Air. Shelter. Water. Food.

Dook · 2017-05-04 20:14:56

kbd512 wrote:

kbd512

There are no windings in a homopolar generator? Okay, how much horsepower does it produce, how efficient is it, and how heavy is it? The Long Range Rover needs 4 DC motors of about 10 hp each. The WAVAR unit needs a small DC motor of about 2 hp for it's rack and pinion set up. The Marscat will need two 30 hp DC motors.

Water isn't deep on Mars? If it's near the surface near the equator it warms up and evaporates every day unless it has salt in it. So, the only pure water you are going to find is going to be deep. Is there salt water near the surface? Probably, but that's not a good thing. If there's too much salt water then that's a dangerous place to drive anything into.

Chips are 3D printed, they absolutely are, but the 3D printer that makes them is not the same 3D printer that spray sulfacrete and neither of those 3D printers is the one that makes rocket engines. You're trying to put all 3D printers into one machine.

If I send a thousand years supply of chips to Mars the GCR radiation will ruin them? We just have to keep them inside the buried habitat.
Rocket engine parts failures are fairly predictable with experience? Yes, they are. You're aware of "high time components". Components that have moving parts, seals, and electronics fail are a much higher rate than metal components that don't move.

The colonists won't have to get instructions on repairing anything from experts on the Earth, they will already have training on how to fix all life support equipment. They will also have training video's on their laptops that show the entire process before they attempt to fix anything.

If you only have to send a couple of rocket engines to Mars, a couple 3D printers, and some powdered metals to repair cracks and conductive inks to replace electronics that cuts down costs?

My plan is expensive because it uses a new rocket engine to deliver everything to Mars? Yep, Mars Direct is pretty expensive.

The rest of you have caught on to the fact that rocket engines are basically reusable? Your plan increases the risk for the colonists because it's way more complicated, depends on crew transfers in space, depends on too many machines, and uses too much water and electricity, just to get back some rocket engines.

Last edited by Dook (2017-05-04 20:15:27)

Dook · 2017-05-04 20:23:21

louis wrote:

Dook - If you really believe that I believe there's only one type of 3D printer, then that is sad...very sad.
Of course I know there are hundreds of 3D printers. Personally I would aim to take along at least two for a first mission to Mars - one working with metal powders and one with plastics. Not that you can't combine the two processes, it's just we may well wish to operate them simultaneously and I doubt on Mission One we will be looking to make complex metal-plastic components.
As Robert points out, 3D printers are only one small but significant element of early industrial production on Mars - there will be CNC and hand operated lathers...saws...compressors...all sorts of machines.

I know there's more than one 3D printer. I've been trying to tell you that it takes MANY machines to make one complex component.

You're the one who tried to link me to a motherboard assembly machine and tried to tell me it was a 3D printer when it wasn't. You're the one who doesn't know how a 3D printer really works. You're the one who doesn't know what things a 3D printer can make and what things it can't.

Of course you know there are hundreds of 3D printers? You mean you finally got it? Now if we just need to get you to understand that they won't make any life support component so they're completely useless on Mars.

As Robert points out, 3D printers are only one small but significant element of early industrial production on Mars? You misunderstood. What Robert was trying to say is that he made a motherboard with hand tools and didn't need a 3D printer. He thought I was for using 3D printers on Mars.

There will be hand operated lathes? For making what component on Mars? You don't know, do you?

Last edited by Dook (2017-05-04 20:24:21)

RobertDyck · 2017-05-04 20:24:56

Mars Direct habitat floor plan, as published in Scientific American - March year 2000.

Note this shows a single floor. The updated version moves the airlock to the lower deck, and the garage for the rover / surface science equipment / inflatable greenhouse will serve as workshop and/or laboratory. A construction mission would carry tools instead of a laboratory. Also remember I said the Mars Homestead Project - phase 1 had assumed 12 crew, delivered via Mars Direct habs. That means 3 habs, plus a 4th as a backup and to carry more tools. The 4th would carry the Mars Bobcat instead of a rover, but also realize the backup need not include furniture in the greenhouse/lounge/library. Actually, in the 21st century a library is just storage space on a server accessible via wifi from any smart phone, table, or laptop. My point is the 4th hab would be packed full of tools.

kbd512 · 2017-05-04 21:02:29

Dook wrote:

You ran into the wrong dugout there buddy and don't even know it.
Louis and KBD are obsessed with 3D printing because they think all 3D printers are the same machine. My argument is that it's a waste of rocket fuel to send one to Mars because it can't make life support equipment.
A 3D printer doesn't require skill, just fill the hopper? Oh, really, hehe... Sounds like you're the one who doesn't know about manufacturing and fabrication. What size particle do you put in the hopper? I'll let you look it up.
I've never fabricated anything out of wood? What life support equipment can you make out of wood? None.
Have I ever operated a lathe? What life support equipment can you make with a lathe? None.
Have I ever designed, etched, and printed a circuit boards by hand? I have people in Taiwan do that for me.
GW Johnson said that some parts can be 3D printed, others cannot? That's somewhat vague. Here's the thing, everything can be made on Mars with a whole lot of machines and a whole lot of time and energy processing massive amounts of regolith to get very tiny amounts of aluminum and copper and alloys. One 3D printer won't make any life support equipment.
You used a soldering iron, a drill, a lathe, a hack saw, a file, a tap and die? So, you're saying that it takes many tools to make one complicated component?

Apart from "people in Taiwan" making things for you, do you have any knowledge of how things are made or is this more argumentation for sake of being argumentative?

