Lego Page Site Index

Mars Pathfinder Sojourner Microrover

The 1997 Pathfinder Mission to Mars featured a small, six-wheeled robot that drove around the Martain surface and sent back lots of data. More information about the rover and the mission can be found via the links at the bottom of this page.

These are some models I made of the microrover.

A tiny model of the Sojourner:

My first prototype is shown here navigating an obstacle course. The goal of this model was to investigate the rocker-bogie suspension.

Note that each set of wheels has two pivot points. The main beam pivots between the rear wheel and the front two wheels. The front wheel assembly can pivot between the front and middle wheels.

The rod that goes across the front top of the vehicle is called the rocker. That black box in the center of the rocker can pivot from side to side because it's mounted on a turntable. So, as the side wheel assembly rocks up and down, a rod transfers the motion to the bogie, which swivels to transfer the opposite motion to the wheel assembly on the other side.

Here's the final model, shown on simulated Martain terrain (blanket).

Lego pieces aren't quite as strong and stable as the metals used in real robots, so I had problems with the legs splaying outward. That's why so many extra beams and bricks are added.

drew at thinkythings dot org
Last updated: 29-JUL-2015
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 2.5 License.