What is the name of the probe which fell into the Atlantic ocean after nasa attempted to send it to mars?

Mariner 8, also known as Mariner-H, was launched May 8, 1971 aboard an Atlas-Centaur SLV-3C booster (AC-24). It failed at an altitude of approximately 148km, 4.7 minutes mission time, when its upper stage booster pitch began to oscillate and eventually caused a complete failure of the vehicle. The spacecraft and Centaur engine (which shut down automatically) were separated and fell through the Earth's atmosphere, splashing down in the Atlantic approximately 1500km downrange of the launch center, and about 560km north of Puerto Rico.