The fact that one machine can't make everything from microchips to houses has no correlation with the utility that comes from the capability to rapidly manufacture or repair components and electronics. If several 3D printers the size of a couple shoe boxes and maybe a few more shoe boxes of raw materials can eliminate the need to have 5 or 10 complete replacements for every little thing that could possibly fail, then my judgement is that that kind of limited manufacturing capability is worth the cost of the rocket fuel as a function of the weight of the complete replacements.

Life support equipment contains numerous sensors, seals, welds, and small parts. Look at a photo of CAMRAS (NASA's next generation CO2 scrubber) to see what I mean. There's no issue with taking several of these units with the colonists to Mars, but at some point the quantity of spare parts or complete units becomes excessive and more weight is devoted to delivery of CAMRAS units than other important things like food and water. That's what 3D printing has the capability to prevent. Rather than taking ten CAMRAS CO2 scrubbers, a 3D printer could easily create or repair the small components that need to be repaired.

The types of 3D printers I had in mind for electronics and small parts repair are so light that a child can effortlessly pick one up with one hand. The electronics of the near future will be more akin to credit cards with embedded chips or rolls of camera film than PCB's with discrete electronic components. Thin film solar panels are already like rolls of camera film. If electronics can be made light and cheap enough, then whether or not the electronics last forever is irrelevant when a new unit can be made in the time it takes to eat breakfast on a machine that's smaller than most shoe boxes.

SpaceNut · 2017-05-04 21:31:52

I can see that each of the forum members are marching to the speed of a different drummer again, with some are proceeding slow but steady with just crawling along while others are sprinting and are doing cartwheels....

Some of the topic has been about what will come first with each new items making possible to proceed along that path to being a colony. But when are we a colony and what makes it so as the first hurdles for being one is staying and not returning. Which brings us to the unknown of where or not the health condition of the crew that stay will do so when we are so accustomed to earth 1G gravity.

So unless we are willing to crawl along (as we are forced to return due to health reasons) then we will need to after being able to make the 5 essential items in quantity provide the means to make sure that we are able to stay earth healthy while on mars for long durations....

Dook · 2017-05-04 22:03:36

RobertDyck wrote:

Mars Direct habitat floor plan, as published in Scientific American - March year 2000.
http://matus1976.com/local_mirrors/mars … ubrin5.gif
Note this shows a single floor. The updated version moves the airlock to the lower deck, and the garage for the rover / surface science equipment / inflatable greenhouse will serve as workshop and/or laboratory. A construction mission would carry tools instead of a laboratory. Also remember I said the Mars Homestead Project - phase 1 had assumed 12 crew, delivered via Mars Direct habs. That means 3 habs, plus a 4th as a backup and to carry more tools. The 4th would carry the Mars Bobcat instead of a rover, but also realize the backup need not include furniture in the greenhouse/lounge/library. Actually, in the 21st century a library is just storage space on a server accessible via wifi from any smart phone, table, or laptop. My point is the 4th hab would be packed full of tools.

The 4th tuna can will be packed with tools? Tools are great. They will need hammers, screwdrivers, wrench's, and a wire repair kit. I don't think we'll wait until the 4th mission to send those basic hand tools though. They need to be on the 1st mission.

Did they tell you one of the tools to go on the 4th mission was a forge?

RobertDyck · 2017-05-04 22:20:25

Dook wrote:

Did they tell you one of the tools to go on the 4th mission was a forge?

Do you have a copy of "The Case for Mars"? You can read it as well as I. As for "Mars Homestead Project - Phase 1, the Hillside Settlement", I was one of the team members who developed it. But you do realize basic tools will be included in the first mission. And when construction phase begins, the 4 habitats with crew and advanced tools will arrive in rapid succession. Exactly how rapid is a matter of opinion.

kbd512 · 2017-05-04 22:24:45

Dook wrote:

There are no windings in a homopolar generator? Okay, how much horsepower does it produce, how efficient is it, and how heavy is it? The Long Range Rover needs 4 DC motors of about 10 hp each. The WAVAR unit needs a small DC motor of about 2 hp for it's rack and pinion set up. The Marscat will need two 30 hp DC motors.

I'd have to design a model and run some analytics to answer your questions. I see no issue with using ordinary electric motors for motive power. My partner is the one who wants to turn it into a motor. My interest in the design is purely as a generator. I can give you reasonable estimates for a generator of a given output, but would then have to model it to determine actual output, efficiency, and component masses.

A firm called Guina Research and Development Australia claims to have a homopolar motor design with liquid metal brushes with a power-to-weight ratio of 30kW/kg, but I think it requires YBCO superconductors to achieve that PWR. The latest and greatest jet engines are about 10kW/kg, for comparison purposes. The best PWR in brushless DC PMM's for aircraft that I'm aware of, that are actual flight test hardware, are about 5kW/kg. That was for a DARPA project. I would stick with brushless DC PMM's for vehicles, but that's just me. Efficiencies of up to 95% are common in the better designs. I think I recall a couple that were up to 97% efficient.

25kW motors for your Marscat could weigh as little as 25kg for both motors, not including the liquid coolant and radiators required to keep the motors from overheating.

Dook wrote:

Water isn't deep on Mars? If it's near the surface near the equator it warms up and evaporates every day unless it has salt in it. So, the only pure water you are going to find is going to be deep. Is there salt water near the surface? Probably, but that's not a good thing. If there's too much salt water then that's a dangerous place to drive anything into.

Our rovers have had problems in sand because their motors are ridiculously underpowered. A toddler can crawl faster than the rovers can drive.

