CHANTILLY, Va. - From across Route 28, amid acres of business parks and grassy islands, rises a series of dazzling light blue buildings that look nothing like a government office complex.
But that is the point.
Behind the gridiron gates and armed guards is the National Reconnaissance Office, possibly the most secret agency in government, one that has long escaped the scrutiny and notoriety of its counterparts at the FBI, CIA and the National Security Agency.
For 40 years, the NRO has designed, built and operated the nation's spy satellites. It's capable of collecting all sorts of communications, from phone calls to e-mails, and photographing cars on the ground anywhere in the world. Some industry experts believe the agency can even read license plates.
Just as the NSA has stood casually for "No Such Agency," the NRO has spent the past four decades nicknamed, "Not Referred to Openly." After the agency began drawing up plans for the complex in 1990, when even its existence was a secret, officials initially asked the contractor to hang its sign out to confuse passersby.
In a recent rare interview at the agency's headquarters, NRO Director Keith R. Hall said the secrecy is a necessary part of a "cat and mouse game" the United States plays with its adversaries.
"I'd like to be known as the agency that's even more super-secret than NSA and leave it at that," Hall said. "We don't attract publicity and we don't seek it. ... People have many more questions about us than answers are available."
These days the agency has made some inroads to declassify some of its earliest satellite projects and hangs its own sign on the front lawn. But much about what it does and how it operates are some of the most closely guarded secrets in government.
Three weeks ago, the agency was dragged into the limelight when retired Air Force Sgt. Brian P. Regan, 38, who worked as a contract employee for the NRO, was charged with conspiring to commit espionage after authorities say he attempted to flee the country with classified documents.
It had last attracted attention in 1995 when it faced harsh criticism from congressional intelligence committee members after the discovery that the agency had accumulated a surplus of $3 billion in secret money and was not readily able to locate the funds. The director and deputy director were replaced.
But overall, the NRO has succeeded in largely avoiding the spotlight. While it has the largest budget of all 13 intelligence agencies, it has the smallest number of employees. And until its complex was finished in 1995, it lacked a central headquarters.
NRO officials acknowledge that the office complex houses about 3,000 workers, and several sources estimate the agency's budget to be well over $6 billion a year. The exact numbers are classified.
More than 95 percent of the agency's budget is contracted out to companies such as Boeing and Lockheed Martin, who build the satellites and launch equipment, NRO officials say.
In the past, the agency would break projects into pieces and contract them out to different companies to maintain secrecy and boost competition. But in a break with that tradition last year, the agency announced that it had selected Boeing to oversee what many industry insiders believe is the largest NRO contract in its history - overhauling the nation's satellite systems. In size and scope, several experts speculate, the overhaul could rival the Manhattan Project, which developed the atomic bomb in the 1940s.
Though classified, the project, called Future Imagery Architecture, is estimated to be worth $25 billion over two decades. It will require thousands of aerospace industry workers to complete and will most likely operate out of Southern California, said John Pike, a space intelligence expert and director of Virginia-based GlobalSecurity.Org.
"By basically just giving the whole thing to Boeing, to a great extent at some point you just have to trust they know what they're doing and are decent fellows," Pike said. "These are extremely complex programs with high risk factors."
Hall declined to discuss the scope and purpose of the project or what he called the "winner-take-all contract," but said the program would focus on building smaller, lighter satellites and more of them. He said the agency did not feel that giving the entire project to Boeing would eliminate competition in the aerospace industry.
Some in the industry believe Future Imaging Architecture will also push the satellites farther out into space, perhaps to thwart the possibility of their being attacked or shot down. Many spy satellites orbit at a little more than 100 miles above Earth, while communication satellites park in geosynchronous orbits around the equator, 22,300 miles high. At that height, their orbit matches the rotation of the earth, so they seem to hover in one place.