Air. Shelter. Water. Food.

Dook · 2017-05-10 09:33:33

kbd512 wrote:

kbd512

I didn't say that bearing grease deteriorates silicone, it deteriorates rubber.

We need an architect to tell us what we can get away with? Architects can design things but their ideas have to be checked by a qualified structural engineer.

See if I can solder a chip on a new computer board, it's all done with robots? Maybe I can't do it but the Voxel 8 can't do it either since it's just a sprayer but I guess a 3D printer with a real laser could.

Marscat could work but not with 4,900 lbs of batteries? Each Marscat would weigh 1,600 lbs and have 12 batteries. So, the batteries would weigh about 600 lbs. All of that is Earth weight.

What geometry would I like to use to get the zeolite panels into a smaller cavity for the microwave to irradiate? Think of a cereal box laid on it's side. All the sides would be zeolite panels. The top and bottom zeolite panels would be large rectangles, the sides all around would be much shorter, and the bottom would not have a zeolite panel but would fit onto a duct that would have a fan that would push Mars atmosphere through. The entire thing would be surrounded by microwave screens and have a wave guide going to it just like a home microwave. An exhaust fan would expel the Mars atmosphere from the microwave chamber out through a dust filter.

A couple of other things I don't like about the U of Wash. WAVAR is that it has a 6' fan built into the ceiling so it would be noisy as hell while the crew tried to sleep. And there would have to be a hole in the roof of the Mars Hab so this fan could expel Mars atmosphere but the roof has to be very strong because the entry parachutes have to attach there.

A compressor would work better than a fan to move Mars atmosphere? Compressors create a lot of heat. A normal jet engine heats the air up to about 600 degrees by the 5th stage.

Last edited by Dook (2017-05-10 09:34:05)

Oldfart1939 · 2017-05-10 09:36:42

Regarding protection from GCR, this topic is something of a red herring. We can analyze what we're talking about doing by first realizing the GCR dosage on the planetary surface is 50% that of "deep space," and that Mars' atmosphere, thin it may be, also attenuates the radiation dosage significantly. What should be considered is how much shielding "is just enough" to reduce this threat to below that of ISS exposure. The major threat from radiation is from Solar Flares, then followed by ongoing exposure to GCR. In "Entering Space," Robert Zubrin addresses these issues, he states there is an analogy of Mars surface exposure to that of an airline pilot flying a big jet at 40,000 feet. The GCR radiation is almost identical to Mars' surface at that altitude. Other than requiring shelter during intense bursts of alpha particle radiation during Solar storms, almost any regolith shielding will be beneficial--even those sandbags on top of the proverbial "Tuna Cans," which don't currently exist and seem never to have been a serious contender by NASA. Shielding is NOT an all-or-nothing issue, since any attenuation is helpful through lengthening of allowable exposure time. Yeah, we sleep under as much regolith as possible, and probably limiting out of shelter activity to an 8 hour work Sol.

Dook · 2017-05-10 09:45:37

Oldfart1939 wrote:

If one wishes to see what robotics are capable of doing, then visit the BMW factory in Germany (Munich). The entire vehicle is robotically assembled with welds executed to a precision no human is capable of making. Everything is controlled by laser alignment. I had a tour of the factory 3 years ago while taking delivery of my new X-1. kbd512 is also correct in regard to soldering connections on circuit boards; it's simply on too tiny a scale for "soldering iron and solder" work by a human--unless the human does this type of work every day. Need a jeweler's loupe to work on such connections. Also: if we needed to bring along replacement circuit boards for all the controls and instrumentation of everything, we'd had literally hundreds--if not thousands of them. Instead we bring a 10% backup number of bare boards (at 10 % the weight penalty) and simply print as needed. Maybe this clarifies things as to weight penalties.

Robots can weld? What if the part that needs welding is in the parking lot. Can the robot go out there, look at it and weld it there? What if the material needed to be welded is aluminum, can the robot distinguish between steel and aluminum and change from MIG to a TIG welder? Robots can perform functions if everything is set up for them.

If we needed to bring along circuit boards for everything we would have to bring literally hundreds, if not thousands of them? My home computer has one motherboard. So, you're saying a mini-Moxie needs more than one computer to operate it? You're saying a WAVAR unit has more than one computer? You're saying the CAMRAS unit has more than one computer? They each have one electronics box. That's three motherboards, not thousands.

