A historic milestone in India’s
space mission !

Kestur Vasuki, Bengaluru

Poets have since time immemorial been inspired by the beauty of the Moon in their literary creativity. On their part, the space scientists have sought to study our Earth’s only natural satellite.

Just as the US Apollo 1 mission to put man on the Moon celebrated 50 years of its launch, India successfully launched its moon mission Chandrayaan 2. After a technical glitch forced the Indian Space Research Organisation (ISRO) to defer the launch of Chandrayaan 2, it successfully launched it from the Satish Dhawan Space Centre in Sriharikota, Andhra Pradesh on Monday, 22 July.

While Chandrayaan-1 was designed just to orbit the moon and make observations without landing, Chandrayaan-2 will conduct a soft landing to study the south polar region of the Moon, a site where no earlier mission has gone. With this mission, India will become the fourth country to soft land rover on the moon after USA, Russia and China.

Pragyan Rover mounted on the ramp projecting from out of the sides of Vikram Lander (ISRO)

The scientific objectives of the mission are to look for water in the South Polar Region, to e x a m i n e scientically how the moon was formed and has evolved, and ultimately to understand the history of the solar system and the Earth.

The lunar mission, in its journey of 384,400 kms to Moon, will reach on 7 September, 2019 when the lander (Vikram) and rover (Pragyan) of the spacecraft will make a soft landing on the surface of the moon. Chandrayaan-2 is set to explore the uncharted lunar South Pole, 11 years after ISRO's successful first lunar mission-- Chandrayaan-1, which made more than 3,400 orbits around the moon and was operational for 312 days till August 29, 2009.

An artist's conception of the Chandrayaan 2 lander
and rover on the Moon. The 640-tonne GSLV Mk-III rocket called Bahubali successfully injected the 3,850-kg Chandrayaan-2 composite module into the Earth’s orbit. According to the revised flight sequence, Chandrayaan-2 would spend 23 days in the Earth’s orbit.
According to ISRO, Chandrayaan-2 is expected to spend 13 days in lunar orbit before the rover and the lander separate from the Orbiter and make their way to the surface of the Moon. The Lander and Rover are designed to work for only 14 days, equivalent to one lunar day, during which they will carry out various experiments and collect data.

An ISRO spokesperson said the lander module would separate from the Orbiter on Day 43, or September 2, and could continue to go around the Moon for another few days in a lower orbit. The actual landing would happen on September 6, as originally scheduled, or in the early hours of September 7.

ISRO Chairman K Sivan ISRO chairman K Sivan said the orbiter, with seven instruments on-board, would remain in the Moon’s orbit for a year. The orbiter is equipped with different kinds of camera to shoot high-resolution 3- D maps of the surface. It also has instruments to study the mineral composition on the Moon and the lunar atmosphere, and also to assess the abundance of water.
According to ISRO, about 16 minutes 14 seconds after lift-off, the vehicle injected Chandrayaan-2 spacecraft into an elliptical earth orbit. Immediately after spacecraft separation from the vehicle, the solar array of the spacecraft deployed automatically and ISRO Telemetry, Tracking and Command Network (ISTRAC), Bengaluru successfully took control of the spacecraft.
ISRO Chairman Dr K Sivan said “Today is a historical day for Space Science and Technology in India. I am extremely happy to announce that GSLV MkIII-M1 successfully injected Chandrayaan-2 into an orbit of 6000 Km more than the intended orbit and is better. Today is the beginning of the historical journey of India towards Moon and to land at a place near south pole to carry out scientific experiments to explore the unexplored.’

On July 15, 2019 ISRO observed a technical snag, which they fixed and corrected within 24 hours. Over the next day and a half, tests were conducted to ensure that the snag was rectified.

In the coming days, a series of orbit manoeuvres will be carried out using Chandrayaan-2’s onboard propulsion system. This will raise the spacecraft orbit in steps and then place it in the Lunar Transfer Trajectory to enable the spacecraft to travel to the vicinity of the Moon.

Bahubali and Chandrayaan

Bahubali, the GSLV Mk III is a three-stage launch vehicle developed by ISRO. The vehicle has two solid strap-ons, a core liquid booster and a cryogenic upper stage. The vehicle is designed to carry 4 ton class of satellites into Geosynchronous Transfer Orbit (GTO) or about 10 tons to Low Earth Chandrayaan-2 is India's second mission to the moon. It comprises a fully indigenous Orbiter, Lander (Vikram) and Rover (Pragyan). The Rover Pragyan is housed inside Vikram lander.

The mission objective of Chandrayaan-2 is to develop and demonstrate the key technologies for endto-end lunar mission capability, including soft-landing and roving on the lunar surface. This mission aims to further expand our knowledge about the Moon through a detailed study of its topography, mineralogy, surface chemical composition, thermo-physical characteristics and atmosphere leading to a better understanding of the origin and evolution of the Moon.

After leaving earth orbit and on entering Moon's sphere of influence, the on-board propulsion system of Chandrayaan-2 will be fired to slow down the spacecraft. This will enable it to be captured into a preliminary orbit around the Moon. Later, through a set of manoeuvres, the orbit of Chandrayaan-2 around the moon will be circularised at a height of 100 km from the lunar surface.

Subsequently, the lander will separate from the Orbiter and enter into a 100 km X 30 km orbit around the Moon. Then, it will perform a series of complex braking manoeuvres to soft land in the South polar region of the Moon on September 7, 2019.

