The first flight takes off from Osan Air Base just after daybreak, ascending high above the Korean Peninsula to collect and send critical data back to US military headquarters in South Korea.
Dubbed the "Dragon Lady" but also known as the Lockheed U-2, the sleek, ebony aircraft is capable of flying 70,000 feet above sea level -- in what's known as near space.
As North Korea boasts about advances in its nuclear weaponry and having missiles ready to hit near the US territory of Guam, the Dragon Lady is the spy plane of choice in helping Washington assess the true threat.
"We're busier here than we've been probably in the last 10 years," said Lt. Col. James Bartran, a veteran U-2 pilot who leads the 5th Reconnaissance Squadron at Osan Air Base, the US Air Force's closest base to North Korea, about 40 miles (64 kilometers) from its border.
The mission is clear -- to keep their eyes and ears on North Korea.
"Everything that this aircraft is sending is almost instantaneously sent down to people who can process, exploit and disseminate that information within minutes to our leadership," Bartran told CNN, which was granted access to Osan Air Base.
High-altitude spy plane
First taking flight during the Cold War in the 1950s, the Dragon Lady was built to fly so high that it couldn't be detected by Soviet planes.
Newer models of the aircraft have been modernized with new sensors and cameras.
At $250 million a piece, the piloted spy planes are equipped to handle a variety of intelligence gathering tasks that newer unmanned aircraft like drones can't do alone. It makes the Dragon Lady a critical asset in detecting what the North Koreans are really up to.
"We provide what's called multi-in (intelligence). We're the only true multi-in in the theater," Bartran explained. "We can both see and hear things at the same time."
In the months since Donald Trump became US President, the rhetoric between North Korea and the US has intensified. Both sides have threatened the other with total annihilation.
The bellicose language has been dialed back for now -- with North Korean leader Kim Jong Un holding off on a plan to strike near Guam, a decision President Donald Trump called "very wise and well reasoned."
But the unpredictability of both leaders could mean tensions could escalate -- and possibly boil over -- at any time.
The Dragon Lady's presence over the Korean Peninsula, Bartran explained, is to ensure the US has the information it needs to act or respond. The intelligence the jet sends back to Washington could mean the difference between peace and war.
On Thursday, US Secretary of Defense James Mattis warned it would be "game on" if North Korea sent a missile towards US territory or any of its allies.
"I can assure you that, in close collaboration with our allies, there are strong military consequences if the DPRK initiates hostilities," Mattis said.
Some of those "consequences" would likely originate from Osan Air Base. In addition to housing Dragon Lady spy planes, it's also the base for two squadrons of F-16 fighter jets -- whose pilots train with the motto to be "ready to fight tonight."
'Ferrari' of planes
A third F-16 squadron is stationed at Kunsan, the other US Air Force base in South Korea.
"This is Ferrari -- that is the best way to describe this thing," Maj. Daniel Trueblood, a F-16 pilot from the 36th Squadron said as he proudly showed off his fighter jet.
He boasted about the aircraft's supersonic speed -- saying it can move at 16 miles per minute.
That means that if either the US decided launch an attack or respond to one from North Korea, the F-16s -- which can carry long- and short-range missiles as well as bombs -- could in theory get from Osan Air Base into North Korean airspace in under three minutes.
Like the spy plane pilots, the F-16 squadrons train daily over the Korean Peninsula -- simulating battles during both day and night. CNN watched as a dozen F-16s took off from Osan on a training exercise.
"We don't know when something's going to happen or what we're going to called on to do, so we need to make sure that across the board we're ready to execute, pretty much at any time," Trueblood told CNN. "We prepare every day like tonight is the night."
He compared the role the F-16s would play in a battle to that of an offensive lineman's in American football.
"We go out as the overall package so load up the jet with both air-to-air missiles, air-to-surface missiles, with the HARM (High Speed Anti-Radiation Missile) we would shoot," Trueblood said.
"Our job is to have the enemy target us with both their air-to-air threat and their surface-to-air threat, and we basically protect everybody else, so we want them to target us."
Despite all the rumblings of potential combat, officials from South Korea and the US insist they'd rather talk than resume hostilities with North Korea.
But Pyongyang's defiant stance has caused concern among many that the current war of words could easily escalate into action.
The pilots at Osan Air Base say if it does, they're ready.
"The mission has always been very clear and dictated down to me that we are ready to fight," Trueblood said.