The Moon - A great place to build space ships

noosfractal · 2005-10-12 06:23:33

Try searching the page for the word "dopant"

GCNRevenger · 2005-10-12 07:35:55

If there are going to be vast quantities of solar cells built, it would be awfully hard to import large quantities of dopant economically I mean... nor does the author make too big of effort to explain the dual-layer nature of silicon cells.

SpaceNut · 2005-10-12 07:56:09

It appears form a quick search that most Dopant materials such as Phosporousoxychloride POCl3 or Phosphoric Acid H3PO4 as well as others contain a phosphorus combination is a liquid form. Which is sprayed on then baked in most of the processes of layered builds.

BWhite · 2005-10-12 08:08:01

If there are going to be vast quantities of solar cells built, it would be awfully hard to import large quantities of dopant economically I mean... nor does the author make too big of effort to explain the dual-layer nature of silicon cells.

Since imported mass is a huge limiting factor, I believe a good solar alternative would be Stirling cycle engines that use supercritical CO2 as the working fluid (Argonne Nat'l Lab has done some work on supercrit CO2 turbines); deploys the "cold end" of the Stirling cycle engine in shaded regolith; and the "hot end" at the focal point of multiple inflatable mirrors.

Austin Stanley has pointed out the amount of solar energy that can be concentrated with a few hundred (or thousand) dollars of very light weight material.

One VSE LSAM redesigned to carry cargo only could deliver the hardware and the CO2 can be harvested from the exhaust of a methane / LOX surface rover.

= = =

Add a "for example" link: supercritical CO2 cycles for advanced nuclear power.

This link is for Brayton cycle but should work with just about any heat engine, the key being 2000 F plus temperatures coming from solar energy concentrated by commerical grade mylar mirrors.

Commodore · 2005-10-12 08:24:42

One VSE LSAM redesigned to carry cargo only could deliver the hardware and the CO2 can be harvested from the exhaust of a methane / LOX surface rover.

I doubt the rovers will be (any)gas powered. Most likely solar, with precharged batteries.

BWhite · 2005-10-12 08:25:11

Lunar night?

Couldn't you heat rocks with passive solar during the 14 days of sunlight and extract the heat during the lunar night to run your heat engines?

Efficient? No! But how mucn would it cost to send 10 square meters of mylar (or 100 sq meters) and inflatable frame?

BWhite · 2005-10-12 08:26:19

One VSE LSAM redesigned to carry cargo only could deliver the hardware and the CO2 can be harvested from the exhaust of a methane / LOX surface rover.
I doubt the rovers will be (any)gas powered. Most likely solar, with precharged batteries.

Why? Especially if a lunar LOX plant has been built.

Import methane and receive a four-fer;

Power
Water
carbon dioxide
cabon monoxide (for Mond process)

= = =

Or, import large numbers of solar cells and/or a nuclear power plant.

Which will be "lighter" and cheaper?

= = =

I assert it will be far cheaper to import methane and extract LOX than dig water out of cold traps and crack into H2 & O2 (let alone process out the impurities)

A Honda power generator (a $1000 item) running methane / LOX will spew what is nearly distilled water from the tailpipe.

Commodore · 2005-10-12 10:20:27

Cause that will end up being a hell of a lot of methane, repeatedly. Verses a reactor in one shot.

Its interesting that for all the talk of microwave solar power plants, no one has thought to set up a power source on high ground and beam the power down to all the things need it in its line of sight. Might not be all that great for long range explorers early on but it will be great for powering all the rovers bringing regolith to a LOX plant.

Hydrogen is the one missing link. Carbon was found in Apollo samples though in low consetrations, be there are probably denser consentrations.

SpaceNut · 2005-10-12 10:27:50

I am wondering if the samples which were at the temp to freeze Hydrogen and other gasses were part of the escape of it to the crews habitat or LM as the temperatures rose. Thus making it hard to find any.

BWhite · 2005-10-12 10:50:35

Cause that will end up being a hell of a lot of methane, repeatedly. Verses a reactor in one shot.
Its interesting that for all the talk of microwave solar power plants, no one has thought to set up a power source on high ground and beam the power down to all the things need it in its line of sight. Might not be all that great for long range explorers early on but it will be great for powering all the rovers bringing regolith to a LOX plant.
Hydrogen is the one missing link. Carbon was found in Apollo samples though in low consetrations, be there are probably denser consentrations.

Methane solves the hydrogen missing link. And the carbon missing link. The Moon lacks both elements.

