The International Space Station is the largest structure in space so far. It has been painstakingly assembled from 32 launches over 19 years, and still only supports six crew in a little-under-a-thousand cubic metres of pressurised space. It’s a long way from the giant rotating space stations some expected by 2001. The problem is that the rigid aluminium modules all have to be launched individually, and assembled in space. Bigelow Aerospace will significantly improve on this with their inflatable modules that can be launched as a compressed bundle; but a British company has developed a system that could transform space flight, by building structures directly in space.
Magna Parva from Leicester are a space engineering consultancy, founded in 2005 by Andy Bowyer and Miles Ashcroft. Their team have worked on a range of space hardware, from methods to keep Martian solar panels clear of dust, to ultrasonic propellant sensors, to spacecraft windows. But their latest project is capable of 3D printing complete structures in space, using a process called pultrusion. Raw carbon fibres and epoxy resin are combined in a robotic tool to create carbon composite beams of unlimited length – like a spider creating a web much larger than itself. Building structures in space has a range of compounding virtues, it is more compact than even inflatables, as only bulk fibre and resin need to be launched. Any assembled hardware that has to go through a rocket launch has to be made much stronger than needed in space to survive the launch, printed structures can be designed solely for their in space application, using less material still. So you can launch much more ‘hardware’ for a given size of rocket, and the raw material is used much more efficiently too. In addition, hydrocarbons, from which more fibres and resins could be made, are widespread in space, offering the prospect of being able to build in space, from in-space resources much sooner than we might expect. Either way the system could dramatically reduce the cost, risk and time (the prototype extrudes material at 1 millimetre per second, or a mile every 18 days!) of building large structures in space.
Their prototype has already been successfully tested in vacuum conditions, and will hopefully see its first in-space application for the Kleos constellation. This will be a network of 20 small satellites that will be used for commercial location services by triangulating radio signals. Magna Parva’s technique will be used to create 200-metre-wide antennae from a tiny central satellite. At present, the system just creates beams, so for human spacecraft it could be brilliant working in combination with Bigelow’s inflatables, forming the structures to dock and connect the pressurised modules. But it may well be possible to form more complex shapes in the future. Perhaps Magna Parva robots might be able to build us the space stations and spaceships of our dreams, spun from fibres made from asteroidal material. It would certainly make space-based solar power (where huge panels make electricity in space and beam it to Earth) more feasible; and perhaps ultimately a similar approach could ‘grow’ a space elevator down from orbit.
This may be the first time you’ve heard of Magna Parva, but if their system works as hoped they could have a very big impact on our future in space!