Engineers use lasers to create paving material from simulated lunar soil
Engineers in Europe have now successfully used lasers to melt the top surface of a simulated lunar regolith in order to turn that lunar soil into paving materials for roads and landing pads.
Though the experiement used a laser, that was only a surrogate for what would be done on the Moon, using sunlight focused by a magnifying lens.
Proceeding through trial and error, they devised a strategy using a 4.5 cm (1.8 inch) diameter laser beam to produce triangular, hollow-centred geometric shapes approximately 20 cm (8 inches) across. These could be interlocked to create solid surfaces across large areas of lunar soil which could serve as roads or landing pads.
Advenit adds: “It actually turned out to be easier to work with regolith with a larger spot size, because at millimetre scale heating produces molten balls that surface tension makes hard to aggregate together. The larger beam produces a stable layer of molten regolith that is easier to control. The resulting material is glasslike and brittle, but will mainly be subject to downward compression forces. Even if it breaks we can still go on using it, repairing it as necessary.”
The press release however noted almost as an aside what might be the most important result from this work: “The most practical response is to keep dust at bay by paving over areas of activity on the Moon, including roads and landing pads.” Lunar dust is very abrasive, is found everywhere, and is considered a fundamental and entirely unsolved problem for any future lunar base. This melting process, by sunlight, could conceivably eliminate the problem entirely at any base location by melting the surface dust.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon. from any other book seller, or direct from my ebook publisher, ebookit.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Engineers in Europe have now successfully used lasers to melt the top surface of a simulated lunar regolith in order to turn that lunar soil into paving materials for roads and landing pads.
Though the experiement used a laser, that was only a surrogate for what would be done on the Moon, using sunlight focused by a magnifying lens.
Proceeding through trial and error, they devised a strategy using a 4.5 cm (1.8 inch) diameter laser beam to produce triangular, hollow-centred geometric shapes approximately 20 cm (8 inches) across. These could be interlocked to create solid surfaces across large areas of lunar soil which could serve as roads or landing pads.
Advenit adds: “It actually turned out to be easier to work with regolith with a larger spot size, because at millimetre scale heating produces molten balls that surface tension makes hard to aggregate together. The larger beam produces a stable layer of molten regolith that is easier to control. The resulting material is glasslike and brittle, but will mainly be subject to downward compression forces. Even if it breaks we can still go on using it, repairing it as necessary.”
The press release however noted almost as an aside what might be the most important result from this work: “The most practical response is to keep dust at bay by paving over areas of activity on the Moon, including roads and landing pads.” Lunar dust is very abrasive, is found everywhere, and is considered a fundamental and entirely unsolved problem for any future lunar base. This melting process, by sunlight, could conceivably eliminate the problem entirely at any base location by melting the surface dust.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon. from any other book seller, or direct from my ebook publisher, ebookit. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Cue Joni Mitchell – They paved paradise, put up a parking lot
I wonder what delicate ecosystem or indigenous people we will be taking the Moon from.
Why not just nuke the moon with a big fusion device and make a big glass parking lot? I mean things might be a little “hot” for a while but they are going to be dealing with radiation exposure anyways so . . .
Was a time when I experimented with sunlight focused through a magnifying lens on leaves, wood, match heads, and ants but never tried green cheese.
Extremely interesting stuff. (I love engineering the heck outa’ stuff, as much as the next nerd.)
That having been said, this sorta feels like’ slavery with extra-steps.
I’m of the general opinion that we sorta need to invent more & varied low-tech solutions to specific high-impact problems (such as this dust thing), rather than always going for the most convoluted thing possible.
Wayne, I accept your challenge. Low tech solutions to high impact problems.
Although I do like the one time nuclear bomb to turn the surface into glass… after the (radioactive) dust settles, I fear it would be uneven and rather useless until you break up the surface and shape it into usable chunks and assemble it like bricks. heavy equipment required.
There are easier time honored methods proven very efficient on earth that’ll work well with the regolith.
The first and most important is plentiful reliable “power”
A nuclear power plant designed for submarine that can power a small city will be perfect. Self contained and miniaturized and will work for dozens of years without refueling.