Dook wrote:

Chips are 3D printed, they absolutely are, but the 3D printer that makes them is not the same 3D printer that spray sulfacrete and neither of those 3D printers is the one that makes rocket engines. You're trying to put all 3D printers into one machine.

You have ideas in your head that don't correlate with anything I ever stated anywhere on this forum. The fact that a different machine is required to make a microchip vs build a house is something I'm fully aware of.

Dook wrote:

If I send a thousand years supply of chips to Mars the GCR radiation will ruin them? We just have to keep them inside the buried habitat.
Rocket engine parts failures are fairly predictable with experience? Yes, they are. You're aware of "high time components". Components that have moving parts, seals, and electronics fail are a much higher rate than metal components that don't move.

You wouldn't need to have five or ten of everything if you could repair some things. Is that not obvious?

Dook wrote:

The colonists won't have to get instructions on repairing anything from experts on the Earth, they will already have training on how to fix all life support equipment. They will also have training video's on their laptops that show the entire process before they attempt to fix anything.

Some things require engineering level support. Apollo 13 is a good example.

Dook wrote:

If you only have to send a couple of rocket engines to Mars, a couple 3D printers, and some powdered metals to repair cracks and conductive inks to replace electronics that cuts down costs?

Exactly.

Dook wrote:

My plan is expensive because it uses a new rocket engine to deliver everything to Mars? Yep, Mars Direct is pretty expensive.

Why make it more expensive than it has to be?

Dook wrote:

The rest of you have caught on to the fact that rocket engines are basically reusable? Your plan increases the risk for the colonists because it's way more complicated, depends on crew transfers in space, depends on too many machines, and uses too much water and electricity, just to get back some rocket engines.

When you're tens of millions of miles from home, being able to repair your own equipment is not "way more complicated" and it's actually "way less risky". When someone forgets to take something with them and that "something" happens to be the one thing needed to repair or refurbish something critical, then the people on Mars just might survive that mistake if they have the tools to repair their own equipment.

Dook · 2017-05-04 22:36:55

kbd512 wrote:

Dook wrote:
You ran into the wrong dugout there buddy and don't even know it.
Louis and KBD are obsessed with 3D printing because they think all 3D printers are the same machine. My argument is that it's a waste of rocket fuel to send one to Mars because it can't make life support equipment.
A 3D printer doesn't require skill, just fill the hopper? Oh, really, hehe... Sounds like you're the one who doesn't know about manufacturing and fabrication. What size particle do you put in the hopper? I'll let you look it up.
I've never fabricated anything out of wood? What life support equipment can you make out of wood? None.
Have I ever operated a lathe? What life support equipment can you make with a lathe? None.
Have I ever designed, etched, and printed a circuit boards by hand? I have people in Taiwan do that for me.
GW Johnson said that some parts can be 3D printed, others cannot? That's somewhat vague. Here's the thing, everything can be made on Mars with a whole lot of machines and a whole lot of time and energy processing massive amounts of regolith to get very tiny amounts of aluminum and copper and alloys. One 3D printer won't make any life support equipment.
You used a soldering iron, a drill, a lathe, a hack saw, a file, a tap and die? So, you're saying that it takes many tools to make one complicated component?
Apart from "people in Taiwan" making things for you, do you have any knowledge of how things are made or is this more argumentation for sake of being argumentative?
The fact that one machine can't make everything from microchips to houses has no correlation with the utility that comes from the capability to rapidly manufacture or repair components and electronics. If several 3D printers the size of a couple shoe boxes and maybe a few more shoe boxes of raw materials can eliminate the need to have 5 or 10 complete replacements for every little thing that could possibly fail, then my judgement is that that kind of limited manufacturing capability is worth the cost of the rocket fuel as a function of the weight of the complete replacements.
Life support equipment contains numerous sensors, seals, welds, and small parts. Look at a photo of CAMRAS (NASA's next generation CO2 scrubber) to see what I mean. There's no issue with taking several of these units with the colonists to Mars, but at some point the quantity of spare parts or complete units becomes excessive and more weight is devoted to delivery of CAMRAS units than other important things like food and water. That's what 3D printing has the capability to prevent. Rather than taking ten CAMRAS CO2 scrubbers, a 3D printer could easily create or repair the small components that need to be repaired.
The types of 3D printers I had in mind for electronics and small parts repair are so light that a child can effortlessly pick one up with one hand. The electronics of the near future will be more akin to credit cards with embedded chips or rolls of camera film than PCB's with discrete electronic components. Thin film solar panels are already like rolls of camera film. If electronics can be made light and cheap enough, then whether or not the electronics last forever is irrelevant when a new unit can be made in the time it takes to eat breakfast on a machine that's smaller than most shoe boxes.

Do I have any knowledge of how things are made? Yep, some things.

3D printers are the size of shoe boxes? The Voxel 8 that you linked to earlier is. The sulfacrete printer you linked to before is much bigger. How big is the 3D printer that makes rocket engines?

Can we send metal powder to fix some things on Mars? Yes, but the weight of the powder equals the weight of the object already made. So, sending powder is not cheaper than sending a new component already made on the Earth. The ability to fix cracks could be somewhat beneficial if the object can be removed and brought to the 3D printer, or vice versa.

You don't need 5 or 10 complete replacements for every little thing. The components that have moving parts, seals, and electronics need to have replacements: electric motors (could just be the rotor with new bearings), o-rings (need a lot), door pressure seals (need a lot), 2-4 magnetrons, 2-4 wave guides, some extra vacuum pumps, acid plates for batteries, filters, sensors for the Moxie, CO2 scrubber absorbent, and I'm sure there's more.

