sentences:  The lander operated for 2245 sols (about 2306 Earth days or 6 years) until November 11, 1982, (sol ), when a faulty command sent by ground control resulted in loss of contact.The command was intended to uplink new battery charging software to improve the lander's deteriorating battery capacity, but it inadvertently overwrote data used by the antenna pointing software.Attempts to contact the lander during the next four months, based on the presumed antenna position, were unsuccessful.