Lunar Resources – Page 2

How to Extract Ice on the Moon

May 18, 2020

Lunar ice water extractor. Concept art credit: George Sowers and MIT Technology Review

Water is essential to space exploration and colonization. Now that it has been demonstrated that billions of gallons of ice and molecular water are found on the Moon, the challenge is to figure out how to extract it.

In MIT Technology Review, space reporter Neel V. Patel lists the obstacles. Super-cold temperatures and radiation could endanger humans and degrade equipment. Lunar dust sticks to everything, wrecking machinery and posing safety issues to workers in spacesuits. And, of course, astronaut miners would have to be housed and supported on the Moon.

Lunar water comes in the form of tiny icy grained mixed with the soil, mostly in permanently shaded regions of craters in temperatures of 40 K (-233.15 °C). To be useful as a rocket fuel the material, only 5.6% water by weight, would require aggressive processing to rid contaminants.

One proposed method would be to build large towers with concave mirrors on the top that could reflect sunlight into the shadowed regions of lunar craters trapping the water. The energy would heat the lunar soil enough to get the ice to sublimate into vapor. A tent (transparent so the light could get through) would capture the vapor, which could be moved into units where it would freeze back into ice, and then purified at a separate location. Ultimately, the water would be separated into oxygen and hydrogen by electrolysis, and then liquified to the constituents used as rocket propellant.

Although humans have demonstrated the ability to operate rovers and landers that can withstand conditions on the Moon, no one knows if industrial infrastructure would hold up. Writes Patel: “It’s not easy to just wake a piece of technology from a 40 K slumber.” more “How to Extract Ice on the Moon”

Carbon More Abundant on Moon than Thought

May 7, 2020

Kaguya Satellite. Image credit: Aero-News.net

Confounding the long-held view that the Moon is depleted of carbon and other volatile elements, a Japanese satellite has detected a steady stream of carbon ions emanating from the lunar surface. Scientists believe the carbon has been there since the Moon’s formation roughly 4.5 billion years ago.

The finding comes from the Japanese Aerospace Exploration Agency’s Kaguya spacecraft, which spent a year-and-a-half in orbit around the Moon a decade ago. One of its instruments was a mass spectrometer, which mapped lunar ions including carbon. Recent analysis of the data, according to Science Alert, identified the carbon traces.

The concentration of carbon ions could not be explained by the deposition of carbon by solar wind, nor by the delivery of carbon on micrometeorites. Concentrations varied: Younger volcanic basalt plains on the lunar near side emitted more carbon ions than the older highlands, which suggests that the carbon is embedded in volcanic lunar glasses.

That’s a problem for the widely held theory that the Moon was formed by a large body colliding with Earth. The so-called Theia collision would have generated temperatures in the range of 4,000 to 6,000 Kelvin, which would have boiled away the volatiles and produced a volatile-depleted “dry Moon.” Instead, the Kaguya measurements suggest that the Moon could be a volatile-rich “wet” Moon.

The implications for lunar colonization are significant as well. Carbon is an essential element in biological processes. Abundant carbon would support the presence of plants and crops without the necessity of transporting it from Earth.

European Lab Develops Method to Extract Oxygen from Regolith

January 19, 2020

Simulated regolith before (left) and after oxygen extraction.

A team of European Space Agency (ESA) scientists think it has found a way to produce oxygen from lunar regolith, and it has opened a “prototype oxygen plant” inside a Dutch lab to refine the process.

“Being able to acquire oxygen from resources found on the Moon would obviously be hugely useful for future lunar settlers, both for breathing and in the local production of rocket fuel,” said Beth Lomax of the University of Glasgow in a statement.

Samples of moon dust returned from the lunar surface confirm that the material is made up of 40-45% oxygen by weight. The oxygen is bound up chemically in the form of minerals and glass oxides.

The European Space Research and Technology Centre (ESTEC), based in Noordwijk, Netherlands, uses a method called “molten salt electrolysis,” in which a simulated regolith is heated to 940 degrees Centigrade in a metal basket and molten calcium chloride salt acts as an electrolyte. Passing a current through the material extracts the oxygen and causes it to migrate to an anode where it can be collected.

As a byproduct, the process creates useful metal alloys. “The production process leaves behind a tangle of different metals,” says Alexandre Meurisse, ESA research fellow, “and this is another useful line of research, to see what are the most useful alloys that could be produced from them, and what kind of applications could they be put to.”

The precise combination of metals will vary depending on where on the Moon the regolith is coming from. There would be significant regional differences.

