When you think of billionaire entrepreneur Elon Musk, chances are good that you think of his electric car company Tesla or his space-exploration venture SpaceX (to say nothing of his history of stirring up controversy on social media, or smoking weed with Joe Rogan). Maybe you just know him as the second-richest person on Earth (Jeff Bezos retook the top spot earlier this year). 

Before long, though, something else might come to mind when you think of Musk: a venture called Starlink that seeks to sell internet connections to almost anyone on the planet by way of a growing network of private satellites orbiting overhead.

After years of development within SpaceX -- and after securing nearly $885.5 million in grant funds from the Federal Communications Commission at the end of 2020 -- Starlink's progress seems to be accelerating in 2021. In January, after about three years' worth of successful launches, the project surpassed 1,000 satellites delivered into orbit. Earlier in February, Musk's company disclosed that Starlink now serves more than 10,000 customers. Now, the service is in the process of expanding preorders to even more potential customers, with people currently living without access to high-speed internet as one of the top priorities.

All of that makes Starlink well worth keeping an eye on in 2021. For now, here's everything you should know about it.