Originally built for astronauts, vertical wind tunnels have since become popular practice areas for professional skydivers and space-bound barbershop quartets. Hone four-part harmonies while simulating flight with today’s Groupon: for $37, you get an Earn Your Wings package and a multimedia package at iFLY Orlando (a $75 total value, including tax). Today’s deal includes:

• Training session
• Flight-gear rentals
• Two one-minute flights in the vertical wind tunnel with hands-on assistance from an instructor
• Personalized flight certificate
• DVD recording of your session<p>

iFLY Orlando’s state-of-the-art indoor wind tunnel lets acrophobic and aerophobic adrenaline junkies experience the sensations of skydiving under safe conditions. Prior to the session, individuals pile on a helmet, goggles, flight suit, earplugs, knee and elbow pads, and a can of gravity repellent. An instructor runs through basic maneuvers and hand signals during a training session, then unleashes students into the vertical tunnel’s artificial, 125-mph wind current for two one-minute rotations of air-swimming. Air acrobats take home a DVD recording of their flight, as well as a personalized flight certificate. iFLY Orlando’s free observation deck allows for maximum showoffiness, so invite along an audience of hard-to-impress friends, lovers, and butlers to marvel at your simulated plummet through the heavens.