Mariner 8 and 9 were virtually identical and designed to continue the atmospheric studies begun by Mariner 6 and 7, and to hopefully map over 70% of the Martian surface.
The Apollo 17 mission was the most productive and trouble-free piloted mission to the moon and represented the culmination of continual advancements in hardware, procedures, training, planning, operations, and scientific experiments.
At 4:56 Houston time, Gene rested the tip of his left index finger on the yellow ignition button.
“As we leave the Moon and Taurus-Littrow, we leave as we came, and God willing, as we shall return, with peace and hope for all mankind. Godspeed the crew of Apollo Seventeen.” – Gene Cernan’s final words from the surface of the Moon.