"to visit the Moon"? It gives us the impression of "will visit the moon"

Why not just use "visited the moon"?
I seem to have the problem of understanding the use of "to + verb".
Have you any difficulty in understanding such grammatical situation?

Context:

Harrison Hagan "Jack" Schmitt (born July 3, 1935) is an American geologist, a retired NASA astronaut, university professor, and a former U.S. senator from New Mexico.

Schmitt was the first of NASA's first scientist astronaut group to fly in space, on the Apollo 17 mission in December 1972. He was the twelfth and last man to set foot on the Moon.[1] As of 2013[update] he is the only professional geologist to visit the Moon.[2] He was influential with the community of lunar geologists supporting the Apollo program, and used this to improve the geological training of the pilot-astronauts who landed on the Moon.

More:
http://en.wikipedia.org/wiki/Jack_Schmitt