The only problem is that there is no known way to pick a successful trip. This is the first book of The Heechee Saga . It is both a Hugo and Nebula Award winner. It is a science fiction story that takes place sometime in the future. Earth is a mess and the best place to live is under the domes.
People also live on Venus in the tunnels.
One way to make enough money to get full medical coverage and to live in the domes is to travel to the last frontier and become a prospector. Gateway was discovered some time ago and a corporation runs it now. On Gateway, multiple HeeChee ships were found, in the hundreds, of three different sizes. Each trip is a crapshoot. The main problem is that each ship is very small and there is only room enough for one year of food.