The Orion Project (Book 13 of the Vadelah Chronicles)

The fragile truce is about to be broken …
A powerful tyrant seizes control of the SIRIUS Project, determined to crush David Decker’s allies into submission. Can David’s friends resist? At what cost? Soon David finds himself facing another dilemma: humans using trelemar invade a planet inhabited by the yerome. In response, David and his allies create a project of their own: The ORION Project.