Pathfinder Plus solar plane has an increased wingspan of 121 feet. Fitted with newer high efficiency solar cells and other improvements, the Pathfinder Plus achieved its set goal by flying a record 80,201 feet.

Two underwing pods contain the landing gear, batteries, instrumentation system, and flight control computer. By the time the aircraft was adopted into the ERAST project in late 1993, solar cells were being added, eventually covering the entire upper surface of the wing. The solar arrays provide power for the aircraft's electric motors, avionics, communications and other electronic systems. Pathfinder also had a backup battery system that can provide power for between two and five hours to allow limited-duration flight after dark. Pathfinder flies at an airspeed of only 15 miles per hour (24 km/h) to 25 miles per hour (40 km/h).