Washing skyscraper windows remains a perilous profession, requiring workers to have the reflexes of a trapeze performer high above city streets. The dramatic rescue Wednesday of two New York City window cleaners — stranded nearly 70 stories off the World Trade Center tower — has put a fresh spotlight on a high-risk job that often begins with modest pay.

And the practice of putting men and women aloft to scrub windows isn’t expected to change any time soon, as the use of labor-saving robots to replace workers has yet to gain a foothold across the industry, experts say. “I guess with our modern technology, we can put people on the moon, but we can’t develop the equipment that can work across the board,” Mark Reinhart, the president of the International Window Cleaning Association, said Thursday.

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One product on the market for homeowners operates like a robotic vacuum cleaner, moving up and down the surface of the windowpane. There are other unmanned machines that scrub larger buildings, typically around 10 stories or lower — but they’re only useful on a handful of structures, said Stefan Bright, the International Window Cleaning Association’s safety director. “They have to be all glass because brick and windows can really mess things up,” Bright said.

Despite the inherent dangers involved in the industry, it can take a while before a window washer sees a soaring salary. A window cleaner washing storefronts or homes might only earn $12 to $15 per hour, Reinhart said. But someone doing larger commercial properties, including skyscrapers, could earn $15 to $25 per hour. In New York, where the risks are presumably higher because of the dizzying heights, it’s not unheard of for veterans with all the know-how to reach $29 to $35 per hour. Getting paid top dollar, however, requires months and years of experience with equipment and certification.

With an emphasis on safety training a top priority, there is a silver lining: Deaths remain rare in the industry. There has been one high-rise fatality per year in the last four years in the U.S., according to the International Window Cleaning Association. That’s with an estimated 1.5 million “exposures” — when workers are on the sides of buildings — a year.

Window washers who spoke with NBC News said they’re in no rush to see their jobs taken over by new technology. This work is demanding but steady, said Brent Weingard, who’s washed skyscrapers in Manhattan as tall as 60 stories. “Some of us think there’s an art to what we do,” he said. “I’ve seen the machines, but I still believe a man on the glass washing windows does it best.”

IN-DEPTH

— Erik Ortiz and Kate Snow