What is the difference in weight between the printing powder and the same component already pre-assembled?

Dook · 2017-05-10 09:50:07

kbd512 wrote:

Those photos I posted of Zvezda's interior are what the inside of real tuna cans looks like, no matter who made it. There's more wiring, piping, and computer-controlled equipment than you can shake a stick at. Maybe there's a simpler way to do things, but every spacecraft I've ever seen looks like that. The engineers who design these things know what works and what doesn't. We've had decades of long duration space habitation. Certain things work well, others... not so much. Mostly, you'll find lots of redundancy. That's a good thing, because electrical and mechanical problems happen. Nothing as complicated as a spacecraft will ever be problem free, but if you have workable methods to resolve problems then it's not a death sentence for the crew.
Unlike what you see in Hollyweird movies, all airlocks are manually controlled with levers or cranks and designed in such a way that no human could actuate the airlock while it's pressurized. Docking and berthing locks are different. Those are electro-mechanical and also employ redundant systems.

Apollo didn't look like that, with cables crisscrossing all over the place. The space shuttle didn't look like that. I don't know why the ISS is like that but it doesn't give me confidence in the ability of aerospace engineers to design things.

Dook · 2017-05-10 09:55:05

SpaceNut wrote:

kbd512 post #265:
Rocket building and repair via the use of a 3 D printer is a leg up of commerce and export as well as for reuseability of rockets that once delivered cargo in a oneway mode to start a reuseable sycle once refueled. This is a step past exploration/science of the first few missions towards settlement or permanent presence and colonization in the future.
Dook post 267
This would lead to independance from the financial burden with an economy of retur for investment via exports of anything...

kbd512 post #265:
The rovers did find sulfur sub serface as the wheels churned it up as it drove through that area.
I got thinking about the use for waste heat and was thinking of using it to create air flow via updraft chimney shape with the WAVAR at the top to capture the moisture. It does not need to go all that high it just needs to act like a large area tent to allow for volume of heat to be obsorb to be funneled to the peak of each direction of intent to make it go through the units....

Repairing rocket engines on Mars would lead to financial independence from the Earth? The best way to achieve financial independence is to provide for yourself. That means produce your own oxygen with plants, grow your own food with plants and chickens and tilapia fish, recycle your water, and maintain your shelter.

If they can do those things, what do they need from the Earth?

louis · 2017-05-10 09:56:02

I can't think of many reasons why humans would be out of their protected habitats much during the sol...certainly not outside of their Rovers. Space-suited EVAs I think will be largely confined to geologists working on particularly interesting sites, or maybe dealing with mechanical maintenance issues where something has gone wrong...

Oldfart1939 wrote:

Regarding protection from GCR, this topic is something of a red herring. We can analyze what we're talking about doing by first realizing the GCR dosage on the planetary surface is 50% that of "deep space," and that Mars' atmosphere, thin it may be, also attenuates the radiation dosage significantly. What should be considered is how much shielding "is just enough" to reduce this threat to below that of ISS exposure. The major threat from radiation is from Solar Flares, then followed by ongoing exposure to GCR. In "Entering Space," Robert Zubrin addresses these issues, he states there is an analogy of Mars surface exposure to that of an airline pilot flying a big jet at 40,000 feet. The GCR radiation is almost identical to Mars' surface at that altitude. Other than requiring shelter during intense bursts of alpha particle radiation during Solar storms, almost any regolith shielding will be beneficial--even those sandbags on top of the proverbial "Tuna Cans," which don't currently exist and seem never to have been a serious contender by NASA. Shielding is NOT an all-or-nothing issue, since any attenuation is helpful through lengthening of allowable exposure time. Yeah, we sleep under as much regolith as possible, and probably limiting out of shelter activity to an 8 hour work Sol.

Oldfart1939 · 2017-05-10 10:09:42

Louis-

Agricultural and construction activities will require EVA exposures. Plants need lots of attention and continual checking. Enough water? Too much water? Not enough water? Cultivation in order to allow atmospheric gasses to reach the roots and lighten the soil. Check greenhouse panels for structural integrity. Harvest crops. Plant new crops. Repair airlocks; check seals. And as you mentioned, doing exploration and research. Having a decent thickness of plastic helmet will also serve to further attenuate radiation to the brain.

