The European Space Agency (ESA) has recently polled industry, seeking new ideas for commercial involvement in the ISS. Most of the suggestions have centred on providing cheaper access to the ISS using simplified equipment, not new industrial processes. So industry has the chance to participate and test new ideas, but on the whole industry’s involvement is in finding cheaper ways of getting to and from space – not doing business in microgravity.
The lifetime of the ISS is limited. ESA will make a decision in December this year whether to extend the operation, in conjunction with NASA, up to 2024. The ISS will almost certainly have to be deorbited and destroyed by 2030.
The next step beyond the ISS is currently being discussed under the opaque title of the Deep Space Habitat – “DSH” in NASA-speak. This could be a temporary “colony”, remote from the Earth and beyond the low-Earth orbit where the ISS floats. It would be built using hardware from the ISS and might manage to process materials from local moons or asteroids to keep it going, reducing the costs of resupply. Water and oxygen would initially be the targets, mostly because a human needs about 30kg a day of these to sustain life.
The far future
Future exploration missions might also benefit from processing materials on asteroids to generate rocket fuels for the return journey or for construction materials – but this is a step much more distant in time. Some of these proposals claim asteroid mining may have long-term economic benefits for everyone. These materials are present on many planetary surfaces but the current factories to process them would need huge transportation resources, more massive than the end products. Even so, missions now being studied may start to test these ideas on the Moon, or Mars' moon Phobos, within a decade or so.
We have yet to identify many materials that can only be created in a microgravity environment but have serious uses elsewhere. There certainly are possibilities. Creating a solid foam by introducing gases into a mixture of molten glass and molten metal and allowing the mixture to cool without gravity separating the components might create a structural material with the strength of steel and the corrosion resistance of glass. But a more likely product from factories in space would be the erection of large structural sections to build further factories and space stations.
Thinkers many decades ago imagined long-term “space colonies” travelling far from Earth. These would provide independence from an Earth in crisis and would need sustainable support systems. American physicist Gerard K. O'Neill proposed huge cylinders, kilometres long, and the attractive illustrations show fields and factories coexisting in this artificial world. Sputnik, the ISS and the future Deep Space Habitat are steps on the way to such colonies. Once established, we may may then need factories in space to keep us alive while we’re so far way from the Earth.