Mars Pathfinder

Spacecraft· NASAinactive

Mars Pathfinder — delivered Sojourner, the first rover on Mars, to Ares Vallis (1997) and pioneered airbag landing.

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Key facts

Distance from Sun

1.5 AU

Status

Completed

Launched

1996

Mission & specifications

Mission

Operator: NASA
Launched: December 4, 1996
Status: Completed

Trajectory

Distance from the Sun: 1.5 AU
Distance from Earth: 1.9 AU
Distance from Mars: 2,499,937 km

Mission

Mars Pathfinder pioneered a bold and inexpensive way to reach the Martian surface, and carried the first wheeled rover to another planet. Launched on 4 December 1996 as part of NASA's 'faster, better, cheaper' era, it dispensed with the expensive retro-rockets of the Viking landers. Instead, on 4 July 1997, it slammed into the atmosphere, deployed a parachute, and — cocooned in a cluster of giant airbags — bounced across the rocky floodplain of Ares Vallis more than a dozen times before rolling to a stop and deflating. Out rolled Sojourner, a microwave-oven-sized, six-wheeled rover weighing about 10 kilograms, which crept up to nearby rocks and analysed their chemistry with a spectrometer. The rocks, nicknamed 'Barnacle Bill' and 'Yogi', and the rounded pebbles around them, supported the idea that Ares Vallis had been carved by catastrophic ancient floods. The mission was also a public sensation: its images were among the first to draw huge crowds to the early World Wide Web. Pathfinder operated for nearly three months, far longer than planned, before contact was lost in late September 1997. It proved both the airbag landing and the rover concept that Spirit, Opportunity, Curiosity and Perseverance would inherit.

1996Launch toward MarsLaunch
A low-cost mission sets out to test airbag landing and a small rover.
1997Airbag landing in Ares VallisLanding
Bounces to a stop across an ancient floodplain cocooned in giant airbags.
1997Sojourner deployedDeployment
The first wheeled rover on Mars rolls onto the surface to examine nearby rocks.
1997Reading the flood rocksMilestone
Sojourner's spectrometer studies rocks like 'Yogi', supporting a history of catastrophic floods.
1997Last contactMission end
Falls silent after nearly three months — far beyond its planned week-to-month life.

Images

Color Mosaic of Rover & Terrain — NASA/JPL · NASA Image Library

Pathfinder Landing Site Observed by Mars Orbiter Camera - Big — NASA/JPL/MSSS · NASA Image Library

Marie — NASA/JPL/Caltech · NASA Image Library

Radiation Calibration Targets — NASA/JPL/University of Arizona · NASA Image Library

Rover Touchdown on Martian Surface — NASA/JPL · NASA Image Library

Rover, Airbags, & Surrounding Rocks — NASA/JPL/University of Arizona · NASA Image Library

Lander, Airbags, & Martian Terrain — NASA/JPL · NASA Image Library

Images from open archives · credit shown per image