This image taken on the morning of Sol 80 (September 23, 1997) shows the Sojourner rover with its Alpha Proton X-ray Spectrometer (APXS) deployed against the rock "Chimp." On the left horizon is the rim of "Big Crater," 2.2 km away. Sojourner spent 83 days of a planned seven-day mission exploring the Martian terrain, acquiring images, and taking chemical, atmospheric and other measurements. The final data transmission received from Pathfinder was at 10:23 UTC on September 27, 1997. Although mission managers tried to restore full communications during the following five months, the successful mission was terminated on March 10, 1998. http://photojournal.jpl.nasa.gov/catalog/PIA01585