Once methane is combusted into CO2 and H2O then we can crack the H2O (exactly as is proposed for mining the cold traps for lunar ice) and then we use the Sabatier process to reform methane from the H2 and CO2.

Is it easier to extract water or ship methane? Depends on how much power is needed to dig out the water, purify it of sediments, and crack into H2 & O2 in the first place.

My main point is that the need for a nuclear plant should not be a mission critical FIRST step, necessary before we can do anything else.

Useful? Yes. But not necessary. [Edit to add: This is a big advantage the Moon has over Mars, abundant insolation. Utilize in situ energy as well as materials]

= = =

Methane gives you carbon as well as hydrogen and can be used to store solar energy by converting CO2 and H2 via the Sabatier process, something we need to practice for Mars anyway.

Test your Mars Sabatier gear on the Moon by making fuel for rovers.

SpaceNut · 2005-10-12 11:03:12

From the methane society thread:
To make use of the available water and hydrogen as well as methane we will need to use fuel cells and electrolysis.

Direct Methanol Fuel Cells (DMFCs)

LOW COST, HIGH EFFICIENCY REVERSIBLE FUEL CELL (AND ELECTROLYZER) SYSTEMS

noosfractal · 2005-10-12 14:13:42

If there are going to be vast quantities of solar cells built, it would be awfully hard to import large quantities of dopant economically

You can use phosphorus for n-doping and aluminium for p-doping. Boron is usual for p-doping, but like you say it would be a hassle to have to import it. The vapor deposition process needs hydrogen, which would have to be imported. But only Si and Al would get used in great quantities, and there is plenty of both of those.

noosfractal · 2005-10-12 14:19:28

I believe a good solar alternative would be Stirling cycle engines that use supercritical CO2 as the working fluid (Argonne Nat'l Lab has done some work on supercrit CO2 turbines); deploys the "cold end" of the Stirling cycle engine in shaded regolith; and the "hot end" at the focal point of multiple inflatable mirrors.

This sounds like a great idea! My only concern would be the in-situ manufacture of Sterling engines. I know they can theoretically be of any size, but the ones I've seen are huge and complex machines. I wonder how simple they can be in practice?

noosfractal · 2005-10-12 14:32:26

I assert it will be far cheaper to import methane and extract LOX than dig water out of cold traps and crack into H2 & O2 (let alone process out the impurities)

At $30000/lb? If I can send a 2 ton machine that can extract 1000 tons of water, I've got a pretty big win.

Is the existence of lunar ice confirmed? I thought there was still some controversy.

noosfractal · 2005-10-12 14:43:27

I am wondering if the samples which were at the temp to freeze Hydrogen and other gasses were part of the escape of it to the crews habitat or LM as the temperatures rose. Thus making it hard to find any.

I think orbiters can detect hydrogen in the soil. In fact, here is one of the images that make people think there is ice in enshadowed craters ...

.

http://nssdc.gsfc.nasa.gov/planetary/ice/ice_moon.html

Hmmm, 6 billion tons with soil concentrations of up to 1%. That isn't too bad.

Grypd · 2005-10-12 15:30:37

To produce Solar cells on the Moon and incidentally Mars you need access to Aluminium and Silicon and the Moon has a lot available. If we make the cells in-situ then the majority that is 90% of the cell is made from local materials and this includes 99% of the weight of the cell.

NASA PDF on the making and use of solar power

These cells are easily manufactured and the airlessness and low gravity of the Moon actually helps in there manufacture. One other point unlike more efficient circuits these silicate cells are considered very hard when it comes to radiation protection. Another useful point is that they are a recyclable commodity and if a cell gets damaged and is replaced the broken cell is simply made into another new one.

As stated previously production of solar cells could be done automatically and there has been plans for many years to have robots do it.

June 2000 spacedaily article

One thing to note these cells would have as a minimum a 25% efficiency and with some propsed technigues this would go up to 35%. The ISS currently is using solar cells that are a very old design and are only 14% efficient. This is how fast the technology is improving. Max efficiency has been recorded at 68% in some ultra efficient designs but they are not rugged enough for space use at the moment.

BWhite · 2005-10-13 06:51:46

I assert it will be far cheaper to import methane and extract LOX than dig water out of cold traps and crack into H2 & O2 (let alone process out the impurities)
At $30000/lb? If I can send a 2 ton machine that can extract 1000 tons of water, I've got a pretty big win.
Is the existence of lunar ice confirmed? I thought there was still some controversy.

