Re: In 250 years, how big and powerful a magnetic field will we be able to build? n/t
I was thinking along less grandiose terms: not the whole planet, just the parts you want to protect.
If you wanted to protect the whole planet, maybe you could fly the thing in a sol-centric orbit inside of, but parallel to Mars' orbit (protecting only from Sol's radiation). Of course the orbit would have to be constantly corrected, to keep it from passing Mars. Maybe the caught radiation can be harvested (certainly the electron portion) to produce usable energy that could be converted to an orbital moment.