The first rover to roll on Mars 🥐⁣ ⁣ NASA’s Mars Pathfinder launched Dec. 4, 1996 and landed on Mars’ Ares Vallis on July 4, 1997. The spacecraft successfully delivered an instrumented lander and the Sojourner rover — the first-ever robotic rover to land and operate on the Martian surface. Pathfinder also returned a then-unprecedented amount of data and outlived its primary design life.⁣ ⁣ Pathfinder used an innovative method of directly entering the Martian atmosphere, assisted by a parachute to slow its descent through the thin Martian atmosphere and a giant system of airbags to cushion the impact. It was the first time this airbag technique had been used. At a speed of 31 mph (14 meters per second) and measuring 19 feet (5.8 meters) in diameter, Pathfinder bounced like a giant beach ball about 15 times, as high as 50 feet (15 meters), before coming to rest 2-1/2 minutes later about six-tenths of a mile (1 kilometer) from the point of initial impact.⁣ ⁣ Image description: The Sojour...