A Princeton graduate student’s contribution to the Apollo 11 mission

When Apollo 11 lifted off for its lunar landing 50 years ago, it carried only three experiments. The German company Heraeus made one of them: the Lunar Laser Retro-Reflector, a triple-prism mirror.

Heraeus made the mirrors of ultra-pure quartz glass at the request of Princeton physics graduate student Jim Faller. He wrote a paper about placing the reflector on the moon and sending a beam of light to it. At the top of his type-written paper Faller hand-wrote, “Professor Dicke, would you see if this makes any sense.” The reflector’s lightweight appealed to NASA which approved it for Apollo 11’s historic flight.

The retro-reflector was to remain in operation for ten years, but 50 years later it remains the only piece of equipment still working and allowing scientists to conduct research.

As the world observes the 50th anniversary of moon landing, it should know that one giant step started in New Jersey with a Princeton graduate student.