At some point the quantity of spare parts or complete units becomes excessive and more weight is devoted to delivery of CAMRAS units?
The weight of any powder sent is exactly equal to the weight of the component already made.

The small 3D printers for electronics are lightweight? It doesn't really matter how lightweight they are if all the powder has to come from the Earth. The weight of the powder is exactly equal to the weight of the object fully made.

Dook · 2017-05-04 23:03:50

kbd512 wrote:

Dook wrote:
There are no windings in a homopolar generator? Okay, how much horsepower does it produce, how efficient is it, and how heavy is it? The Long Range Rover needs 4 DC motors of about 10 hp each. The WAVAR unit needs a small DC motor of about 2 hp for it's rack and pinion set up. The Marscat will need two 30 hp DC motors.
I'd have to design a model and run some analytics to answer your questions. I see no issue with using ordinary electric motors for motive power. My partner is the one who wants to turn it into a motor. My interest in the design is purely as a generator. I can give you reasonable estimates for a generator of a given output, but would then have to model it to determine actual output, efficiency, and component masses.
A firm called Guina Research and Development Australia claims to have a homopolar motor design with liquid metal brushes with a power-to-weight ratio of 30kW/kg, but I think it requires YBCO superconductors to achieve that PWR. The latest and greatest jet engines are about 10kW/kg, for comparison purposes. The best PWR in brushless DC PMM's for aircraft that I'm aware of, that are actual flight test hardware, are about 5kW/kg. That was for a DARPA project. I would stick with brushless DC PMM's for vehicles, but that's just me. Efficiencies of up to 95% are common in the better designs. I think I recall a couple that were up to 97% efficient.
25kW motors for your Marscat could weigh as little as 25kg for both motors, not including the liquid coolant and radiators required to keep the motors from overheating.
Dook wrote:
Water isn't deep on Mars? If it's near the surface near the equator it warms up and evaporates every day unless it has salt in it. So, the only pure water you are going to find is going to be deep. Is there salt water near the surface? Probably, but that's not a good thing. If there's too much salt water then that's a dangerous place to drive anything into.
Our rovers have had problems in sand because their motors are ridiculously underpowered. A toddler can crawl faster than the rovers can drive.
Dook wrote:
Chips are 3D printed, they absolutely are, but the 3D printer that makes them is not the same 3D printer that spray sulfacrete and neither of those 3D printers is the one that makes rocket engines. You're trying to put all 3D printers into one machine.
You have ideas in your head that don't correlate with anything I ever stated anywhere on this forum. The fact that a different machine is required to make a microchip vs build a house is something I'm fully aware of.
Dook wrote:
If I send a thousand years supply of chips to Mars the GCR radiation will ruin them? We just have to keep them inside the buried habitat.
Rocket engine parts failures are fairly predictable with experience? Yes, they are. You're aware of "high time components". Components that have moving parts, seals, and electronics fail are a much higher rate than metal components that don't move.
You wouldn't need to have five or ten of everything if you could repair some things. Is that not obvious?
Dook wrote:
The colonists won't have to get instructions on repairing anything from experts on the Earth, they will already have training on how to fix all life support equipment. They will also have training video's on their laptops that show the entire process before they attempt to fix anything.
Some things require engineering level support. Apollo 13 is a good example.
Dook wrote:
If you only have to send a couple of rocket engines to Mars, a couple 3D printers, and some powdered metals to repair cracks and conductive inks to replace electronics that cuts down costs?
Exactly.
Dook wrote:
My plan is expensive because it uses a new rocket engine to deliver everything to Mars? Yep, Mars Direct is pretty expensive.
Why make it more expensive than it has to be?
Dook wrote:
The rest of you have caught on to the fact that rocket engines are basically reusable? Your plan increases the risk for the colonists because it's way more complicated, depends on crew transfers in space, depends on too many machines, and uses too much water and electricity, just to get back some rocket engines.
When you're tens of millions of miles from home, being able to repair your own equipment is not "way more complicated" and it's actually "way less risky". When someone forgets to take something with them and that "something" happens to be the one thing needed to repair or refurbish something critical, then the people on Mars just might survive that mistake if they have the tools to repair their own equipment.

Our rovers had problems in the sand? They did. That should have been expected. We should have a good idea about the area we intend to put the base and not journey out over Mars and end up stuck in salt water sand. If you plan on traveling around Mars to get tons of ice you're going to have to go into places where we just don't know what the conditions are like.

You're aware that the 3D printer that makes chips is different than the 3D printer that sprays homes? Okay.

You wouldn't need to have five or ten of everything if you could repair some things? But that's exactly what I'm talking about, replacing worn or torn seals, replacing filters, replacing burned out chips with new chips, replacing shorted out wire sections by splicing in new wire.

I'm not talking about sending whole systems. The only difference is that you think it's better to make the new item on Mars instead of already having a new one on hand even though the weight is the same for powder and finished object.

Some things require engineering level support? I don't know the CAMRAS but the Moxie's are not that complicated, and the WAVAR unit is rather simple. I don't think they would attempt to repair sensors. Certain electronics they could repair depending on how much damage there was. A motherboard could be replaced and the damaged one fixed later. Hard drives would be replaced. Filters would be blown out with a small CO2 canister. Wires would be spliced. Door seals and o-ring seals would just be replaced.

Why make it more expensive than it has to be? I think you're the only person who thinks that Mars Direct is expensive. When lives are at stake, profit should not be the most important thing. NASA doesn't need to make a profit. Elon Musk does, that means more risk.

