There are ideas for slowing them down and even returning them back to Earth, at least in principle: http://www.centauri-dreams.org/?p=31913 http://www.centauri

There are ideas for slowing them down and even returning them back to Earth, at least in principle: http://www.centauri-dreams.org/?p=31913 http://www.centauri-dreams.org/?p=31913 Nothing that could be implemented in any foreseeable future though.