Equatorial Low Orbit Schmidt Cassegrain Sintering Satellite for Lunar Regolith

This telescope sinterer may be a bit different from most schmidt cassegrain telescopes with which you may be familiar. Specifically, there is only the mirror pair and no refractive lens involved. I was just trying to express the two mirror concept with the focusing beam passing through the center of the larger mirror. The sinterer would not likely have shortening the tube as a major goal like many telescopes do. Also the smaller mirror may not necessarily be curved. We are going for energy density (per area in the focal spot) and for the in-one-end-and-out-the-other geometry rather than for optical perfection and sharp imaging.

_____________

thewildotter

We just need faster dune buggies....

Roads?! We don't need no stinking roads!

I was hoping that a low orbit would function as a virtual "stinkin' road" but...

Because of my Earth bias and the biggest(175 m deep, Barringer Crater) remaining terrestrial crater rims being less than 200 m in height reduced only by a bit of wind and water erosion I incorrectly assumed that moon craters would be of similar magnitude. I should have looked up moon crater depth before posting but that ship has already sailed. I thought that regolith splash from other impacts would tend to level out moon craters to some (almost comparable to Earthly water and wind) degree but that effect seems to be unimportant relative to a snowball Earth megaglacier grader scraping off kilometers of rock. I could start my satellite sinterer at max surface elevation and hope to fill in the troughs but that sharply reduces the active sintering area per orbit and would dramatically reduce productivity until a genuine leveled road could be substantially developed, but that requirement sharply increases my "full production rate" startup time. So, Emmett Brown, "Who needs a stinkin' road ?" All the way around the equator of the moon at a uniform elevation ? I do.
And it ain't there to start with, so I cannot limit my focal length overhead to something effective at orbital speeds with a "reasonably" large primary mirror with a short enough focal length for focusing on a small enough spot to achieve sintering at speed. And now I know why no one is planning such a large 3D printer for lunar development. Thanks(GA), Rixter, for your lunar crater depth of knowledge. I have looked a little more and found this:
"
The missing piece of the puzzle comes from the study of Earth’s past climate records. Bottke showed that the paucity of ancient craters on Earth may coincide with periods in Earth’s history when its surface was completely covered with ice, the "Snowball Earth" scenario. The most compelling evidence for a Snowball Earth in the distant past comes from geology, which records evidence of glaciation near the equator. As glaciers move across continents, they cause deep erosion, removing kilometers' worth of material from the surface. Bottke proposed that glacial erosion during the Snowball Earth was such an extensive erosional process, especially in the period just before 650 million years ago, that it led to erasure of most of the large impact craters on Earth. However, extremely large impact craters like those at Sudbury (Canada) and Vredefort (Africa), which have very deep roots, survived the glacial scraping.
"
________________
thewildotter

Kinetic Diamond Production ?

On a bit of a tangent, it is interesting that Sudbury and also South Africa are both known as diamond sources. This suggests that perhaps more terrestrial diamonds may have impact sources than many people realize.

_____________

thewildotter

An important distinction is whether kinetic delivery or kinetic excavation or kinetic pressure and heat are responsible for transporting or revealing or creating diamonds.

____________

thewildotter

Why hasn't the Moon rover detected any diamonds? they should be everywhere...

https://en.wikipedia.org/wiki/Extraterrestrial_diamonds

Proposed Mechanisms for Why Lunar Rovers are Not Finding Diamonds on the Moon

As a wild guess: Earth has a very important elemental carbon concentrator, namely life. Additionally, the atmospheric erosion tends to pack that life modified, predominantly pure, elemental carbon tightly underground in (coal, oil, and graphite) layers with silicon rich layers of sediment on top of it. This geometry forms an anvil gasket for meteorites to use to achieve high temperatures and pressures on nearly pure elemental carbon caches underground. Wham ! visible sized diamond production, but it is still at depth. Now, over time, more glacial, and water and wind erosion and, voila, large, sparkly diamonds brought to or near the surface and worn right out of their surroundings.

Still guessing.... The carbon on the moon and in most meteors is predominantly chemically bound and unconcentrated carbon. Those non-carbon elements and pre-contaminated carbon compounds interfere with high temp, high pressure "pure carbon crystal" production. Even if a meteor arrives with some existing diamonds, it comes with and strikes material with carbon(and non-carbon) compounds which make large diamond production less likely and may even further reduce any existing crystal diamond load due to recombination. Furthermore, with no subsequent low temperature erosion to speak of, whatever diamonds (existing or produced) remain sequestered in rock or get blasted into microscopic specs too small to be noticed in huge quantities of normal regolith.

"they should be everywhere..." may be a large part of the problem since being everywhere frustrates being "precisely somewhere enough" to get noticed. Diffusion in the limit is oblivion.

______________

thewildotter

Apparently, some diamonds do come from meteor strikes...

"For decades the Popigai crater has fascinated paleontologists and geologists, but the entire area was completely off limits because of the diamonds found there. However, a major investigatory expedition was undertaken in 1997, which greatly advanced understanding of the enigmatic structure.^[7] The impactor in this event has been identified as either an 8 km (5.0 mi) diameter chondrite asteroid, or a 5 km (3.1 mi) diameter stony asteroid.

The shock pressures from the impact instantaneously transformed graphite in the ground into diamonds within a 13.6 km (8.5 mi) radius of the impact point. These diamonds are usually 0.5 to 2 mm (0.020 to 0.079 in) in diameter, though a few exceptional specimens are 10 mm (0.39 in) in size. The diamonds not only inherited the tabular shape of the original graphite grains but they additionally preserved the original crystals' delicate striations.^[7]"

https://en.wikipedia.org/wiki/Popigai_crater