Author Topic: Impact of lunar free water on Exploration Architecture  (Read 31749 times)

Offline Steven Pietrobon

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Re: Impact of lunar free water on Exploration Architecture
« Reply #260 on: 08/25/2016 05:55 AM »
Yes, that's me. I remain indebted to you for your help and advice with that book. You improved it a great deal. I sell about one or two of those a month.


Thanks. Even I find it useful now and again!

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I had thought LEO to a soft lunar landing was about 6 km/s. But I could be wrong.

No, you are correct. I was getting ahead of myself. TLI is 3185 m/s, LOI 940 m/s, PDI 25 m/s and Lunar descent 2042 m/s. Total 6192 m/s or about 6.2 km/s.

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The rocks I'm enthusiastic about can be parked in the lunar neighborhood for as little as .17 km/s. See the Keck report. Asteroid 2008 HU4 is one of the rocks I looked at. The rocks a Keck style vehicle can park in Lunar orbit might have hydrated clays. But volatile ices are unlikely.

Yes, having a resource rich asteroid in fairly easy reach could be quite useful.
« Last Edit: 08/25/2016 05:57 AM by Steven Pietrobon »
Akin's Laws of Spacecraft Design #1:  Engineering is done with numbers.  Analysis without numbers is only an opinion.

Offline savuporo

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Re: Impact of lunar free water on Exploration Architecture
« Reply #261 on: 07/28/2017 04:30 AM »
Bump.

Very much on topic:
http://www.airspacemag.com/daily-planet/ashes-and-water-180964225/

https://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2993.html

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Abstract

Laboratory analyses of lunar samples provide a direct means to identify indigenous volatiles and have been used to argue for the presence of Earth-like water content in the lunar interior. Some volatile elements, however, have been interpreted as evidence for a bulk lunar mantle that is dry. Here we demonstrate that, for a number of lunar pyroclastic deposits, near-infrared reflectance spectra acquired by the Moon Mineralogy Mapper instrument onboard the Chandrayaan-1 orbiter exhibit absorptions consistent with enhanced OH- and/or H2O-bearing materials. These enhancements suggest a widespread occurrence of water in pyroclastic materials sourced from the deep lunar interior, and thus an indigenous origin. Water abundances of up to 150 ppm are estimated for large pyroclastic deposits, with localized values of about 300 to 400 ppm at potential vent areas. Enhanced water content associated with lunar pyroclastic deposits and the large areal extent, widespread distribution and variable chemistry of these deposits on the lunar surface are consistent with significant water in the bulk lunar mantle. We therefore suggest that water-bearing volcanic glasses from Apollo landing sites are not anomalous, and volatile loss during pyroclastic eruptions may represent a significant pathway for the transport of water to the lunar surface.
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Offline Warren Platts

That was an interesting article by Milliken et al. I took the liberty of overlaying some of their maps on my own database. Here is the coolest one I think:



As you can see there is a lot of stuff in relatively close proximity to each other. It definitely looks to me like something is going on! The yellow markers are locations of the IMPs (Irregular Maar-like Pits), the false color hotspots are the locations of the pyroclastic deposits identified by Milliken et al., and the region marked out in black represents a zone where the Kaguya Lunar Radar Sounder identified powerful radar reflections at a depth of a few hundred meters.

The significance of the Milliken results IMHO is what they say: that the glass beads found by 2 out of 6 Apollo missions are not extremely rare anomalies. No doubt if there was more time to do exploration at the other 4 sites, I'd bet you'd find some glass beads there as well.

But more than that, it's pretty convincing proof that the lunar mantle has Earth-like water contents, on the order of a ppt. Thus we have a source rock, that can provide water, the IMPs show where there are conduits from deep within the Moon that allow water to move up, and the Kaguya reflectors are, arguably, consistent with free water confined within interflow zone reservoirs sandwiched between hundred meter thick basalt flows.

All three elements in a single graphic...

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Offline Lampyridae

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Re: Impact of lunar free water on Exploration Architecture
« Reply #263 on: 08/07/2017 11:03 AM »
That was an interesting article by Milliken et al. I took the liberty of overlaying some of their maps on my own database. Here is the coolest one I think:



As you can see there is a lot of stuff in relatively close proximity to each other. It definitely looks to me like something is going on! The yellow markers are locations of the IMPs (Irregular Maar-like Pits), the false color hotspots are the locations of the pyroclastic deposits identified by Milliken et al., and the region marked out in black represents a zone where the Kaguya Lunar Radar Sounder identified powerful radar reflections at a depth of a few hundred meters.

The significance of the Milliken results IMHO is what they say: that the glass beads found by 2 out of 6 Apollo missions are not extremely rare anomalies. No doubt if there was more time to do exploration at the other 4 sites, I'd bet you'd find some glass beads there as well.

But more than that, it's pretty convincing proof that the lunar mantle has Earth-like water contents, on the order of a ppt. Thus we have a source rock, that can provide water, the IMPs show where there are conduits from deep within the Moon that allow water to move up, and the Kaguya reflectors are, arguably, consistent with free water confined within interflow zone reservoirs sandwiched between hundred meter thick basalt flows.

All three elements in a single graphic...



I've always been quite convinced of the "wet moon" hypothesis, myself.

One thing I considered was that water vapour outgassing would precipitate (not really the right word) onto lava channel surfaces. Fractured Floor Craters (FFCs) have vertical sheets of fractures which fill with magma (or not) but also seem to be ideal conduits for interior outgassing, especially when the impact melt reaches into the volatile-rich mantle. Lava tubes may have similar ice reserves. Well, frosty rock - not solid blocks of ice, but even then the North Polar ice seems to be metres thick and fairly pure.

The deep radar reflection events from Kaguya are intriguing... too bad there's no practical way to get to them, but we may have convenient access in the form of those lava tube pits. I wonder if there are the equivalent of kimberlite pipes* on the Moon. If those were drained instead of clogging up like on Earth, they would provide really deep access as well as making for extremely cool future habitats. :P

*ie diatremes
« Last Edit: 08/07/2017 12:09 PM by Lampyridae »
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