Luna 2076

The Moon is dotted with steep-walled holes known as pits, or skylights, which likely lead to sub-surface lava tubes that could serve as sheltered underground environments for human settlers. Engineers are developing specialized robots to explore these hard-to-access topographical features.

The trick is designing these vehicles to be compatible with small landers, making them capable of negotiating steep pit aprons, and equipping them to acquire cross-pit images. A team led by William “Red” Whittaker, a robotics professor at Carnegie Mellon University, has developed the PitRanger, a 33-pound mini-robot outfitted with a solar panel and an adjustable telephoto camera and tested it in a massive sinkhole in Utah.

Whittaker explains his challenge to Space.com:

“The scenario is to rove to a pit with a micro-rover, peer into the pit, acquire images of walls, floors, caverns, and then generate pit models,” Autonomy for fast exploration is the critical technology since the small, solar-powered rovers won’t be able to carry direct-to-Earth radio for supervision or guidance.

In addition, “the rover must succeed in a single illumination period” on the moon, because it needs the sun for energy and heating. (A lunar day lasts about 14 Earth days, and the lunar night is equally long.) “It only has 12 days, not 12 years, to complete its mission.”

The rover would circumnavigate the rim, identify the overlooks offering the required, and deploy a tiltable camera to obtain the required angles needed to create a high-fidelity, 3D-quality image, The result will be far superior to anything that a Moon-circling satellite could capture.

Not only do pits provide potential habitats, they are windows into lunar geology. Scientists expect to gain insights into volcanology, morphology and much more, Wittaker said.

BBC’s Science Focus magazine provides an interesting spin on the primary challenges behind establishing a Moon base.

Where to locate. Given the high cost of getting material to the Moon — $10,000 per kilogram just to escape the Earth’s gravity well — the idea is to use materials on hand to the greatest extent possible. That explains the keen interest in settling in the poles where abundant water ice is sequestered in craters that never see the light of day. Another advantage of a polar location is the ability to install solar panels in mountain peaks that are exposed to the sun around the clock.

Building the base. Planners expect to make extensive use of 3D printing. Experiments on Earth with imitation regolith have shown that it is possible to build large structures with the technology. However, it remains to be seen how well the process will work in the Moon’s light gravitational field. more “How to Build a Moon Base”

The Pentagon began developing work on electrically powered solid-state laser weapons two decades ago. By 2013 the Navy was testing a 30-kilowatt fiber laser on a ship. Then focus shifted to fiber lasers in the 50- to 100-kilowatt class. Now aerospace giant Boeing has teamed with General Atomics to build lasers achieving the 250-kilowatt threshold needed to defend against nuclear missiles, reports IEEE Spectrum.

The design of high-energy solid-state lasers entails a tradeoff between size, weight and power, and the problem of dissipating heat. General Atomics had the idea of developing a liquid laser, considered crazy at the time, but DARPA funded it. Liquid lasers are similar to solid-state lasers but they use a cooling liquid that flows through channels integrated into the solid-state laser material. The trick was achieving a perfect match in the refractive index between the liquid and the solid material. more “Boeing, General Atomics to Advance Work on Liquid Lasers”

Recognizing the Moon dust could be one of the biggest problems facing lunar colonists, NASA’s Space Technology Mission Directorate is conducting research in the Mojave Desert to find ways to cope with the ubiquitous substance.

Measuring dust ejecta. One project involves a sensor for  measuring the ejecta — gravel, small rocks, and lots of dust — that shoot out from the landing zone when a vehicle lands on the Moon. “This can cause widespread damage from sandblasting spacecraft surfaces and solar cells to actually striking and breaking optical sensors or other instruments, says Philip Metzger, a planetary physicist at the University of Central Florida.

“Having ejecta sensor data from actual lunar missions can help us improve those recommendations and will also help us protect the new spacecraft we’re sending to the Moon and even spacecraft orbiting around it – all of which is important not just to the U.S. but to the international space community as well,” Metzger said in a NASA publication. “And then we can develop physics equations that are truly predictive to inform mitigation strategies.”

more “Designing Lunar Dust Busters”

Astronauts walking on the surface of the Moon will be exposed to radiation levels 200 times higher than that on Earth,

The first systematically documented measurements of radiation on the Moon were undertaken in January 2019 when China’s Chang’e 4 robotic spacecraft landed on the far side of the Moons, according to an article published in Science Advances. Different sources of lunar radiation include galactic cosmic rays, solar particle events, and neutrons and gamma rays from interactions between space radiation and the lunar soil.

“The radiation levels we measured on the Moon are about 200 times higher than on the surface of the Earth and 5 to 10 times higher than on a flight from New York to Frankfurt,” said Robert Wimmer-Schweingruber, a professor of physics at the University of Kiel in Germany and the corresponding author of the study. “Because astronauts would be exposed to these radiation levels longer than passengers or pilots on transatlantic flights, this is a considerable exposure.”

NASA scientists describe radiation as the “most menacing” of the five main hazards of human space flight, surpassing isolation and confinement, distance from Earth, lack of gravity, and hostile/closed environment.

Chronic exposure to galactic cosmic rays may induce cataracts, cancer or degenerative diseases of the central nervous systems or other organ systems, reports CNN in summarizing the article’s findings. Additionally, the study said, exposure to large solar-particle events without sufficient shielding may cause “severe acute effects.”

Astronauts living on the International Space Station for as long as a year reside within the Earth’s protective magnetic shield. They are exposed to ten times more radiation than what they would experience on Earth, but that’s a small dose compared to what astronauts would be subjected to on the surface of the Moon or in deep space.