Dook · 2017-05-10 10:15:03

Question: normally the mini-Moxie takes in Mars CO2 and converts it to oxygen and CO and discharges the CO overboard. Can the mini-Moxie take in habitat air and convert it to oxygen and discharge the CO?

It should be able to do that. If so, you don't need the CAMRAS unit to scrub CO2.

Oldfart1939 · 2017-05-10 10:48:25

Short answer: yes. The moxie unit of the ISS does precisely that, discharging the CO to space. This essentially renews oxygen content by removing spent breathing air CO2. Of course the overall oxygen still needs an additional supply from time to time.

2 CO2 ---------------------------> O2 +2CO
Moxie catalysis

This indicates that for every 2 moles of Carbon Dioxide scavenged, only one mole of Oxygen is regenerated; this slowly depletes the surrounding atmosphere of Oxygen via metabolism followed by Moxie.

kbd512 · 2017-05-10 10:56:44

Dook,

MOXIE for CO2 Filtering:
You have to filter the CO2 out of the air. The amine swing bed (CAMRAS) does that.

Spacecraft Complexity:
Apollo looked like Zvezda and so did the Space Shuttle. The fact that you haven't seen pictures of the wiring says nothing about what the internals of the vehicles actually looked like. I just looked at a picture of the wiring and piping in the LEM. Same thing. The LEM had core wire rope memory. The Space Shuttle contains 230 miles of wiring and is actually more complicated than Orion, which only has 20 miles of wiring. The Apollo spacecraft had 15 miles of wiring.

Dook · 2017-05-10 11:11:00

kbd512 wrote:

Dook,
MOXIE for CO2 Filtering:
You have to filter the CO2 out of the air. The amine swing bed (CAMRAS) does that.
Spacecraft Complexity:
Apollo looked like Zvezda and so did the Space Shuttle. The fact that you haven't seen pictures of the wiring says nothing about what the internals of the vehicles actually looked like. I just looked at a picture of the wiring and piping in the LEM. Same thing. The LEM had core wire rope memory. The Space Shuttle contains 230 miles of wiring and is actually more complicated than Orion, which only has 20 miles of wiring. The Apollo spacecraft had 15 miles of wiring.

If the mini-Moxie converts CO2 to oxygen, why would I then have to filter the CO2 out of the air? I'm fine with still having two backup CAMRAS units and an emergency fan that blows cabin air through a CO2 absorbent but if the mini-Moxie can do it then you don't have to power up the CAMRAS constantly.

The Apollo capsule and the space shuttle looked like the ISS with cables sticking out all over the interior? No, they didn't.

Last edited by Dook (2017-05-10 11:11:28)

louis · 2017-05-10 12:34:25

My conception of a farm hab is one with an airlock that can accommodate a small taxi rover taking people from one pressurised hab to another, e.g. central accommodation hab. With construction activities, again I don't really envisage EVA as my construction proposal would be for cut and cover i.e. use a robot (or human passenger pressurised) Rover digger to dig the trench, and human directed robots would then cement the walls and put in place steel supports over which Mars brick arches would be built. An air lock (imported initially) would be placed at one end of the trench. The whole lot would have regolith piled on top and then you would pressurise the space. Settlers would then finish off the interior, having brought in battery operated heaters. Obviously all this would be trialled on Earth first and practised a hundred times over to get it right.

We might alternatively consider a pressurised construction hab to go over the construction site. This would need to have an air lock and be anchored all around, with regolith piled up...I would see that further down the road, but I would argue against EVA construction.

Human powered construction (amazingly still the way we put up most things!) is slow - weeks and more often months. I really can't see early settlers being able to cope with the stress of working on laborious construction projects in EVA suits sol after sol after sol. The novelty would soon wear off and be replaced by stress leading to pyschological problems or accidents. But being able to walk around in a breathable atmosphere (albeit in some sort of protective suit and carrying oxygen, to allow escape in event of a pressure event).

Oldfart1939 wrote:

Louis-
Agricultural and construction activities will require EVA exposures. Plants need lots of attention and continual checking. Enough water? Too much water? Not enough water? Cultivation in order to allow atmospheric gasses to reach the roots and lighten the soil. Check greenhouse panels for structural integrity. Harvest crops. Plant new crops. Repair airlocks; check seals. And as you mentioned, doing exploration and research. Having a decent thickness of plastic helmet will also serve to further attenuate radiation to the brain.

