vacation on the Moon: |Mond2020

Would you like to vacation on the Moon:

— -ice- (@icelefant) 29. Dezember 2015

Lunar and Planetary Science Conference

A lasting lesson from Apollo. The lunar exosphere gets into everything, fine as talcum, abrasive as broken glass, and a significant cumulative threat to seals and any and all working parts generally, whether biological and mechanical. Beyond its demonstrated mission threat the Moon's dusty environment is a delicate, "pristine" and important  part of a 4.5 billion year history of space weather near Earth. Apollo 17 lunar module pilot and geologist Harrison H. "Jack" Schmitt moves forward with the patina of 22 hours activity on the lunar surface clinging to his suit. AS17-145-22157 [NASA/JSC/ALSJ].

The Moon's sodium tail, Potter and Morgan (1998).

The Lunar Dust Environment:
Expectations for the LADEE
Lunar Dust Experiment (LDEX)

Mihaly Horanyi, Sternovsky & Shul

with Colette, Grün, Kempf, Srama & Mocker

43rd Lunar and Planetary Science Conference, #2635

Introduction: The lunar dust environment is expected to be dominated by submicron-sized dust particles released from the Moon due to the continual bombardment by micrometeoroids, and due to plasma-induced near-surface intense electric fields. The Lunar Dust EXperiment (LDEX) is designed to map the spatial and temporal variability of the dust size and density distributions in the lunar environment on-board the upcoming Lunar Atmosphere and Dust Environment Explorer (LADEE) mission

LDEX is an impact detector, capable of measuring the mass of submicron sized dust grains. LDEX will also measure the collective signal of dust grains below the detection threshold for single dust impacts; hence it can search for the putative population of grains with r ~ 0.1 μm lofted over the terminator regions by plasma effects.

LDEX has been developed at the Laboratory for Atmospheric and Space Physics and Colorado Center for Lunar Dust and Atmospheric Studies (LASP/CCLDAS, University of Colorado at Boulder) and has a high degree of heritage based on similar instruments on the HEOS 2, Ulysses, Galileo, and Cassini missions. The LDEX flight model will be tested and calibrated at both the (Max-Planck-Institute for Nuclear Physics, Heidelberg, Germany) and Boulder dust accelerator facilities.

At the Lunar and Planetary Science Conference, March 21, 2012, Dr. Horányi summarized expected capabilities of LDEX and made predictions for its measurements in lunar orbit, based on current theoretical models. The authors also discussed a proposed LDEXPLUS instrument being developed for a possible LADEE follow-up mission to add the instrument's design capability for in-situ chemical analysis of impacting dust particles, perhaps to verify "the existence of water ice on the lunar surface and map the density of valuable resources of commercial interest".

Figure 1. LDEX EM and FM units and the schematic drawings of the instrument.

The LDEX instrument: The two expected sources of dust in the lunar environment are ejecta production due to continual bombardment by interplanetary meteoroids and lofting due to plasma effects. LDEX is an impact ionization dust detector with a sensor area of ~0.01 m\2. LDEX is a low risk, compact instrument and uses no flight software (Figure 1). In addition to individual dust impacts of grains with radii r > 0.3 μm, LDEX can identify a large population of smaller grains (0.1 < r < 0.3 μm) by measuring their collective signal.The expected impact rates, and the signature of lofted small grains expected over the terminators are shown in Figure 2.

Figure 2. Expected impact rates on a 30x100 km orbit with its pericenter over the morning terminator.

Initial test and calibration of the LDEX FM model were done at the CCLDAS dust accelerator facility. Full calibrations are planned in early 2012 at both the Heidelberg and the Boulder facilities. Figure 3 shows the preliminary test results, indicating that LDEX will meet or exceed its measurement requirements.

Figure 3. Initial test results for the LDEX FM instrument showing the detected particle mass versus their velocity. At the expected impact speed of 1.6 km/s,

LDEX will detect particles with radii r > 0.4 μm. The ratio of detected and undetected particles matches the expected value due to the duty cycle of the electronics and the transparency of the screens that provide shielding and exclude the solar wind electrons from entering LDEX.

The LDEX-PLUS instrument extends the LDEX capabilities to also measure the chemical composition of the impacting particles with a mass resolution of M/ΔM > 30. Traditional methods to analyze surfaces of airless planetary objects from an orbiter are IR and gamma-ray spectroscopy, and neutron backscatter measurements. A complementary method is to analyze dust particles as samples of planetary objects from which they were released. The source region of each analyzed grain can be determined with accuracy at the surface that is approximately the altitude of the orbit.

This ‘dust spectrometer’ approach provides key chemical constraints for varying provinces on the lunar surfaces. LDEX-PLUS is of particular interest to verify from orbit the presence of water ice in the permanently shadowed lunar craters. LDEX-PLUS combines the impact detection capabilities of LDEX with a linear time-of-flight system, similar to the Cassini Cosmic Dust Analyzer (CDA) instrument. Figure 4 shows an example time-of-flight mass spectrum of an ice-bearing dust grain.

