How does one of the world’s most elite restaurants remain in business, when it caters to only one diner at a time in an incredibly cramped dining room, has just 19 items on its menu and does not even provide utensils? It even has a rather unappetizing name: The Coffin Corner.

What in the world keeps an exclusive clientele, which numbers only about 100 people a year, coming back time and time again?

Maybe it’s the view.

At this bistro, seating is reserved for Air Force U-2S pilots, whose seat by the window is over 13 miles high and offers a panorama like no terrestrial establishment—a view of the curvature of the Earth.

But dining in this area of the atmosphere can be deadly; hence the restaurant’s apt, if unpleasant, name. Lose concentration while downing your first course, the aircraft’s speed can fall too low and the wings will stall; let your speed rise too high, and the critical Mach number will be surpassed and you can potentially tear the wings off the jet.

Either way: no dessert for you.

Nonetheless, “Dragon Lady” pilots have been straddling the troposphere and stratosphere for more than six decades—gathering some of the most integral imagery, electronic measurements, and significant intelligence used by the U.S. and its allied forces. But one interesting fact that tends to be overshadowed by their battlefield and research prowess is how these adrenaline junkies eat.

“It’s not uncommon to spend upwards of 12 hours flying missions in the U-2,” said U-2 pilot Maj. Jared Hieb. “When you are conducting operations for that long, its integral to maintain your nutrients, your calories, your hydration.”

Seems simple, right? Not when you consider that each pilot that steps into the Dragon Lady’s lair is wearing a pressurized spacesuit, making cramming a hoagie down their throats at The Coffin Corner restaurant a bit difficult.

Tasty paste, anyone?

Since kindergarten, and maybe into high school for some, students were constantly reminded not to eat the paste. But U-2S pilots are actually encouraged to do so. Flying on the edge of space, pilots quickly learn to “embrace the paste.”

Operating above 70,000 feet means the air pressure is so low, that if the pilot lifted their visor to eat, their blood would literally boil. In order to allow for packing in some much-needed nutrients during their long missions, special probes were engineered and installed in the helmet so pilots could slurp down their chow from what resembles a tube of toothpaste. Though the very thought may sound less than appetizing—they say it’s actually quite the opposite.

“Here, at the Combat Feeding Directorate of the Natick Soldier Research, Development and Engineering Center, we research, develop, sample, package, and distribute 19 different types of U-2 foods, which we call ‘tube food,’” said Dan Nattress, an 18-year food technologist and project officer for the tube feeding program. “Each one of our tube foods have been developed in our research kitchens by culinary and nutrition experts. However, much has changed in the 50-plus years.”

When combat feeding was first established, there was little-to-no input from the pilots as far as meal preferences were concerned. So, if you were the unlucky jock that got the Manhattan Clam Chowder—good luck keeping it down. But, in 2010, the Air Force flew Nattress and his head chef Deborah Haley to Beale Air Force Base in California to speak with the consumers. The feedback resulted in the half-century-old purees getting a well-deserved modernization.

“We didn’t know exactly what to expect when we met with the pilots, but what we quickly found out, is that they were extremely excited to meet us,” said Nattress. “Next thing we knew, we were back in the kitchen, doctoring up new recipes and making improvements to their favorite menu items.”

The outcome of the pilot surveys resulted in four product requests: key lime pie, beef stroganoff, peach melba, and the development of a breakfast item that included bacon. All were fulfilled, with the request for tubed bacon, turned into a highly anticipated entrée: hash browns with bacon.

For those that are concerned about gulping down a cold tube of chicken a la king or truffle mac and cheese, don’t be. Within the U-2 there is a specially designed tube heater that caters specifically to this psychological comfort. Imagine a car cigarette lighter, but instead of being thumb-sized, it’s 6 inches in length and 3 inches diameter—that’s what the 5-ounce tubes are warmed in.

“I always make sure I have a big breakfast before I fly, and for a typical eight to nine-hour mission, I make sure that I have three tubes in my side-pack,” Hieb said. “Every pilot has their favorite tubes. For me, I prefer the foods with fruit, like apples, peaches and pears.”

Justifiably, staying hydrated and well fed is integral to a mission of such length.

“When I’m ready to eat, I reach for the food bag on the left side of my suit, fish around for the tube I want, and prep it,” Hieb explained. “This includes me finding a food straw, screwing it into the tube, inserting the straw into the food port on my helmet, and start slowly squeezing the tube. Plus, if I want my truffle mac warmed, I throw it in the heater.”

Sounds easy enough, but the pilots must take their time and cautiously squeeze their meals.

“The first time I flew and used a tube food, it didn’t go so well—it actually exploded,” Hieb said, jokingly. “Because I was unfamiliar with the delicacy of the process, I squeezed my chocolate pudding too hard. The funny thing about the situation was that I had no idea what had happened, because you don’t always have the best sense of your immediate surroundings when you are new to wearing the suit. When I landed, my mobile pilot came up to me and asked if I enjoyed my pudding or not—I then realized it was all over the front of me.”

Food with altitude: Plus the good stuff.

Without explanation, it may seem like the chefs at Natick’s Combat Feeding Directorate just grab ingredients, throw them in a massive blender, and pack them in tubes—but the process is more complicated and deliberate. Often times it takes months of research, planning and preparation to get the recipes just right. Additionally, the Air Force has strict guidance on nutritional values for each of their 19 U-2 meals, which include nine entrees, five fruits and five deserts. They control the percentage of fats, proteins, carbohydrates, and most importantly to the pilots—they insure there is an acceptable taste.

Though all those ingredients are important for maintaining the pilots’ stamina, there was still one thing that was completely missing; a highly sought after commodity amongst the Dragon flyer community. It’s in coffee – what American’s wake up to on a daily basis: caffeine.

Yep, they now have that, too.

Included in three of the 19 tube foods are between one and three cups of coffee worth of caffeine. This inclusion is important, given the exhaustion levels driven from the cognitive and physical taxations the pilots undergo to complete a mission.

Understandably so, this is also the reason that the three caffeinated products, apple pie, chocolate pudding, and jazzy mac are hard to keep stocked. They are just that good.

Whether it be the chicken a la king, the jazzy mac and cheese with caffeine, or the delectable taste of the peach melba, one thing is certain—the Air Force and the Combat Feeding Directorate have the pilots best interests in mind. This is why both groups are continually evaluating new methods to support the physiological need of the pilots through nutritional supplementation.

“The convenience of tube foods are fantastic; they are great when you are hungry or in need of an energy boost,” Hieb said.

“But, let’s be realistic; although the food tastes good, and I get to enjoy it in a place that beats any restaurant on Earth’s surface, I probably wouldn’t order puréed hash browns and bacon at IHOP,” he said, laughing. “However, during the next set of annual surveys, I’m going to suggest that Dan and his crew find a way to package a barbacoa fajita burrito tube—but, I won’t be holding my breath.”