$30,000/lb? Proton is $1000 per pound to LEO today.

Besides, how do you supply power to that machine?

Is there any lunar hydrogen that is recoverable? As far as I know, it's not confirmed yet.

RobS · 2005-10-13 09:00:49

We'll know in a few years what sort of enriched hydrogen deposits exist. They aren't solid ice, the radar data precludes that. So they are a mix of regolith and frost. If the frost is more than 1-2% of the material by mass, a Colorado School of Mines team says it is economically recoverable. If it is less than that, it is not.

My guess is that local concentrations should go higher than 1-2% so there should be some recoverable supplies. We'll know soon enough.

-- RobS

noosfractal · 2005-10-13 16:25:17

Proton is $1000 per pound to LEO today.

Which is $10000/lb to GEO, which is at least $30000/lb to lunar surface? Even then I'm giving you the next 5 years of tech. What estimates have you seen for reaching the lunar surface?

Besides, how do you supply power to that machine?

I like the Sterling engine idea.

Mars_B4_Moon · 2023-08-04 13:04:18

This might be an interesting thread to bump seen as there is now a return to the Moon for the USA and other nations have openly stated their goals.

I have often disagreed with people who said the tech for the Moon cross over to Mars and using the Moon as a test site for Mars is a good option, I think it is a bad option. I think it is possible to do 'Mars Direct' style mission instead of wasting resources on the Moon. However the Moon can be an option for a smaller colony and you might be able to test things like a Railgun Track to Orbit or other concepts you can't do on Earth today.

As for Moon colonization news

Chinese Flying Detector and China to launch a Hopper that Jumps into a Crater in Search of Water Ice
https://www.youtube.com/watch?v=TecH94d1TTw

Along with China, the USA has its own political drive to the Moon with new human lunar exploration program with NASA’s Artemis, a Gateway station and a mission mentioned by the US Joe Biden Kamala Harris Admin whose goal is to land the first woman and person of color on the lunar surface.

India, Russia, Japan and the US have launched the next phase of lunar exploration
https://thehill.com/opinion/technology/ … ploration/

The Luna-Glob Lander Payload

Russia’s Return to the Moon With Luna-25: High Risk, High Stakes
https://spaceref.com/science-and-explor … gh-stakes/

The Russian mission will carry 30 kg (66 lb) of scientific instruments, including a robotic arm for soil samples and possible drilling hardware. LINA-XSAN, a Swedish payload, was to fly with Luna 25, but delays to the launch date caused Sweden to cancel this plan. Instead, LINA-XSAN flew on Chang'e 4 in 2019.

I don't see Russia going anywhere fast with Putin so focused on warmongering and his imperial invasion of Ukraine, also a lot of former partners cancelled due to sanctions, the Soyuz is no longer in Guiana but maybe sometime in the future war will stop and maybe relations between Russia and the West might return to some form of normal, Russia the Federal semi-presidential republic under an authoritarian dictatorship.

Last year in June 2021, Roscosmos and the China National Space Administration (CNSA) held a joint session in St. Petersburg on the auspices of the Global Space Exploration Conference (GLEX 2021), dedicated to the presentation of the Roadmap for the creation of the International Lunar Research Station or ILRS. It was reported ILRS's lab director Wu Weiren also led in-depth talks with officials from France’s Thales Group, which considers the possibility for future cooperation with the Chinese space agency.
https://www.scmp.com/news/china/science … on-project
a letter of intent was also signed with the Hawaii-based, non-profit Lunar Observatory Association (ILOA) (which already participated in the Chang’e-3 lander mission) for cooperation on the ILRS initiative, despite earlier restrictions by U.S. Congress limiting American collaboration with the China National Space Administration.
https://weibo.com/5027345285/N87okAPzO

