The spacecraft-building firm SpaceX is working on plans for a network of micro-satellites that could deliver low-cost Internet service to people around the world, according to billionaire founder and tech whiz Elon Musk. Musk said in a tweet Monday that an announcement about the program is just a few months away.

"SpaceX is still in the early stages of developing advanced micro-satellites operating in large formations. Announcement in 2 to 3 months," tweeted Musk, who -- in addition to being SpaceX's CEO and CTO -- is co-founder, CEO and product architect of Tesla Motors.

In response to a Twitter comment that said, "I hope this is about free and unfettered Internet access for the masses," Musk added, "Unfettered certainly and at very low cost."

The Other 3 Billion

As reported last week in The Wall Street Journal, Musk is working on the project with former Google exec Greg Wyler. Wyler founded the communications services company O3b Networks in 2007, and briefly joined Google after it acquired O3b in 2013.

Wyler and O3b had Google's backing for a venture called WorldVu Satellites, which is based in the UK's Channel Islands. Earlier this year, WorldVu acquired the rights to a portion of the radio spectrum formerly held by a satellite-focused company called SkyBridge. In September, Wyler and other O3b employees left Google to lead WorldVu independently.

O3b stands for the "other 3 billion," meaning the number of people in the world who lack reliable access to the Internet.

According to The Wall Street Journal, the project being pursued by Musk and Wyler calls for a network of some 700 small (less than 250 pounds) satellites that would circle the Earth in low orbits. That is about half the weight of existing communications satellites.

Drones and Loons

Several leading tech firms are exploring ambitious programs to deliver Internet service to a global population. In addition to the satellite-based project it pursued with Wyler, Google has also floated the idea of balloon-based Internet service. (The proposal has been dubbed "Project Loon" for its far-out nature.)

Facebook, meanwhile, is looking into the possibility of providing Internet service to under-served regions via unmanned aerial vehicles, also known as UAVs or drones.

Using micro-satellites to create a sky-based network for Internet connectivity faces a number of obstacles, including technical and financial hurdles. According to The Wall Street Journal, Musk's proposal could "cost $1 billion or more to develop." The scope of the proposed network is also 10 times as large as the largest existing network of communications satellites, a low-Earth-orbiting, 66-satellite fleet currently operated by Virginia-based Iridium Communications.