Amazon’s drone delivery program has finally taken off with the tech giant successfully delivering packages to customers in Lockeford, California, and College Station, Texas, on Christmas Eve.

Three months ago today, Amazon announced that customers in Lockeford, California, will be the first to see Prime Air drones delivering packages in their backyards. The company is currently awaiting a decision from the regulators on the possible environmental impact of its operations. But, in the meantime, here’s a lowdown on how Amazon plans to operate its commercial delivery drones in California.

As it prepares to bring free Prime Air drone deliveries to customers in California and Texas, Amazon is offering an inside look at how its drone delivery system works. A new video released by the company shows rigorous flight tests being conducted at one of its facilities in Oregon.