The Genesis Fleet - Vanguard

Earth is no longer the centre of the universe. After the invention of the faster-than-light jump drive, humanity is rapidly establishing new colonies. But the vast distances of space also mean that the old order of protection offered by Earth has ceased to exist. When the colony of Glenlyon is attacked, its up to Robert Geary, a young former junior fleet officer, and Mele Darcy, a former enlisted Marine, to face down warships and armored soldiers — or die trying.