Part 1 of a series highlighting the history of solar/electric flight…
Aircraft Specifications

Wingspan: Solar Challenger, 46.5 feet (14.8 meters); Pathfinder, 98.4 feet (29.5 meters); Pathfinder-Plus, 121 feet (36.3 meters) Centurion, 206 feet (61.8 meters)
Length: Solar Challenger, 30.3 feet (9.22 meters); Pathfinder, Pathfinder-Plus, and Centurion, 12 feet (3.6 meters)
Wing chord: Solar Challenger, 5.8 feet (1.78 meters); Pathfinder, Pathfinder-Plus, and Centurion, 8 feet (2.4 meters)
Gross weight: Solar Challenger, about 336 pounds (152.8 kg); Pathfinder, about 560 pounds (252 kg.); Pathfinder-Plus, about 700 pounds (315 kg.) Centurion, varies depending on power availability and mission profile; approximately 1,900 pounds for a mission to 80,000 feet altitude.
Payload: Solar Challenger, weight of pilot, up to 150 pounds Pathfinder, up to 100 pounds (45 kg.); Pathfinder-Plus, up to 150 pounds (67.5 kg.) Centurion, varies depending on altitude; about 100 pounds. to 100,000 ft., 600 pounds. to 80,000 feet.
Airspeed: Solar Challenger, approx. 25-34 mph cruise Pathfinder, Pathfinder -Plus. approx. 17-20 mph cruise Centurion, approx. 17-21 mph cruise
Power: Arrays of solar cells, max. output: Solar Challenger, 2,700 Watts Pathfinder, about 7,500 Watts; Pathfinder-Plus, about 12,500 Watts Centurion, 31,000 Watts
Motors: Solar Challenger, one electric motor, 2.7 kW Pathfinder, six electric motors, 1.25 kW each Pathfinder-Plus, eight electric motors, 1.5 kW maximum each Centurion, 14 electric motors, 2.2 kW each
Manufacturer: AeroVironment, Inc.
Primary materials: Composites, plastic, foam.

Pic 1.0: Pathfinder NASA Photo
Flying Free
It’s been a long road, or flight, rather, from Kitty Hawk, USA 1903 to the fields of dreams that launch today’s amazing aeronautical achievements. Air flight has changed world culture and how we interact with each other and the planet. We are on the verge of another historical convergence of design, technology and determination that could have dramatic and long term effects on how we live and see our world: Electric Flight.
What’s so promising about electric flight? Electric flight and the alternative energy sources available to power it make perpetual flight possible. Imagine the uses of airborne platforms capable of sustaining flight indefinitely. Thanks to the long term public and private investments into both electric flight and alternative energy sources we are now seeing a dramatic convergence of technologies extending the possibilities of perpetual flight.
Whether powered by solar, fuel-cell or some other process, a perpetual-flight airborne platform has many uses. Flying under its own power, a solar airplane could replace satellites which are costly to launch and almost impossible to repair or retrieve. Low-cost, long-term flight aids in commercial mapping, surveillance, weather-monitoring even agricultural management.