mersenneforum.org manned Mars mission - your thoughts?
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2021-06-30, 20:28   #23
diep

Sep 2006
The Netherlands

52×31 Posts

Quote:
 Originally Posted by chalsall I respectfully disagree. Musk and China (possibly others) will have "footprints on the ground" on Mars in less than ten years. I agree with Musk et al. There needs to be a "backup". CV19 should make this abundantly clear. And we are about to reach the point of technological advancement where we can actually do this. This capability /might/ be constrained to a narrow "window" in the temporal domain. Best do it as soon as we can, while we can. IMHO.
The 'backup' argument is the next total BS argument. A settlement in Mars cannot survive without regular rockets from Earth - each rocketmission costing a 10 billion dollar - with several tons of supplies.

Without this any settlement dies very quickly on Mars.

The amount of spareparts to 'live' on Mars is so huge.

If life as we know it would die on planet Earth - no settlement on Mars is going to survive long enough let alone be capable of launching a mission back to earth.

Say we have a nuclear war on Earth where hundreds of nukes get launched which pollute entire earth and all life larger than bacteria will die on earth. Including all spiders will die as they get no more food. It takes millions of years for earth to be livable again and probably not for humans yet for creatures at mouse size and probably those look very different than life as we know it.

Whereas any 'settlement' on Mars everyone will be dead very quickly after the rockets stop arriving.

To now waste trillions of dollars on a mission to Mars just for the 'backup' reason is total nonsense argument. Backup of what? Backup of the human society as we know it?

Then export it back to earth in case some crazy Mullah decides to destroy all life on earth for the coming millions of years?

The settlement on Mars would need to survive probably 10 million years before they can 'go back to earth'. You believe a few dudes on Mars will manage to keep alive when the rockets full of supplies stop?

Total nonsense thought.

Humans on Mars can only survive thanks to technology and energy created by machines exported from earth. They cannot produce such machinery on Mars. The amount of factories you would need on Mars to produce everything to survive is so huge - that's impossible to ship in rockets to Mars in short.

Yet even if you manage to do all this - you still need tooling and support from earth how to get things done.

Let's start with granite stones. Getting them flat to micrometerlevel. First you need create a granite stone. Then you need the SKILLS by hand to flatten them. Not everyone can do this. Guys on Mars will be pilots. No chance in hell they manage to flatten those stone to micrometer precision themselves without help from Earth how to do it.

So building their own tools is not gonna happen to some extend. The important tooling requires too much skill simply.

It requires so much skills that there is all kind of nonsense stories about the big pyramid of gizeh. The tomb there. Guys from 1000s of years ago would not have the skills to produce a tomb from granite this flat and precise.

Well in fact that's exactly how skilled persons do it today. They use like 3 granite stones and with each other they flatten them to sub micrometer precision.

The fact that historians still do not realize this and we hear the same nonsense arguments come back in documentaries about just 1 small thing that's solved - there is a million things like that that you need on Mars.

Any settlement on Mars will have a limited amount of persons anyway. Because the energy you generate with nuclear reactors is the limit to how many persons can live there and the huge bunkerspace and therefore energy you need to keep those bunkers alive.

A settlement on Mars is never autonomeous. So let's drop the nonsense argument of having a 'backup' on Mars.
Mars is a planet that is not survivable without regular rockets with spareparts arriving from planet Earth.

a handful of persons never has the skills to produce all those parts themselves - besides that you would need huge amount of factories with millions of tons of equipment to produce all those parts. And after some dozens of years you would need to replace half of that as it eroded away.

If you have a society on Mars that required 2000 tons to get settled there - you can be sure that every 20 years you need to ship 2000 tons of supplies to Mars - as simple as that.

