Mariner 9: First Spacecraft to Orbit Mars

[Judi Lynn]

By Elizabeth Howell, Space.com Contributor | November 8, 2018 11:48am ET

Mariner 9 was the first orbital mission to Mars. After arriving at the Red Planet in November 1971, imagery from Mariner 9 transformed our perception of Mars from a cold, crater-filled planet to a world full of past geological activity and a planet that once had water.

Mariner 9's cameras were the first to capture the gamut of Martian geology. The spacecraft's imagery included pictures of Mars' polar caps, the vast Valles Marineris canyon and the Martian moons (Phobos and Deimos). Marine 9 also discovered evidence that water had flowed on the planet in the ancient past.

An extended operation
NASA had sent spacecraft to Mars several times before, but those missions were relatively brief flybys.

In the early days of planetary exploration, the agency's strategy was to launch pairs of spacecraft to Mars so that there would be a backup if one of the spacecraft failed.

More:
https://www.space.com/18439-mariner-9.html

[Victor_c3]

1. I still find it fascinating that we haven't ruled out that life could have formed on mars

Despite all of our studying and work, more questions seem to be raised than answered.