Moon is the only natural satellite of the earth. Due to its size and composition, moon is classified as the terrestrial planet.
It is 380,000 km from the Earth and its diameter at the equator is 3,476 km while its mass is only 1/81 of the mass of the earth. Since moon's revolution around the earth and rotation on its axis requires 27.32 days, moon rotates with the same side always facing the earth.
Being the closest companion of earth, moon has always been an object of mankind's space exploration. A great number of space probes have circled and landed on the surface of moon. 12 astronauts have conducted survey on the surface of moon. It is possible to observe about 59 percent of moon's surface from earth.
In 1959, soviet Luna 3 took pictures of the far side of the moon. Apollo space program helped in analyzing lunar rocks and study the chemical composition of the moon, thus contributing great deal to the research of origin of moon.
On July 20, 1969, the human race accomplished its single greatest technological achievement of all time when a human first set foot on another celestial body.
Apollo –11 was the first manned mission to moon. Its crewmembers were:
Neil A. Armstrong, Commander
Edwin E. Aldrin, Jr., Lunar Module Pilot
Michael Collins, Command Module Pilot
Six hours after the landing of Apollo-11 at 4:17 pm eastern daylight time, Neil Armstrong took the first step. Aldrin shortly joined him and both of them spent 2 1/2 hours on the surface of the moon and took 46 pounds of the lunar rocks to the earth surface. Apollo-11 achieved its primary mission of performing a manned lunar landing and returning the mission safely to earth.
The Apollo –11 spacecraft is made up of 3 sections
Command module (CM)- Columbia, crew quarter and flight control section
The service module(SM) for the propulsion and spacecraft support system
Lunar module (LM)-eagle
Launch escape system and adapter are special purpose units that are abandoned early in the mission once their purpose is over.