Already sold out on its opening night, May 15, the new TWA Hotel at John F. Kennedy International Airport, in the former 1962 TWA Flight Center designed by the architect Eero Saarinen, will have 512 mid-century-furnished rooms, an infinity pool and lounge on the roof, a shop from the Detroit-based watchmaker Shinola and a restaurant by the chef Jean-George Vongerichten.

[Look at more photos of the new TWA Hotel]

Nostalgia for both the period architecture and a defunct airline once considered the carrier to the stars is expected to be as much a driver of bookings as are Kennedy fliers enduring long layovers. But the TWA hotel is not alone among a new generation of airport hotels getting upgrades in style and amenities across the country.

As flying grows worldwide — the International Air Transport Association forecasts that passenger numbers will double in 20 years to 8.2 billion by 2037 — airports are betting they can capture some of these fliers at on-site hotels, which share revenue with their landlords. Better food, more diversions and calm settings designed to ease the stress of traveling aim to attract both long-haul fliers seeking an overnight en route and more transient airport users looking for a between-flight workout, craft cocktail or quiet plane-spotting perch.