Red Planet Run

From the back cover of the Ace first edition: "Catch a moving star - Even though business is booming, Star Svensdotter is ready to leave her "prefab world" business behind. She's weary of mourning her dead husband, weary of her well-meaning family, and weary of feeling weary. It's time for a change. So Star accepts a commission to explore Mars - and gets far more than she bargained for. Space pirates are on a raiding spree, taking everything they can. And a mysterious obelisk has been discovered... which may finally explain why no mission to the Red Planet has ever been heard from again..."