Michael McCollum 
Antares Passage [EPUB ebook] 

After more than a century of isolation, the paths between stars are again open and the people of Alta in contact with their sister colony on Sandar. And yet, the opening of the foldlines has not been the pure blessing the Altans had supposed.The reestablishment of interstellar travel has brought with it news of the encroaching Ryall, an alien race whose goal is the extermination of humanity. If they are to avoid defeat at the hands of the alien forces, Alta must seek out the military might of Earth. The only suitable path, however, requires a journey into the heart of a supernova…