A New Way of Creating Space

Our space stations are currently quite volume limited, and various ways around this have been proposed. But what if one has been staring us in the face for centuries?

I speak a lot here about the mass constrain of space settlement, but there is another constraint in play - that of volume. We want to make large spaces for people to live in, and at present all living spaces have to be launched from Earth and are thus constrained to the size of the rocket fairing they fly in. This has made human outposts in space somewhat cramped.

One way round this is to deploy inflatable modules. This has a long history, with the first example in human spaceflight being Voskhod 2’s airlock in 1965, and there is currently a small inflatable demo module called BEAM attached to the ISS. But today I’m talking about another solution, one with a heritage going back centuries: glassblowing.

A new company Skyeports hopes to bring this technology to use in space, to produce extremely large volumes. Their main product is a furnace that will manufacture glass spheres from lunar regolith, which is rich in silicate. Additives such as titanium, or possibly graphene which has recently been detected on the Moon, will be added for increased strength allowing the glass to be used as habitable structures.

The company is working with Cal Poly on materials research, and with veteran glassblower Josh Simpson. I spoke to the CEO Martin Bermudez to get some details on this concept.

The Price of Volume

The raw potential of this idea is huge. In the example I was given, a 20 tonne furnace on the surface of the Moon could produce a shielded, habitable space 100 metres in diameter. Let’s put that in perspective with comparison to some rigid and inflatable habitats.

Note the log scale here. The Skyeports habitat would provide an astonishing 524,000 cubic metres of habitable volume, more than 100 times that provided by the largest proposed inflatable habitat.

Such volumes as well as innate value solve another problem - current pressurised volumes are not large enough to enable artificial gravity by rotation. The closest we got was running laps on the interior of Skylab. Rotating a 100 metre diameter structure (or, perhaps more reasonably, a centrifuge inside a fixed sphere) at around 4 rpm would provide Earth gravity at the rim, a tolerable level of rotation for humans to adapt to.

Architecture

The glass spheres are blown from a tube in the top of the furnace, and this tube then provides access to the interior. Once a sphere is blown, a smaller tube may be bought up inside the outer one to make another glass sphere in the same way.

This allows multiple layers, for instance two concentric spheres can have the gap between them filled with regolith to function as a radiation shield. A layer outside can be used as a high CO2 greenhouse for growing plants. And the inner layer can be the shielded living space.

Currently Skyeports are aiming for construction on the surface of the Moon. The furnace requires some gravity to handle the molten regolith, and so attempting to use it in space would likely require some sort of spinning arrangement to provide the force required.

Barriers

This technology is at an early stage - Martin estimates TRL 2 - so what is going on at the moment is research and development.

I’m not a materials scientist - but a few things occurred to me to ask about. For instance, anything in space will be bombarded by micrometeorites. What will happen to the glass? According to Martin, they expect them to melt and become part of the structure. How will cosmic radiation impact the strength of it over long periods? The glass may be strong enough for its job at the beginning, but will its mechanical properties be altered after decades of GCR exposure? This one is harder to answer.

In space, and especially on the Moon, there can be extreme temperature variations which can cause thermal shock. Martin tells me that the R&D team is developing a type of glass that will will dissipate heat

more efficiently, preventing the glass overheating and weakening due to thermal stresses.

Skyeports plan to send samples of their materials to the ISS for long duration space exposure, which should provide some answers. In addition, they are aiming to build a terrestrial prototype of the furnace this year.

One scaling issue might be that the furnaces require argon to use, which is not easily available on the Moon. The most readily available gas is oxygen but that is dangerously reactive at the temperatures the process happens at.

Looking Forward

Martin had one more plan he wanted to share with me. The glass spheres can be doped so as to work as inefficient photovoltaic cells, and mass produce them in huge numbers on Mercury. This is a plan to build a Dyson swarm.

A lot of techno-optimist, or accelerationist types make a meme of “dismantle Mercury” but this is the first time I’ve heard someone with a plan to actually do it. I’m skeptical myself, and it’s a long way off, but it still is an intriguing proposal.

In the meantime, the technology can be developed for more near term uses. I think its got the potential to be a worthwhile addition to our space construction toolkit, and I look forward to what Skyeports do next.

---

This is the end of the article. This one is free for all readers, but some of my work is for paid subscribers only. Upgrading gets you full access to articles like these:

• An analysis of Japan’s contribution to the Artemis program and what the UK can learn from it.

• The history and current state of the art of partial gravity research, important for building human colonies on Mars or the Moon.

• How the threat of ASAT weapons and satellite constellation technology could lead to a militarisation of space.

• And my overarching philosophy for human expansion.

…and many more, including my regular monthly Mass Value Report where I apply a unique analytical lens I developed in this paper to the launch and space industries.

To subscribe costs about the same as a cup of coffee every month. Would you buy me a coffee to hear a complete set of my insights each month?