They seem to be sure there is some form of Waters trapped in the Poles of the Moon. One mission aiming for the X-Prize was the Astrobotic Technology Icebreaker mission was a mission concept planned for a 2015 mission, then delayed to 2016, and then cancelled.
There have been a lot of spacecraft sent to the Moon from Soviet Union, United States, European Union ESA, China, India, Israel, United Arab Emirates United Arab Emirates, Luxembourg, Italy and now South Korea looking at the Moon. The Canadian GEC might have been involved with Doge-1 a meme named satellite, on the site of Geometric Space, a subsidiary of Geometric Energy, the launch date of DOGE-1 is not currently indicated and is subject to change. DOGE-1 is scheduled to launch with Space-X September 2023, Space-X have already sent a South Korean satellite to the Moon. NASA the USA is the only nation to have Men on the Moon, so the USA is ahead with manned experience. Some people think there could be ices trapped in craters of permanent shadow, craters like Sylvester in the North a lunar impact crater, it is thought that Whipple a lunar impact crater located on the lunar far side near the northern pole.
PDF
https://web.archive.org/web/20110721072 … c_1_lo.pdf
Map of northern lunar pole
The LRO spacecraft or Lunar Reconnaissance Orbiter a NASA spacecraft currently orbiting the Moon in an eccentric polar mapping orbit, it has been checking for possible water ice deposits and lighting environment and examining characterization of deep space radiation in lunar orbit, results indicated the presence of both water and hydroxyl, an ion related to water.
https://web.archive.org/web/20200929185 … -the-moon/
the Moon is getting more busy and LRO and the Indian Chandrayaan-2 orbiter were expected to come dangerously close to each other
https://web.archive.org/web/20211115105 … critically
Artifical Machine Colonization of the Moon has been taking place ever since human made artificial objects reached the Moon after 1959. Luna landers scattered pennants of the Soviet Union on the Moon, and U.S. flags were symbolically planted at their landing sites by the Apollo astronauts, but no nation claims ownership of any part of the Moon's surface. Russia, China, India, and the U.S. are party to the 1967 Outer Space Treaty, defining the Moon and all outer space as the "province of all mankind", restricting the use of the Moon to peaceful purposes and explicitly banning military installations and weapons of mass destruction from the Moon.
https://web.archive.org/web/20100421232 … awfaq.html
,
There might be water at the South Pole–Aitken basin and a possibility of beaming Solar Power from mountains, such as Epsilon Peak at taller than any mountain found on Earth. Scientists think Cold traps are some of the important places on the lunar south pole region in terms of possible water ice and other volatile deposits.

Social Media Video

US and China exploration, who is ahead and are missions even comparable?

https://www.youtube.com/watch?v=n4vuDXE8dx0

what is happening in 2025, 2027, year 2029 and 2030 and 2033

Last edited by Mars_B4_Moon (2023-08-04 13:19:33)

Mars_B4_Moon · 2023-08-30 07:43:28

Indian rover confirms sulphur on Moon's south pole
https://www.spacedaily.com/reports/Indi … e_999.html

Russian space agency chief blames decades of inactivity for Luna-25 lander's crash on the moon
https://www.independent.co.uk/news/ap-r … 96859.html

Mars_B4_Moon · 2023-10-30 05:09:30

'Literally a complete guide to build an underground lunar research station, by HIT Research Center for Extraterrestrial Architecture.'

https://twitter.com/CNSAWatcher/status/ … 8752565280

HIT - The Harbin Institute of Technology China.

Mars_B4_Moon · 2024-03-01 06:47:28

Legislation would make spaceports eligible for tax-exempt bonds
https://spacenews.com/legislation-would … mpt-bonds/

GW Johnson · 2024-03-01 10:01:14

What I have often suggested is that the moon would be a great place to test and development the high-risk nuclear propulsion concepts that we ultimately will need. Do it down in a crater to limit flung debris. There is no air or water to pollute, and there are no neighbors to annoy. The items that occur to me are gas core nuclear thermal rockets, and nuclear explosion propulsion. This is the kind of thing that is the best when it pushes interplanetary vehicles, it doesn't land anywhere. Take along a selection of less-exotic landers for that.

I would add that such ought to be done on the near side of the moon. Any bases or settlements or colonies should be there, too. The far side should be reserved for science outposts that are shielded from all of Earth's radio noise.

And in keeping with the thread title, consider the advantage of the moon's low gravity. Once you have a working propulsion system, if you choose to build some sort of ship with it, launch from the moon is easy. Shipbuilding on the moon makes sense, but that happens much later, when the propulsion testing has been successful, and it becomes time to plant the infrastructure to build the ships to take advantage of it.

GW

Mars_B4_Moon · 2024-04-07 14:00:50

Queqiao-2 began a 19-minute braking burn at 1646 UTC March 24 and successfully entered lunar orbit. Further manoeuvres to enter its planned 24-hour period orbit. Tiandu-1 & 2 are also in lunar orbit, completing burns at 1743 UTC.

https://twitter.com/AJ_FI/status/1772184355357467099

Elon Musk: New Details on Making Life Multiplanetary

https://www.leonarddavid.com/elon-musk- … planetary/

New Mars Forums

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