This week’s image is a scan of a photograph I took at JPL back in 1989, it’s a small model of the Mariner 9 spacecraft:
The 1971 Mariner Mars mission was originally supposed to consist of two complimentary spacecraft — but Mariner 8 was lost in a launch accident, leaving Mariner 9 to soldier on alone. Still, it became the first spacecraft to orbit another planet (narrowly beating the Soviet Mars 2 and 3 spacecraft), and over the next year would return images covering 100% of the Martian surface.
Mariner 9 also proved the superiority of orbiting spacecraft to flyby missions — when it arrived at Mars, a planet-wide dust storm completely obscured the surface. It was only after months of delay that the atmosphere again became clear enough to allow for photography of surface features.