Mars Pathfinder
NASA/JPL · NASA Jet Propulsion Laboratory
Mass
10.6 kgas of [1]Landed
July 4, 1997Landing Site
Ares Vallis, Chryse PlanitiaOperational
83 sols (designed for 7 sols)as of [1]Last contact September 27, 1997 — nearly 12× design lifetimeLaunch
December 4, 1996
Landing
July 4, 1997
Ares Vallis, Chryse Planitia
Mission End
September 27, 1997
83 sols (designed for 7 sols)
| Agency | NASA/JPL |
| Operator | NASA Jet Propulsion Laboratory |
| Vehicle Type | Rover |
| Power System | Solar panels + non-rechargeable lithium thionyl chloride batteries |
| Primary Contractor | NASA Jet Propulsion Laboratory |
| Instruments | 3 science instruments (APXS ×2, ASI/MET) + 3 camerasas of [1]Alpha Proton X-ray Spectrometer (fore/aft), Atmospheric Structure Instrument/Meteorology Package |
| Landing Site | Ares Vallis, Chryse Planitia19.13°N 33.22°W |
| Distance Traveled | 0.1 km (100 metres)as of [1]Traveled ~100 m over 83 sols; contact lost when lander base station batteries depleted |
First Mars rover in history. Deployed by the Mars Pathfinder lander on July 4, 1997, Sojourner operated 83 sols — nearly 12× its 7-sol design lifetime. Its APXS instrument analyzed 16 rocks and soil patches, including 'Barnacle Bill' and 'Yogi', revealing andesite-like compositions suggesting a more geochemically differentiated volcanic history than expected. The mission proved roving exploration on Mars was feasible.
See how Sojourner stacks up side-by-side against other Mars surface vehicles.