Several projects he considered "successes," he said, were scaled-back versions of an initial vision that "took us forward from where we were, but it really didn't meet the aspirations of what we would have liked to have had."
Alexander plans to hire a new executive to run the NSA's technology programs, and Trailblazer will be one of this executive's top priorities, said an intelligence consultant.
Alexander declined to comment for this article, but in August he told The Sun that he would look to shift the agency's approach away from large programs such as Trailblazer and toward smaller programs that build on each other.
"I think the way to do it efficiently is smaller steps, more rapidly done, rather than try to take one big jump and make it all the way across," he said.
Those steps would involve significant changes in the way the NSA manages data, including, he said, "how you handle data, how you visualize that data and how we jump from industrial age analysis to the information age analysis that our country needs."
Intelligence experts with extensive knowledge of the program said Alexander is likely to salvage what he can from Trailblazer and largely start over, casting it as a kind of "Trailblazer 2.0."
The country's new spymaster, Director of National Intelligence John D. Negroponte, is taking on the job of connecting the technology systems of all 15 intelligence agencies, and former intelligence officials said Trailblazer's troubles should serve as a cautionary tale.
If Negroponte wants to learn the details, he won't have to go far. Since last spring, his top deputy has been Hayden, the former NSA chief.