Some have been successful. More have not. USSR Mars shots, both failed due to booster malfunction. USSR Mars shot, exploded in Earth orbit. USSR launches Mars probe which later falls out of Earth orbit, burns in Earth's atmosphere.
Spacecraft trapped within protective shroud, solar panels recieve no sunlight.
Craft orbits sun, powerless. First successful Mars flyby. Craft suffers communications failure. U.S. launch of Mariner 7 . Successful flyby of Mars.