Skunk Works

Kelly was pleased with our progress. On the drawing boards was a design for the dart-shaped CL-400 that would fly at 100,000 feet at Mach 2.5 with a 3,000-mile range. The body was enormous, dwarfing any airplane on the drawing boards. On the playing field at Yankee Stadium, for example, the tail would cover home plate and the nose nudge the right-field foul pole, 296 feet away. It was more than twice the size of the B-52 bomber. And the reason the body was so gigantic was that it would carry a fuel load of liquid hydrogen weighing 162,850 pounds, making it the world’s largest thermos bottle. Flying at more than twice the speed of sound, the outer shell of the body would blaze from heat friction above 350 degrees F while the inside skin would hold the frosty fuel at temperatures of minus 400 F—an 800-degree temperature differential that represented an awesomely complicated thermodynamic problem. Undaunted, Kelly promised to have a prototype ready in eighteen months.

The Air Force allocated $96 million, and we were off and running. The code name was Suntan, and it was classified above top secret. That was a first even for us. Only twenty-five people at the Skunk Works were cleared to work on it. And around the time that the U-2 overflights of Russia revealed that no bomber gap existed, the CIA dropped a bombshell by presenting Eisenhower with strong indications that the Russians were crashing development of a hydrogen-powered airplane of their own.

They had released from a Siberian gulag a brilliant scientist named Pyotr Kapitsa, who had been arrested by Stalin in 1946 for refusing to work on their atomic bomb development. Kapitsa was Russia’s foremost expert on liquid hydrogen. He was now back in Moscow working on a top secret program. Allen Dulles and Dick Bissell agreed that it was likely the Russians were rushing development of a liquid hydrogen–propelled interceptor that could easily climb to the U-2’s heights and shoot it down. The CIA came to Kelly and asked his opinion. “They might be working their tails off to get this airplane into production,” he told Dulles, “but they won’t have a prototype finished in less than three years or even longer.”

So suddenly we found ourselves in a contest with the Russians to build the first hydrogen-powered airplane. The Air Force contracted with Pratt & Whitney to build the engines at its Florida complex, and a special hydrogen liquefaction plant was constructed to fuel the engine tests. The Massachusetts Institute of Technology was working on an inertial guidance system, and Kelly ordered two and a half miles of aluminum extrusions in advance of construction.

But six months into the project the furrows deepened on Kelly’s brow. He was growing increasingly concerned that the airplane would not have adequate range to get the job done. “We’ve crammed the fuselage with as much fuel as it can hold,” he complained at our weekly progress meeting, “and we can’t extend the range by more than twenty-five hundred miles.” The problem was complicated by the fact that the Air Force engineers at Wright Field had come up with wildly more optimistic figures. They predicted a range of thirty-five hundred miles, which was more than acceptable, matching the U-2’s. Kelly stepped up design changes and wind tunnel testing of various wooden models but remained convinced that Wright Field’s calculations were dead wrong.

Meanwhile I was having troubles of my own. Inside a hangar I built a half-scale model of the fuselage and constructed a double-walled fuel tank. I wanted to simulate supersonic flight temperatures, so I installed a wooden-framed oven over the fuselage to heat it to 350 degrees F or higher. And on a clammy spring evening in late 1959, the damned stove caught on fire only a few feet away from a storage tank containing seven hundred gallons of liquid hydrogen. We tried to put the fire out with commercial fire extinguishers but they had little effect. I sure as hell was reluctant to call the Burbank Fire Department and have them discover all that liquid hydrogen. I thought fast and told the workers, “Okay, dump that damned hydrogen. Bleed that tank dry.” By now the hanger was filled with smoke and flames were visible above the model fuselage. The workers looked at me funny but did what I told them, and on that damp evening the cold hydrogen filled that hangar with a fog five feet thick. All we could see of one another were our heads. If it wasn’t for the fire we might have had a good laugh. But the fire department noisily arrived at our hangar door and the next problem was that security didn’t want to let them in. The firemen weren’t cleared and this was a project above top secret. I couldn’t believe the stupidity, but I took one of the security guys aside and said, “The whole place is under fog. They won’t see what’s on fire.”

“What is inside?” the fire chief asked me.

“National security stuff. Can’t tell you,” I replied.