Galileo didn't have a single "helper" in the way we think of assistants today. He collaborated with many people throughout his life, including:

* His father, Vincenzo Galilei: He was a musician and supported Galileo's early scientific endeavors.

* His students: Galileo taught and mentored many students, some of whom became notable scientists in their own right.

* His colleagues: Galileo interacted and debated with other scholars and scientists of his time, including Kepler and Kepler and other astronomers.

* Artisans: He worked with artisans to build and refine his instruments, such as telescopes and compasses.

So, there isn't one specific name that stands out as Galileo's "helper." His accomplishments were the product of collaboration and influence from many individuals.