Cover illustration by John Picacio for Gateway, Frederik Pohl, 1977
Seeded among the stars are troves of valuable artifacts left behind by the enigmatic, long-vanished alien race called the Heechee. For the right price, anyone can climb aboard one of the abandoned Heechee spaceships, cast off on an autopilot voyage to parts unknown, and take a chance on finding wealth…or facing death.” Robinette Broadhead took that chance and walked away a winner. But at what cost?
summary from here