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Saturday, September 7, 2019

Nation is proud of Chandrayaan 2 ~ attempt to soft land at South pole of Moon


Nation was awake ~ the midnight of 6th Sept [rather early hours of 7th Sept 2019] – not any movie show or World Cup Cricket or football or any such event.  The Nation waited with bated breathe for that happen ~ a lunar soft landing ! close too close !!

Just 2.1 km short of landing, all connections with the Vikram Lander was lost. The Lander, which had detached from Chandrayaan 2’s Orbiter on September 2, had been manoeuvring around the Moon for nearly five days.   The lunar south pole is of special interest to scientists because of the occurrence of water ice in permanently shadowed areas around it. The lunar south pole region features craters that are unique in that the near-constant sunlight does not reach their interior. Such craters are cold traps that contain a fossil record of hydrogen, water ice, and other volatiles dating from the early Solar System. In contrast, the lunar north pole region exhibits a much lower quantity of similarly sheltered craters.

After the unsuccessful attempt by Luna 1 to land on the Moon in 1959, the Soviet Union performed the first hard Moon landing - "hard" meaning the spacecraft intentionally crashes into the Moon – later that same year with the Luna 2 spacecraft, a feat the U.S. duplicated in 1962 with Ranger 4. Since then, twelve Soviet and U.S. spacecraft have used braking rockets (retrorockets) to make soft landings and perform scientific operations on the lunar surface, between 1966 and 1976. In 1966 the USSR accomplished the first soft landings and took the first pictures from the lunar surface during the Luna 9 and Luna 13 missions. The U.S. followed with five unmanned Surveyor soft landings.  Many missions were failures at launch. In addition, several uncrewed landing missions achieved the Lunar surface but were unsuccessful, including: Luna 15, Luna 18, and Luna 23 all crashed on landing; and the U.S. Surveyor 4 lost all radio contact only moments before its landing.

Chandrayaan 2  is the  Indian lunar mission that boldly challenged to  go where no country has ever gone before — the Moon's south polar region. Through this effort, the aim is to improve our understanding of the Moon — discoveries that will benefit India and humanity as a whole. Moon provides the best linkage to Earth’s early history. It offers an undisturbed historical record of the inner Solar system environment. Though there are a few mature models, the origin of Moon still needs further explanations. Evidence for water molecules discovered by Chandrayaan-1, requires further studies on the extent of water molecule distribution on the surface, below the surface and in the tenuous lunar exosphere to address the origin of water on Moon.

The lunar South Pole is especially interesting because of the lunar surface area here that remains in shadow is much larger than that at the North Pole. There is a possibility of the presence of water in permanently shadowed areas around it. In addition, South Pole region has craters that are cold traps and contain a fossil record of the early Solar System. Chandrayaan-2 attempted  to soft land the lander -Vikram and rover- Pragyan in a high plain between two craters, Manzinus C and Simpelius N, at a latitude of about 70° south.

Reflecting its growth as a global power, India has achieved some impressive progress in space lately. In the past decade, the Indian Space Research Organization (ISRO) has sent robotic spacecraft into orbit, to the Moon, and also to Mars. And today, they made their first attempt at a soft lunar landing by sending the Vikram lander towards the surface of the Moon. This move would have made India the fourth nation in the world to land a spacecraft on the lunar surface. The landing sequence went as planned until the lander reached an altitude of 2.1 km (1.3 mi) above the surface. Unfortunately, communications with the lander was lost at that point and it is unclear whether the lander crashed. At the moment, the ISRO is analyzing data collected by the orbiter to determine what happened. 

