Lunar Mission: What is the story of 15 minutes of panic for the lunar mission, why is a safe landing on the moon so difficult?

Posted on 23rd Aug 2023 by rohit kumar

The much-awaited Chandrayaan-3 mission of the Indian Space Research Organization (ISRO) will land on the lunar surface on the evening of 23 August. Before this favorable conditions for Vikram Lander will be identified. The final decision on landing or not landing the vehicle will be taken exactly two hours before the scheduled time for landing. If Chandrayaan-3 is not landed on August 23, then it can be landed on the moon on August 27 as well.

 

Earlier ISRO had launched Chandrayaan-2, but it could not land safely on the surface. Landing on the lunar surface is the most difficult phase of the entire mission. Meanwhile, it is important to know why it is difficult to land on the surface of the Moon. Why the safe landing of Chandrayaan-2 could not be done? What is the story of 15 minutes of panic for the lunar mission? Let\'s know...

 

First, know what is Chandrayaan-3.

According to ISRO officials, the Chandrayaan-3 mission is the next phase of Chandrayaan-2, which will land on the lunar surface and conduct tests. It will have a propulsion module, a lander, and a rover. Chandrayaan-3\'s focus is on making a safe landing on the lunar surface. New equipment has been created for the success of the mission. The algorithms have been improved. The reasons why the Chandrayaan-2 mission could not land on the lunar surface have been focused on.

 

What happened to the first two missions?

Earlier on 22 July 2019, Chandrayaan-2 was launched. It was the first space mission by any country to perform a soft landing on the south-polar region of the Moon. However, the Chandrayaan-2 mission\'s Vikram lunar lander crashed on the Moon on 6 September 2019. About three months later, NASA discovered its debris. Despite this, the mission was not a complete failure. This was because the orbiter component of the mission continued to function smoothly and collected a lot of new data, giving ISRO new information about the Moon and its environment.

 

Unlike Chandrayaan-1, Chandrayaan-2 attempted to soft-land its Vikram module on the lunar surface. Along with this, Chandrayaan-2 deployed the six-wheeled Pragyan Rover to conduct much more scientific research. The take-off weight of Chandrayaan-1 was 1380 kg, while that of Chandrayaan-2 was 3850 kg.

 

Chandrayaan-1 was India\'s first lunar mission, launched on 22 October 2008 from the Satish Dhawan Space Center in Sriharikota, Andhra Pradesh. As of 29 August 2009, it remained operational for 312 days and completed more than 3,400 lunar orbits. It lost contact after battling technical difficulties for almost a year.

 

Apart from ISRO, did anyone else miss its mission?

In the same month, on August 10, the Luna 25 mission was launched by Russia. However, this mission did not succeed in soft landing on the Moon and this is the fourth such case in recent times. In April this year, the Japanese company Ispace launched a satellite named Hakuto-R Mission-1. However, this mission was not successful in soft landing on the Moon. Israeli company SpaceIL and India\'s space agency ISRO both attempted in 2019 but failed to land safely on the moon. The last successful soft landing was made in the same year by China\'s Change 4 lander, which was also the first satellite to land on the far side of the Moon. Apart from China, Russia and the US are among the countries to safely deliver scientific equipment to the Moon.

 

Why is it so difficult to land on the moon?

The Moon doesn\'t have enough air and too much dust. When a spacecraft lands on the Moon or Mars, it has to slow down so that the gravity of its target pulls it in.

 

As with Earth and, to a lesser extent, Mars, the biggest initial challenge is the planet\'s atmosphere. When a vehicle leaves the vacuum of space and collides with a large wall of gas, the collision generates a lot of heat energy. That\'s why spacecraft returning to Earth or landing on Mars carry heat shielding to protect themselves. But they can use to carefully slow themselves down once they enter the atmosphere.

 

However, there is hardly any atmosphere on the Moon so a is not an option. This is convenient when it comes to heat dissipation, as the vehicle does not need to carry extra weight. But it needs to be able to use its engines to slow down and abort the landing. It also means that limited reserves of fuel leave little room for error.

 

The second concern that comes with having enough fuel is that the Moon\'s surface is covered with a material called regolith. Regolith is a mixture of dust, rock, and glass fragments. There was also a concern during the crewed Apollo missions to the Moon that a large spacecraft could sink into the surface.

 

But the real problem astronauts face is that dust tends to accumulate everywhere and a considerable amount of gravity helps to keep it in check. This also applies to landing. When a spacecraft is landing, its rocket thrusters throw up dust that affects its sensors. The fault steers the vehicle in the wrong direction, turning a flat landing area into a crater.

There is talk of 15 minutes of panic while landing a spacecraft on the moon, what is that?

In the last four years, government and private space agencies of four countries India, Israel, Japan, and now Russia have tried to land their spacecraft on the Moon, but could not meet their objectives. All four missions encountered problems during the final stage i.e. the landing process and crashed on the lunar surface.

 

Before the Chandrayaan-2 mission in 2019, the then chairman of ISRO K Sivan had called the final phase of the landing as \'15 minutes of terror\'. This statement reflects the difficulties involved in descending from lunar orbit to the surface of the Moon. This is the reason why it is considered to be the most difficult part of the lunar mission.

 

On September 6, 2019, India\'s ambitious lunar mission Chandrayaan-2 was lost after coming just two kilometers from the moon. Lander Vikram, moving towards the lunar surface, lost contact 2.1 kilometers before the lunar surface. Everything was going well just before this, but due to this untoward incident, sudden silence spread in ISRO\'s control room. Then ISRO chairman K. Sivan had described these moments as \'15 minutes of terror\'. Of. Sivan had said that Vikram went through four stages during the last 15 minutes of landing.

 

In the first stage, Chandrayaan-2 came from 30 km to 7.4 km. The whole process took 10 minutes. After this ISRO did not have control over it. In the second stage, Chandrayaan-2 descended from 7.5 km to five km. In this, Chandrayaan took 38 seconds. During this, four engines of Vikram started. Due to this, his speed was reduced from 550 km to 330 km per hour.

 

ISRO lost communication with the lander Vikram during the third stage. Actually, in the third phase, Chandrayaan-2 had to descend below five km. It was supposed to take 89 seconds, but ISRO lost contact. After this, no information was received.

 

In the fourth stage, 400 m. 100 m from the top Vikram had to stay till There are two craters there. The first is Maginius C and the second is Simpelius. The distance between these two craters is 1.6 km from each other. Lander Vikram had to select one of these sites. 100 m while descending in his direction. 10 m from the height of It was to take 65 seconds to reach.

 

Then 10 m. The fifth engine of the lander was to start after reaching the height of. This had to slow down the pace further. It would take a total of 13 seconds to reach the surface from here. But unfortunately, this process could not be completed.

 

Also Read: Luna-25 Crashed On Moon: Russia missed out on creating history, these are five reasons for Luna-25 mission failure