ of energy when released.  Put another way, the chemical energy content of the Martian atmosphere is 5KJ/kg or 65J per cubic metre at 6.1mbar.  This is almost certainly too little for any release of net energy from compressing and combustion of the Martian atmosphere.  None the less, it may be interesting to consider this as an energy storage mechanism.  The compressed CO2 has its own value as a CAES working fluid.  Heating it above 31°C would produce high pressure gas that could drive a compact gas turbine.  The stored compressed residual CO containing mixture has chemical energy density 100KJ/kg.  Taking the Cv of the gas to be 1KJ/Kg.K, complete combustion would raise the temperature of the gas by 100°C.  So along with its internal pressure energy, it could be a useful energy storage mechanism for short range vehicles and compressed air tools.  It is worthy of further investigation, I think.

Natural light is important for mental health if nothing else.  Windows at the ends of tunnel areas could be constructed from segmented steel frames, with smaller glass panes within them.  They could rely on friction with the tunnel wall to hold them in place.  If they are slightly curved inwards, the shape would transfer compressive stress into the rock.  So long as the weight of overburden is sufficient, then friction will hold the window in place without the need for any tensile forces.

I keep going back to the Expanse in these discussions.  There is a scene showing a residential street on Ceres, which is clearly a tunnel with LED panels mounted on the roof.  The sides of the tunnel have had spaces cut out for individual houses and commercial premises.
https://www.space.com/31584-dwarf-plane … panse.html

The panels simulate a blue sky, even with the occasional white patch representing clouds.  So all living spaces and buildings, look out onto a street with a blue sky, albeit a fake one.  I wonder how practical that would be in real life?  Could we produce thin LED wallpaper, that we attach to the roof of a tunnel to simulate a real sky?

Regarding transportation.  One of the interesting things about transportation in narrow tunnels, is that vehicles have comparatively few degrees of freedom.  You can go backwards and forwards, but not too far from side to side without hitting the walls.  This suggests to me that most motorised transportation should be able to use direct electric power drawn from a cable running under the roof, to which they would be connected via a pole.  There would be no need for batteries.  This is a huge advantage, as batteries have high embodied energy, low energy density and require a high mass of relatively rare components.  If all vehicles are powered directly from the grid, they become much easier to produce using native resources.

If a tunnel is circular or parabolic in shape, then the rock forms a natural arch.  This should avoid the need for supporting steelwork.  The same for any other cavities dug into the side of the tunnels.  It is a highly elegant solution, that neatly avoids the need for structural materials.  Cast basalt pillars are possible in situations where a large flat area is desirable.  Basalt typically melts at 1200°C, so could be cast into cast iron molds that have been lined with sand or clay.

It sounds like Zubrin is risk averse and was worried about the prject not working and damaging the Mars Society reputation.  He also sounds a little possessive; like all of us he has an ego.  None the less, from what Robert describes, the balloon mission must be considered a lost opportunity.  The same with the wiki.  There is little danger in allowing non-engineers to produce useful articles, as there are engineers available to guide them on technical facts.  And the site owner can always withdraw articles that don't stand up to peer review, so I don't really understand the problem.

But how long and of what mass are the smaller boring machines that we use on earth? As we could sent one to mars....
Finish the grinding of what could become the first mars soils for a garden and process the ores that are high in any minerals that we would use to turn into metal items from this same chips.

Noah's reminder;
https://i.imgur.com/VzE9uz2.png

The crew size is determined when the amount of mass from each incremental person slows the amount of change in ship dry mass to get man leaving Earth to go to mars as to the only thing changing are the life support quantities.

Which effects recycling numbers.

What goes into the selection process
https://www.mars-one.com/mission/mars-one-astronauts

Some of the risk
https://ieeexplore.ieee.org/document/6836241

Nasa Gateway mission to Phobos is a prover that we can survive
https://www.space.com/29562-nasa-manned … hobos.html

The Cost and Equivalent System Mass of Space Crew Time
https://spacecraft.ssl.umd.edu/design_l … e_cost.pdf

This is the one that talks to all of how the rockets are designed all the way to its surface and back to earth for the crews survival which means it covers the ballistic entry to mars
Part 1 & 2
https://space.nss.org/wp-content/upload … o-Mars.pdf

The only thing effecting growth on mars is health issues to crew under reduced gravity, extended stays for growth of population for mars. This is where we learn from the ISS for type of medical monitoring, exercise program and mediation counter action effects program. In investigation of spin tables for increased AG needs to be done as well as weighted arm, wrist, ankle plus clothing as counter measures.

tahanson43206 wrote:

My concept of the NewMars version of a Wiki...

A bit of a caution. Robert Zubrin is an amazing leader, founded the Mars Society and continues as president. I have met him at Mars Society conventions, and we've worked together enough that he has gotten to know me. However, everyone is human. Let me tell you a little story.