Being able to fix things on Mars is great, if the machines you bring can actually fix the important machines, like life support. I don't see a 3D printer fixing a Moxie.

kbd512 · 2017-05-05 00:22:49

Dook wrote:

Our rovers had problems in the sand? They did. That should have been expected. We should have a good idea about the area we intend to put the base and not journey out over Mars and end up stuck in salt water sand. If you plan on traveling around Mars to get tons of ice you're going to have to go into places where we just don't know what the conditions are like.

The sand was expected and the rover was even tested in sand. The problem is that the rover just couldn't store enough power in order to facilitate the use of more powerful electric motors. NASA is well aware of the problems, but the technology to do what they want to do just barely works well enough to make what they want to do achievable.

We have armored vehicles that can drive over snow here on Earth without sinking into the snow and we have armored vehicles that actually float. Sinking into the sand will not be a problem. It's not an issue when the ground pressure applied by the vehicle is low enough.

Dook wrote:

You're aware that the 3D printer that makes chips is different than the 3D printer that sprays homes? Okay.

I'm glad we cleared that up.

Dook wrote:

You wouldn't need to have five or ten of everything if you could repair some things? But that's exactly what I'm talking about, replacing worn or torn seals, replacing filters, replacing burned out chips with new chips, replacing shorted out wire sections by splicing in new wire.

If I strip the threads out of some aluminum or plastic component, then I can fill the hole in with a printer and re-cut the threads. I don't need a 10 ton 101-axis CNC machine center the size of a CONEX box to do that, either.

Dook wrote:

I'm not talking about sending whole systems. The only difference is that you think it's better to make the new item on Mars instead of already having a new one on hand even though the weight is the same for powder and finished object.

A 3D printer is just another tool. It happens to be an incredibly useful tool for those times when you don't know exactly what will go wrong, forgot the correct part in your other spaceship back at Earth, or break something that would otherwise be difficult to fix or replace.

Dook wrote:

Some things require engineering level support? I don't know the CAMRAS but the Moxie's are not that complicated, and the WAVAR unit is rather simple. I don't think they would attempt to repair sensors. Certain electronics they could repair depending on how much damage there was. A motherboard could be replaced and the damaged one fixed later. Hard drives would be replaced. Filters would be blown out with a small CO2 canister. Wires would be spliced. Door seals and o-ring seals would just be replaced.

Humans make mistakes and sometimes those mistakes are not predictable. If it turns out that the circuitry design is defective and all the replacement parts sent are the same defective design, then being able to create a functional replacement would be priceless. Testing is supposed to resolve all of those issues, but that seldom happens in the real world for any system of non-trivial complexity.

Damn near ever car made has had at least one recall for something and a spacecraft is a hell of a lot more complicated than a car.

Dook wrote:

Why make it more expensive than it has to be? I think you're the only person who thinks that Mars Direct is expensive. When lives are at stake, profit should not be the most important thing. NASA doesn't need to make a profit. Elon Musk does, that means more risk.

There is no profit when money doesn't change hands, although it's a safe bet that nobody goes if you make it expensive enough.

Dook wrote:

Being able to fix things on Mars is great, if the machines you bring can actually fix the important machines, like life support. I don't see a 3D printer fixing a Moxie.

What do you think will break on MOXIE?

Dook · 2017-05-05 10:18:52

kbd512 wrote:

kbd512

We have armored vehicles that can drive over snow and that actually float? We also have vehicles designed just to pull them out when they get stuck or flip over.

If a worker strips out the threads on something they could use a 3D printer to fill in the hole and recut threads? If the object is moveable. How are you going to move a Moxie or WAVAR unit or CAMRAS to the 3D printer?

If it turns out some circuitry design is defective all the replacement parts could be made with a 3D printer? Every operational and backup system will be tested before launch. I wouldn't say that every backup part will be tested but I'm sure they will be looked at to see it's condition.

What parts do I think will break on Moxie? The dust imager will go out at some point, the electronics box will have a short, the SOXE will break, the accumulators will start to leak internally in about 5 yrs once the o-ring seals wear out, the P sensor will quit working, the CO2 condenser will crack, the cryocooler will need to be replaced, the vacuum pump bearings will wear out and need to be replaced.

Your 3D printer can't make the dust imager. The Voxel 8 could make the electronics chips, someone would have to solder the old chip out and solder the new chip in. I don't know if your 3D printer can make synthetic rubber o-rings, maybe, but the weight of the material is exactly equal to shipping the part already made on the Earth. Your 3D printer won't make the P sensor. Your 3D printer might be able to repair a crack in the CO2 condenser. Your 3D printer will not be able to make a cryocooler. Your 3D printer can make a two piece vacuum pump housing and cover, the two impeller blades, possibly the bolts, but the threads would have to be tapped in and the printer won't make new bearings so you would also need to have them and use a press.

Last edited by Dook (2017-05-05 10:27:59)

kbd512 · 2017-05-05 12:36:22

Dook wrote:

We have armored vehicles that can drive over snow and that actually float? We also have vehicles designed just to pull them out when they get stuck or flip over.

That's true. That's why you need more than one vehicle if you want to go off-road anywhere, even on this planet. That said, I haven't seen very many snow cats stuck in the snow.

Dook wrote:

If a worker strips out the threads on something they could use a 3D printer to fill in the hole and recut threads? If the object is moveable. How are you going to move a Moxie or WAVAR unit or CAMRAS to the 3D printer?