Figure 4. Spectrum of a water ice particle obtained at ~ 4 km/s impact speed by the Cassini CDA instrument in Saturn's E ring. The dominant peaks are mass lines of water cluster ions (H2O)nH+, generated upon impact of an ice-bearing particle.

Schematic of documented species of horizon glow, such as the famous mid-lunar night imagery captured by Surveyor 7 in 1968.

Conclusions. LDEX, on-board LADEE, is scheduled to launch in May 2013 and will be capable of mapping the density distributions of both the large ejecta particles and the collective signal of small lofted grains. LDEX-PLUS, on-board a follow-up lunar mission, can collect a large number of samples from a greater part of the entire surface for analysis.

The instrument is especially sensitive to the metallic compounds of minerals and any species which easily form ions (e.g. water). The accuracy of the trajectory back-tracing to the surface is comparable to the altitude of the satellite. This in-situ method allows compositional surface mapping of the Moon. Since the dust spectrometer is particularly sensitive to refractory compounds which are difficult to access by other methods it is also complementary to remote sensing spectroscopy and an ion or neutral mass spectrometer. A ram pointing dust spectrometer and a nadir pointing remote sensing instrument collect data from approximately the same spot on the surface of the Moon, hence the combination of these measurements greatly enhances our ability to map the chemical composition of the surface and identify water-bearing regions.






An LDEX-PLUS type instrument can also address many of the science goals of a Europa Jupiter System Mission (EJSM) regarding the surface chemistry of icy satellites. See original Conference abstract, HERE, for citations.

Lunar Horizon Glow (LHC) as televised (vidicon photography) in local night, early 1968 [NASA].

The 'Dust, Atmosphere, and Plasma: Moon and Small Bodies' (DAP-2012) meeting will take place in Boulder, June 6-8, 2012. Please visit our webpages http://ldap2012.colorado.edu/  to register and submit an abstract by 3/30/2012, if you plan to attend.


We are looking forward to see you in Boulder!




- Alan Stern and Mihaly Horanyi

Lunar Pioneer, LLP


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Craggy Peak, Impact Melts |LROC

Northern slope of one of four central peaks in Hayn crater, on the northern edge of Humboldtianum basin. Downslope direction is from top to bottom (North is down), image field of view is 594 meters, sunlight is from upper left. LROC NAC observation M128754462L, orbit 4108, resolution 0.54 meters from 51.78 kilometers. View the full size LROC Featured Image HERE  [NASA/GSFC/Arizona State University].

Hiroyuki Sato

LROC News System

Due to the tremendous energy released by an impact event large portions of the target rock is melted. This impact melt forms distinctive flows and ponds both inside and outside of its parent crater. In many young craters the #LROC-NAC has captured deposits that look as if they formed yesterday.

Today's Featured Image is on the northern slope of the Hayn crater central peak. Due to the peak's steepness, it is rough and craggy. In many places on the peak wavy deposits are seen between crags and blocks; these deposits are most likely impact melt. Truly amazing, first the central peak formed then impact melt splashed down and coated it. If this interpretation is correct you can say that the peak formed in matter of a few seconds, quickly enough that melt that was thrown during the impact had not yet landed! Quantitative measurements of these kind of spectacular outcrops, using new accurate topography from LROC NAC stereo will help reveal how impact craters form.

#LROC QuickMap WAC monochrome 125 meter per pixel projection of Hayn and vicinty, centered at 64.34°N, 83.94°E. The yellow arrow indicates the locations of LROC Featured Image field of view [#NASA/#GSFC/#Arizona-State-University].

Hayn is an exceptionally deep crater because it is situated just within the northern mountainous ring of 550 km-wide Humboldtianum basin, which extends far beyond its deep interior Mare Humboldtianum. The entire basin straddles the 90° east meridian, though Mare Humboldtianum is a nearside basin visible at favorable lunar librations. The floor of Hayn is 4.9 kilometers below global mean elevation and it's northern crater rim is still more than a half kilometer below global mean. The mountain directly north of Hayn, a worn remnant of the Humboldtianum basin rim is 2.3 kilometers above global mean, nearly a seven thousand meter change in elevation over the eighty kilometers between that massif and the center of Hayn. LROC Wide Angle Camera (WAC) 100 meter per pixel digital terrain model, color shaded relief, orthographic projection centered on 60° east [NASA/GSFC/Arizona State University].

Explore the craggy peak and impact melt deposits, both on the peak and the floor of Hayn crater, HERE.

Related Posts:

On the floor of Green M

Splash and flow

Ejecta in Tycho crater

Natural Bridge on the Moon!

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News |Lunar Networks

"Slide show" comparing an illumination model of the lunar north pole region, made using a three-dimensional printer and LRO laser altimetry by Howard Fink of New York University, with standard representations of LOLA data and one LROC WAC mosaic [Howard Fink/NYU/NASA/GSFC/ASU].

