A Defense Advanced Research Projects Agency (DARPA) contest to develop a small spy drone capable of performing a series of maneuvers, including landing briefly to capture surveillance video, has concluded without a winner. DARPA says the $100,000 prize will not be awarded.

DARPA launched the competition to create a portable unmanned aerial vehicle (UAV) for intelligence gathering a year ago. The goal was to develop a "military-relevant, backpack-portable UAV" capable of vertical take-off, flying out of sight, landing, capturing video, and returning. More than 140 teams entered the contest, called UAVForge, but none of them successfully completed the required maneuvers.

"While some teams were able to reach the observation area, none were able to land on a structure and complete the mission," DARPA said in a statement announcing the results.

DARPA established a website, UAVForge.net, to encourage and support crowd-sourcing of ideas during the competition. The entries were narrowed to nine teams of finalists, which participated in a "fly off" at Fort Stewart in Georgia. The course required the UAV to fly below 1,000 feet, maneuver around obstacles, land on or hover above a physical structure, and visually track moving objects in real time...