For all those watching ~ closer to 2 km of the planned surface - jubilation turned to despair as the Chandrayaan-2 lander lost contact with Earth minutes before it was to land on the Moon. All was going well for the Vikram lander, which was descending on to the lunar surface as planned. Scientists at the Indian Space Research Organisation were visibly excited and loudly cheered and clapped as Chandrayaan-2's Vikram lander successfully aced various stages of its lunar descent. The stage was set and the big bang announcement -- Chandrayaan-2 lands on the Moon! -- was around the corner when suddenly the Isro control room in Bengaluru went silent. For those watching the live visuals on television, there was no clue as to what was happening apart from the worried faces of the Isro scientists.

And then, then word came in that Isro had lost touch with the Vikram lander.  At 1:40 am: The Chandrayaan-2 lander Vikram began its descent 1:50 am: The Chandrayaan-2 lander Vikram successfully completed its rough braking phase and entered into a fine braking mode. At this point, the Vikram lander was around 4 kilometres away from the lunar surface. .. minutes later updates stopped coming !   Shortly after 2 am, Isro chief K Sivan was seen going up to the viewing gallery where PM Narendra Modi was present. Sivan briefed the prime minister, who patted him on his back before proceeding to leave the viewing gallery.

For a better understanding .. .. the Vikram lander is part of the Chandrayaan-2  which consisted of an orbiter, lander and rover element. This mission launched from Earth on July 22nd, 2019 and achieved a lunar orbit by August 20th. This was followed by a series of orbital maneuvers designed to put the spacecraft into a polar orbit about 100 km (62 mi) above the Moon’s surface. Earlier this week (Monday, September 2nd) the Vikram lander successfully separated from the Chandrayaan-2 orbiter. Multiple maneuvers were then conducted to make sure the lander was in the right position to achieve a soft landing in a high plain region between the Manzinus C and Simpelius N caters (located around 70° latitude South).

Prior to the landing, this region was imaged in order to find a safe and hazard-free landing zone. After touching down, the lander was to deploy the Pragyan (“Wisdom” in Hindi) rover, which would conduct a series of experiments for a period of 14 days (or one lunar day). These experiments would gather data that is vital to the Chandrayaan program.

Prime Minister Narendra Modi today addressed scientists at ISRO, hours after India's attempt to make a "soft" or controlled landing on the Moon's surface and probe the unexplored lunar South Pole suffered a setback.    PM Shri Narendra Modiji  sought to boost the morale of the scientists after the Chandrayaan heartbreak, and praised their "resilience and tenacity". Speaking at the ISRO Control Centre in Bengaluru, he told the scientists: "India is with you! You are exceptional professionals who have made an incredible contribution to national progress".

Like any voyage to a world beyond Earth, Vikram’s flight was a risky endeavor, requiring the lander to slow itself down to a near standstill, autonomously scan for surface obstacles, and then take steps to avoid them during touchdown. The majority of attempts to land robots on the moon have ended in failure, either during launch or on the way to the surface. “Even though we got a successful lunar orbital insertion, landing is the terrifying moment,” Sivan said in an August press conference. In an interview before the attempt, Dana Hurley, a planetary scientist at Johns Hopkins University’s Applied Physics Laboratory, expressed the nervousness that planetary scientists around the world feel with every spacecraft landing—because they know all too well what can go wrong.

The Lander of Chandrayaan 2 had been  named Vikram after Dr Vikram A Sarabhai, the Father of the Indian Space Programme. It was  designed to function for one lunar day, which is equivalent to about 14 Earth days. The Lander was designed to execute a soft landing on the lunar surface after which a  Rover,  a 6-wheeled robotic vehicle named Pragyan, which translates to 'wisdom' in Sanskrit was to come out and put imprints of India on the moon.  For the time being, it is unclear whether or not the lander crashed or not. And while the ISRO looks over the mission data to determine why communications were lost, there has been an outpouring of support from around the country.

On 11 April 2019, Israeli space company SpaceIL attempted to land the first privately-funded mission on to the Moon safely. While the mission failed in the final moments before it reached the surface, it seems the spacecraft might have tainted the moon's surface with tardigrades, or water bears, from Earth.

With regards – S. Sampathkumar
7th Sept. 2019.

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