It's a key challenge facing emergency response teams after a natural disaster – how to get important supplies to the people who need them when roads, railway tracks and airports can't be used?
DARPA – the Defense Advanced Research Projects Agency of the US Department of Defense – is wrestling with this problem.
One of the ideas it's exploring is biodegradeable, cardboard drones that can carry a few kilos of supplies and deliver them to within 15 metres of the people who need them on the ground.
"Vanishing air vehicles that can make precise deliveries of critical supplies and then vaporise into thin air" could be the answer, says Roy Olsson of DARPA's Project ICARUS (Inbound, Controlled, Air-Releasable, Unrecoverable Systems).
"Vanishing delivery vehicles could extend military and civilian operational capabilities in extenuating circumstances where currently there is no means to provide additional support" - ICARUS program manager Troy Olsson