SpaceNut · 2017-05-10 18:53:36

Dook post #280:

You were talking about an individual which can not even pay back his ticket ride out let alone pay for the complete home to which he or she will reside in let alone all the stuff you would need to survive as they would as well carry a hugh fee for shipping.

I was talking about the community of settlers which is a collective strength to allow for buying of the habitat and more 1 at a time by producing its own means to turn the tables on those that sent them to work. So that they can cut the ties back to earth.

Dook post #283: question in post 286:

Not sure as the ISS reports the levels in PPM's to which It’s Taking Less CO2 Than Expected To Cause Health Risks In Astronauts

Those studies found the shocking result that CO2 has a direct and negative impact on human cognition and decision-making in the 900 to 1000 ppm range and very possibly at lower levels. CO2 levels in the air are currently 400 parts per million. In other words, “it makes up 0.04% of the atmosphere, equating to a partial pressure of 0.3 mm Hg at standard pressure,” as the JOEM article puts it.

Crew Health and performance Improvements with Reduced Carbon Dioxide Levels and the Resource Impact to Accomplish Those Reductions

Humans generate CO2 at a rate of 0.9-1.2 kg per day and may experience subtle acute symptoms at concentrations somewhat below 1.0% (7.6 mmHg). It is not feasible to achieve earth-normal levels of about 0.3 mmHg in spacecraft.

0*s6K4vew6_CWgKV0a.jpg

Why Living in Space Can be a Pain in the Head A new study says carbon dioxide levels on board the station should be lowered.

The team was able to study more than 1,700 reported and non-reported observations of headaches since the first carbon dioxide monitors were activated on the station in February 2001.
Due to the difficulties in “scrubbing” an artificial atmosphere, carbon dioxide levels on the station have always been higher than they are on the ground, but NASA always assumed the levels were within the non-harmful range. Between 2001 and 2012, carbon dioxide levels on the ISS typically stayed between 2.3 and 5.3 mm Hg (a measure of concentration); those levels, however, sometimes change fairly quickly over hours or days.
On Earth, carbon dioxide is a trace molecule in our atmosphere, at a low 0.3 mm Hg. In space, exhaled CO2 builds up in the cabin, and would even linger in a cloud around the astronauts’ heads were it not for fans that circulate the onboard air. Tests on the ground have shown that healthy males have no ill effects when breathing a CO2 concentration up to 7.5 mm Hg, and can handle as much as 11 mm Hg for up to eight hours with no acute effects, like headaches.

MOXIE for CO2 Filtering: also is to remove the chances of hair, skin and other dirt particles from entering the system... the second is to remove the concentraton from the air to stop astronauts from becoming sick from it....

Dook · 2017-05-10 19:24:27

SpaceNut wrote:

SpaceNut

What did NASA or the US charge the Apollo astronauts? What did they charge the space shuttle astronauts? We don't do things in space to make money.

Elon Musk might, but that's his problem.

SpaceNut · 2017-05-10 19:48:25

You are right nasa does not charge its astronauts but then again its nearly 20 billion a year for it to operate and not going down....However it did cost the tourists that did go to the ISS and those were billionaires that could do so and they still needed to work as well plus pay for the seat up and down....

kbd512 · 2017-05-10 19:58:32

Dook wrote:

We need an architect to tell us what we can get away with? Architects can design things but their ideas have to be checked by a qualified structural engineer.

Ok, a structural engineer. We need one of them.

Dook wrote:

Marscat could work but not with 4,900 lbs of batteries? Each Marscat would weigh 1,600 lbs and have 12 batteries. So, the batteries would weigh about 600 lbs. All of that is Earth weight.

I fat-fingered the Lithium-ion battery weight in Post #265. It's 720lbs of Lithium-ion batteries, not 270lbs. So 720lbs gives you 1 hour of usage at a consumption rate of 22kW/hr. That assumes the use of two 30hp electric motors consuming an average of 22kW/hr, like you said you wanted in your Marscat.

Edit: Stupid mistake alert. Disregard the next two paragraphs. The Tesla EV battery packs are only 5.3kWh per pack. 660lbs of EV batteries is only 63.6kWh. If it was 21.2kWh for 55lbs, nobody would be using gas powered cars anywhere.

