The Rev. Stan Esterline’s Sunday morning routine is pretty typical for a minister. With a Bible tucked under his arm, he enters the chapel where he works, passes out hymnals and proceeds to read from the gospel and conduct his sermon.

His chapel, however, is anything but typical. With a Sony boom box for a choir and a mix of travelers and airport employees for a congregation, Esterline’s house of worship is a tiny square room inside Reagan National Airport.

Tucked in a narrow hallway at the end of the airport’s main terminal – between a police station and a bagel stand – is the airport chapel, added in 1997 as part of a multi-million dollar renovation project. For nearly a decade it has served as a sort of spiritual rest stop where jetsetters can pray, meditate or just have a space to put luggage down.

“The population is so mobile today,” said Esterline, senior chaplain at the National Airport chapel. “A lot of people travel for a day or two or three at a time, and this gives them a place to express their faith.”

While its discreet location may make the chapel easy to overlook, those running the church say it gets plenty of use. Tim Tatum, director of ministry for Metropolitan Washington Airports Interfaith Chapels, which oversees the chapels at Reagan National and Dulles International Airport in Virginia, estimates that between 18,000 and 20,000 worshippers use the facility each year.

The number of visitors has increased since Sept. 11, Tatum said, as air travel has become more stressful. With the looming threat of terrorism, more people are turning to airport chapels for relaxation and comfort.

“I think they’re critical,” Tatum said. “We’re serving the needs of people that are separated from and isolated from their normal means of support, whether it’s religious support or social support, whether it’s religious support or social support. We’re filling a gap that otherwise wouldn’t be filled.”

While the chapel itself exists for prayer and meditation, the ministry’s primary role is a little different. In addition to having weekly sermons, the chapel makes at least one staff member available during the day to respond to emergencies with spiritual support, and all ministers are on call around the clock.

In the case of large-scale disasters, half a dozen chaplains from within the airport ministry are available to arrive at the scene. When American Airlines Flight 77 crashed into the Pentagon on Sept. 11, the Washington airport chaplains were the first to receive victims’ families and offer religious counseling.

“It’s a professional job,” Esterline said. “In our experience and training, these are things we expect to be involved in. In our own way we’re kind of an emergency response team.”

Though disasters of that magnitude are rare, chaplains are frequently called on to alleviate travelers’ and workers’ personal crises. The chapel receives several prayer requests a day from flyers en route to see ill friends or relatives, and the ministers will often hold memorial services for airport employees who pass away.

Though the ministry at Reagan National Airport is just eight years old, airport chapels have been around since the early days of commercial air travel when the first church like it opened at Boston Logan Airport in 1950.

Over the last half-century, places of worship have become common fixtures at many major airports. The International Association of Civil Aviation Chaplains lists 39 chapels in the United States and more than 100 others internationally.

At Reagan National Airport, three brief services are held each weekend – one Protestant worship and two Catholic masses – while the room is open all hours for personal use. Most churchgoers, Tatum said, are airport employees who may not have home churches to attend.

Although only Christian services are held on a regular basis because of demand, those in charge are quick to point out the interfaith nature of the chapel, stressing that spiritual guidance is their sole intent.

“We take special care to ensure that people are encouraged in the nature of their faith, whatever that may be,” Esterline said. “Churches or mosques or synagogues don’t get built to encourage people of a different faith, which here we have a unique interfaith perspective.”

For some travelers, that multiculturalism is the appeal of airport chapels. With worshippers hailing from all corners of the world, visitors can experience a level of diversity they may not find at their churches back home.

“We don’t have a very cosmopolitan type of people where we’re from, and here you do,” said Arthur Arbogast of Albany, Ind., who attended last Sunday’s services with his wife Dolores while waiting for their flight. “Here you have people from all over the United States and all over the world, and we wouldn’t get that at home.”

Yet even as the popularity of airport chapels has risen, they remain an obscurity of sorts to the general public. While nearly all major hubs have a chapel, most smaller airports don’t, and Esterline said he frequently runs across people praying at their gates who are unaware that the chapel exists.

Still, airport ministers maintain they’re filling an important public need. As long as there are travelers seeking spiritual support, they say, airport chapels will play a role.

“There’s a lot of ministry to be done,” Esterline said. “Very nearly everyone flying today has a faith persuasion of one kind or another, and this gives them a place to express that.”