Chandrayaan-2 is India’s second lunar exploration after Chandrayaan-1, which has been developed by the Indian Space Research Organization (ISRO). This mission is supposed to be launched to the moon by a Geosynchronous Satellite Launch Vehicle – Mk III. Through this exercise, the organizations aims to improve our understanding of the moon. It includes a lunar orbiter, lander (Vikram) and rover (Pragyan), all of which have been developed by India. Initially, the lander was supposed to be developed by Russia, but they cited their inability to provide the lander by 2015, following which India decided to go solo. The mission is currently entirely Indian, and attempts to soft-land on the moon’s surface at a latitude of about 70° south, that would plausibly be on a high plain between two craters. If this mission is successful, it would be the first satellite to land near the lunar South Pole.
Chandrayaan-2 was all set to head on its 3.84 lakh km voyage to the moon on Monday, July-15 2019. The ISRO had scheduled the launch from the country’s Sriharikota spaceport at 2.15 am, and the countdown was to begin on the previous day at 6.51 pm. While Chandrayaan-1 was launched in 2008 and only orbited the moon at a distance of 100 km, Chandrayaan-2 was to be the first attempt by any nation to make a landing on the moon’s mineral rich South Pole. However, the launch was called off just 56 minutes prior to the scheduled time, and a new date for the mission is yet to be announced.
According to ISRO, the objective of this mission was to use and test various new technologies and conduct new experiments. The wheeled rover was supposed to move on the lunar surface and pick up soil or rock samples for on-site chemical analysis, following which this data was to be relayed to back to Earth through Chandrayaan-2’s orbiter.
This mission was earlier orchestrated in 2013, but the space agency witnessed a big hurdle as Russia failed to provide the lander to ISRO by 2015. ISRO decided to make its own lander, albeit facing many technical glitches, they were finally successful. The first time India attempted a soft landing on the moon, Chandrayaan-1 suffered a crash landing with its impacts probe, but this time the rover was expected to make a soft landing with the lander. The rover itself weighed about 20 kg, and was supposed to function solely on solar power. It had six wheels to navigate across the surface, and was supposed to collect rock and soil samples to be analyzed, and subsequently the collected data was to be transmitted back to Earth.
The Chandrayaan-2 orbiter, which weighed 2379 kg at launch, was supposed to carry a propulsion module, including a liquid propulsion engine and on-board fuel for raising its orbit from its initial elliptical parking orbit on Earth, in which it was to be placed before launch. A high-resolution camera aboard Chandrayaan-2 was to image the planned landing site to help fine-tune the landing phase of the mission. It was also supposed to carry communication equipment to facilitate communications between the lander and rover, and the mission control center on Earth. The orbiter’s primary mission was believed to last for a year.
The lander weighed 1250 kg and was named Vikram. The Vikram lander was to detach from the orbiter and descend to a lunar orbit of 30 km × 100 km using its 800 N liquid main engines, thereby making a soft landing, deploying the rover, and performing some scientific activities for approximately 15 days. After reaching the moon the orbiter would have detached the lander and subsequently been orbiting around the moon. The orbiter was expected to work at a height of 100 km above the moon with its five payloads, with a total mass of 1400 kg.
The Pragyan rover was a 27 kilogram, 6-wheeled robotic vehicle with the ability to move autonomously within a 500 radius of the landing site. It had a 50-watt solar panel for powering its propulsion system, scientific instruments and communication equipment. The GSLV-MK3 was a 3-stage rocket, consisting of a pair of S-200 solid boosters that could be lit at the time of lift-off, at a core liquid L-110 stage that can burn hypergolic liquid fuel, and a CE-20 cryogenic upper stage that uses liquid hydrogen as fuel.
The Chandrayaan-2 was supposed to orbit around the moon and engage in the activity of remote sensing. According to the Aero Journal of India, “The payloads were supposed to collect scientific information on lunar topography, mineralogy, elemental abundance, lunar exposure and signature of hydroxyl and water ice”. After reaching the 100 km lunar orbit, the lander housing the rover was to separate from the orbiter, and post a controlled decent, the lander was expected to soft land on the lunar surface at a specified site and deploy the rover. The mission was to carry a six-wheeled rover which was to move around the landing site in semi-autonomous mode as decided by the ground commands. The instruments on the rover had been conceptualized to observe the lunar surface and send back data, which could be useful for analysis of the lunar soil.
ISRO explains on its website, “The moon is the closest cosmic body at which space discovery can be attempted and documented. It is also a promising test bed to demonstrate technologies required for deep space missions. Chandrayaan-2 attempts to foster a new age of discovery, increase our understanding of space, stimulate the advancement of technology, promote global alliances, and inspire a future generation of explorers and scientists”.
The earth and the moon are believed to have a common origin with regard to the mineral composition of their surface. Water is the strong link between them. Up until now only traces of water have been found on the moon’s sub surface, but scientists believe that the polar regions of the moon contain greater quantity of water. “The lunar south pole is especially interesting because of the lunar surface area here that remains in shadow and 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, the South Pole region has craters that are cold traps and contains fossil records of the early solar system”, explains ISRO.
The 640-tonne rocket GSLV-MK3, standing about 44 meters tall is nicknamed ‘Bahubali’, with reference to the protagonist in the successful film by the same name. In the same way that he lifts the heavy Shiva Lingam in the movie, the rocket was envisaged to carry the 3.8 tonne Chandrayaan-2 spacecraft. About 16 minutes into its flight, the GSLV-MK3 rocket priced at ₹375 crore, was expected to sling Chandrayaan-2 into an earth parking orbit.
The distance between the earth and the moon is 3.844 lakh km. On 6th September 2019, the lander Vikram was expected to make a soft landing on the moon, following which Pragyan was to roll out to conduct the experiments. This was to be a scientific mission, carrying 14 instruments distributed over the orbiter, lander and rover; such attempts have the potential to be path breaking. The project involved an assessment of the quantity of water present in the polar region, an investigation into the presence of helium-3, which is considered as a crucial energy source for future permanent stations to be erected on the moon and detection of seismic activity on the lunar surface. Other instruments would attempt to produce a three-dimensional topographical mapping of the lunar surface, therefore presenting a detailed analysis of the elemental composition of the surface, while preparing a map of the content of mineral present, and studying the solar radiation.
Scientists believe that the water in the polar regions of the moon might be attributed to its primordial origin, and thus, the water frozen in polar regions of the moon could be 3-4 billion years old. It has remained preserved due to the unique geometry of solar illumination that prevents direct sunlight from entering the craters. This revelation is a giant leap towards space exploration. Bringing water to Earth from the moon is an unfathomable dream. But the success of Chandrayaan-2 could aid us in taking this giant step. A sample of primordial water could be the way to understand the origin of water on the moon and possibly on Earth as well. It has the potential of unravelling the mystery of water in the Solar System.
Picture Courtesy- Indian Express Malayalam