The first spacecraft to successfully reach Mars was Mariner 4, launched on November 28, 1964, by NASA.

While it wasn't a rocket itself, it was launched on top of an Atlas-Agena D rocket.

It's important to note that while Mariner 4 was the first to reach Mars, it didn't land on the planet. It performed a flyby, capturing the first close-up images of the Martian surface.