Chandrayaan-2 successfully entered an elliptical orbit around the Moon on Tuesday, as India officially "reached the moon" for the second time, eleven years after its first mission to detect water on the lunar surface.
Tuesday's "heart" -stopping move was named by the chairman of the Indian Space Research Organization (ISRO), K Sivan, as an "important milestone".
A successful soft landing, due to take place on September 7 at 1:15 pm, will make the Indian mission the first of all times to land near the South Pole of the Moon at a latitude of 70 degrees south of the equator.
India will be the fourth country to land on the lunar surface after the US, the former USSR and China.
"The unique requirement Chandrayaan 2 mission, which had no other country, was to reach the lunar orbit with a slope of 90 degrees. This is to ensure that the spaceship lands near the south pole of the moon. The trans-moon injection maneuver on August 1
All other lunar landings have so far been in areas about 30 to 40 degrees from the lunar equator.
Lunar Orbit Entry
It involved a high-precision transmondal injection and introduction to the lunar orbit maneuvers, which ensured that the spaceship reached its intended slope, Sivan said. "To give you the perspective, a deviation of 10 cm per second on a spacecraft moving at a speed of 10.9 km / s would have resulted in a 7 degree change in lunar orbit slope," he explained.
At 9:02 am, ISRO scientists fired the propulsion system aboard the spacecraft for 1,738 seconds (nearly 29 minutes) to reach the highly elliptical orbit of 114 x 18,072 km and an inclination of 88 degrees. In four maneuvers in the next 12 days, the orbit is reduced to 100 x 100 km and reaches a 90 degree incline.
"For almost 30 minutes, our heart has almost stopped," Sivan said. 19659002] A trans-lunar injection maneuver on August 14 threw the Chandrayaan-2 composite module (Orbiter, Lander and Rover) at a speed of 10.9 km / s towards the moon.
This maneuver increased the apogee or Earth's farthest point to 418,000 km. On August 19, around 3:00 pm, as the moon approached the spacecraft as it returned from apogee, Chandrayaan-2 entered the Moon's sphere of influence.
"When this happened, Chandrayaan-2 began to gain speed by the influence of the moon's gravity. To ensure that it enters orbit around the moon, the maneuver reduced the speed from 2.4 km / s to 2.1 km / s.
In the past, lunar missions such as US Ranger 3 of 1962 and Explorer 33 were carried out in 1966 and the Luna 6 of the USSR in 1965 dropped out and flew over the moon at that point.
Separation and Landing
The next big milestone for the mission is September 2nd. The Lander Rover separates from the orbiter.
On September 3, there will be a small maneuver to check the system, after which the space agency will review various parameters of the lander. "As soon as we have confirmed that the system is in order on September 7th, the power-driven descent will begin at 1:40 am and at 1:55 pm the lander will land at the construction site," Sivan said.
"The landing will be a terrible moment for." us. So far, we have not operated the systems aboard the lander, especially the propulsion system. This is the phase, including the powerful descent, which we will perform for the first time while we have already inserted the lunar orbit once, "he added, pointing out that only 37% of the attempted moon landings were successful.
Earlier this year, Israel's Beresheet mission crashed to the surface of the moon due to engine damage.
"The Landing Place [on September 7] is autonomously selected by the Lander Rover by comparing the images it takes with those of on. The main considerations will be that the slope of the landing pad should be less than 12 degrees and free of boulders to prevent the lander from tipping over, "Sivan said.
The Lander-Rover is said to land in a plateau between two plains, Manzinus C and Simpelius N. This region was chosen because the craters have been untouched by sunlight for billions of years and are undisturbed in documenting the formation of the solar system. The permanent shaded craters contain an estimated 100 million tons of water.
The location and availability of resources such as hydrogen, ammonia, sodium, methane, mercury, and silver at the South Pole also makes them an ideal stopover for future space exploration missions
"This is the first time that an Indian mission has been terrestrial surface lands, and also the south pole of the moon. Isro did not want to go to an area that has already been explored because it does not contribute to our scientific understanding, "said Rajeswari Rajagopalan, head of the Observer Research Foundation's nuclear and space policy initiative.
"Following our space The program will attempt more complex missions, but this remains a very complex mission, and we have to wait and see what happens on the day of landing," she added.
August 21, 2019 00:10 IST