On a recent afternoon, pilots on the ground prepared to launch an unmanned Predator aircraft in Corpus Christi.
The drone is not on a military mission and is not equipped with weapons; instead, the Predator is fitted with surveillance gear.
?There are several cameras in here that allow us to see infrared at night through several different focal lengths,? said Scott Peterson, Supervisory Air Interdiction Agent.
?We can identify vehicles very well,? said Agent Peterson, pointing to a ball-shaped cover that houses multiple cameras that capture images in daylight and darkness.
Agent Peterson is in charge of the Custom and Border Protections Unmanned Aircraft program in Corpus Christi.
There are a total of nine Predators that fly over the U.S. Four are based in Sierra Vista, Arizona. The two based at the Corpus Christi Naval Air Station patrol the Gulf of Mexico and Texas border.
Terrorist threats are the top priority, but the drones see a lot of smuggling activity in this region.
?It could be anything. It could be weapons. It could be narcotics. It could be people, ?said Agent Peterson.
The Department of Homeland Security?s new targeted enforcement strategy relies more heavily on unmanned aircraft to gather intelligence that helps agents break up cartel smuggling rings rather than just nab drug mules at the border.
As the Predator took off in Corpus Christi late one afternoon, the unmanned aircraft, hugging the coastline, headed south to the Rio Grande Valley.
Mission Control keeps track of it all, shares real time data and responds to requests from border patrol agents on the ground. A Border Patrol liaison is in the control room as well.
?There are a couple of points on the beach that are known for smuggling, so we hit those too on the way down,? said Ernesto, an agent in mission control who does not want his last name used for security reasons.
The Predator hones in on two docks in a remote area of the King Ranch.
?With the intercostal waterways and proximity to Mexico, that?s just a very, very good spot for people to do any type of activity they don?t want to be seen doing,? said Agent Peterson, looking at one of the screens in the control room.
It would take border patrol agents an entire day to reach this spot in a vehicle.
"The 66 foot wing span allows the aircraft to slow down. It?s very miserly with fuel,? said Peterson.
Predators can fly up to 18 hours straight. Each unmanned aircraft costs $18.5 million dollars and some critics question their cost effectiveness.
According to the Customs and Border Protection's Office of Air and Marine, in fiscal year 2011 unmanned aircraft contributed to the seizure of more than 7,600 pounds of narcotics and the apprehension of more than 75 individuals taking part in illicit activities.
But CBP officials say the Predators offer advantages that go beyond the amount of drugs seized.Their vantage point has been critical for agents in dangerous situations.
Agent Peterson recalled an incident in the Rio Grande Valley when suspects rammed a border patrol truck with their vehicle then took off running into the brush.
?The good guys don?t know where the suspect guys are, so we came overhead with the cameras and were able to take a look at the whole thing, the God?s eye view looking down.?
But some question whether the drones can also be used to spy on unsuspecting Americans.
?These aircraft are doing nothing different than what the manned aircraft have been doing all along,? said Agent Peterson.
The Guardian is the latest unmanned aircraft to patrol the coast as well as the border. It has a maritime radar system that allows the drone to also ?see? over water. The sea view radar covers 250 square miles.
?We?ve seen everything from rafts crossing rivers to shrimp boats to launcher boats, which are little shark boats, little single engine boats, coming up from Mexico,? said Agent Peterson.
The Guardian in Corpus Christi is one of two that exist in the world. The other one is based at Cape Canaveral, Florida. CPB plans to add a third Guardian by the end of the year but has not announced the location.
After sweeping the Texas Gulf Coast, the drone reached the tip of Texas, the Rio Grande Valley.
The people who run the system will work late into the night as the Predator flies over a stretch of the Rio Grande that borders a drug war hot spot in Mexico.
?Hook a right and start coming down the river into our areas,? said Chris, another agent in mission control who does not want his name used for security reasons.
?We?ll follow the river and patrol.?