Humans have spread beyond the confines of Earth, colonizing and mining various planets. Ships nearly able to achieve faster-than-light travel with engines powered by nuclear fission go between the mines of the planetoid nicknamed Solitude and Ascendant Station in orbit around Saturn. The material sought after most is the highly unstable mineral UE-31. Scientists have been working for nearly seventy years on the best way to transport UE-31 and, with any luck, how to synthesize it with mixed results; scientists have died, ships of scientists have gone missing, and none of the artificial versions of UE-31 have proven to be comparable in energy output versus mass.
Those people with the highest levels of influence hope to solve the mystery of UE-31, hoping that one of the missing scientist ships has solved the mystery; hence a lot of laws and backroom deals have been made to ensure that any lost ship is found and recovered.