Says Tommaso Ghidini, head of ESA’s Structures, Mechanisms and Materials Division: “We’re shifting our engineering approach to a systematic use of lunar resources in-situ. We are working with our colleagues in the Human and Robotics Exploration Directorate, European industry and academia to provide top class scientific approaches and key enabling technologies like this one, towards a sustained human presence on the Moon and maybe one day Mars.” more “European Lab Develops Method to Extract Oxygen from Regolith”

Correlating Water Resources with Crater Age

December 8, 2019

These NASA images show distribution of surface ice at the Moon’s south and north poles.

A paper published in the January 2020 issue of Icarus examines the relationship between the age of lunar craters and the abundance of surface ice. Surface ice at the lunar south pole is found predominantly in ancient craters, 3.1 billion years or older. Some smaller, newer craters also host surface water. But surface icy is “very patchy” in spatial distribution, suggesting high overturn or destruction rates by meteor and micrometeor bombardment.

The authors examined 20 south polar craters that host surface water ice and quantify the available cold-trapping surface area occupied by water ice, according to the abstract for “Analyzing the ages of south polar craters on the Moon: Implications for the sources and evolution of surface water ice.”

States the abstract:

“The majority of surface ice is contained in old craters ≥∼3.1 Gyr, where the majority of cold-trapping area on the pole exists. The ice [in] these ancient craters is very patchy in surficial distribution, occupying <11.5% of cold-trapping surface area available in individual craters. This patchy distribution of ice in old craters is likely to be due to impact bombardment and regolith overturn within the polar regions. more “Correlating Water Resources with Crater Age”

Solar Wind Interacts with Moon’s Surface

December 1, 2015

Areas in red mark where solar wind is reflected the most. (Click for larger image.)

The Moon may not have an atmosphere, but it does have “weather” after a fashion. Researchers have found that the particles in solar wind appear to interact with the Moon in an unexpected way, reports the Daily Mail.

The solar particles interact with the Earth’s magnetic field to create the aurora borealis. But the Moon lacks a magnetic field, so scientists thought it passively absorbed the solar wind. But measurements made by Indian’s Chandrayaan-1 lunar orbiter have revealed that 10% of the solar wind is reflected back into space, creating turbulence as solar wind streams past the Moon. Vortexes billow onto the dark side of the Moon.

Charles Lue, a researcher at the Swedish Institute of Space Physics, has found that the reflection of solar wind varies with localized magnetic fields on the lunar surface.

Explains the Daily Mail:

In areas with strong magnetism, caused by iron in the crust, the solar wind flow is restricted, while adjacent areas receive increased flow. This results in unusual spirals of ions streaming off the dayside of the moon, where the solar wind strikes first, to the nightside.

The weathering of the moon’s surface by the solar wind may be less than previously predicted, which could mean there is less water hidden beneath the crust. Said Lue: “The reduced solar wind weathering allows us to separate micro-meteorite and solar wind-inducing weathering, including the effects of different solar wind species, differently well shielded.”

CubeSats to Probe for Water on Moon

October 8, 2015

CubeSats measure about four inches on each side — an oversized Rubik’s Cube. Photo source: NASA

The SpaceTrex lab at Arizona State University is partnering with NASA to create a tiny satellite, called the CubeSat, designed to measure and locate water on the Moon in the Lunar Polar Hydrogen Mapper or “Luna-H Map” project.

The competition is intense to be included on mission payloads. CubeSats are small enough, writes Popular Science, that they can hitch rides on rockets with larger payloads and get released on their own trajectories to conduct their own science. The first official launch of NASA’s Space Launch System and Orion spacecraft, scheduled for 2018, will carry 11 separate CubeSat missions into deep space, including one that will measure the effects of space radiation on yeast. The spacecraft will drop off LunaH-Map potentially along with two other lunar CubeSats to settle the question of how much water there is on the Moon and where it is.

The question for lunar water has strategic significance that the other scientific endeavors, as interesting as they may be, do not have. As Popular Science notes, lunar water will fuel exploration deeper into the solar system.

Jekan Thanga, the head engineer on LunaH-Map, dreams of a lunar gas station for astronauts. “Just think, we could have a refueling station at the L2 point,” he says, referring to a point beyond the Moon where gravitation alignments would allow supplies in space to remain stationary. “Our astronauts could stop there to refuel and stock up on supplies before heading out to Mars, or Europa.”

Since 2000 more than 300 CubeSat missions have been deployed in Earth Orbit, including the Planetary Society’s LightSail this year.

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Category: Lunar Resources