- 05.09.71: Launch
- 05.09.71: End of Mars Mission
- Status: Reentered Earth's atmosphere approximately 1,500 kilometers downrange from the launch site.
- imaging system
- ultraviolet spectrometer
- infrared spectrometer
- infrared radiometer
- S-band occultation experiment
- celestial mechanics experiment
Mariner 8 was launched on an Atlas-Centaur SLV-3C booster (AC-24). Launch of Mariner-71H was nominal until just after separation of the Centaur upper stage. The main Centaur engine was ignited 265 seconds after launch, but the upper stage began to oscillate in pitch and tumbled out of control. The Centaur stage shut down 365 seconds after launch due to starvation caused by the tumbling. The Centaur and spacecraft payload separated and re-entered the Earth's atmosphere approximately 1500 km downrange and fell into the Atlantic Ocean about 560 km north of Puerto Rico.


