Rocketship X-15

Does ANYONE remember a movie probably in the 50's with this title??! I saw it as a kid, and it stayed in my mind all these years: the exploratory rocketship was sent out presumably to Mars and returned with "spores" that then began covering e.g., airplanes etc. and made a sound as it grew exponentially in the oxygen rich atmosphere of Earth that was remarkably like the sound of a human heart.... ...

Arlene