how many people have been to moon and when

As of 2023, total of 12 astronauts have walked on the moon during the Apollo program's manned lunar missions. Here are the names, missions, and years of the astronauts who have been to the moon:

1. Apollo 11 (1969):

   • Neil Armstrong: Commander
   • Edwin "Buzz" Aldrin: Lunar Module Pilot

2. Apollo 12 (1969):

   • Charles "Pete" Conrad: Commander
   • Alan L. Bean: Lunar Module Pilot

3. Apollo 14 (1971):

   • Alan B. Shepard: Commander
   • Edgar D. Mitchell: Lunar Module Pilot

4. Apollo 15 (1971):

   • David R. Scott: Commander
   • James B. Irwin: Lunar Module Pilot

5. Apollo 16 (1972):

   • John W. Young: Commander
   • Charles M. Duke: Lunar Module Pilot

6. Apollo 17 (1972):

   • Eugene A. Cernan: Commander
   • Harrison H. Schmitt: Lunar Module Pilot

These astronauts conducted various scientific experiments, collected samples, and performed tasks during their lunar surface activities. Each Apollo mission had a command module pilot who remained in lunar orbit while the other two astronauts explored the moon's surface.

No humans have been on the moon since the Apollo program, but there are plans for future lunar exploration missions, such as NASA's Artemis program, which aims to send astronauts back to the moon's surface by the mid-2020s.

Also note that Apollo 13 mission was aborted due to oxygen tank explosion during the space travel.