 2021-06-30, 20:35 #24 diep     Sep 2006 The Netherlands 11000001112 Posts Sardonicus - i do not know what world you live in - but in 1969 we didn't have autonomeous robotic systems. In fact factories weren't even using CNC milling machines back then. We do have all this nowadays. So today for a mission into space - you ship a robot. 100 times cheaper than a manned mission and the robot is a one way launch and doesn't need to come back - besides that most launches take years to arrive somewhere - so you do that with robots obviously. Autonomeous robots preferably over humans.
2021-06-30, 20:39   #25
chalsall
If I May

"Chris Halsall"
Sep 2002

132·59 Posts

Quote:
 Originally Posted by diep The 'backup' argument is the next total BS argument. A settlement in Mars cannot survive without regular rockets from Earth
Incorrect. And, man, is your SNR ever low! Ever heard of the "short form"?

Using "in situ" gets you to self-sustaining quiet quickly.

2021-06-30, 20:39   #26
diep

Sep 2006
The Netherlands

52·31 Posts

Quote:
 Originally Posted by Uncwilly And we now know why diep's ancestors never left Europe, it is impossible to settle in a far off land.
You want to pay 10 trillion dollar for a settlement on Mars and pay each 20 years again 10 trillion dollar to keep them alive over there?

So say for a period of a few years you paid 10 trillion dollar then the Marsonauts, provided they still alive (as my guess is they all die within short period of time and that's not only my guess - some over here specialized in radiation do not believe they will arrive alive on Mars or die from radiation sickness within a few months). Then they get back.

You gained 0 knowledge. You gained 0 scientific knowledge. And you no longer have a settlement there. Yet you lost trillions of dollars.

The same missions carried out with autonomeous robots would cost you couple of dozens of billions at most and they do not need to get back.

