Space Manufacturing: How space has become an indispensable practical resource

Space is no longer simply an exciting new frontier to explore, it’s become an indispensable practical resource. Today when we think of this “useful” side of the space business we may include things like direct-broadcast satellite TV and GPS-style satellite navigation, soon to be joined by SpaceX’s Starlink broadband service.

These all exploit the “ultimate high ground” aspect of being in Earth orbit, but it has another unique facet that we can make use of too. This is the lack of g-forces, technically referred to as microgravity, which promises to revolutionise a number of manufacturing processes.

Easily missed among more dramatic, headline-grabbing activities, research into in-space manufacturing has been going on for decades. As long ago as 1973, NASA used its first space venture after the Moon landings, the Skylab orbital laboratory, to try out a number of potential fabrication processes such as growing crystals and mixing metals to produce alloys.

The same kind of research is still carried out today onboard the International Space Station. As a result, it’s now firmly established that microgravity can offer significant advantages over Earth-based manufacture for certain types of product – even to the extent of offsetting the cost of transporting goods and materials to and from orbit.

One key factor is the extreme purity that can be achieved when materials are made in space. This is increasingly important in the manufacture of electronic components, with the trend towards ever greater miniaturisation, faster speeds and lower energy usage. For example, semiconductor crystals grown in space have significantly fewer defects and impurities than their terrestrial counterparts.

Another tech product that may end up being made in space is fibre-optic cable. This has become virtually indispensable for high-speed, high-bandwidth communications, but there’s still room for improvement. Current fibres, essentially long strands of drawn-out glass, suffer from significant transmission losses.

In principle, these losses could be cut to a tenth by employing a fluoride glass such as ZBLAN – but that’s not an easy thing to do on Earth. Terrestrially fabricated ZBLAN ends up peppered with tiny crystals, which negate much of the performance gain. If you want to make top-quality ZBLAN fibre, there’s only one place to do it – and that’s in the zero-g environment of space.

Looking beyond the electronics industry, there are other markets for the kind of high-purity materials that can be manufactured in space. One area of interest is in metal alloys – not so much the familiar mass-produced alloys used in things like car wheels, but specialised ones for which there’s high demand, but in nothing like such large quantities.

The super-strong, lightweight alloys used in medical implants are a good example. It turns out that getting the necessary metals to mix properly, especially if they include highly reactive elements like magnesium, is much easier in the absence of g-forces.

One commercial firm has already experimented with in-space manufacturing for real. In December 2020, the aptly named Made In Space, Inc. used a 3D printer on the International Space Station to produce a ceramic turbine disc which, thanks to fewer defects, should be stronger than one made under gravity. Another company hoping to break into this new sector is Axiom Space, which is looking at a number of potential markets including optical fibres, super-alloys and medical implants.

Written by Andrew May, author of The Space Business

Andrew May is a freelance writer and science consultant. The Space Business is his fourth book in the Hot Science series, following Destination Mars, Cosmic Impact, and Astrobiology. He lives in Somerset.

Andrew: https://twitter.com/DrAndrewMay

The Space Business: https://uk.bookshop.org/books/the-space-business-from-hotels-in-orbit-to-mining-the-moon-how-private-enterprise-is-transforming-space/9781785787454