The American armed forces have not only enthusiastically accepted UAVs (Unmanned Aerial Vehicles), but are particularly keen on mini-UAVs. On the low end, there are several models that weigh less than ten pounds and cost less than $3,000 each. Like most mini-UAVs, these can be controlled via 20-40 pounds of radio equipment and a laptop computer. What makes these smaller UAVs useful is not just their cost and portability (especially for ground combat units), but for their potential use in naval and air force operations as well. Small naval patrol ships could use them to get a look "over the horizon" and the aircraft could carry one as part of their emergency equipment (as the aircraft goes down, the mini-UAV is launched and circles the crash site, broadcasting locations data, to make it easier to find). Submarines can launch them via a torpedo tube, have them fly inland to do some reconnaissance (via a pre-programmed course) and broadcast what they find back to a small antenna buoy linked to the still submerged sub (which never has to surface or broadcast and give away its position.) In 2002, the air force experimented with having a Predator carry a 57 pound mini-UAV, which it released for some close in recon in a particularly well defended position. The mini-UAV was more expendable than the Predator, but the larger UAV could pick up what the mini-UAV saw and transmit it back via its satellite communications link. Manned aircraft could also carry several of the mini-UAVs, which have the advantage of being harder to see or hear and more capable of spotting hidden enemy troops on the ground. Some of the mini-UAVs have impressive operational capabilities. For example, the Albatross weighs 11 pounds, cruises at 50 kilometers an hour at up to 13,000 feet and can stay in the air for up to 20 hours. Although this UAV only carries a payload of 2.2 pounds, this is enough for a camera and transmitter. Something like the Albatross can be used to escort vehicle convoys, or convoy routes in a place like Iraq, looking for people setting up road side bombs. Already, such UAVs are being used by law enforcement agencies for stakeouts. For military use, mini-UAVs can be equipped with an explosive charge, and sent to attack particularly high value targets. There are over a dozen mini-UAV research projects underway at the moment, some of them secret, and more smaller UAVs will be entering service in the next few years.