NY: Ballantine Books, 1984.
This is the third volume in what turned out to be a four-decker featuring the now-aging Robin Broadhead, who, decades ago, turned a lucky strike as a prospector of alien artifacts into an immense fortune, with which he has been trying ever since to save the world from itself. When they vanished a few hundred thousand years ago, the Heechee left a lot of interesting stuff lying around the galaxy (deliberately, it turns out), and some of it may help our world solve its starvation and poverty problems.