The challenges to even get close seem insurmountable. At that speed, microscopic grains of dust hit like bullets. It's not like the nearest is much of a prize -

The challenges to even get close seem insurmountable. At that speed, microscopic grains of dust hit like bullets. It's not like the nearest is much of a prize - we know that the Centauri system is likely inhospitable and that Tau Ceti has an enormous debris field.