Next is kill the tech heavy high input, low output laser, (which actually works best in the vacuum) and replace it with tungsten heating coils or better yet, arc electrodes used in modern smelting furnaces which can heat regolith into molten glass to pour a landing pad a meter thick and a meter wide in a continuous pour. (The iron form that the glass is poured into will have a foot-long? indentation on the side, to make a tongue and groove so the long blocks can’t come apart)
Where will the iron come from? When the site for a permanent base is chosen, The ground will be leveled out, shakers to separate the dust from the gravel and the larger rocks, just like any gravel pit on earth, with the addition of a magnet to collect iron ore from meteorites to be melted by the same electrode process. A trench will be dug and regolith glass poured into it as a proof of concept, the addition of imprinting the top of the glass with a groove so the molten metal can be poured on top of it at a future date. Yes this form will be rough, but functional in an 18th-century fashion… But after the crude tools will come more complicated and specialized as foundries for vacuum are built to feed the light weight 3-D printing machines that will make the pressurized domes and the tools and machinery….
The gravel can be washed, then dried without losing any of the solvent/water. Place gravel down near habitats and workstations, like a home gravel driveway, for dustless movement until a slow moving heating coil can pass above it, like an easy bake oven, turning it into glass. (optional)
Nowhere in our solar system, except for earth, can humans live on the surface, tunneling machines will be necessary. If a body of a ore is located, then housing and raw materials can be created with the same resources. The larger the underground mine, the larger the habitation and industrialization for the colony.
If uranium is found? Then there will be no limit to what can be accomplished. If not, it can still be supplied by earth.
If power is limited, the sun still shines continuously for 14 days. Mirrors can increase the energy density for molten products, or for the power to turn turbines the old fashion way if other needed resources can be found.
Playing around with fragile glass a few millimeters thick doesn’t inspire confidence in the reality of the requirements of landing with a heavy load, or taking off with the most powerful engines ever created.
60 Minutes had a program showing NASA doing something similar. I wasn’t impressed.
https://www.cbsnews.com/news/company-3d-prints-houses-on-earth-partners-with-nasa-to-3d-print-on-moon-60-minutes-transcript/
My personal lunar home made from an old rocket fuel tank, will have a 20 foot high radiometer that will spin an alternator and recharge my batteries from a 14 day 300° blow zero night!
https://en.wikipedia.org/wiki/Crookes_radiometer
Perhaps I can find me an old plutonium battery out of an old rover to keep me warm?
A magnifying lens to create lunar concrete. What an intriguing idea. I’m sure that they will continue to explore this technique, including trying to embed some form of rebar (reinforcing bar, such as in concrete) to help reduce the effects of cracking. Maybe they can be made pre-stressed in order to prevent cracking. 1.8 cm is about 3/4 inch, which holds some promise for interesting construction techniques.
Once constructed, would dust collect on a landing pad? After all, there is no atmosphere to kick up dust and deposit onto the pad. The answer turns out to be, “yes.”
A bizarre and unexpected phenomenon was observed. As the Sun shines onto the surface of the Moon, all that solar energy starts to knock electrons off the regolith, and the dust particles become charged. The teensy-weensy, nanoscopic dust particles lift off the surface, the charge on them overcoming gravity, and “float” in a sort of charged atmosphere of their own making. Larger, microscopic particles can also defy gravity.
Thus, over time small amounts of dust can collect on solar arrays, mirrors, thermal surfaces, road surfaces, landing pads, and other places that dust would be less than desirable. Paving would be a huge help, but there will always be a dust problem to overcome. Lunar dust has sharp edges, because unlike Earth and Mars, the dust does not get blown around, bumping into surfaces that abrade the sharp edges.
This may affect the topology of lunar stations, bases, and towns. In the northern hemisphere, the landing pads may be better placed north of the solar arrays so that the dust blown off the landing pads impinge the back sides of the arrays rather than the optical surface.
Dust will always be a problem on the Moon, but its affects can be reduced and minimized with careful planning, management, and operations.
Edward: The phenomenon of dust being lifted off the surface by solar energy is as yet still unconfirmed. Something has been observed, but the observations were uncertain, and spacecraft specifically set to look for this phenomenon failed to detect it.
Ah. I’m behind the times!