The Chandrayaan-3 mission, which took off from the Satish Dhawan Space Center (SDSC) in Sriharikota on July 14 2:35 pm, is India’s third lunar mission and second attempt to make a soft landing on the surface of the Moon. It’s one of the several space missions lined up to go to the celestial body, including Russia’s Luna 25 mission and NASA’s Artemis II. In the past one-and-a-half-decade, there has been a renewed interest in exploring the Moon. After the last Apollo mission in the early 1970s, there was a complete lull regarding sending spacecraft there as everything that could be done on the Moon with the technology of that time had been done. Although this began to change in the 1990s, the real impetus came after Chandrayaan-1, in 2008, discovered the presence of water on the lunar surface. Here are the different kinds of moon missions that have been launched so far: *Flybys: These are the missions in which the spacecraft passed near the Moon but did not get into an orbit around it. These were either designed to study the Moon from a distance or were on their way to some other planetary body or deep space exploration and happened to pass by the celestial body. Some early examples of flyby missions were Pioneer 3 and 4 by the United States and Luna 3 of the then USSR. *Orbiters: These were spacecraft that were designed to get into a lunar orbit and carry out prolonged studies of the Moon’s surface and atmosphere. India’s Chandrayaan-1 was an Orbiter, as were 46 other Moon missions from various countries. Orbiter missions are the most common way to study a planetary body. So far, landings have been possible only on the Moon, Mars and Venus. All other planetary bodies have been studied through orbiter or flyby missions. Chandrayaan-2 mission also consisted of an orbiter, which is still operational and orbiting the Moon at an altitude of around 100 km. *Impact Mission: These are an extension of Orbiter missions. While the main spacecraft keeps going around the Moon, one or more instruments on board make an uncontrolled landing on the lunar surface. They get destroyed after the impact, but still send some useful information about the Moon while on their way. One of the instruments on Chandrayaan-1, called Moon Impact Probe, or MIP, was also made to crash land on the Moon’s surface in a similar way. ISRO claimed that the data sent by the MIP had presented additional evidence of the presence of water on the Moon, but these findings could not be published because of calibration errors. *Landers: These missions involve the soft landing of the spacecraft on the Moon. These are more complicated than the Orbiter missions. In fact, the first 11 attempted lander missions had all ended in failure. The first landing on the moon was accomplished on January 31, 1966, by the Luna 9 spacecraft of the then USSR. It also relayed the first picture from the Moon’s surface. If you want to read why Chandrayaan-2’s lander failed to make a soft landing on the lunar surface, click here. *Rovers: These are an extension of the lander missions. The lander spacecraft, because they are bulky and have to stand on legs, remain stationary after landing. The instruments on board can carry out observations and collect data from close quarters but cannot come in contact with the Moon’s surface or move around. Rovers are designed to overcome this difficulty. Rovers are special wheeled payloads on the lander that can detach themselves from the spacecraft and move around on the moon's surface, collecting very useful information that instruments within the lander would not be able to obtain. The rover onboard Vikram lander in the Chandrayaan-2 mission was called Pragyaan. *Human missions: These involve the landing of astronauts on the moon’s surface. So far only NASA of the United States has been able to land human beings on the moon. So far, six teams of two astronauts each have landed on the moon, all between 1969 and 1972. After that, no attempt has been made to land on the Moon. But with NASA’s Artemis III, currently planned for 2025, humanity is set to once again to the lunar surface in more than 50 years.
