Falling for Sky by Laurann Dohner

Mick knew signing up to run a solo mining operation would be boring, but a ten-year stint will earn her enough credits to retire. She’s got her robot companion to keep her company, and she even makes a friend via communications who she gets to talk to every few months when Sky is flying within range. Once her years are up, she fantasizes about confessing her true identity as a woman and maybe he’ll be interested in more than friendship. Until then, she must follow protocol by keeping her voice synthesizer on, pretending to be a man.
As the cyborg expert on all things human, Sky’s job includes chatting with Earthers, gleaning any intel that might lead to the deadly Markus Models—androids who are bent on ending all life. He particularly enjoys talking to Mick, a friendly Earther stationed on a mining planet. But Sky gets the shock of his life the next time he hails him and discovers not only is his friend under attack by pirates, but “he” is actually a “she.” Mick is short for Mickayla—and she’s captivating.
Sky’s always wanted an Earther woman for his own, someone he’ll never have to share with another cyborg, and Mick is his for the taking. All he has to do is disobey direct orders, abandon his current mission, and rescue Mick, all before his council can punish him for his misdeeds.
Piece of cake, as the humans would say.