Jacob (Richard) Matijevic, also known as "Jake" Matijevic, was an American NASA engineer of Croatian origin who worked on Mars Exploration Rovers. Dr. Matijevic was involved in developing the "Sojourner", "Spirit", "Opportunity" and "Curiosity" rovers. For his contributions to the rover projects, NASA named several landmarks on the planet Mars after him.

Sojourner is a robotic Mars rover that landed in the Ares Vallis channel in the Chryse Planitia region of the Oxia Palus quadrangle on July 4, 1997. Sojourner was operational on Mars for 92 sols. It was the first wheeled vehicle to rove on a planet other than Earth and formed part of the Mars Pathfinder mission.