She sent a message to the moon.

Ahead of the Apollo 11 moon landing in 1969, dozens of world leaders were invited to write "messages of goodwill" that were transferred onto a small silicon disc. That disc is still sitting on the surface of the moon — Neil Armstrong and Buzz Aldrin placed it just below the American flag they planted at the landing site. 

"On behalf of the British people I salute the skill and courage which have brought man to the moon," the Queen wrote in her moon message. "May this endeavour increase the knowledge and wellbeing of mankind."