You’d think that long duration space travel was something of a solved problem, given the numerous astronauts who’ve spent multiple months aboard the International Space Station. For some aspects of space travel this is correct but there are still many challenges that face astronauts who’d venture deeper into space. One of the biggest challenges is radiation shielding as whilst we’ve been able to keep people alive in-orbit they’re still under the protective shield of the Earth’s magnetic field. For those who go outside that realm the dangers of radiation are very real and currently we don’t have a good solution for dealing with it. The solution to this problem could come out of research being done at CERN using a new type of superconducting material.
The material is called Magnesium diboride (MgB₂) and is currently being used as part of the LHC High Luminosity Cold Powering project. MgB₂ has the desirable property of having the highest critical temperature (the point at which it becomes superconducting) of any conventional superconducting materials, some −234°C, about 40°C above absolute zero. Compared to other conventional superconductors this is a much easier temperature to work with as others usually only become superconducting at around 11°C above absolute zero. At the same time creating the material is relatively easy and inexpensive making it an ideal substance to investigate for use in other applications. In terms of applications in space the Superconductors team at CERN are working with the European Space Radiation Superconducting Shield (SR2S) project which is looking at MgB₂ as a potential basis for a superconducting magnetic shield.
Of the numerous solutions that have been proposed to protect astronauts from cosmic radiation during long duration space flight a magnetic shield is one of the few solutions that has shown promise. Essentially it would look to recreate the kind of magnetic field that’s present on earth which would deflect harmful cosmic rays away from the spacecraft. In order to generate a field large and strong enough to do this however we’d have to rely on superconductors which does introduce a lot of complexity. A MgB₂ based shield, with its lower superconducting temperature, could achieve the required field with far less requirements on cooling and power, both of which are at a premium on spacecraft.
There’s still a lot of research to go between now and a working prototype however the research team at S2RS have a good roadmap to taking the technology from the lab to the real world. The coming months will focus on quantifying what kind of field they can produce with a prototype coil, demonstrating the kinds of results they can expect. From there it will be a matter of scaling it up and working out all the parameters required for operation in space like power draw and cooling requirements.
It’s looking good for a first generation shield of this nature to be ready in time for when the first long duration flights are scheduled to occur in the future, something which is a necessity for those kinds of missions. Indeed I believe this research is certain to pave the way for the numerous private space companies and space faring nations who have set their sights beyond earth orbit.
