A Simple Solar Rover

Build your own planetary explorer.
Dan Bracaglia

Don’t let NASA monopolize robotic exploration of the solar system. Using a couple of gear motors, solar panels, and leftover LEGOs, you can build a sunshine-powered robot that ambles around a strange landscape: your backyard. Obstacles such as rocks and curious children can’t be avoided, since there’s no software or sensors to control the steering, but this project is a fun introduction to solar-powered electronics.


  • Two gear motors
  • Two solar panels
  • Assorted LEGO pieces
  • Cyanoacrylate glue
  • Hookup wire


  • Soldering iron
  • Wire cutter


  1. Use the LEGOs to build a rover frame to support the gear motors, solar panels, and four wheels. (Note: Wheels 2 inches or more in diameter are best for traversing a yard.)
  2. Glue your rover chassis together, but not the wheels—they need to move!
  3. Attach a wheel to each gear motor. You may need to glue the inner axis to the drum of the motor.
  4. Mount the gear motors, one to a side, on the rear of the chassis using hookup wire. Loop wire around each motor, and carefully twist the ends together to secure everything to the rover’s chassis.
  5. Join the solar panels together at their edges with glue, or tie them together with a rubber band.
  6. Solder one solar panel to the right-rear gear motor. Solder the second solar panel to the left gear motor with the polarity reversed—wire the positive solar panel to the black motor wire, and the negative solar panel to the red motor wire.
  7. Release the rover into the wild. In bright sunlight, your bot should scoot along at about 2 feet per minute.

Source info and URLs:

Approximate time to build this project: 3 hours

Cost: About $50

Difficulty: 2/5

This article originally appeared in the June 2014 issue of Popular Science_._