The Light Years — R.W.W. Greene

A long-lost battleship and an arranged marriage may hold the key to faster-than-light travel -- and humanity's future -- in this thrilling science fiction debut.

Hisako Saski was born with her life already mapped out. In exchange for an education, better housing for her family, and a boost out of poverty, she's been contracted into an arranged marriage to Adem Sadiq, a maintenance engineer and amateur musician who works and lives aboard his family's sub-light freighter, the Hajj.

Hisako is not happy with the deal. The arcane branch of physics it requires her to study broke off a thousand years before, and she is not keen on the idea of giving up everything she knows to marry a stranger and move onto an aging spaceship. 

Onboard the Hajj, Hisako soon learns her dilemmas are overshadowed by the discovery of ancient secrets, a derelict warship, and a chance at giving the survivors of Earth a fresh start.