Free Astronomy Magazine March-April 2021

4 MARCH-APRIL 2021 MARS ROVERS I n the mid-1970s, NASA accom- plished the extraordinary feat of landing two science laboratories on Mars as part of the Viking 1 and Viking 2 missions. For the first time, two landers managed to land softly on the surface of the red planet, studying soil samples and transmit- ting data over an extended period. Five years earlier, a Soviet Union probe named Mars 3 had already managed to reach the surface un- Mars Rovers from Sojourner to Perseverance T wo spacecraft engineers stand with a group of vehicles providing a comparison of three generations of Mars rovers devel- oped at NASA's Jet Propulsion Laboratory, Pasadena, CA. The setting is JPL's Mars Yard testing area. Front and center is the flight spare for the first Mars rover, Sojourner, which landed on Mars in 1997 as part of the Mars Pathfinder Project. On the left is a Mars Exploration Rover Project test rover that is a working sibling to Spirit and Opportunity, which landed on Mars in 2004. On the right is a Mars Science Laboratory test rover the size of that project's Mars rover, Curiosity, which landed on Mars in August 2012. Sojourner and its flight spare, named Marie Curie, are 2 feet (65 centimeters) long. The Mars Exploration Rover Project's rover, including the "Surface System Test Bed" rover in this photo, are 5.2 feet (1.6 meters) long. The Mars Science Laboratory Project's Curiosity rover and "Vehicle System Test Bed" rover, on the right, are 10 feet (3 meters) long. [NASA/JPL] by Michele Ferrara ❖ Based upon NASA sources ❖ Revised by Damian G. Allis, NASA Solar System Ambassador