I joined the Mars Society in 1999. I had purchased "The Case for Mars" in spring of 1998, and it described "The Case for Mars" conventions every 3rd year, the next was later that same year. But I couldn't afford to go. That convention was the founding convention for the Mars Society; if I went, I could have called myself a founding member. In 1999 there was the first forum, before this one. Members were excited, the society got a lot of donations from individuals who got rich from the internet bubble. The purpose of the society said: "Starting small, with hitchhiker payloads on government funded missions, we intend to use the credibility that such activity will engender to mobilize larger resources that will enable stand-alone private robotic missions and ultimately human exploration." It's changed now, but that's what it was. This was seen by members as a goal to send a Society mission to Mars, hitchhiking on a "government" mission. Deep Space One was in space at the time, so I asked why don't we send something small now? As a hitchhiker payload on NASA Space Shuttle. Members debated what the mission should be. That first forum didn't have a feature to vote, so I wrote code and hosted it on a work server to let members vote. The majority voted for a balloon. Ok, so let's get serious. Can we design a balloon mission for Mars?

Members from the Spain chapter wanted to build and pay for the balloon itself. I suggested we use Robert Zubrin's design for a balloon. He got a contract from JPL to build a proof-of-concept balloon. His idea was to prefill with methanol, store the balloon in a hard clam-shell. The balloon would be deployed while hanging on a parachute. Aeroshell to enter Mars atmosphere, then when it slows to sufficiently open a drogue 'chute, then a main parachute. While dangling on the parachute, deploy the balloon. The balloon would be coloured black, so during the day sunlight would warm the balloon, causing it to expand and ascend. At night it would get cold, descend. A heavy rope dangling would strike the ground first, as weight is taken by the ground, the balloon would stop descending. This allowed a soft landing. The test funded by JPL used a stratospheric balloon to take it to air that has the same pressure and temperature as Mars atmosphere, then deploy the Mars balloon there under the stratosphere balloon. It worked. Ok, so let's do that. I asked interested members what their skill and job or certification was. An electrical engineer who specialized in building power supplies for Cisco equipment wanted to design/build the power supply for our mission. Another member worked for a military contractor who had bid to supply the propellant tank for the multiple warhead bus for Minuteman missiles. They didn't get the contract, but the idea was interesting: a titanium tank that would collapse like a cinnamon roll as propellant drained, providing constant pressure. He wanted his employer to provide the tank for our mission. At the time my job was Senior QNX Analyst, developing software for the QNX operating system. The company that developed/sold QNX bragged that the vision system for CanadArm2 on ISS used QNX. It's a high reliability version of Unix developed in Canada. VxWorks is a high reliability version of Unix developed in USA, used for Mars rovers; a competitor of QNX. So I said that I would write the software. I found a company in California that built commercial-off-the-shelf space hardened electronics: computers, memory, etc. Another member just finished his Ph.D. in aerospace engineering in Australia, specializing in aeroshells. He asked to provide the aeroshell for our mission. Wow! Of course I said yes. That engineer Paul Wooster, he's now Principal Mars Development Engineer at SpaceX.

Turned out there was 3 other groups within the Mars Society who wanted to build a balloon; one was the Spain chapter. I got them all to work together.

I called NASA/Glenn Research Centre to ask what information I could get about the NSTAR ion engine used for Deep Space One. They had the lead engineer who developed NSTAR call me back. He sent me everything that was allowed outside USA. As he put it, everything short of the blueprints. I called the Small Shuttle Payloads Project. The Director himself answered my call. I asked how much for a Get-Away Special. He said it was $8,000 for a US educational institution, or $27,000 for anyone else. But the catch is it had to go up and come down. If something deployed out of the Shuttle payload bay, then it was $2 million, and that's called a Hitchhiker mission. He apologized profusely, said it wasn't his idea, that NASA executives didn't want to compete with commercial launchers. But he then said that with my connections, I should be able to get a NASA agency (as he put it) to sponsor our mission. With that we would get a free ride to space. And he gave me the form number that we would have to fill out.

So I went to Robert Zubrin to ask to make this an official Mars Society project. After all, we would need someone at a NASA cost centre to sponsor us. A few NASA employees were members of the Board of Directors. Dr Zubrin said no. He said not everyone on our team were professional engineers. Uh... the whole point was to send an official Mars Society mission to Mars. For real. The Mars Society was supposed to be about enabling average citizens to work together with professional scientists and engineers: NASA, CSA, ESA, etc. So... uh... what?

Without it being an official project, I stopped working on it. Without me, the project died. I had become the de facto project head.

After our project died, the German chapter started a balloon project. They restricted it to professional aerospace engineers. It hasn't happened.

Of course after the Columbia accident, NASA said no small explorers on Shuttle. So we lost our ride to space. And now Shuttle doesn't fly at all.

In "The Case for Mars" Robert Zubrin wrote that Mars would allow anyone who could do work to do so. Not restrict you by certification. However, when it comes down to it, he is focused on academic qualifications. I thought we had a Wiki on NewMars at one point. But not now. James Burk is webmaster for the main Mars Society website, and works with Dr Zubrin. He's one of the administrators for NewMars. Not surprising that the Wiki is now just for those with qualifications.