Something is "off" with that number for Lithium-ion, though (maybe it's old tech), because a 21.2kWh Tesla EV battery pack only weighs 55lbs and produces double the voltage of that 12V 260AH SmartBattery. If the Marscat had 4 Tesla Lithium-ion packs, it'd have 84.8kWh of electrical power storage onboard and the packs would weigh 220lbs, which does not include aluminum cooling plates. That's enough power for 3 hours of continuous operation. 660lbs of 21.2kWh Tesla EV battery packs provide enough power for 9 hours of continuous operation.

If the Marscat works to fill HESCO for 9 hours per day, the regolith shield will be done in a matter of weeks. We could even skip HESCO and just pile up regolith. The 254.4kWh 660lb Lithium-ion pack has enough juice for us to use it just like a bulldozer and dispense with the weight of HESCO barriers.

The 600lb Lead-acid battery pack only provides 10.8kWh of power with 12 batteries, assuming you completely drain the battery, which would quickly kill the batteries. I'm not sure what you're going to do with that little battery capacity in an earth mover.

Dook wrote:

What geometry would I like to use to get the zeolite panels into a smaller cavity for the microwave to irradiate? Think of a cereal box laid on it's side. All the sides would be zeolite panels. The top and bottom zeolite panels would be large rectangles, the sides all around would be much shorter, and the bottom would not have a zeolite panel but would fit onto a duct that would have a fan that would push Mars atmosphere through. The entire thing would be surrounded by microwave screens and have a wave guide going to it just like a home microwave. An exhaust fan would expel the Mars atmosphere from the microwave chamber out through a dust filter.

The box geometry affects mass flow from the fan or turbine, even if the waveguide geometry is better for this application. I thought you wanted to stack panels up, as in a grid arrangement. That would be problematic. I'm not really sure how to approach this one. I've never seen someone stick a microwave in a jet engine. Maybe a bunch of smaller magnetrons and wave guides? At least that way, there's redundancy if one of the magnetrons fails. It's an interesting problem.

Dook wrote:

A couple of other things I don't like about the U of Wash. WAVAR is that it has a 6' fan built into the ceiling so it would be noisy as hell while the crew tried to sleep. And there would have to be a hole in the roof of the Mars Hab so this fan could expel Mars atmosphere but the roof has to be very strong because the entry parachutes have to attach there.

I'm not sure how much noise would actually be transmitted through a near-vacuum and the per-second mass flow is low, but vibrations from the motor could be transmitted through the habitat module. It has a large, high-RPM fan attached so there will definitely be vibrations.

A habitat of this sort would be propulsively landed, most likely a flexible inflatable followed by retro-propulsion. The parachute would have to be huge for something in this mass class to have much effect in the brief amount of time it could operate.

Dook wrote:

A compressor would work better than a fan to move Mars atmosphere? Compressors create a lot of heat. A normal jet engine heats the air up to about 600 degrees by the 5th stage.

We could use a 1 or 2 stage RamGen:

Ramgen Power Systems Workshop on Future Large CO2 Compression Systems

The outlet pressure of a 2 stage system would only be 600mb with 10:1 compression or 1,350mb with 15:1 compression. That should greatly increase the production rate. One thing's pretty certain. It'd be a lot more compact than a fan-based WAVAR.

Last edited by kbd512 (2017-05-10 23:42:44)

Dook · 2017-05-10 20:21:25

kbd512 wrote:

kbd512

I think I'm going to have to increase the number of batteries to 14 but lithium-ion is fine. I still like the idea of adding the electrolyte when they get to Mars. Even so, three hours of use would discharge each battery about 30%, which might be too much.

And if I only dig down 12 feet instead of 17 then I can cut the three Marscats down to only 2 and it would take 23 days, 3 hours of use a day, to dig out the area for the buried cylinder habitats.

You thought I wanted to stack zeolite panels up, in a grid arrangement? I did for the zeolite cart, not stack them up but put five or six in a row that a fan or two would blow the atmosphere through. For a built in WAVAR unit having panels in a row inside microwave screens would be okay as long as the air has to flow through them. I want the WAVAR unit to go in the Rover Hanger, probably built into the inside wall with an intake vent and an exhaust vent.

You're not sure how much noise would be transmitted through a vacuum? Yeah, don't know for sure, but not being able to get easy access to fix it is also a problem.

We could use a Ramgen? How much electricity would it use to spin it up and what kind of motor would spin it that high? Jet engines spin at 11,000 rpm.