MOXIE is mounted in an aluminum box or chassis. I think we'd unscrew the box, take it inside the habitat module, and work on it there. If someone strips the threads in the soft aluminum, then a printer can fill the hole in and a small cutting head can "re-thread" the aluminum. It's like welding, but with less heat and thus power, a lighter machine, and less material used. CAMRAS is already mounted inside the habitat module.

WAVAR would be more difficult since it's permanently mounted to the outside of the habitat module, but there are portable printers and machine tools that can be affixed to various surfaces using magnets, mount points, or lashings. I think it'd be useful to have a removable / mountable / portable print head that can be placed in a cradle in a normal print enclosure or used outside the habitat.

Dook wrote:

If it turns out some circuitry design is defective all the replacement parts could be made with a 3D printer? Every operational and backup system will be tested before launch. I wouldn't say that every backup part will be tested but I'm sure they will be looked at to see it's condition.

Testing generally eliminates obvious issues or failures, but there are also issues that don't become obvious until the equipment is used and those issues are much harder to deal with.

Dook wrote:

What parts do I think will break on Moxie? The dust imager will go out at some point, the electronics box will have a short, the SOXE will break, the accumulators will start to leak internally in about 5 yrs once the o-ring seals wear out, the P sensor will quit working, the CO2 condenser will crack, the cryocooler will need to be replaced, the vacuum pump bearings will wear out and need to be replaced.

Chips and cracks are what 3D printers will be best at fixing. If there are leaks from small punctures or fractures in pieces of plastic or metal, then a printer can reinforce that area. It's not necessary for the printer to build an entirely new object to restore the serviceability of the damaged object. Fewer spares and less raw materials are required as a result.

Dook wrote:

Your 3D printer can't make the dust imager. The Voxel 8 could make the electronics chips, someone would have to solder the old chip out and solder the new chip in. I don't know if your 3D printer can make synthetic rubber o-rings, maybe, but the weight of the material is exactly equal to shipping the part already made on the Earth. Your 3D printer won't make the P sensor. Your 3D printer might be able to repair a crack in the CO2 condenser. Your 3D printer will not be able to make a cryocooler. Your 3D printer can make a two piece vacuum pump housing and cover, the two impeller blades, possibly the bolts, but the threads would have to be tapped in and the printer won't make new bearings so you would also need to have them and use a press.

I have no idea what a "dust imager" is, so probably not. Why would an oxygen generation unit need to "see" dust? Why wouldn't we just filter the dust out and replace or clean filter cartridges as required?

Voxel 8 can "solder" and "unsolder" components if the circuit boards were manufactured using conductive inks to begin with. The people who created the technology recognized that humans make mistakes, especially with prototypes, and simply accounted for that in the design of the machine so that components could be removed if they were accidentally affixed improperly.

There are already 3D printed gas sensors and pressure transducers, so yes, the printer would manufacture the sensors since we're starting to make those sensors that way in factories on Earth. If, after 6 months, someone realizes there's a flaw in the design of the sensor, then we can make an improved model using design specs E-Mailed to the colonists.

There are now all-solid-state cryocoolers that use lasers to cool to temperature below which Oxygen turns into a liquid. The printer probably can't make a new device, but it could repair the electronics in an existing device.

If you simply cut out the damaged portion of the O-ring with a knife and have the printer reprint the damaged section of the seal, then why do you need an entirely new O-ring? If the printer can repair the seal without cutting using commercial seal repair liquids, then maybe it wouldn't even be necessary to cut the O-ring.

If someone sends the wrong seals, the seals are stored improperly, or you didn't take enough of the type of seals that were actually failing on a regular basis, then you have a problem.

The bearings would have to be brought from Earth, but there aren't that many types of bearings compared to the plethora of electronics, seals, and vessels subject to cracking or puncture. Bearings also typically last a long time and have fewer failures.

I'm by no means suggesting that we try to print absolutely everything or make an entirely new part if a repair on an existing part will suffice. The printer obviously adds a lot of flexibility to how you handle the problem. Maybe a few complete replacement parts for things like bearings or cryocoolers will suffice and we just use the printer to repair damaged plastics or metals and electronics.

My notion of how the printer would be used was as a way to deal with the uncertainty that comes with complicated electronic and mechanical systems when combined with human mistakes like not bringing the right parts. That's all.

Dook · 2017-05-05 13:50:36

kbd512 wrote:

kbd512

A full Moxie for an ERV will be large, maybe 30 feet by 30 feet. I think they should have tracks under them so after the exploration teams leave Mars the settlers can drive over with the long range rover and tow them back to the base.

Anyway, there shouldn't be any aluminum threads in anything. Everything bolted to the aluminum chassis should have steel bolts that go through a hole in the chassis and use a steel washer and a lock nut on the other side.

I think most of the components in a full sized Moxie will be large but they could be removed and brought back to the base for repair. Some of them could be taken inside the long range rover and rebuilt (accumulators).

The mini-Moxies and the CAMRAS in the Mars Hab should be completely accessible from the inside.

The WAVAR unit built in to the ceiling could have an access hatch on the inside but many of it's components would be too big to be removed. The fan motor could be replaced, the magnetrons and wave guides could, not the zeolite panels, not the fan itself, sections of the rack and pinion could be replaced, the rack and pinion motor should be small and could be replaced.

Chips and cracks are what 3D printers will be best at fixing? Yeah, it might be useful to fix cracks and punctures in metal tanks. The WAVAR unit, the mini-Moxies, and the CAMRAS should be protected by the Mars Hab structure. The bottom of the Rover Hanger would get hit with some rocks thrown up by the rocket engine landing.

