Shortly after the failed launch of Mariner 8 to Mars (which shattered into pieces due to a rocket problem), NASA successfully launched Mariner 9 toward the Red Planet. On the same days, the Soviets launched Mars 2 and 3. Both the Americans and Russians often launched probes in pairs, aware of the unreliability of their own rockets. Unfortunately, the signal from Mars 2 was lost shortly after the start of its descent toward the planet. Mars 3, however, arrived on the planet, and the Soviet rover began transmitting the first photo, but after just 15 seconds the signal was cut off forever. Mariner 9, however, functioned properly and sent the first clear images of the enormous Valles Marineris, the largest canyon in the Solar System, which was named in honor of Mariner 9. It also photographed for the first time the tallest and largest volcano in the Solar System: Olympus Mons (22 km above the surrounding plains).
