Mars Pathfinder & Sojourner Rover launched 1996

Sojourner on Mars

Mission patch

The Mars Pathfinder and Sojourner Truth Rover were launched on December 4, 1996 to Mars.  It reached the Red Planet July 4, 1997 and proceeded to exceed all expectations.  Anticipated to last only a week to a month,  Sojourner Truth lasted almost three months, sending its last communication on September 27.  Its on-board battery was designed to last a month, but probably failed due to repeated charging and discharging. 

It opened a new era into interplanetary rovers.  The Soviets had been sending  rovers to the moon but their attempts at Mars failed.  NASA's mantra of 'faster, better, cheaper' seemed to have paid off since the cost of the mission was less than $150M, which is one-fifteenth of the cost to send the Viking landers. 

The Mars Pathfinder sent back more than 2.3 billion bits of information, made 8.5 million measurements of the atmosphere and 16,500 pictures.

The Viking has landed (1976)!

Viking 1, the first of two spacecraft sent to Mars as NASA's Viking program, landed on Mars, July 20, 1976, on the 7th anniversary of the historic Apollo 11 moon landing.  Viking 1 touched down in the Chryse Planitia and transmitted its first picture within 25 seconds, taking 4 minutes to complete the transmission.  The Viking spacecraft were designed to search for life on the Red Planet, but did not find any evidence.

Viking 1 operated for about 6 years until a faulty command sent to the lander resulted in loss of the signal.  The Mars Reconaissance Orbiter took a picture of it in 2006.

Viking 1 launched 1975

First color photograph of the Martian surface

Viking 1, the first probe to the Martian surface, to land and complete its mission successfully was launched August 20, 1975.  It landed on July 20, 1976 on the western slope of Chryse Planitia (the Plains of Gold) and began transmitting about 25 seconds later.

It continued operating for about 6 years, the longest record until Opportunity broke the record on May 19, 2010.  Contact was lost when a faulty command was sent from ground control to upload battery charging software but it overwrote data used by the antennae pointing software on November 11, 1982.