(NewsNation) — As the nation prepares to commemorate the 23^rd anniversary of the September 11 terrorist attacks this week, the National Security Agency has released new information about its role in helping track down Osama bin Laden, the founder of al Qaeda and the mastermind behind the attacks that killed nearly 3,000 people in 2021.

On the day that U.S. military forces raided a compound in Abbottabad, Pakistan, only around 50 people of the tens of thousands of NSA employees knew of the plan to find bin Laden, Jon Darby, the former director of operations at the NSA, said on a recent episode of the “No Such Podcast.” The podcast was launched this month by the NSA as a way of sharing information about operations that take place within the federal agency.

“Because it’s sensitive, we can’t talk about some of our work, but it’s time to start telling more stories that we can talk about, sharing more of that expertise, and highlighting these incredible public servants,” Sara Siegle, NSA’s chief of Strategic Communications, said in a statement sent to CBS News.

Darby said that locating bin Laden had taken nine and a half years after the September 11 attacks on the World Trade Center and Pentagon. The NSA relied on a complicated Signal Intelligence (Sig-Int) to track down and analyze information that was being transmitted and shared within al Qaeda. Before the 2001 attack, the terrorist network had carried out a series of attacks on American targets, including the World Trade Center in 1993, the USS Cole in 2000, and various attacks on U.S. Embassies.

“But after the September 11 attack, the urgency to find bin Laden intensified,” Darby said.

How tracking Osama bin Laden worked

“Osama bin Laden was a Sig-Int target for a while,” Darby said on the podcast. “Clearing he was of interest; he was leading an organization that intended to inflict harm on the United States.”

The agency has used NSA Sig-Int operations to collect and analyze data in several international conflicts, including the Russian invasion of Ukraine as well as the Chinese origins of chemical-used synthetic fentanyl, according to Natalie Laing, the NSA’s director of operations, said on the podcast.

For the NSA to launch a Sig-Int operation, Laing said that an order must be placed by the President or other top security officials, and it must involve foreign-based data, she said.

Although bin Laden and al Qaeda had been targets of the NSA before 2001, Darby said that the carrying out of the September 11 attacks intensified locating bin Laden. The mission, Darby said, was to prevent another attack from taking place on U.S. soil.

The National Security Agency had collected data from a satellite phone used by bin Laden before 2001. But when media coverage about the NSA’s attempts to analyze information shared through the al Qaeda network began to surface, communications stemming from that satellite phone stopped, Darby said.

“So we had to be creative to get him,” Darby said on the podcast.

NSA officials began to work to understand better how communications within al Qaeda worked. Analysts worked off of leads that came out of the September 11 attacks, including materials used by al Qaeda members who hijacked the planes used to fly into the World Trade Center.

Because of the complexity of the mission to find bin Laden, Darby said the NSA partnered with other federal agencies including the Central Intelligence Agency and U.S. military to devise a plan. The operation often went in fits and starts, Darby said. Naysayers warned that bin Laden was likely dead and that even if he was alive, he could be nearly impossible to find.

“If he is alive, we will find him,” Darby said on the podcast. “That’s not an option just to give up.”

The NSA creates the big picture

Officials working on the operation centered their attention on the courier who was working as bin Laden’s caretaker to try to narrow down where bin Laden may be. Darby compared using small bits of data to construct a puzzle that could lead to a bigger picture of where bin Laden was hiding.

Darby said that confidentiality became key. Knowing that al Qaeda tracked U.S. media coverage, keeping the operations buttoned up was critical. If word leaked, NSA officials knew that bin Laden could easily leave the compound and lead government officials on another 10-year search.

Yet, as more pieces of the puzzle began to fit together, the NSA believed that they knew where bin Laden was hiding. Yet, even on the day in 2011 when the raid on the Pakistani compound took place, Darby said there was never a 100% certainty that bin Laden was actually inside.

Darby says that in addition to analyzing information, the other part of the NSA’s role in the mission was supporting what the government chose to do with the information that had. The day of the raid included making sure that U.S. forces were able to get in and out of the area safely.

Once the raid began, Darby called the remainder of the operation “surreal”.

“(We knew) this could be a really big deal,” he said on the podcast. “And then when it turned out to be (bin Laden) it was (surreal).”