It is extremely rare for a civilian – even a journalist – to be able to fly in the back seat of a U-2. So-called DV (Distinguished Visitor) flights are usually offered to high-ranking military officers.

For those who don’t know, the U-2 is an American spy plane that has been gathering intelligence for nearly seven decades. In 1960, pilot Gary Powers was shot down by a surface-to-air missile while taking secret photos at an altitude of over 70,000 feet above the former Soviet Union.

Powers managed to escape from the plane and survive, but was imprisoned in the USSR for two years. President John F. Kennedy eventually secured Powers’ early release in 1962. The Cold War incident attracted international attention and introduced the world to high-altitude espionage.

In 2018, I visited Beale Air Force Base near Sacramento, California, where the venerable U-2s are housed. I experienced a flight in a T-38 trainer aircraft, “chased” U-2s on landing in a Dodge Charger—and, to see if I could withstand the claustrophobia, was squeezed into the tight yellow spacesuit that pilots wear when they ascend to the edge of space.

My ultimate goal was a U-2 flight. But planning it proved much more difficult. After several postponements and disappointments, as well as the Covid-19 pandemic, I finally got my chance last week. (Special thanks to Charlene Spade for helping make it happen.)

The three-day training program before my flight turned out to be surprisingly strenuous and extensive. The reason: the heavy pressure suit you have to wear. At around 60,000 feet above sea level – the Armstrong Line – the blood boils, so high-flying U-2 pilots must be protected from such hostile conditions as they kiss the skies. And although a two-seat U-2 cockpit is partially pressurized – up to 29,000 feet, the height of Mount Everest – that altitude is still not enough for humans to function for long periods of time.

Then there is a sudden loss of pressure in the cabin. If that were to happen at, say, 70,000 feet, the pilot would be dead within seconds without the additional protection provided by the suit.

I’ve flown supersonic in the tail of six different fighter jets, including the F-15, F-16 and F-18, and have been subjected to forces up to 9 Gs, but I’ve never experienced the rigors of preparing for such a flight. For example, simply removing and inserting pins to activate and deactivate the ejection seat is pretty easy in the average fighter jet. Why? Because you don’t have to contend with the inflated suit and cumbersome gloves. It was difficult.

After receiving an hour of 100 percent oxygen in our spacesuits to remove the nitrogen from our blood, my pilot Jethro and I were escorted to a transport and taken to the aircraft. There, the oxygen we had been breathing was taken from us and we were hooked up to the aircraft’s. Once strapped in, the takeoff is steep, about 40 degrees. It only takes about 45 minutes to reach apogee.

Up there, at 70,000 feet, it’s extremely peaceful. Jethro put the plane into autopilot mode and it felt like we were just floating. Everything below us looked tiny. Visibility was hundreds of miles in every direction. Still, we could see landmarks like Lake Tahoe, Beale AFB, El Capitan, and the Golden Gate Bridge.

At one point, a commercial airliner flew over the clouds far below us. We were more than twice as high as it was flying. The thing resembled an ant crawling slowly on a bed of snow. Smoke from the California wildfires seeped into the valleys between the mountains like an insidious poison gas. And the sky above us was pitch black like space, and the horizon was noticeably curved. A blue, thin atmosphere hung over it.

Jethro mused that I was the tallest person on Earth at that moment, aside from the astronauts on the International Space Station. I corrected him by saying that “we” were the tallest people. He laughingly corrected me by saying that I was taller because my cockpit was a little higher than his. I’ll take that.

Our entire flight lasted about two and a half hours, half of it at 70,000 feet. When it was over, I felt a mixture of elation and sadness—elation because I had just participated in one of the most amazing experiences of my life, but also sadness because I knew I would never be up there again.

(Editor’s note: This is part of a series on U-2 flights. More parts coming soon, including interviews with the pilots, base maintenance and security personnel, pursuit pilots, etc. Stay tuned to the Forbes Lifestyle channel.)