Going up: What can be made in orbit?

Since Yuri Gagarin’s trailblazing flight in 1961, humanity has been steadily extending its reach beyond Earth. For almost a quarter of a century, astronauts have lived and worked continuously aboard the International Space Station - a home in orbit that has redefined what is possible. Today, China’s Tiangong Station orbits alongside it, and new stations are already in development. Private companies are even hoping to develop space hotels, farms, renewable energy sources…everything that might be needed for orbital tourism. Behind every leap forward are scientists and engineers solving problems that once seemed insurmountable. To explore just how far we’ve come, and what’s next for life beyond our planet, I’ve been speaking to space writer and broadcaster David Whitehouse…

David - Space is a unique environment. We cannot recreate space here down on the ground. Principally, I mean microgravity. Now, you can do experiments with so-called drop towers, where you drop canisters from a large height, and for a few seconds they experience weightlessness. That is interesting, but it's not very effective if you want to examine what weightlessness does to drugs, materials, the human body, or structures. You really need to get up into space to see what this environment is like and what you can do there. Of course, there's an almost perfect vacuum up there in space, which also has its uses with experiments mounted on the outside of satellites. You have sunlight, which, if you're in the right orbit, provides perpetual energy. You have resources on the Moon, you have resources on asteroids which, potentially, if you have the means of getting up there and bringing the material back down, or even manufacturing and using it in orbit, is far more effective and much more interesting than the huge labour required to dig things up on the ground and launch them into space to work on. If we want to explore space, we've got to learn how to live off the land, if you like—live off the space.

Chris - So what steps have we taken towards those goals so far?

David - It depends on which area you're talking about. Since the 1950s, there has been a great debate about getting energy from space. Most studies aim to make electricity from sunlight and then transmit it back down to Earth. There are two big problems with that. First, you need a huge area to gather this sunlight, which involves a lot of space construction. And of course, you've got to get the energy back down. Most studies involve microwave beaming to a receiving station, and that has to be done very carefully, because where do you put the receiving station? And what are the health implications if the beam is misaligned or accidentally irradiates a city? So, it’s a great idea, but we're still in the early stages of working out the practicalities. The principal challenge is how to get so much material up into space.

Chris - What about making things in space? People are talking about exploiting microgravity because crystals grow in a certain way on Earth due to the influence of gravity. So can we get exciting, exotic crystals in space that you couldn't produce on the ground?

David - Theoretically, you could. There have been many experiments on the International Space Station and on the Space Shuttle to grow crystals and alloys. For example, John Brown, the tractor company, very famous in the United States, had an enormous project to mix alloys in space to see if they could be made stronger, cheaper, and lighter. They gathered some information, and that was instructive, because what they discovered didn’t mean they were going to manufacture in space, but it did improve their manufacturing on the ground. That was useful information. There are many case studies of purifying drugs, growing crystals, mixing alloys, and studying combustion in space, all of which have produced useful insights to help ground-based processes. None of them, however, has been exciting enough to scale up in the sense that the process, mixing, or alloy developed in space could be reproduced a hundred or a thousand times in quantity and then brought back to Earth to generate profit. Nobody has made that leap yet, because it is currently too expensive to send material into space and bring it back. We're waiting for people to develop proper, cheaper routes into space.

Chris - Is the alternative then to say, well, why bring it back? Why not envisage a future in space and build an industry around us living there?

David - That's a very good question, and that probably is the direction we are going to go. One of the most impressive developments in recent years has been Elon Musk's SpaceX launching Starlink satellites for internet communications across the world. Believe it or not, two-thirds of all operational satellites in space are Starlink internet satellites. He has launched thousands of them, and they work in an exquisitely coordinated way. You could imagine that the first solar farms would be mass-produced satellites like the Starlink satellites, launched aboard Falcon rockets. They would then automatically assemble themselves, in the same way drones fly in formation on Earth. They would form larger structures and experiment with beaming their energy back down to Earth. That would be fascinating, because AI could control the configuration. If a panel were damaged, it could fly away, and a new one could take its place. The system could change its shape and orientation. That is a very exciting conceptual idea using something we've already achieved. We've already put thousands of satellites of a similar design into space. That concept could be applied to space-based energy within the next 10 years.