Chandrayaan-2: India's Orbiter-Lander-Rover Mission

After the successful launch of Chandrayaan-1, Indian Space Research Organisation (ISRO), developed a second mission to the moon Chandrayaan-2.  At 2:43 p.m. IST on 22nd July 2019 the mission was launched from the second launch pad at Satish Dhawan Space Centre at Sriharikota in Andhra Pradesh by the help of Geosynchronous Satellite Launch Vehicle Mark III. 45475 km of apogee and 170 km of perigee is the planned orbit for the mission, which has a weight of about 3290kg. The mission has a lunar orbiter, a lander and a lunar Rover which is named Pragyan, all of them developed in India. Mapping the location and abundance of lunar water is the main scientific objective of the mission. On 7th September 2019, the lander and the rover will is said to land near the lunar South Pole In a high plain which lies between two craters at a latitude of about 70° South. For a period of 14 days (which equals to one lunar day) an on-site chemical analysis will be performed by the six-wheeled Pragyan rover which will move on the lunar surface in a semi-autonomous mode following the instructions from the ground commands. The data will get transferred to Earth by the orbiter and lander of Chandrayaan-2. For about one year the orbiter will keep working ina circularized lunar polar orbit of 100×100km. The launch of Chandrayaan-2 was scheduled on 14th July 2019 but got cancelled due to a technical issue which was found while filling the engine of the rocket with helium. The countdown for the launch was set at 56minutes and 24seconds before the launch. After the space agencies of the USSR, US and China, a successful landing of the mission would make India the fourth country to get a soft landing on the Moon. The mission is aimed to land at 67°S or 70°S latitude which will be the southernmost lunar landing.

The Start Of This Launch Process

For working together on the Chandrayaan-2 project, the two agencies the Russian Federal Space Agency and ISRO signed an agreement on 12th November 2019 which was approved by Indian Government in the Union Cabinet meeting held on 18th September 2008. It was agreed between the two agencies that the prime responsibility for the orbiter and Rover will be of ISRO while the lander was to be provided by Roscosmos. The scientists of both the countries conducted a joint review and with that, the design of the spacecraft got completed in August 2009. The mission got postponed from January 2013 to January 2016 as Russia was unable to develop the lander on time. It was in 2015 that Russia stated it's the inability to provide the lander, after which India decided to develop the lunar mission on its own. The launch of the spacecraft was scheduled for March 2018, which got delayed to April and then to October for conducting further tests on the vehicle. Several changes in configuration and landing sequence were planned for implementation after the fourth Comprehensive Technical Review meeting for the program on 19th June 2018 which further pushed the launch to the first half of 2019. The technical glitch that happened during the final date of launch was a leak in the 'nipple joint' of the helium gas bottle which is speculated to have been caused due to micro-shrinkage of the joint which could happen at low temperature. As the leak was not serious enough to postpone the mission, so after the repair, the mission to the moon finally got successfully launched on 22nd July 2019.

Objectives Concerned With The Launch Of Chandrayaan-2

Demonstrating the ability to soft-land on the lunar surface and also operating a robotic rover on it was the main objective concerned with the launch of Chandrayaan-2. But when it comes to Scientific goals associated, they are studies associated with mineralogy, lunar topography, the lunar exosphere, the abundance of elemental, together with signatures of water ice and hydroxyl. The launch is also concerned with providing details of the location of water on a lunar surface whose data will be used further by the proposed program of Artemis. The Chandrayaan-2 orbiter is said to help prepare the 3D maps by mapping the lunar surface and the radar of it will not only help study the water ice of south polar region but will also help map the surface together with thickness measurement of lunar regolith, etc.

Design Of The Orbiter

The orbiter design carries 5 instruments in together which are scientific and it will orbit Moon at an altitude of 100 km or 62 mi. when talking about the 5 instruments, it is being said that the 2 of them are the better version which was used in Chandrayaan-1 while the other three of them are newly used in the orbiter. 2376 kg or 5245 lb is the mass of launch made through Chandrayaan-2 which is said to have been installed with OHRC or High-Resolution Camera which will provide better or high definition observations (before there is a separation of the lander and the orbiter) of the site where the same will land. The Hindustan Aeronautics Ltd. is said to be the manufacturer of respective Orbiter’s structure which was made available to the ISRO satellite centre as on the date of 22nd June 2015. Talking about the structure, the same as a gross mass (lift-off mass) of 2,379 kg or 5,245 lb, which has dimensions 3.2 × 5.8 × 2.2 m. The Propellant mass of the orbiter is said to be 1,697 kg or 3,741 lb having a dry mass of 682 kg or 1,504 lb. The orbiter is said to be having a mission life in lunar orbit as one year with a better power generation capacity of 1000 W.

Payload Associated With The Orbiter

8 scientific instruments selected by ISRO are divided as follows:

1. 4- lander
2. 2- Rover.

As per some news obtained it was reported that NASA together with ESA was going to be an active participant in the launch and provide therein some scientific instruments but later it was said that due to weight restrictions for the orbiter the ISRO, clarified that no foreign payloads will be carried by the orbiter. Apart from same reports show that there still was a small contribution by NASA which added a small laser retroreflector therein. The same is said to help scientists associated with the measurement of exact distances to Moon and lunar libration.

The Orbiter

The orbiter is installed with varied payloads, which are mentioned below:

1. ISRO satellite in Bangalore provided Soft X-ray Spectrometer which covers a large area of the orbiter.
2. SAC provides the same with Dual Frequency L and S-Band Synthetic Aperture Radar. The same is said to look for the water ice or other important constituents out there. The same also aims to find the existence of the presence of water ice below shadowed regions of Moon.
3. PRL is said to provide the orbiter with Solar X-ray monitor which will help map major elements out there on the lunar surface.
4. SAC, Ahmedabad, provided support with Imaging IP spectrometer which will help map the lunar surface on a wide range of wavelength and make a study of minerals or water molecules or any kind of Hydroxyl present therein.
5. Apart from same Terrain mapping, camera-2 was provided by SAC, Ahmedabad together with SPL special radio anatomy of moon-bound hypersensitive ionosphere and Atmosphere-dual frequency radio science experiment.
6. Another important part of same was Chandrayaan-2 Atmospheric Compositional Explorer 2 by SPL, Thiruvananthapuram, which will help get a detailed study of the lunar exosphere
7. The orbiter is also said to have a part by SAC which will scout a better spot for landing and it is the Orbiter High-Resolution Camera. Images collected from same will help prepare a digital elevation model of lunar surface out there.

Team Members Who Made The Launch Of Chandrayaan-2 Success Starting with Project director we have Muthaya Vanitha, with Deputy Project Director as Chandrakanta Kumar. There are other members too, like Ritu Karidhal who was the mission director, Anuradha T K as programme director at ISRO satellite centre and Nandini Harinath, the deputy operation director of mars orbiter mission. These are some of the leading hands who made this launch a big success and made the country proud.