Internet for the billions of underserved around the globe continues to get closer to reality. The latest is Facebook’s plan to trial a version of its solar-powered drones this summer.

The Aquila drones will have the wingspan of a Boeing 737, but will only weigh as much as a small car. And they will beam Internet across the land, at a fraction of the cost of building cell towers and trenching backhaul.

How to connect people in economically sensitive rural and emerging markets has been an ongoing topic of conversation in both world economic and tech circles. The problem of course is the fact that building out a brand-new broadband communications infrastructure using traditional mobile or terrestrial technology is expensive; and the markets that it would be serving can typically only support pricing that is orders of magnitude lower than what would be necessary to recoup the expense in a reasonable amount of time. That is, data plans would likely need to be between $1 and $10 per month to see any uptake, especially in places like Africa and India.

So, absent substantial public-private partnerships, regular builds don’t make a lot of sense. Yet, broadband is a proven economic engine, and

could kickstart a new era for currently under-connected communities—which total some 4 billion people around the globe according to the ITU.

So, innovation has come to the fore. There are plenty of companies eyeing new satellite technology, for instance. And, Google is trialing white space approaches in Africa, which would leverage low-cost Wi-Fi and unlicensed spectrum. It also has Project Loon, which uses hot-air balloons on the edge of space that would blanket the earth with broadband and hook into existing cellular networks.

For Facebook, it’s all about the drones.

The Wall Street Journal reported that earlier this month, Facebook tested a prototype drone, about one-tenth the size of the planned 737-sized models. Key considerations going forward will be basic safety, security, technological readiness and business modeling.

“We are working towards a real test flight this summer sometime,” vice president of engineering Jay Parikh told the WSJ. “Depending on how this test flight goes, we’ll see what happens. This is a big plane, this is a big project and it’s never been done before.”

One of the biggest challenges is the solar and battery technology. What the company was using even a year ago when the project was hatched “wasn’t good enough for what we’re trying to do with this plane,” he said.

The initiative is part of Facebook’s larger Internet.org strategy, which has already, via carrier partnerships, connected seven million people in seven countries with basic Internet services. In February for instance Facebook and Reliance Communications announced the launch of the Internet.org app and free basic services in India. Reliance customers in six states (Tamil Nadu, Mahararashtra, Andhra Pradesh, Gujarat, Kerala, and Telangana) now have access to more than three dozen free services ranging from news, maternal health, travel, local jobs, sports, communication and local government information.