This Day in History

[Carruthers]

On this day, Apollo 10 was launched from Cape Kennedy.

Fifty years ago and a quarter of a million miles away, three astronauts carried out the dress rehearsal for one of the greatest events in human history.
On May 18, 1969, Apollo 10 lifted off from Launch Complex 39B at the Kennedy Space Center. Its mission: to return to the Moon and make the final flight tests that would pave the way for the Apollo 11 lunar landing two months later.

Though Apollo 8 had already orbited the Moon and Apollo 9 had tested the Lunar Module (LM) in Earth orbit, there were still many questions that had to be answered and tests to be conducted.
Until Apollo 10, the Apollo spacecraft, crew, mission support facilities, procedures, and communications systems had never been fully tested under actual lunar mission conditions.
Until this was done, the success of Apollo 11 was very much in doubt.

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Incidentally, the Apollo 10 Command Module was displayed at the Science Museum in London.
To the best of my knowledge it remains there today.