Mars is cold and practically airless. Even if we discover a way to add atmosphere, with no protective magnetic field, gases will be stripped away as we watch. And cosmic and solar radiation will continue to fry the surface.
Sometimes, actual science beats science fiction. Researchers have now come up with an even better way that we might be able to make Mars habitable… Once the generator landed on Phobos, it would subject surface material to extreme heat until it morphed into a gaseous state or at least vaporized. An electrical current would then be zapped through that gas or vapor to ionize it… With every orbit around Mars, the ring would be reinforced with more plasma until it built up a powerful enough current that would be similar to the magnetic field which surrounds Earth. SyFy
Fusion reactors would be needed to generate enough power, but fusion is only 20 years away, isn’t it? (Hasn’t it been 20 years away for generations? Well, bound to be true someday.)
In my science fiction series, the colony ultimately arrives at a terraformed Mars in a very different way. Check out the final book in the series to find out how.
Don’t worry about starting at the end. Each book covers a different generation with a different hero , each on their own journey through danger on the deadly Red Planet. Or, do yourself a favor and buy all five stories in a value-priced box set.