In 1975, NASA launched two spacecraft called Viking 1 and Viking 2. The spacecraft reached Mars nearly one year later. Find out more in Missions to Mars, one of the titles in the Space Exploration series
Read More
In 1975, NASA launched two spacecraft called Viking 1 and Viking 2. The spacecraft reached Mars nearly one year later. Find out more in Missions to Mars, one of the titles in the Space Exploration series
Read Less