2021-06-30, 20:52   #27
Uncwilly
6809 > 6502

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Aug 2003
101×103 Posts

37×271 Posts

Quote:
 Originally Posted by diep The amount of spareparts to 'live' on Mars is so huge.
As pointed out there is ISRU. Also, 3D printing is a thing. Ship bits not atoms.
Quote:
 If life as we know it would die on planet Earth - no settlement on Mars is going to survive long enough let alone be capable of launching a mission back to earth.
Apollo 17 sent people back from the moon. And they had to carry their fuel to the surface.
Quote:
 Humans on Mars can only survive thanks to technology and energy created by machines exported from earth. They cannot produce such machinery on Mars. Yet even if you manage to do all this - you still need tooling and support from earth how to get things done. Let's start with granite stones. Getting them flat to micrometerlevel. First you need create a granite stone.
So, we can build AI here on earth and not a small milling center? And again CNC does not require great brains or skill to operate.
Quote:
 Guys on Mars will be pilots.
Have you ever heard or Mission Specialists? Oh, the Dragon capsule can fly itself to the ISS and back. Starship did all of its crazy flying with no hand on the throttle. Astronauts are now picked to be more generalists and adaptable than 'throttle jockeys'. Your view of them is way out of date. And again knowledge is cheap to ship and store.
Quote:
 Because the energy you generate with nuclear reactors is the limit to how many persons can live there
Solar panels?
Quote:
 If you have a society on Mars that required 2000 tons to get settled there - you can be sure that every 20 years you need to ship 2000 tons of supplies to Mars - as simple as that.
That works out to 1 Starship delivery a year. Current estimates for that would run less than $200M. How much is that to the cost to run Formula1 or the English Premier League? 2021-06-30, 20:55 #28 diep Sep 2006 The Netherlands 52×31 Posts Quote:  Originally Posted by xilman The full post above.is too large to deal with in one go, so I will restrict myself to a number of responses to individual points, quoting each in turn, The main issue with the first is that it completely ignores in situ resource utilization, commonly known as ISRU in the trade. You do not need to take everything with you. You need take only enough to be able to build future requirements from local resources. Incidentally, rockets are not necessary to launch from airless bodies. Linear electric motors can accelerate material to lunar escape velocity. Once in orbit, rockets are not necessary for many purposes. Solar or laser sails are not rockets, neither are aerobraking or gravitational sling-shots. The last two have been used for decades. Technology which is now almost sixty years old was sufficient to get humans substantially further away than the ISS. Do the names Armstrong, Aldrin and Collins mean anything to you? More later. Xilman - so here we have a response that ignores what i tried to point out. I have some experience in industry and make industry. We already assume that you can melt things local over there. But you simply cannot produce the hundreds of thousands of objects that you typically need for a technological society. It's too complicated for a handful of persons. Which only can survive if they keep getting new pressure suits, vents, bearings, grease and so on. To open a mine on Mars to mine for resources you still need mining machines from steel. You want to use a local resource? Your problem still is the energy needed. So i didn't even 'bother' calculating when you also would need steel from Earth. You need thousands of tons of supplies just to have something there that can use local raw materials. All kind of things break down. Over here if i tighten bolts - they need to get tightened at say 50% - 70% of breaking strength of the bolts. You want to produce those bolts on Mars? Do you realize how complicated this is? Probably this would be one of those things you do want to produce on Mars. Yet to produce those bolts - what tooling do you need? right - you need all sorts of different steel alloys. Tungsten tools. You need chemicals to treat the bolts. In short it's far more complicated than you guess just to maintain a factory producing bolts on Mars. And that's just to produce 1 part. If you would produce the bolts with a normal lathe as we have it over here - then each bolt produced on mars is going to eat a lot of sweat of a guy there. Just a bolt. Besides a bolt you also need something to create threads into a part. We call that drilling and tapping. Any idea how many drills break here? You also want to produce drills local? Those drills say M42 or M35 drills are very hard alloy steel coated in a manner they are even more hard. There is no way you can do all that on Mars. You ship new drills simply and bunches of taps. So to just produce all the parts you need from local materials you still need immense amount of tooling. And lots of bearings. Fansblades you might be able to produce. How about the electric motor and wiring and the bearing that runs them? Oh the electric motor requires something that guides electricity. Say aluminium or preferably copper and for the motor itself copper. How to source that from planet Mars? If you go use sleeve bearings everywhere on all fans there - those wear out so quickly if you produce those yourself. The amount of raw materials you need just to produce parts with are quite a lot. Not 20 or 30. Really hundreds. You simply cannot open hundreds of mines on planet Mars - as you do not have the digging machinery to do so. A digger from steel - which is much better to use than anything you'll find easily on Mars - that steel wears out quickly. How to source the steel needed? So you need huge operations everywhere which all needs tooling to get the operations done. That requires so much different tooling - you have no idea. some sort of scientific constructed digger you cannot use in a mining operation. It needs to move lots of material. If underneath the surface of Mars it is all rock there you will have another major problem. How to crack the rock? Use dynamite? Good luck with that on Mars! Digging on Mars to mine different minerals might be very complicated. Kind of hard rock mining on Earth. For that the wear on your tooling is so so so huge. It's the huge amount of tools you need to get something done that will kill you.  2021-06-30, 20:58 #29 Uncwilly 6809 > 6502 """"""""""""""""""" Aug 2003 101×103 Posts 37·271 Posts 2021-06-30, 21:04 #30 diep Sep 2006 The Netherlands 52×31 Posts Quote:  Originally Posted by Uncwilly As pointed out there is ISRU. Also, 3D printing is a thing. Ship bits not atoms. Apollo 17 sent people back from the moon. And they had to carry their fuel to the surface. So, we can build AI here on earth and not a small milling center? And again CNC does not require great brains or skill to operate. Have you ever heard or Mission Specialists? Oh, the Dragon capsule can fly itself to the ISS and back. Starship did all of its crazy flying with no hand on the throttle. Astronauts are now picked to be more generalists and adaptable than 'throttle jockeys'. Your view of them is way out of date. And again knowledge is cheap to ship and store. Solar panels? That works out to 1 Starship delivery a year. Current estimates for that would run less than$200M. How much is that to the cost to run Formula1 or the English Premier League?
Uncwilly - you clearly didn't read yourself into the subject.

