Atlanta-based UPS is one step closer to using drones to deliver packages to its customers.

Using such a van is key, because drones require a significant amount of battery power, so they can only stay in the air for a limited amount of time. Most drones can operate between 20 and 30 minutes.

According to UPS, the drone docks on the roof of the delivery truck. A cage suspended beneath the drone extends through a hatch into the truck. A UPS driver inside loads a package into the cage and presses a button on a touch screen, sending the drone on a preset autonomous route to an address. The battery-powered drone recharges while it's docked. It has a 30-minute flight time and can carry a package weighing up to 10 pounds.

The world's largest package delivery company used a drone to drop off a package at a home in the Tampa, Florida, suburb of Lithia.

UPS has tested drone deliveries in the past, but this week's test was notable because it launched the drone from the top of a UPS electric van outfitted with a recharging station for the battery-powered drone.

"This test is different than anything we've done with drones so far," said Mark Wallace, UPS senior vice president of global engineering and sustainability, said in a statement. "It has implications for future deliveries, especially in rural locations where our package cars often have to travel miles to make a single delivery."

He added, "Imagine a triangular delivery route where the stops are miles apart by road. Sending a drone from a package car to make just one of those deliveries can reduce costly miles driven. This is a big step toward bolstering efficiency in our network and reducing our emissions at the same time."