Paul D. Spudis

The Once & Future Moon

Smithsonian Air & Space

Of all the wonders depicted in science fiction books and movies, one of the most intriguing is the machine that makes anything
that you need or desire.  Merely enter a detailed plan, or push the
button for items programmed into the machine – dials twirl, the machine
hums and out pops what you requested.  Technology gives us Aladdin’s
Lamp.  A handy device that will find many uses.

We’re not quite there yet but crude versions of such imagined
machines already exist.  These machines are called “rapid prototype”
generators or three-dimensional printers.
They take digitized information about the dimensions and shape of an
object and use that data to control a fabricator that re-creates the
object using a variety of different materials.  Typically, these
machines use easy to mold plastics and epoxy resins but in principle,
any material could be used to create virtually any object.

3-D printers contribute to the advancement our understanding of lunar morphology, as LRO fills long-neglected gaps in lunar morphology. Malapert Massif (85.9°S, 0.42°E). From an 80 meter resolution image of the South Pole region of the Moon built from a 20 meter original supplied by the LRO/LOLA science team [Howard Fink/NYU].

For comparison nearly the same area modeled by laser altimetry (LOLA) above, Malapert from the LROC Wide Angle Camera (WAC) RDR 100 meter Global Mosaic [NASA/GSFC/Arizona State University].

What’s the relevance of this technology to spaceflight and to the Moon?  One of the key objects of lunar return is to learn how to use the material and energy resources of the Moon
to create new capabilities.  To date, we have focused our attention on
simple raw materials like bulk regolith (soil) and the water found at
the poles.  It makes sense to initially limit our resource utilization
ambitions to simple materials that are both useful and relatively
massive, which currently have those killer transportation costs when
delivered from Earth.  Bulk regolith has many different uses, such as shielding (e.g., rocket exhaust blast berms) as well as raw material for simple surface structures.

However, once we are on the Moon and have met the basic necessities
of life, we can begin to experiment with making and using more complex
products.  In effect, the inhabitants of the Moon will begin to create
more complicated parts and items from what they find around them, just
outside their door.  The techniques of three-dimensional printing will
allow us to discover what makes life off-planet easier and more
productive.  We will experiment by using the local materials to maintain
and repair equipment, build new structures, and finally begin
off-planet manufacturing.

To illustrate the obliquity of the view angle and the problem posed in gathering information about the tantalizing but permanently shadowed regions of the Moon, Shackleton crater, with the Moon's South Pole on its rim (upper left) together with Malapert Massif on the horizon, seen with Earth as a back drop. HDTV still from Japan's Kaguya orbiter released November 2007 [JAXA/NHK/SELENE].

During the early stages of lunar habitation, material and equipment
will be brought from Earth.  With continued use, particularly in the
harsh lunar surface environment, breakdowns will occur.  Although
initially we will use spare parts from Earth, for simple uncomplicated
structures that are needed quickly, a three-dimensional printer can make
substitute parts using local resource materials found near the
outpost.  Most existing 3-D printers on Earth use plastics and related materials
(which are complex carbon-based compounds, mostly derived from
petroleum) but some processing has used concrete, which can be made on
the Moon from sieved regolith and water.  In addition, we also know that
regolith can be fused into ceramic using microwaves,
so rapid prototyping activities on the Moon may eventually find that
partially melting particulate matter into glass is another way to create
useful objects.

The lunar surface is a good source of material and energy useful in creating a wide variety of objects.  I mentioned simple ceramics and aggregates, but additionally, a variety of metals (including iron, aluminum and titanium) are available on the Moon.  Silicon for making electronic components and solar cells is abundant on the Moon.  Designs for robotic rovers
that literally fuse the in-place upper surface of the lunar regolith
into electricity-producing solar cells have already been imagined and
prototyped.  We can outsource solar energy jobs to the Moon!

These technical developments lead to mind-boggling possibilities.  Back in the 1940s, the mathematician John von Neumann imagined what he called “self-replicating automata,”
small machines that could process information to reproduce themselves
at exponential rates.  Interestingly, von Neumann himself thought of the
idea of using such automata in space, where both energy and materials
are (quite literally) unlimited.  A machine that contains the
information and the ability to reproduce itself may ultimately be the
tool humanity needs to “conquer” space.  Hordes of reproducing robots
could prepare a planet for colonization as well as providing safe havens
and habitats.

We can experiment on the Moon with self-replicating machines because
it contains the necessary material and energy resources.  Of course, in
the near-term, we will simply use this new technology to create spare
parts and perhaps simple objects that we find serve our immediate and
utilitarian needs.  But things like this have a habit of evolving far
beyond their initial envisioned use, and often in directions that we do
not expect; we are not smart enough to imagine what we don’t know.  The
technology of three-dimensional printing will make the habitation of the
Moon – our nearest neighbor in space – easier and more productive. 
Even now, creative former NASA workers have found a way to make this technology pay off.  In the future, perhaps their talents could be applied to making the Moon a second home to humanity.

Originally published October 24, 2011 at his Smithsonian Air & Space blog The Once and Future Moon,
Dr. Spudis is a Senior Staff Scientist at the Lunar and Planetary Institute in Houston. The opinions expressed are those of the author and
are better informed than average.

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