Luna 2076

I don’t know… Someone will to have to do better than this if space tourism is going to take off. I can safely say that the zero-G space toilet would dissuade 90% of the women of my acquaintance from ever leaving the Earth. — JAB

NASA has released its five-year, $28 billion budgetary plan to return four astronauts to the surface of the Moon by 2024 — for the first time in more than 50 years. The aggressive timeline hinges on Congress approving $3.2 billion to kick-start development of new lunar landers.

The plan unveiled Monday, reports Spaceflight Now, assumes that crews will lift off on NASA’s Space Launch System (SLS) heavy-lift rocket, fly to the Moon on an Orion capsule, then transfer on a commercially developed lander to shuttle astronauts to and from the lunar surface where they will maintain a base for exploration and scientific investigation.

The 2024 date is “the most ambitious possible,” states “NASA’s Lunar Exploration Program Overview.”

The Artemis Plan calls for developing a base camp on the lunar South Pole, possibly in Shackleton Crater. Key infrastructure includes the Orion spacecraft to deliver humans to lunar orbit, the Gateway orbiting the Moon to function as a transfer-and-docking station for the lunar lander, and The Habitation and Logistics Outpost (HALO) on the surface of the Moon.

Key elements of the base camp include an unpressurized lunar terrain vehicle, a habitable pressurized rover, a habitation module, power systems, and systems to exploit in situ resources.

NASA also envisions using upgraded spacesuits designed for the lunar surface, allowing more frequent spacewalks, with new-and-improved safety features, custom fitting, simplified maintenance, and better communications. more “NASA Releases Artemis Program Overview”

The Defense Advanced Research Projects Agency (DARPA) has awarded a $14 million task order to Gryphon Technologies to support development of a rocket that can use nuclear thermal propulsion (NTP) in Earth orbit, reports Space.com.

The rocket would use fission reactors to heat propellants to extreme temperatures and eject the gas through nozzles to create thrust. The technology would have a thrust-to-weight ratio about 10,000 times higher than that of electric propulsion systems and a specific impulse, or propellant efficiency, two to five times that of traditional chemical rockets, DARPA documents say.

NASA has lauded the potential of NTP technology as well, suggesting that nuclear-powered spacecraft could reach Mars in three to four months, half the time needed by chemical rockets.

Gryphon Technologies, based in Washington, D.C., bills itself as providing engineering and technical solutions to national security organizations.

Indian scientists have developed what they claim is a sustainable process for making brick-like structures on the Moon. The Microbial Induced Calcite Precipitation process would use bacteria to create a solid structure from lunar soil. The bricks, they suggest, could be used to assemble habitation structures on the lunar surface.

To create the brick, scientists with the Indian Institute of Science and Indian Space Research Organization mixed the Sporosarcina pasteurii bacteria, which produces calcium carbonate crystals, with a simulant of lunar soil. Next, reports Tech Explorist, they added urea and calcium along with gum extracted from guar beans. After a few days of incubation the resulting material was found to possess significant strength and machinability.

The material can be fabricated into any freeform shape using a lathe. “This is advantageous because this completely circumvents the need for specialized molds – a common problem when trying to make various shapes by casting,” says Koushik Viswanathan, assistant professor in the Department of Mechanical Engineering. “This capability could also be exploited to make intricate interlocking structures for construction on the moon without additional fastening mechanisms.”

The next step in the development process is to make larger bricks with a more automated production process, and to test them under varied loading conditions like impacts and moonquakes.

Geoff Brooks, a chemical engineer with Australia’s Swinburne University, has been giving considerable thought to the challenges of building structures under the extreme conditions of the Moon. Temperatures swing from -180° C to 120° as the Moon alternates between intense light and deep darkness. The surface is bombarded by solar and cosmic rays. Glass-like dust particles get everywhere. Even the chemical behavior of materials changes.

“If you think about the way bricks are made, a bit like pottery, imagine trying to make pottery on the moon, where the perfect vacuum changes the way materials heat up and the shape that they take,” Brooks tells Create, an Australian engineering publication. “These are the kinds of experiments we’re now building, to test not only how the materials will react on the moon but how we can work with those conditions to create a structure.”

Humans will need structures to shelter them from cosmic rays and moon dust. “We will need buildings with thick walls to protect space travelers,” he says. “However, on the moon we have only the rocks on the ground and the sun to work with. Everything else is difficult and expensive to get there.”

Other research priorities include finding ways to manage abrasive dust, and recycling space junk. 

Brooks heads a team of approximately 15 academics and PhD students encompassing disciplines such as mechanical engineering, mechatronics, product design, and physics.

Lava tubes are formed by lava flowing through a volcanic vent beneath a hardened surface. If the lava empties, it leaves behind a cave, typically in a long worm-like shape. These tubes have been spotted on Earth, on Mars and on the Moon. On Earth these structures range in diameter between 10 to 100 meters in diameter. Because there appears to be a strong correlation between gravity and tube-depth, Martian tubes are estimated to be 100 times wider, and lunar tubes 1,000 times wider.

In a new study, “Lava tubes on Earth, Moon and Mars: A review of their size and morphology revealed by comparative planetology,” a team of researchers from Italian universities has assembled a database of tubes and potential tubes. Typically, they leave long, sinuous channels that can be spotted on the surface. Sometimes, they leave cave openings.

“We measured the size and gathered the morphology of lunar and Martian collapse chains (collapsed lava tubes), using digital terrain models, which we obtained through satellite stereoscopic images and laser altimetry taken by interplanetary probes,” said Riccardo Pozzobon, as reported by Universe Today. “We then compared these data to topographic studies about similar collapse chains on the Earth’s surface and to laser scans of the inside of lava tubes in Lanzarote and the Galapagos. These data allowed us to establish a … relationship between collapse chains and subsurface cavities that are still intact.”

Many scientists have suggested that lava tubes on the Moon may make favorable spots for human habitation because they would be protected from cosmic and solar radiation and they would experience less temperature variability between long lunar days and nights. A major concern, however, is how stable the structures are. Many orbital photographs show collapsed tubes. The Italians believe they are most likely stable, thanks to low gravity on the Moon. Collapses are likely due to meteor impacts.

NASA is working on plans for robotic exploration of the tubes. The proposed “Moon Diver” mission would use a rover tethered to a lander to explore the tubes. Thelander would land near a skylight, then a tethered rover would climb its way down to the tube floor.