If there are leaks from small punctures in plastic or metal a 3D printer can reinforce that area? But you have to be able to move the item to the 3D printer. I would just take some sand paper, scuff up the plastic, mix up some two part quick setting epoxy with fiberglass thread in a dixie cup, and fix it on the spot rather than mess around with moving the thing back to the Mars Hab.

If it's a puncture in a metal tank, then you have to weld it up.

So far it seems the 3D printer can make chips, repair cracks in small plastic and aluminum components that can be moved, that's useful but not that useful.

You could simply cut out the damaged portion of the o-ring and 3D print a new section? That's mechanic blasphemy. 0-rings are 25 cents each. You always replace them. Anyway, when they fail it's usually because they've become heat hardened, losing their elasticity, and losing their torus shape and have become square.

If you take the wrong seals or not enough of them then you have a problem? The same can be said if you take the wrong powder or not enough, and what if your 3D printer breaks?

Bearings typically last a long time? They do but if Mars dust gets in them they will be toast. Even so, they will need to be replaced at some point.

Last edited by Dook (2017-05-05 13:52:48)

kbd512 · 2017-05-05 15:56:34

Dook,

If we could predict ahead of time exactly what was going to go wrong, how bad the problem would be, and what was required to fix it, then we'd never need any replacement parts or repair tools because we'd simply engineer the components not to fail. The problem is, real life never seems to work that way and space exploration certainly doesn't work that way.

The astronauts never had water leakage problems with their EMU suits when the STS program was in operation and then we nearly drowned a couple people aboard ISS with the same design decades later. Unexpected things happen. Things fail in ways that nobody ever thought about. If the replacement part has the exact same issue as the original part, then replacing like-kind components isn't fixing anything. That happens quite often in electronics. On Earth where you can select a different replacement component with a few mouse clicks, it's typically not a major problem. Tens of millions of miles from home, when there's no ability to go home or use a different component, it could be a matter of life and death.

The most complicated components in modern spacecraft are the electronics and software. If you have no way to get back to Earth in any reasonable amount of time, then it's a good idea to have the capability to quickly repair or modify the electronics and software. I'm not talking about completely redesigning things, I'm talking about something silly like a specific transistor or capacitor routinely receives more voltage than it was rated for and gets toasted as a result. Soldering in a replacement component won't fix that. Should that have been found and fixed in testing? Yes, but will it be? Whatever can happen, will happen.

If you have the capability to make minor modifications and repairs to the equipment you use because you brought the tools with you to do that, then there's a better chance of surviving human mistakes that fall into the category of things that nobody ever thought of. This is the first time people are going to another planet. What are the odds that we discover some electronics or other small components weren't engineered correctly after we've already committed peoples' lives to the endeavor?

SpaceNut · 2017-05-05 16:11:47

Time to mars to wait for a tool that you need today to survive or a ready and waiting 3 D printer that could make that tool....thats a no brainer....Sure each type of 3 d unit is used for different material feed stock which are intended for items usually made of that material. 3 D units they are a supplement for not sending every type of tool nor for sending back ups of that complete set. We will always send uncommon tools drills, saws ect..that would be difficult to make completely by these machines.

Dook · 2017-05-05 17:24:55

kbd512 wrote:

Dook,
If we could predict ahead of time exactly what was going to go wrong, how bad the problem would be, and what was required to fix it, then we'd never need any replacement parts or repair tools because we'd simply engineer the components not to fail. The problem is, real life never seems to work that way and space exploration certainly doesn't work that way.
The astronauts never had water leakage problems with their EMU suits when the STS program was in operation and then we nearly drowned a couple people aboard ISS with the same design decades later. Unexpected things happen. Things fail in ways that nobody ever thought about. If the replacement part has the exact same issue as the original part, then replacing like-kind components isn't fixing anything. That happens quite often in electronics. On Earth where you can select a different replacement component with a few mouse clicks, it's typically not a major problem. Tens of millions of miles from home, when there's no ability to go home or use a different component, it could be a matter of life and death.
The most complicated components in modern spacecraft are the electronics and software. If you have no way to get back to Earth in any reasonable amount of time, then it's a good idea to have the capability to quickly repair or modify the electronics and software. I'm not talking about completely redesigning things, I'm talking about something silly like a specific transistor or capacitor routinely receives more voltage than it was rated for and gets toasted as a result. Soldering in a replacement component won't fix that. Should that have been found and fixed in testing? Yes, but will it be? Whatever can happen, will happen.
If you have the capability to make minor modifications and repairs to the equipment you use because you brought the tools with you to do that, then there's a better chance of surviving human mistakes that fall into the category of things that nobody ever thought of. This is the first time people are going to another planet. What are the odds that we discover some electronics or other small components weren't engineered correctly after we've already committed peoples' lives to the endeavor?

If we could predict what was going to go wrong we would engineer the components not to fail? No, we engineer them the best we can. We know things won't last forever. We can predict what is going to go wrong. We know that filters get clogged, bearings on motors and pumps wear out, batteries last 8 years, o-rings harden over time and last about 5-10 years, door seals will last maybe 4 yrs, electronics heat up and eventually the tiny connections break, wires get loose and short out, insulation on wires wears, and some things will bend and crack.

The filters can be sprayed out with a CO2 bottle, or replaced. The motor and pumps would hve to be disassembled and new bearings pressed in. The batteries would have to have their acid plates replaced. The accumulators would have to be disassembled and their o-rings changed. The door seals would be pulled out and new ones installed. Electronics would have to have the board removed and replaced, or a new wire spliced in, cracks we would stop drill and live with depending on where they are.

