Titania foam

West Virginia University are talking about 3D-printing in microgravity. The base-product is titanium-dioxide foam, which they call titania.

This foam blocks ultraviolet at 0.2 millimeters, about the width of a thin coat of paint. That makes it useful for shields around structures as are also in microgravity, namely the stations we currently got in LEO. It might also be photocatalytic.

And it might be cheap, in LEO. Much of our space junk is titanium. Maybe we could just sweep up some rubbish and use that to make the foam.

The researchers used a Vomit Comet in freefall so only had 20 seconds at a time to print this stuff. The next step would be to try this longer-term in LEO proper. If we're ever allowed to do this.