Darkship Renegades — Sarah A. Hoyt

After rescuing her star pilot husband and discovering the dark secret of her own past on Earth, Athena Hera Sinistra returns to space habitat Eden to start life anew. Not happening. Thena and Kit are placed under arrest for the crime of coming back alive. The only escape from a death sentence: return to Earth and bring back the lost secret to creating the Powertrees, the energy source of both Eden and Earth whose technological secrets have been lost to war. But that mission is secondary to a greater imperative. Above all else, Thena must "not" get caught. If she does, then suicide is to be the only option.

With the odds heavily stacked against not only success, but survival, Thena comes to understand what her cynical accusers do not: it is not merely one woman's life on the line anymore. For it's on Earth where the adventure truly begins, and a secret is discovered that must be revealed and exploited, else humanity's days are most certainly numbered. Thena realizes that what is truly at stake is the fate of Eden and Earth alike, the continuance of the darkship fleet-and freedom for all in the Solar system-and beyond.