Star Raiders and the Lost Expedition — M. Shaunessy

Two freelance adventurers Mike Tippin and Justin Jobbs, take an unusual mission from a beautiful Princess Tygla Tyger to rescue her brother from the evil humanoid, Lord Drax of the Xatu Empire. But the mission goes awry as Tygla's Brother, Xman, escapes the dreaded battle ship Hades and joins up with the adventurers. Now they must join forces to stop Drax from siphoning the ultimate power from the center of the galaxy.