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.
Looking at the ingredients labels on food can be both an insightful and frightening affair. I’ve long been in a habit of doing it and I always find it fun to research some of the more esoteric ingredients, well that is right up until I find out where some of them come from. It’s the old adage of not finding out how the sausage is made, although in reality you should probably consider that with all things that you put in your body. Still when I watched the following video I was honestly surprised to see the outcome, as I didn’t think the effect of extracting iron from cereal would be so dramatic:
The first half of the video explores the idea that there’s elemental iron within cereal which can then be attracted by a magnet. Whilst this is true to some degree, the iron within the cereal will feel an attraction to a magnet, you can actually perform the exact same experiment with cereal that is bereft of any elemental iron content. This is because water is a diamagnetic material which is a fancy way of saying that in response to a magnetic field it will create its own inverse field in response. For the cereal and magnet experiment this means the water actually divots around the magnetic field which the piece of cereal then falls into. The iron in the cereal helps this process along of course, but it’s not the only force at play here.
However the extraction of the iron from the cereal was pretty astonishing, especially considering just how simple it was to do. Trying to extract other elements from the cereal would prove a much harder endeavour which is why I think an experiment like this is such a powerful visual aid. You’re literally seeing the iron being pulled from the food you eat which, in turn, makes you think about all the other things that are listed on the ingredients label. It might not be a particularly pretty picture that you end up with, but at least you’ll be far more aware.
I wish I knew about these kinds of science experiments when I was a kid!