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(CNN) — What was once the gleaming pride and joy of the Soviet space program now lies covered in dirt and bird droppings in a disused hangar in Kazakhstan.

With their broken windows, missing tiles and ransacked interiors, these shuttles are a haunting -- and fascinating -- piece of space history, rarely seen by the outside world.

Indeed, when 36-year-old Russian photographer Ralph Mirebs discovered the derelict shuttles and rocket at Baikonur Cosmodrome, he was touched by the sad end for these "wonderful winged machines."

In another lifetime, these prototypes are thought to have been part of the Soviets' Buran Program, which began in 1974 and was discontinued in 1993.

For Mirebs, a lecturer in computer programming and longtime space enthusiast, it was the discovery of a lifetime.

We spoke to the urban explorer about his remarkable find.

Did you already know what was inside these buildings?

"Yes, seeing the shuttles and rocket was the main purpose of my trip to Baikonur. I had read about it in books on the history of Soviet space exploration.

"However, I did not know what state they would be in, and didn't know about the other equipment inside the hangar."

How did you get inside the hangar?

"It wasn't locked, and there were no people inside.

"When I first saw the shuttles, I marveled at their size. I was also surprised by a lot of the equipment on the walls of the hangar."

And what was it like inside?

"It was during the day, so it was very light inside the hangar. Looking at the shuttles, I admired their coolness.

"I think if they were in a good and clean condition, my photographs would not have created such a stir around the world. It's all about the contrasts."

How did you get access to the Baikonur Cosmodrome site?

"Let it remain secret."

What else is on the site?

"The hangar is located a few kilometers from the Gagarin launchpad (where cosmonaut Yuri Gagrin became the first person to fly into space, in 1961).

"And next to the shuttle hangar, there is another abandoned building housing the test model Energy-M space rocket."

What do you think should be done with the shuttles?

"I would like to see the hangar, with shuttles and equipment inside, become a museum."

You describe yourself as an "urban explorer"; what does that involve?

"I like a variety of man-made or underground places that people have left. There is a sense of mystery in these places. You never know what is waiting for you around the next corner or through the next door.

"These are places where you can touch history. There are no restrictions; it's just you and the ruin."

What is the allure of these images?

"I think because space shuttles are known around the world. They are associated with the progress of mankind, with new horizons of knowledge. And while everyone knows about the American space shuttles, less is known about the Russian models.

"Since publishing the photos, I've received two types of comments. The first are surprised that Russia still has shuttles. And the second are horrified at what condition they are in, covered in dust and bird poo.