Treasure of Gor — John Norman

A brilliant woman's dangerous discovery on Earth leads to her enslavement on the planet Gor in this long-running sci-fi fantasy series.

In a remote corner of the American southwest, there is a small, private observatory. To most of the staff, it is just another stargazing facility. But a select few know its true function as a liaison point between two alien worlds: the decimated planet of the warlike Kurii, and the planet Gor, which the Kurii now covet. 
When the young scientist Agnes Morrison Atherton comes across an unintelligible file containing mysterious coordinates, she decides to decode them -- and discovers two large, spherical, seemingly artificial objects in the asteroid belt. But it seems that Atherton's remarkable discovery is less than welcome. Abducted and drugged, she awakens to find herself on the planet Gor -- being sold as a Gorean slave girl.