Things fail in ways nobody ever thought about? Yes, but that's extremely rare. Most of the time we see the same problems over and over again.

If the replacement part has the same problem as the original then we can't just replace it with another copy? Everything will be tested on the Earth well before launch. I would expect they would also do long term testing, leave the thing on for a year to see how it does.

Could there be a manufacturing mistake in some component? Sure, there could also be a manufacturing mistake in your 3D printer.

It would be great to be able to make everything you need with one or even a few machines, it's just not possible. 3D printers are good for a few applications but they can't really do very much.

Oldfart1939 · 2017-05-05 17:46:52

We certainly would be taking along several 3-D printers, for the same reason a professional carpenter takes more than a single hammer to a job. He has a framing hammer, a general purpose utility hammer, a finishing hammer, and maybe even a tack hammer. This is the era of specialization, so a printer capable of making a motor housing isn't the same one used for making printed circuits (did you catch that? PRINTED circuits!). You seem to be mixing what are known as WEAR PARTS with parts that either break from overuse/misuse, getting dropped, or simply due to premature retirement from getting old. Sure, we're going to bring extra O-rings, seals, extra wire because they're small and are WEAR PARTS. I'm reasonably certain that you don't REALLY expect a single machine to create a working "widget," whatever that might be? These 3-D printers will manufacture COMPONENTS, and do it with almost zero wastage of metals, plastics, ceramics, etc.
Sure, they may not be called upon to make everything, but not having them around means that the colony will be forever dependent on Earth for resupply of even the most trivial "shelf brackets."

Dook · 2017-05-05 18:13:20

Oldfart1939 wrote:

We certainly would be taking along several 3-D printers, for the same reason a professional carpenter takes more than a single hammer to a job. He has a framing hammer, a general purpose utility hammer, a finishing hammer, and maybe even a tack hammer. This is the era of specialization, so a printer capable of making a motor housing isn't the same one used for making printed circuits (did you catch that? PRINTED circuits!). You seem to be mixing what are known as WEAR PARTS with parts that either break from overuse/misuse, getting dropped, or simply due to premature retirement from getting old. Sure, we're going to bring extra O-rings, seals, extra wire because they're small and are WEAR PARTS. I'm reasonably certain that you don't REALLY expect a single machine to create a working "widget," whatever that might be? These 3-D printers will manufacture COMPONENTS, and do it with almost zero wastage of metals, plastics, ceramics, etc.
Sure, they may not be called upon to make everything, but not having them around means that the colony will be forever dependent on Earth for resupply of even the most trivial "shelf brackets."

The powder used to make a component in a 3D printer on Mars weighs exactly the same as the component already pre-made on the Earth.

Oldfart1939 · 2017-05-05 18:38:23

So?

The issue isn't the weight of the powder versus the part, but the combined weight of ALL the parts that DON'T get used. Powder and the printer(s) along with a couple CDs represent an entire parts warehouse.

Dook · 2017-05-05 18:58:30

Oldfart1939 wrote:

So?
The issue isn't the weight of the powder versus the part, but the combined weight of ALL the parts that DON'T get used. Powder and the printer(s) along with a couple CDs represent an entire parts warehouse.

The issue isn't the weight of the powder vs the part but the combined weight of all the parts that don't get used? Why wouldn't a new filter get used? Or new bearings? New acid plates for batteries? New o-rings for the accumulators? New electric motors? New vacuum pumps? New fan motors? New P sensors? Why wouldn't a new motherboard or hard drive get used? Are you saying those things will somehow last forever on Mars?

A 3D printer and powder represents and entire parts warehouse? Which of the above things can a 3D printer make?

The real issue is not weight of powder vs the weight of the part already made. They're exactly the same weight. As for size the powder actually takes up a bit more space because it's not compacted and full of air molecules. The issue is that you "think" the powder is lighter in weight than the pre-made object.

Oldfart1939 · 2017-05-05 19:42:16

Dook-

You certainly have a poor short term memory. Simply refer back to post # 143. I stated there that WEAR PARTS would be brought along, such a O-rings, etc. Either that, or you're being deliberately dense.

Dook · 2017-05-05 20:28:00

Oldfart1939 wrote:

Dook-
You certainly have a poor short term memory. Simply refer back to post # 143. I stated there that WEAR PARTS would be brought along, such a O-rings, etc. Either that, or you're being deliberately dense.

I don't have a short term memory. Your post was about all the different types of hammers that there are. Thanks for that. That really added to the Mars mission architecture discussion. I don't know where we'd be without that contribution.

So, not only do you not know what parts are in the life support equipment but you don't know what components a 3D printer can and can't make and you still think we should have a bunch of them just to cover it and you think that shipping powder would weigh less than shipping the component pre-made.

If we have to ship "wear parts" like: filters, bearings, acid plates, electric motors, O-rings, motor seals, door seals, what exactly are you going to use the 3D printers to make?

Oh, shelf brackets, right...

RobertDyck · 2017-05-05 20:52:03

And so it continues: Dook vs The Mars Society

Dook · 2017-05-05 23:07:35

RobertDyck wrote:

And so it continues: Dook vs The Mars Society

That would be a good movie script, kind of like the movie "Rudy".

Dook would be played by Brad Pitt.

RobertDyck would be played by the Matrix Revolutions Trainman guy, Bruce Spence.

Oldfart would be played by a Marty Feldman lookalike.

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