The Waxing of the Moon

We are on the verge of taking the first real step towards becoming a spacefaring civilisation. More and more countries and national space agencies are signing onto the Artemis Accords, securing an international cooperative future for lunar exploration. Dozens of companies big and small follow, with many talking seriously about not just lunar transport and science but resource utilisation and industrialisation. Through the transport of water, propellant and metals from the Moon to low Earth orbit we will be able to scale orbital industry by orders of magnitude – with lunar operations forming the keystone of the whole thing. The future of the Moon is bright, and only getting brighter.

Let’s start with the steps being taken right now, and the groundwork being laid. Against the expectations of many, the Biden administration has not stepped away from the Artemis Program. On the contrary they appear to be doubling down on the 2024 landing date – in no small part thanks to Jim Bridgenstine’s work signing international partners onto the Artemis Accords. Hardware is already being laid down for the Lunar Gateway space station; the selection of Lunar Starship represents an incredibly bold step and there’s a whole spate of commercial lander missions lined up. Between the wave of Commercial Lunar Payload Services (CLPS), crewed orbital and eventually crewed landing missions, we are looking at a pace of missions to the Moon unmatched since the early 60s.

There is reason to be optimistic about the new state of affairs. The architecture being laid down with Artemis isn’t as bold as the Apollo program but is far more sustainable with easier potential for long term growth. Lunar Gateway will help normalise deep-space crewed operations and hopefully lead to the first permanent human presence beyond low orbit. Combined with the tremendous lift capability of the next generation of reusable rockets, technology and capability are finally converging at a point where sustainable surface ISRU is practical.

Human Landing Systems Astronaut Regolith

I won’t harp on about the importance of ISRU for the long-term longevity of space exploration, It shouldn’t really be news to anyone. It’ll allow for cheaper, larger scale operations with locally produced materials and propellant – no different to Mars or anywhere else. Instead, the almost unique capability the Moon offers isn’t in-situ resource utilisation but ex-situ (off-site) resource utilisation or ESRU. Unlike Mars or the asteroid belt, the rich resources – water ice, metal ores – are within spitting distance of low Earth orbit. Resources in-situ are valuable as a way of saving money by reducing the need for imports. Resources ex-situ have the potential to make money in a way that almost nothing else in space can.

There’s a huge amount of potential for massive profits in any microgravity environment. This industry is just beginning, with a lot of interest in specialised high-value products like ZBLAN optical fibre and 3D printed organs. These are only possible to make in microgravity environments and retail for tens or even hundreds of thousands of dollars per kilogram when returned to Earth. As launch and operational costs fall this will expand to include products that are merely superior in microgravity – with metallurgy, crystallography and vapour deposition all standing to benefit. To top it all off, there’s a whole slew of non-money-spinning things that can be done with a properly industrialised space environment. Building structures too big to be feasibly launched from Earth in any future rocket, from radio telescopes to propellant depots to deep space exploration vehicles.

There’s just one problem. Products are made of matter and space is famous for not having lots of matter in it. So to make things in space, you need to bring lots of matter from somewhere else. In the short term that means launching it from Earth – on a relatively expensive rocket from a crowded launch site, over busy flight corridors and with complex launch site logistics. Even if single stage to orbit vehicles decide to start working, you’re mathematically required to use about 9km/s of delta-v and all the corresponding fuels. Contrast to shipping raw materials from the Moon. Not only are propellant demands substantially lower (around 2.5km/s if you utilise Earth’s atmosphere for accelerating) but you can use systems entirely optimised for vacuum operation. Initially that means simple tugs but could one day evolve into the fabled lunar mass driver.

The Stanford Torus, the boldest future enabled by the development of the Moon. Image credit National Space Society.

This is a role that only the Moon can fill – every other celestial body is too far away to be practical – and the possibilities for a developed system are mind-boggling. The ultimate evolution is a pipeline for many thousands of tonnes of lunar material to refinery stations at the Lagrange points and then back to LEO for manufacturing and sale. The lunar mass driver – a massive electromagnetic launch track that can fling payloads all the way back to Earth without requiring a drop of fuel – cuts the bottom out of the market for launching bulk material to space. It’ll never compete with prices on Earth, where developed supply chains bring metal prices to tens of pennies per kilogram. But for orbit, the tyranny of the rocket equation holds prices about two orders of magnitude higher – and that’s where the Moon can really compete. Cutting an order of magnitude off the price of propellant (thank you lunar ice reverses) or metals means the greenlighting of enormous projects that nobody thought possible. And it drops the cost of mundane projects – like rotating space stations holding tens of thousands of people – to levels where a moderately rich country could happily pay for its own.

That’s the final step of the evolution of the role of the Moon. It’s not necessarily a good place in isolation – it’s deeply barren, has long nights and a hostile dusty environment. It will take a mammoth effort to live and thrive there. So we must remember that while Mars may be the better place to found a second home, and the riches of the asteroid belt may sing to us, it’s the Moon that will allow us to flourish like nothing else. So I embrace the renewed push towards the Moon, from all the state and private enterprises now doing so. They’re on the rising edge of the development of the Moon, a development that will reflect back and benefit Earth far more than the vague technological benefits of a deep space settlement. With any luck that development will be continued and pay itself off a hundred times in the step change in industrial development of space.. For now there is no sign of that progress slowing off, so I don’t think it’s an understatement that the future of the Moon – and with it, humanity in space – is waxing strong.

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A lunar mass driver mining base. Image credit: Lunar Resource Utilization (LRU) for Space Construction study, 1979.

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