Last edited by Dook (2017-05-10 20:21:55)

SpaceNut · 2017-05-10 20:27:52

The secret to the telsa battery is in how its constructed to keep from catching fire...by small cells that have cooling built in to wick the heat away....

tesla battery pack images

SpaceNut · 2017-05-10 20:41:21

The low level discharge is for storage and not use levels....when you discharge li-ion batteries that far you risk damaging the cell structure causing a barrier to charging to form which can cause the battery to short and not charge to full capacity. Recomended discharge in operation is only to 70% of its value before recharging....

http://www.techrepublic.com/blog/five-a … tery-life/

Characteristics of Rechargeable Batteries

Safe Lithium-ion Battery Designs for Use, Transportation and Second Use

Guidelines on Lithium-ion Battery Use in Space Applications

Dook · 2017-05-10 20:50:45

SpaceNut wrote:

The low level discharge is for storage and not use levels....when you discharge li-ion batteries that far you risk damaging the cell structure causing a barrier to charging to form which can cause the battery to short and not charge to full capacity. Recomended discharge in operation is only to 70% of its value before recharging....
http://www.techrepublic.com/blog/five-a … tery-life/
Characteristics of Rechargeable Batteries
Safe Lithium-ion Battery Designs for Use, Transportation and Second Use
Guidelines on Lithium-ion Battery Use in Space Applications

I wasn't clear enough on the lithium-ion battery discharge, three hours of use (two 30 hp motors in each Marscat) would use 30% of the batteries (14 lithium-ion batteries). So, the batteries would be drained to 70% of their capacity.

Now, I have to figure out how long it would take to fully recharge the two Marscats from base power so they can be used the next day for 3 hours again.

Oldfart1939 · 2017-05-10 21:20:07

One way to minimize the regolith moving would be to excavate a trough just deep enough to have half the cylinder sunk in place, then use the excavated "spoil" to recover it. That would cut the battery usage a lot. If we need more regolith, just dig up the surface and keep heaping it on until "enough" has been moved. That's how I was envisioning a "passageway" from the habitat units exteriors into the greenhouses would be built.

Dook · 2017-05-10 22:14:15

Oldfart1939 wrote:

One way to minimize the regolith moving would be to excavate a trough just deep enough to have half the cylinder sunk in place, then use the excavated "spoil" to recover it. That would cut the battery usage a lot. If we need more regolith, just dig up the surface and keep heaping it on until "enough" has been moved. That's how I was envisioning a "passageway" from the habitat units exteriors into the greenhouses would be built.

That's why I changed the depth from 17 feet to 12.

I could raise it further but the seven buried cylinders need 8 feet on top of them for radiation protection and I would like to put a 100 foot domed greenhouse over them to provide heat and I didn't want there to be a big hill inside the greenhouse.

A hill a few feet high would be fine but not too much.

kbd512 · 2017-05-10 23:17:51

Dook wrote:

I think I'm going to have to increase the number of batteries to 14 but lithium-ion is fine. I still like the idea of adding the electrolyte when they get to Mars. Even so, three hours of use would discharge each battery about 30%, which might be too much.

Edit: Stupid mistake alert. 12 packs are 63.6kWh, which only equates to 2 hours 20 minutes of run time at 80% DoD for the Marscat.

The depth-of-discharge issue applies to every battery, but Lithium-ion batteries are designed to discharge 80% of their rated capacity and that's what all manufacturers test against. 12 Lithium-ions (12 Tesla packs) gives 9 hours of power per Marscat. The batteries should last for at least a thousand of cycles if you discharge them that way. If the cats are stored outside, and for all practical purposes they have to be, then RHU's (Radioisotope Heater Units) must keep the batteries warm. I like RHU's because there's no reliance on batteries or base power to keep the packs above their minimum charging temperature at night. The RHU's provide a gradually declining output over a decade or so. RHU's are small (26mm / 1in by 32mm / 1.3in) and light (40 grams / 1.4oz), but expensive because they contain Pu238.

Dook wrote:

And if I only dig down 12 feet instead of 17 then I can cut the three Marscats down to only 2 and it would take 23 days, 3 hours of use a day, to dig out the area for the buried cylinder habitats.

