The reason the AGM-114 Hellfire missiles cannot be used in bad weather is that they rely on laser-guidance to the target, and this needs to be done by the opto-electronics of the firing aircraft, or “painting the target” by another airborne designator or ground-based troops. Without visibility, the Hellfire cannot home in on the reflected laser beam aimed at the target.
The GBU-38 bomb, unlike the two main current weapons deployed by the MQ-9 Reaper UAV (the laser-guided GBU-12 bomb and Hellfire missile), employs GPS to find its target and hence can be fired “blind” through cloud, rain or fog with remarkable accuracy.
The GBU-38 is a $2000 general-purpose, 500 pound, Mk 82 dumb bomb with an $18,000 guidance system fitted, turning it into a surgically-accurate weapon delivering 192 pounds (89 kg) of Tritonal high explosive from a range of up to 15 miles (24 km).
That 15 mile range is in addition to the MQ-9 Reaper’s range of 1,150 miles (1,850 km), making it ideal for loitering above the battlefield for hours, while providing surveillance, then striking when a target is identified.
Other than accuracy in bad weather and cost, another advantage of using the GBU-38 is that its load time is almost half that of the currently used GBU-12 and Hellfire weapons, enabling the Reaper to get into the air some 15 minutes quicker. Given that rapid deployment to hit targets that might only be available for a short window of time is a huge advantage, the new weapon will significantly add to the warfighter’s toolbox.
Some observers liken the rapid development of drones during the Iraq war to the evolution of the aircraft as a weapon of war during WW1. When the first World War began, aircraft were seen primarily as sources of ISR (Intelligence, Surveillance and Reconnaissance) but within four years, the attack capabilities of aircraft had changed war forever.
When the Iraq war began in 2003, America had just a handful of “drones,” but within a decade it had more than 10,000 pilotless aircraft in the arsenal and though the General Atomics MQ-9 only makes up a few hundred of those UAVs, it is both highly cost-efficient and lethal.
Source: New Atlas