All aboard the space train - DARPA has commissioned defense contractor Northrop Grumman to figure out what would be necessary for a railroad network on the Moon.

Northrop Grumman announced that DARPA selected it yesterday, describing the defense agency's vision for a Moon train as one that could transport humans, supplies, and resources for future commercial ventures on Earth's natural satellite.

The lunar rail project is part of DARPA's 10-Year Lunar Architecture (LunA-10) project that aims to develop scalable, interoperable standards and systems for a permanent human presence on the Moon. Northrop is one of 14 companies DARPA has commissioned to work on various aspects of the project.

For its work on a Moon train concept, Northrop Grumman will be investigating what sort of interfaces and resources would be needed to build it, determining how much it would cost and the logistical risks, identify prototypes and explore construction concepts. 

None of the tasks Northrop outlines include actually building the thing, mind you. Rather, the boffins involved will be sketching space rails on spreadsheets and whiteboards.

"LunA-10 is not funding technology construction, transportation to the lunar surface, or integration with lunar delivery vehicles," a DARPA spokesperson told The Register. Questions about funding amounts or a timeline weren't answered, and Northrop Grumman hasn't responded to our questions.

First stop - actually getting to the Moon

This isn't the first time a Moonorail has been proposed. NASA announced its own sci-fi worthy maglev system three years ago. Dubbed FLOAT - Flexible Levitation on a Track - the idea was to build a system that shuffled passively floating robots along a track that could simply be rolled out like a space-age red carpet.

The three-layer flexible design of FLOAT tracks were supposed to include a graphite layer to keep bots afloat using diamagnetic levitation, a circuit layer to generate electromagnetic thrust to propel the floater at speeds greater than 0.5 m/s, and a third solar film layer to add the ability for the track to be used to generate electricity.

FLOAT was designed to overcome a key problem for life on the Moon - the incredibly abrasive nature of lunar regolith. Apollo astronauts reported sore throats and watering eyes after returning from moonwalks, and it's now known that the silicate-rich particles are sharp enough to destroy vacuum seals on equipment, wear away spacesuits, and generally lead to serious harm to equipment and personnel.

"FLOAT robots have no moving parts and levitate over the track to minimize lunar dust abrasion/wear, unlike lunar robots with wheels, legs, or tracks," NASA said of the concept.

FLOAT, NASA Jet Propulsion Laboratory's Ethan Schaler, principal investigator on the project told us, ran from a little over a year and is no longer in development. That said, Schaler describedthe project as "quite successful," and said the team behind it is actively looking for new opportunities to continue the work.

Northrop Grumman hasn't contacted the FLOAT team regarding their Moon train work, but "we’re happy to collaborate on any lunar infrastructure initiatives that want to include [it]," Schaler said. "We have always believed that FLOAT could be just one key component of a larger lunar infrastructure system to support a human-tended lunar base."

Of course, the entire project rests on whether we're actually going to get boots on the Moon anytime soon.

Artemis II, the first mission to take astronauts back to the Moon on a fly-by, was scheduled for late this year, but has been postponed until late 2025. Artemis III, which would involve humans actually landing back on the Moon, has likewise been postponed until late 2026, with NASA citing safety concerns in both cases.

Meanwhile, Starship, SpaceX's design for a reusable rocket to take humans and equipment to the Moon, has yet to truly succeed at a launch. Even the most recent attempt, when Starship made it to near-orbit, wasn't entirely successful, with both the craft and its Super Heavy booster breaking apart before the planned end of the mission. 

Odysseus, the hero private Moon lander, touched down in February and then immediately fell over, tipping onto its side as its batteries drained.

Artemis III is supposed to take astronauts to the Moon on a SpaceX Starship in just two years, and there's a lot of work to be done between now and then if the program is going to succeed. With all that in mind, a Moon train seems like wishful thinking at this stage. ®

https://www.theregister.com//2024/03/20/darpa_moon_train/