Pathfinder with Sojourner

Mission Profile

Mars Pathfinder with Sojourner was a NASA Discovery-class mission launched on 4 December 1996 aboard a Delta II 7925, landing on Mars in Ares Vallis on 4 July 1997 using a novel airbag-cushioned landing system. The lander and its small Sojourner rover were the first operational Mars rovers ever deployed, with Sojourner conducting soil and rock chemistry measurements over 83 Martian days of surface operations. Pathfinder's innovative approach — using inflatable airbags for landing rather than retrorockets — dramatically reduced mission cost and was later adapted for the Mars Exploration Rover missions Spirit and Opportunity. The mission captured worldwide public attention and demonstrated that cost-effective Mars surface exploration was achievable within the then-new NASA Discovery program framework.