We've recently written about a fantastic aid program in Rwanda where drones are used to quickly get medical supplies like blood and medicines to villages that can't be reached by car or motorbike. In that case, small drones fly out from a central hub and then return once they've made their deliveries, but in cases of natural disasters or humanitarian missions, the logistics aren't always that simple.

Deliveries can be intercepted or the vehicles damaged in the process. The solution for safe deliveries during times of conflict or emergencies is a stealth system, which is why DARPA put out a call for disappearing unmanned systems and San Francisco-based Otherlab responded.

Otherlab came up with an idea for a drone called APSARA that could make one-way emergency relief trips and degrade quickly once it reached its target. The body of the small drones are made from a cellulose-based material that's a lot like cardboard and filled with fungal spores to help it to biodegrade faster. The body itself looks like a stealth fighter jet in miniature.

"DARPA was interested specifically in something that could degrade fairly quickly so when you deliver your supplies with a hundred of these, you don't have drones littering the ground for the next 20 years," said Mikell Taylor of Otherlab.

The inside of the prototype drone contains off-the-shelf electronics that allow it to be remotely controlled. If these drones were used in a real-world application, the electronics would also be degradable -- DARPA has a separate program developing electronics that dissolve on impact.

The drones are designed to land within a 33-foot radius of programmed GPS coordinates after being dropped from an aircraft tens of thousands of feet in the air though for testing they have been limited to using octocopters to lift the drones high off the ground. Depending on the mission, the body of the drone could be covered in water resistant coating to protect it from rain or floods or made from more durable materials if necessary.

You can watch the prototype in action below.

Our editors found this article on this site using Google and regenerated it for our readers.