The top of the Afghan mountain called Takur Ghar was a shower of bullets, and American soldiers there were wounded, dying and trapped. Operation Anaconda, the fight against Taliban and al-Qaida holdouts in March, was too hot for a daytime helicopter rescue. One airman died waiting for darkness.
"There's really only one safe way to go into a situation like that," said John Sundberg, a deputy project manager at the Army's Redstone Arsenal in Huntsville, Ala. "You need an unmanned aircraft."
Motivated and frustrated by the casualties in Afghanistan, Army and defense industry officials are developing a method of air-dropping blood, bandages or other small packages of medical supplies from an unmanned aerial vehicle, or UAV.
Tentatively named "Quick-MEDS," an acronym for Medical Emergency Delivery System, the concept calls for dropping a small, missile-shaped canister loaded with as much as eight units of blood from beneath the Shadow UAV, made by AAI Corp. in Hunt Valley. The canister would use fins and a parachute to slow its descent and a collapsible nose cone to dampen its impact with the ground.
UAVs have already emerged as the high-tech celebrities of the war on terrorism.
One jet-powered craft called Global Hawk was rushed into service to fly long-range surveillance and tracking missions over Afghanistan, while the smaller Predator was armed with missiles and used, for the first time, as an offensive weapon, including a strike that killed a suspected terrorists in Yemen.
But recent battlefield experience has caused many military and defense industry planners to rethink their lofty claims that unmanned aircraft will someday replace their piloted cousins, analysts say.
Rather, planners are learning that UAVs are best used to complement other tools of war, with novel missions - like air-dropping blood and medical supplies - that were never contemplated before the age of pilotless flight.
"We've gotten away from talk about replacing manned aircraft with UAVs, because we've figured out that they can't do everything," said Richard Aboulafia, an aerospace analysts for Teal Group Corp., a defense consulting firm in Fairfax, Va.
"What is now becoming clear, however, is that the UAV can do a whole lot of new things that you never considered."
Conceived and designed strictly as a means of surveillance, UAVs took perhaps their greatest evolutionary leap last year when the Predator began flying missions armed with Hellfire anti-tank missiles.
Last February, a CIA drone fired on a group of men in Afghanistan thought to include Osama bin Laden, though officials later suspected the men were local villagers collecting scrap metal.
Research and testing of potential new uses for UAVs and other automated or remote-controlled vehicles have since exploded, and are being conducted by dozens of defense contractors and all of the armed services, sometimes with an eye toward rushing new systems into service over Iraq.
Companies are outfitting UAVs with new sensors to detect chemical or biological contaminants, and the Pentagon's Defense Threat Reduction Agency is developing an airborne radiation-detection system.
The Army is developing a system that will allow UAVs to accompany and work in partnership with tank units, while General Dynamics Corp. is working to extend pilotless technology to the tanks themselves so that one driver can operate several vehicles.
The Navy is researching methods of launching UAVs underwater from submarines, then using them as shoreline scouts or lookouts for teams of SEALs. It is developing unmanned underwater vehicles for mapping coastlines and detecting mines and enemy targets.
Researchers also are designing unmanned inflatable boats for exploring jagged coastlines or protecting larger vessels from mines or terrorists.
One new idea that observers expect to see in the field soon is the capability of UAVs to not just carry things but to drop them on demand.
Besides delivering medical supplies, the Army envisions using drones to place ground-based sensors or listening devices into enemy territory, or to drop emergency supplies of ammunition or food to soldiers pinned down in a firefight. Researchers are considering a pilotless cargo lifter that could deliver pallet-loads of supplies, and perhaps even vehicles.
The Quick-MEDS concept, endorsed by the Army surgeon general, could be available in as little as 60 days, according to Sundberg, deputy project manager for UAVs at the Redstone Arsenal, where the Army conducts most of its UAV research.
The Army has experimented by dropping bags of blood from a 300-foot tower and is engineering a prototype to find the proper weight, balance and placement beneath the Shadow UAV's wing.
The earliest model would be a free-falling canister, capable of hitting a circular landing zone 100 meters across. Models with a satellite guidance system also are contemplated, Sundberg said, improving accuracy to within 15 meters of a target point.
"If there are troops in trouble and in need of supplies, and if the situation is too dangerous to get to them, you could send in a UAV with pods strapped to the wings and place the supplies somewhere within an area about the size of a tennis court," said Sundberg, the deputy project manager at Redstone Arsenal. "We're finding this for a lot of different missions - a UAV is often the best solution."
The air-drop concept has other proponents. Northrop Grumman Corp. conducted a mostly classified test last month in which it dropped a mock payload from the wings of a Firebee, a jet-powered UAV previously used as a flying test target.
The company would not say what was dropped, where, or for which branch of the government - only that a "customer" requested the system, and that it was developed and deployed in just eight weeks.
Besides the relative safety of sending a robot into battle, the absence of a pilot also allows UAV systems to be developed and tested much faster than devices that would be used on conventional aircraft, where the potential for human casualty must be considered.
Technology on unmanned aircraft is also typically cheaper. The Quick-MEDS system, for instance, could conceivably be designed, built and sent into battle for several hundred thousand dollars, not counting the cost of the aircraft, Army officials said.
And unmanned systems enjoy a perception as relatively benign military hardware - not nearly as aggressive or threatening as F-16s and stealth bombers, analysts said.
"A UAV buzzing around is a lot less politically sensitive than a piloted jet loitering over Yemen would be," said the Teal Group's Aboulafia.
Political considerations are a key motivator for UAV research concerning submarines. Besides being virtually undetectable before use, submarine-launched surveillance craft would require little advance notice to deploy and no sensitive negotiations with foreign governments over the use of ground-control sites or air bases.
Northrop Grumman and Raytheon Co. are designing prototype launching capsules that jettison from a submarine, float on the surface and can be fired remotely. Northrop Grumman's version would be fired from torpedo tubes, while Raytheon's would attach to the outside hull. Both could be used to launch UAVs or missiles.
Surveillance drones have been used in combat since the Vietnam War but have mostly been a niche industry dominated by small specialty manufacturers. General Atomics, a 1,600- employee defense contractor in San Diego, is an industry star thanks to its success building the Predator and its predecessor, the GNAT.
So, too, is AAI, a slightly smaller company whose Pioneer drone flew missions from Navy battleships during the Persian Gulf war. AAI's Shadow was just awarded the military's first full-production contract for a UAV.
But today most of the giant defense contractors are involved as well. Boeing Co. is developing a large UAV for the Air Force that can fire missiles or drop bombs, and a smaller Navy drone for use at sea.
Lockheed Martin Corp. is designing underwater mine hunters and other systems. And Northrop Grumman, manufacturer of Global Hawk and a pilotless Navy helicopter called Fire Scout, posted a $224 million quarterly profit last week, attributed mostly to recent mergers but also to a surge in sales of unmanned aircraft.
The pilotless vehicle business is still a mere fledgling in the defense industry, where the United States alone spends more than $375 billion a year.
The market research firm Frost & Sullivan issued a report late last year estimating that the global market for unmanned vehicles was $1.4 billion in 2002. But it is growing rapidly.
The Pentagon, which spent about $760 million on the technology last year, expects its UAV spending to grow to more than $2 billion over the next five years.