Space trade refers to all exchanges of goods and services related to space travel, exploration, and colonization, envisioned as crucial for the economic viability and self-sufficiency of future human settlements. Experts like Robert Zubrin suggest that a Martian colony could prosper from asteroid mining due to Mars's advantageous position relative to the asteroid belt, while Jim Plaxco proposes that Phobos and Deimos could become key interplanetary trading posts.

Future exchanges could involve valuable ores from the asteroid belt and high-tech production from Earth, with the energy efficiency of transportation being a critical economic factor. However, a major obstacle identified by John Hickman is the vast distances involved, which might limit trade primarily to intangible goods and complicate the enforcement of financial agreements. To facilitate such commerce, the development of high-capacity commercial spaceports, integrated with terrestrial transport networks, would be essential infrastructure.