an eight-month voyage to Mars, Mariner 4 makes the first flyby of
the red planet, becoming the first spacecraft to take close-up photographs
of another planet. The images show lunar-type impact craters, some
of them touched with frost in the chill Martian evening. A television
camera onboard takes 22 pictures, covering about 1% of the planet.
Initially stored on a 4-track tape recorder, these pictures take four
days to transmit back to Earth.
Although originally not expected to survive much past the Mars flyby
encounter, Mariner 4 lasts about three years in solar orbit, continuing
long-term studies of the solar wind environment and making coordinated
measurements with Mariner 5, a sister ship launched to Venus in 1967.