Youthful brilliance aside, Ray Franke to this day was never impressed with -- nor particularly proud of -- the tiny electrical relay switch he invented at Union Switch & Signal Inc. in 1959.

At 22, he had an idea to shrink the relay switch by half or more to a size smaller than a die. Key was discovering a more efficient way to wrap copper wire. Although that invention was "a flop," the persistent Mr. Franke eventually did create a miniature 26-volt switch that, to his knowledge, was the world's smallest at the time.

Fifty years later, that invention might be long forgotten in electrical history, save for one notable detail: The tiny switch, or perhaps several of them, could be collecting dust on the moon.

Mr. Franke's not sure, but the switches might have been used in the Eagle lander. The Eagle then blasted off from the moon, leaving the lander behind, and docked with the Apollo 11 command module Columbia. After the docking, the Eagle was released into lunar orbit and crashed somewhere on the moon about one month later.

If not on the moon, switches might have been used on the command module, Columbia, which splashed down July 24, 1969, in the Pacific Ocean and is now on exhibit at the Smithsonian Institution's National Air & Space Museum in Washington, D.C.

After the first moon walk, Union Switch & Signal, which made miniature relay switches for the aerospace industry, advertised Mr. Franke's invention and credited it with helping America land on the moon.

But to this day, Mr. Franke, 72, of Shaler, knows only that the switch was used in the moon mission. And the mystery may never be resolved without a considerable search of NASA archives, contracts and blueprints.

Key to Mr. Franke's invention was its size. It was so small it had to be made in a clean room under a microscope.

After the invention became a marketable product, Union Switch & Signal got the device on the military's qualified products list, which meant it could be used in military projects. Its small size proved a plus for NASA, whose goal was to reduce the size and weight of Apollo 11 command module and Eagle. The switch could have been used to start engines during the landing or blast off, among other uses. Whatever role the switch performed, it was successful on the moon.

"It is my understanding it was on the lunar lander," Mr. Franke said. "Whether it returned or is still up there, I don't know.

"In the early 1970s, the company advertised it, trying to convince everyone that we were innovative," he said. "At a minimum, I got an 'attaboy.' I took it in stride. Since then I've done things significantly more innovative, but I was only 22 at the time [of the invention]."

Mr. Franke still works part time for Ansaldo STS, an electronics company that bought Union Switch & Signal, which had been based in Swissvale.

"It was a neat little component -- a good device," he said. "I'll take that much credit."