Definition of "pathfinder"

The cow is the true pathfinder and pathmaker.

1910, John Burroughs, “Phases of Farm Life”, in In the Catskills, page 67

Pathfinders are trained to improve the viability of potential planets, initiate first contact with unknown species, find suitable outpost sites, and handle any external threats before the first colonist touches soil. The presence of a Pathfinder is a reassurance that a planet can be settled safely and with a high expectation of success.

2017, BioWare, Mass Effect: Andromeda (Science Fiction), Redwood City: Electronic Arts, PC, scene: Role of a Pathfinder Codex entry