Mars Pathfinder lifted off from Cape Canaveral on December 4, 1996, carrying a novel airbag-cushioned landing system that let it bounce onto the Martian surface rather than use a costly rocket-powered descent. Its rover, Sojourner, became the first wheeled vehicle to operate on another planet, transmitting images and soil data that reinvigorated American planetary exploration after years of budget cuts.
Pathfinder was NASA's answer to critics who said interplanetary missions had become too expensive and too rare. Built under the agency's 'faster, better, cheaper' mandate, it cost a fraction of previous Mars missions and used a landing method that sounded almost absurd on paper: encase the spacecraft in giant airbags and let it crash-bounce across the Martian surface like a beach ball.
It worked. After a seven-month cruise, Pathfinder bounced to a stop in Ares Vallis on July 4, 1997, and released Sojourner, a rover roughly the size of a microwave oven, onto the rust-colored rocks. Sojourner crept along at a top speed of about half an inch per second, analyzing rock chemistry and beaming back panoramic images that captivated a public that had grown used to thinking of Mars missions as agency also-rans.
The mission's success reset expectations for what small, cheap spacecraft could accomplish and set the template for the rover missions—Spirit, Opportunity, Curiosity, Perseverance—that would follow over the next quarter-century, each one a lineal descendant of that first bouncing landing in the Martian desert.