In the pre-dawn hours of Sept. 1, 2005, a U-2 surveillance aircraft known as the Dragon Lady lifted off the runway at Beale Air Force Base in California, the home of the U.S. Air Force 9th Reconnaissance Wing and one of the most important outposts in the U.S. intelligence world. Originally built in secret by Lockheed Corp. for the Central Intelligence Agency, the U-2 has provided some of the most sensitive intelligence available to the U.S. government, including thousands of photographs of Soviet and Chinese military bases, North Korean nuclear sites, and war zones from Afghanistan to Iraq.

But the aircraft that took off that September morning wasn't headed overseas to spy on America's enemies. Instead, for the next six hours it flew directly over the U.S. Gulf Coast, capturing hundreds of high-resolution images as Hurricane Katrina, one of the largest storms of the past century, slammed into New Orleans and the surrounding region.

The U-2 photos were matched against satellite imagery captured during and after the disaster by the National Geospatial-Intelligence Agency. Relatively unknown to the public, the NGA was first organized in 1996 from the imagery and mapping divisions of the CIA, the Department of Defense and the National Reconnaissance Office, the agency that builds and maintains the nation's fleet of spy satellites. In 2003, the NGA was formally inaugurated as a combat support agency of the Pentagon. It is responsible for supplying overhead imagery and mapping tools to the military, the CIA and other intelligence agencies-including the National Security Agency, whose wide-reaching, extrajudicial spying inside the United States under the Bush administration has been a heated political issue since first coming to light in the media nearly two years ago.

The NGA's role in Hurricane Katrina has received little attention outside of a few military and space industry publications. But the agency's close working relationship with the NSA—whose powers to spy domestically were just expanded with new legislation from Congress—raises the distinct possibility that the U.S. government could be doing far more than secretly listening in on phone calls as it targets and tracks individuals inside the United States. With the additional capabilities of the NGA and the use of other cutting-edge technologies, the government could also conceivably be following the movements of those individuals minute by minute, watching a person depart from a mosque in, say, Lodi, Calif., or drive a car from Chicago to Detroit.

Prior to Katrina, the NGA had been used sporadically during domestic crises. Its first baptism of fire came after the 9/11 terrorist attacks, when the agency collected imagery to help in the recovery efforts at the World Trade Center and the Pentagon. But the storm of 2005 triggered NGA activity on a scale never before seen inside the borders of the United States. "Hurricane Katrina changed everything with what we do with disasters," John Goolgasian, the director of the NGA's Office of Americas, told Salon. In New York after 9/11, the NGA had only a handful of people on the ground, but "with Katrina, we put a lot of people down in the theater," he said, using a term usually reserved for overseas military battlegrounds. The agency now deploys its staff on a regular basis to hurricane zones and also provides assistance to law enforcement agencies during events such as the Super Bowl, the baseball All-Star Game and political conventions.

On one level, the engagement of the NGA and the U-2 flights over the Gulf Coast during Katrina were commendable efforts to use America's vast surveillance powers for the safety and support of its citizens. But at the same time, the incident apparently marked the first time in history that U.S. intelligence agencies created to spy on foreign countries were deployed to collect extensive information on the U.S. "homeland." Their role during Katrina is just one aspect of an enormous domestic surveillance infrastructure put in place by the Bush administration ever since the Sept. 11 terrorist attacks sparked a radical restructuring and expansion of America's intelligence system. Although the full scope of domestic surveillance under Bush remains elusive, we now know from press accounts, lawsuits, and Attorney General Alberto Gonzales and other top Bush officials' descriptions and denials that the NSA has been involved in multiple domestic surveillance programs—in apparent violation of federal law—including spying on Americans' telecommunications and Internet traffic, as well as data mining.

In December 2004, the NSA and the NGA announced the signing of an agreement to share resources and staff and to link their "sources, data holdings, information infrastructure, and exploitation techniques." The document spelling out the agreement itself is classified. But in a press release the NGA explained that the pact allows "horizontal integration" between the two agencies, defined as "working together from start to finish, using NGA's 'eyes' and NSA 'ears.'"