I guess what I'm getting at is that you have real power with a vehicle of this sort and it can get the job done pretty quick. Two cats should get the job done in a matter of a month or so, even with an 11m high tuna can. Since WAVAR is not on top, there should be a hatch on top. Once the tuna can is buried, this is how the astronauts must exit the can.

Dook wrote:

You thought I wanted to stack zeolite panels up, in a grid arrangement? I did for the zeolite cart, not stack them up but put five or six in a row that a fan or two would blow the atmosphere through. For a built in WAVAR unit having panels in a row inside microwave screens would be okay as long as the air has to flow through them. I want the WAVAR unit to go in the Rover Hanger, probably built into the inside wall with an intake vent and an exhaust vent.

I think I'd make the device as a movable piece of equipment since it has to run 24/7.

Maybe a rover tent instead of a rover hangar? Rovers and WAVARs arrive on Mars first, followed by the tuna can. If the tuna can is lower to the ground, burying it becomes a lot easier.

Dook wrote:

You're not sure how much noise would be transmitted through a vacuum? Yeah, don't know for sure, but not being able to get easy access to fix it is also a problem.

A turbine produces even more vibration since it's spinning much faster. It would be irritating to the crew and a potential hazard. It's best to keep the WAVAR away from the module. Also, we can choose an ideal site for it.

Dook wrote:

We could use a Ramgen? How much electricity would it use to spin it up and what kind of motor would spin it that high? Jet engines spin at 11,000 rpm.

To figure out exactly how much power RamGen requires, you need their CFD codes. This is something that typically requires a computer to accurately model, and a very powerful computer at that.

Here are the equations for calculating compressor power and efficiency:

Compressor Power and Efficiency Equations

Maybe you can estimate using this method:

How to Estimate Compressor Efficiency?

Last edited by kbd512 (2017-05-10 23:44:51)

kbd512 · 2017-05-10 23:38:27

Dook,

Again, apologizes for the mistake. I can't seem to get my numbers straight for these stupid EV batteries. The Tesla battery packs are only 5.3kWh and weigh 55lbs. Something in the back of my head kept telling me that couldn't be right, or nobody would be using gasoline. That means it's 220lbs for 21.2kWh, so 660lbs only nets 50.88kWh at a 80% DoD, which means 2 hours 20 minutes or run time per charge.

Dook · 2017-05-11 09:24:36

kbd512 wrote:

kbd512

I don't know where I want to store the Marscat's yet. They will probably be stored outside and connected to the base power to recharge every night. I would like to bring them inside the rover hangar but I don't like the idea of having to pressurize and depressurize the rover hangar each day to drive the Marscats out to do work. Also, the rover hangar would need a large door and if we pressurized the rover hangar to even 2 psi the force on the door would be incredible. I could just not pressurize the rover hangar at all and use it as a warmer place to store the Marscats while they recharge.

And I still need to figure out how long it takes to recharge the batteries over night and how much energy it will need. At night the RTG will be the only power source.

Those radiation heaters should be installed under all the batteries in the Marscats and the Long Range Rover.

I never planned on burying the tuna can. I would leave it on the surface as a backup habitat once the seven buried cylinder habitats are finished. The tuna can would have the rover hangar under it so burying it would be like building the pyramids in Egypt. Plus, the WAVAR unit in the rover hangar needs to have access to Mars atmosphere. Also, the tuna can would be very visible and seen from far away so the crew heading back to the base in the Long Range Rover could more easily identify where the base is.

Maybe make the WAVAR movable? Yeah, I actually had an idea for an aluminum zeolite cart that has a large intake filter, intake valve, intake fan, many zeolite panels surrounded by microwave screens with a magnetron and wave guide, then an exhaust fan, exhaust valve, and exhaust filter. The aluminum would heat up in the day and the microwave would be turned on so water vapor would fill the inside of the cart and a built in vacuum pump would collect and compress the water vapor into a removable tank that could be taken into the habitat. I still think I prefer having the WAVAR built in to the rover hangar inside wall.

Maybe pre-deliver the rover instead of having a rover hangar? The crew that arrives has to have it's own Long Range Rover because they will need a way to go and get stuff. You guys think that everything is going to land near the main base, they're not. Things are going to be landing all over the place. You're going to need a good sized rover that can go far out and pull a Mars Cart loaded down with heavy things (buried habitat components, greenhouses, food, water, supplies) back to the base.

Last edited by Dook (2017-05-11 09:28:08)

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