This Mule unmanned aerial vehicle is huge, fast and crazy. It's just going through its first wind tunnel testing, but it might someday be hauling injured troops back to base with no pilot involved.
This is one serious UAV, one that puts most others to shame. Just look at these specs:
With a payload of 318kg (700lb) per single 31km (57nm) radius sortie, each Mule will be capable of delivering about 3,180kg over 24h, including the ferrying on return trips of casualties where medevac flights are needed. Mule's maximum operating altitude is 12,000ft (3,660m).