Putin's war turned this little Polish airport upside down. It rose to the challenge.

• Rzeszów-Jasionka Airport is just 50 miles from Poland's border with Ukraine.

• The once quiet airport is now a hub for heavy weapons, international aid, and medical evacuations.

• Staff are "running on adrenaline" as they welcome refugees, soldiers, and VIPs from Bono to Biden.

Adam Hamryszczak realized something big was happening when US military personnel started turning up at his office.

It was January 2022, a month before Russia invaded Ukraine, and he was the president of Rzeszów-Jasionka, a small airport in a sleepy town in southeast Poland.

It's only the eighth-busiest airport in Poland, having served some 730,000 passengers in 2022. In comparison, New York's JFK Airport served more than 4 million passengers in January alone.

But the unremarkable airport, which usually ferried Polish travelers to its capital, Warsaw, or to countries including Italy and Croatia, was about to become extraordinary.

Ukraine has been a no-fly zone since the war started. So, because of Rzeszów-Jasionka's location just 50 miles from Poland's — and NATO's — border with the country, traveling to or from Ukraine by air means going through the little Polish airport.

It's now a hub for heavy weapons, international aid, and high-profile passengers like US President Joe Biden, Ukrainian President Volodymyr Zelenskyy, Richard Branson, Sean Penn, and Bono — while still serving regular passengers who travel alongside missiles, soldiers, refugees, and medical-evacuation teams.

The war thrust airport staff into a new reality as soon as it started. Hamryszczak said in December that they have been "running on adrenaline".

He told Insider: "I realized that a great challenge was ahead of us and that any mistake on our part couldn't be an option."

'We only slept for a few hours per night'

The first batch of US troops arrived at the airport on February 5, 2022.

They were some of the 1,700 soldiers — mostly paratroopers — deployed to provide security in Poland as Russia massed its troops along Ukraine's borders. They're still there today.

"We only slept for a few hours per night," Hamryszczak told Insider, explaining the transition as his workers scrambled to arrange transport for military cargo and medical evacuations — all while maintaining the flow of ordinary travelers on budget European carriers such as Ryanair.

The airport hired extra workers from the nearby Lviv Danylo Halytskyi International Airport in Ukraine, which has been shuttered since the country closed its airspace.

Hamryszczak told Insider that he had to rise to "countless" challenges, including making complex arrangements with world leaders and welcoming the world's media. "They certainly don't teach about this in MBAs," he joked.

Missile-defense systems and US troops are now an everyday sight 

The US sent two of its Patriot missile-defense systems — considered among the world's best — to Rzeszów-Jasionka in March 2022 to counter any threat to NATO countries, according to US European Command.

Pointing to the skies behind a wire fence at the airport's perimeter, the Patriots offer a "sobering" welcome to civilian travelers, one visitor commented on Twitter.

They've even become a tourist draw, according to Konrad Fijołek, the mayor of Rzeszów: "We joke that it's our main attraction."

He told Insider that the airport's global prominence has placed Rzeszów on the map: "Our city used to be on the outskirts of Poland and on the outskirts of Europe. Now, I say to our guests: Welcome to the center of Europe."

Rzeszów-Jasionka has welcomed international VIPs