I do design CNC machines and i know how to 3d print. In fact i design professional 3d printers. Hope to release one to market soon. Yet cnc milling is a specialistic thing. Let me assure you this. Yes i do it do. As we speak i have a cnc milling machine working here and i'm walking back to it to get something done.

Yet cnc milling is already an expertise that requires years of experience and not everyone can do it.

3d printing is basically 3d printing plastics. A 3d printer has a nozzle which can wear out. On Mars you'd expect the nozzles to wear out. Do you know how to produce small nozzles?

You realize that to produce for example copper/brass (copper alloy in short) nozzles you need throw away drills?
So this is drills that you use to drill 1 time and after this you throw away the drill.

You cannot use the drill a 2nd time in short.

Did you realize this?

so you need to ship those tiny drills to Mars. There is no way they are ever gonna be able to produce drills on Mars.

 2021-06-30, 21:17 #31 diep     Sep 2006 The Netherlands 77510 Posts So if you produce parts yourself on Mars - you need CNC centers. A few years ago just during a visit to a factory - the bridgeport machining center they got (weighing roughly 15000 kilo or 30k pounds) the milling spindle was broken. Even the best machinists make mistakes! So they had to replace it. That took some time. On Mars how to replace it? Now to mill basically those machining centers are spewing cooling liquid - not to confuse with water. You need special oil inside the water and a specific percentage to cool during milling. How to produce all this oil on Mars? Another factory you need there! You want to mill 1000 kilo of raw metal material? Well you need then a specific amount of cooling liquid which is water and a specific percentage special cutting oil. How to produce this on Mars. If i add it up - you can really produce a very limited amount of parts on Mars itself. And remember - you need to build a bunker there deep underground which is a much better bunker quality wise than any bunker that's currently existing on planet Earth. Just to survive another day on Mars. The amount of resources needed - 2000 tons from planet Earth is really a very optimistic estimate mine. (and that is assuming In Situ Resource Utilisation) edit: Oh by the way - solar panels on Mars have at least 1 problem - there is storms on Mars. They can last for years. There is no sunlight then that reaches the surface. Last fiddled with by diep on 2021-06-30 at 21:26
2021-06-30, 21:20   #32
chalsall
If I May

"Chris Halsall"
Sep 2002

100110111100112 Posts

Quote:
 Originally Posted by diep There is no way they are ever gonna be able to produce drills on Mars.
For anyone interested... I would *highly* recommend watching (or reading) The Expanse.

Hard SF in our near future. Anyone who enjoyed B5, Star Trek, Space: 1999 et al (in the video form) and/or Asimov, Clark, Niven et al (in the written word) would appreciate the dedication to real physics.

They do use an "Epstein Drive" with an insane ISP which we couldn't currently match, but at least they don't do faster-than-light until the portals open...

2021-06-30, 21:24   #33
Uncwilly
6809 > 6502

"""""""""""""""""""
Aug 2003
101×103 Posts

100111001010112 Posts

Quote:
 Originally Posted by diep Sardonicus - i do not know what world you live in - but in 1969 we didn't have autonomeous robotic systems. In fact factories weren't even using CNC milling machines back then.
That is utterly false.
https://en.wikipedia.org/wiki/Histor...erical_control
Numeric control dates to the 1940's and 1950's. I personally know people that worked machining aerospace parts of the X-1 while it was at Edwards (I worked in his shop years ago). Also I know the people that built the first microprocessor based CNC systems.
Quote:
 Redacted had a degree in mathematics, and had began programming computers as early as 1955 for Rocketdyne a division of Rockwell International. The experience Redacted had helped him have a clear picture of how the software, for the CNC control, should be laid out.
Prior to that CNC was accomplished via paper tape systems, but the computers were used to program the commands that were punched. That company has parts on the Viking landers on Mars. I have talked to the guy that operated the machine.
Quote:
 besides that most launches take years to arrive somewhere
Mars and Venus are around 6 months.

Last fiddled with by Uncwilly on 2021-06-30 at 21:34

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