Drones have been hailed as the most important technological development in aviation since the invention of the jet engine. They have changed the nature of modern warfare and they are also catalysing developments in fields as diverse as law enforcement, film production, disaster management, news gathering and agriculture. The availability and prevalence of drones in everyday life is increasing and creating enormous challenges in the fields of ethics, law and regulation – not least managing the flight paths of a potentially enormous number of small planes. Bridget Kendall explores the history, present and future of drones. She is joined by Marke "Hoot" Gibson, the Federal Aviation Administration’s senior adviser on Unmanned Aerial Systems Integration; Sarah Kreps, associate professor of Government at Cornell University in the US; Michael Nautu who designs and builds drones for purposes ranging from agriculture and aerial mapping to “next-generation conservation” in Namibia. (Photo: A drone flying above the New York City skyline. Credit: Getty Images)