Last December, Amazon.com Inc. created a buzz by releasing a video of a drone delivering a package to a customer's home. If Amazon launches its Prime Air service as planned in 2015, we could soon see unmanned aircraft whizzing through the skies to deliver purchases in as little as half an hour.

Not wanting to be left behind, Google Inc. bought a drone maker in April and released its own delivery video late last month.

Interest in drone technology is rising fast, raising the possibility that miniature copters will be a common sight in the near future, carrying out such tasks as delivery, surveillance or inspection of hard-to-access infrastructure.