50th anniversary of Apollo 11: How we came to know a lot about the Moon

The Moon has been a subject of fascination since time immemorial. It has always found a place among all kinds of stories  through astrology, poetry, myths, religion et al. More than two and a half millennia before man set his foot on the Moon, he set his mind towards understanding it. 

There are references in the works of ancient Babylonian, Greek, Indian and Chinese philosophers around 500 BCE. Throughout the next two thousand years, the Moon was studied by various astronomers. The big breakthrough, however, happened in 1609, when Galileo Galilei drew one of the first telescopic drawings of the Moon in his book Sidereus Nuncius and noted that it was not smooth but had mountains and craters. After Isaac Newton discovered gravitation, astronomy picked up speed. Over the next few centuries, science not only devised means of looking at faraway objects clearly, but also started dreaming of travelling to them one day.

Here's a brief timeline of the landmark moments of lunar exploration in modern times:

The Space war era

During the late 1950s at the height of the Cold War, the United States Army conducted a classified feasibility study that proposed the construction of a manned military outpost on the Moon called Project Horizon with the potential to conduct a wide range of missions from scientific research to nuclear Earth bombardment. The study included the possibility of conducting a lunar-based nuclear test.

1959: Soviet Union touches the Moon

The Moon was first visited by the Soviet Union’s uncrewed Luna 1 and 2 in 1959. The US sent three classes of robotic missions to prepare the way for human exploration: the Rangers (1961–1965) were impact probes, the Lunar Orbiters (1966–1967) mapped the surface to find landing sites, and the Surveyors (1966–1968) were soft landers.

Spacecraft from the Soviet Union's Luna programme were the first to accomplish a number of goals: following three unnamed, failed missions in 1958, the first human-made object to escape Earth's gravity and pass near the Moon was Luna 1; the first human-made object to impact the lunar surface was Luna 2, and the first photographs of the normally occluded far side of the Moon were made by Luna 3, all in 1959.

1961: Kennedy declares manned mission

US President John F Kennedy commits to a manned moon landing before the end of the decade.

1969: The first moon landing

The first human landing on the Moon was on July 20, 1969. During the Apollo missions of 1969–1972, 12 American astronauts walked on the Moon and used a Lunar Roving Vehicle to travel on the surface and extend their studies of soil mechanics, meteoroids, lunar ranging, magnetic fields, and solar wind. The Apollo astronauts brought back 382 kilograms (842 pounds) of rock and soil to Earth for study.

Till 1972: US repeats success despite a few hiccups

In the three intervening years,12 astronauts on five manned missions walked on the moon's surface, and six of them drove lunar roving vehicles on it. A couple of missions were aborted due to technical glitches.

Space war ends as Soviets fail

The Soviet crewed lunar programmes were a series of programmes pursued by the Soviet Union to land a man on the Moon.  The Soviet government publicly denied competing with the US but secretly pursued two programmes in the 1960s: crewed lunar flyby missions using Soyuz 7K-L1 (Zond) spacecraft launched with the Proton-K rocket, and a crewed lunar landing using Soyuz 7K-LOK and LK Lander spacecraft launched with the N1 rocket. Following the dual American successes of the first crewed lunar orbit on December 24–25, 1968 (Apollo 8) and the first Moon landing on July 20, 1969 (Apollo 11), and a series of catastrophic N1 failures, both Soviet programs were eventually brought to an end. The Proton-based Zond programme was canceled in 1970, and the N1 / L3 programme was de facto terminated in 1974 and officially canceled in 1976. 

1980s to present times: Manned missions take backseat

Sending a man to moon has not been a priority for space programmes anymore. Perhaps, because of the costs and risks involved. Those resources were seen to be better utilized with unmanned lunar probes. Moreover, mankind's curiosity of celestial bodies has gone much beyond the Moon, to galaxies millions of light years away.

However, as of April 2019, seven nations have followed the US in sending spacecraft to orbit the Moon and probe the lunar surface -- one of them being India's Chandrayaan 1 mission. The land of Aryabhatta, who was one of the first astronomers to say that the Moon reflects the Sun's light, won't stop at that. Chandrayaan-2 will be launched from Satish Dhawan Space Center at Sriharikota on-board GSLV Mk-III on July 22, 2019. A manned mission to the Earth's closest celestial companion, dubbed Gaganyaan, is also being planned by the Indian Space Research Organisation.