Alan Barney 
New Nauru [EPUB ebook] 

This sequel to the author“s Gliese 4 depicts mankind“s first exploration of an extra-solar planet, the fourth one orbiting Gliese 876, and its surprising ecology. The novel also follows the efforts of the stranded human colony to confront its own mental and physical problems, and to repair its crippled ship for a return to Earth. Then hostile representatives of an alien master race arrive!