Following this, the Rover will roll out from the lander and carries out experiments on the lunar surface for a period of 1 lunar day, which is equal to 14 Earth days. The mission life of the lander is also 1 lunar day. The Orbiter will continue its mission for a duration of one year. The orbiter had a lift-off weight of about 2,369 kg, while the lander and rover weighed 1,477 kg and 26 kg respectively. The rover can travel up to 500 m (half a kilometre) and relies on electric power generated by its solar panel for functioning.

Chandrayaan-2 has several science payloads to facilitate a more detailed understanding of the origin and evolution of the Moon. The Orbiter carries eight payloads, the lander carries three, and the rover carries two. Besides, a passive experiment is included on the lander. The Orbiter payloads will conduct remotesensing observations from a 100 km orbit while the Lander and Rover payloads will perform in-situ measurements near the landing site.

The ground facilities constitute the third vital element of Chandrayaan-2 mission. They perform the important task of receiving health information as well as scientific data from the spacecraft. They also transmit the radio commands to the spacecraft. The Ground Segment of Chandrayaan-2 consists of Indian Deep Space Network, Spacecraft Control Centre and Indian Space Science Data Centre.

The idea of undertaking an Indian scientific mission to the Moon was initially mooted at a meeting of the Indian Academy of Sciences in 1999 that was followed up by discussions in the Astronautical Society of India in 2000. Based on the recommendations made by a National Lunar Mission Task Force was constituted by the Indian Space Research Organisation, which provided an assessment on the feasibility of an Indian Mission to the Moon as well as dwelt on the focus of such a mission and its possible configuration.

A dream of Vajpayee

Atal Bihari Vajpayee Prime Minister Atal Bihari Vajpayee was responsible for the Indian Moon mission. He was the one who churned the dream of ISRO to go to moon. In his Independence Day speech at the Red Fort in 2003, Vajpayee announced the Chandrayaan project which was conceived by ISRO. He called it Chandrayaan and said the mission was a major boost to India's space program. Then the Government of India approved ISRO's proposal for the first Indian Moon Mission, called Chandrayaan-1 in November 2003.

Chandrayaan -1
Chandrayaan-1 has been the first Indian lunar mission launched on 22nd October, 2008 and was designed to study the lunar surface in terms of photogeology, chemical and mineralogical mapping, elemental abundance, radiation environment and exploration of Polar Regions of the Moon. The satellite had 11 instruments on-board which were selected to meet the specific science objectives.

The Chandrayaan-1 mission performed highresolution remote sensing of the moon in visible, near infrared (NIR), low energy X-rays and high-energy Xray regions. One of the objectives was to prepare a three-dimensional atlas (with high spatial and altitude resolution) of both near and far side of the moon. It aimed at conducting chemical and mineralogical mapping of the entire lunar surface for distribution of mineral and chemical elements such as Magnesium, Aluminium, Silicon, Calcium, Iron and Titanium as well as high atomic number elements such as Radon, Uranium & Thorium with high spatial resolution.

According to ISRO, the Moon Impact Probe of the Chandrayaan -1 has found the presence of water in the lunar soil . The Chandrayaan -1 also mapped the Apollo Moon Mission landing sites to understand more about landing of Apollo.

The data provided by the instruments onboard Chandrayaan-1, have been extensively used to pursue questions related to lunar science and applications of remotely sensed data to understand early history of lunar evolution. During the last seven years, a significant contribution to newer aspects of lunar geosciences has been addressed using data provided by Chandrayaan-1 instruments. A large number of lunar science studies initiated by Indian researchers, in particular, morphology, surface age determination and composition of the lunar surface, studies on the possible presence of magmatic as well as exogenic water on the Moon have provided enhanced thoughtful views regarding lunar evolutionary processes.

Father of India’s space mission

Vikram Sarabhai The Vikram Lander is a module named after late Dr Vikram Sarabhai, who was the former chairman of ISRO and is widely regarded as the ‘Father of the Indian Space Programme’.
Vikaram enables the delivery of the Pragyan Rover to the lunar surface while conducting a few experiments of its own. The rover will roll out once the lander has successfully landed at the desired spot. It also consists of several instruments or payloads that will be constantly carrying out experiments throughout its mission time.
It operates for 14 days or one Lunar day. During this time period, the Vikram Lander will be constantly communicating with the Indian Deep Space Network (IDSN) in Byalalu near Bengaluru. The same network will be used by the Orbiter and Rover for communications. The lander weighs 1,471 kg including the Pragyan Rover (27 kg) inside and it’s capable of generating about 650 W of electricity.

Initially, Russia’s Federal Space Agency known as Roscosmos was commissioned with developing the lander in collaboration with ISRO back in 2007. However, the delivery was postponed as Russia wasn’t able to build the lander within the deadline. After Roscosmos failed in its Fobos-Grunt mission to Mars, Russia pushed back the delivery and wasn’t able to provide the lander even by 2015. At the end, ISRO had no choice and decided to take up its development on its own.
Chandrayaan 2 will boldly 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. These insights and experiences aim at a paradigm shift in how lunar expeditions are approached for years to come — propelling further voyages into the farthest frontiers.

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.

Chandrayaan-2 will attempt 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.

Words of praise

Narendra Modi watching on a screen the successful
launch of Chandrayaan-2 Prime Minister Narendra Modi, who was watching the Chandrayaan-2 launch live showered praises on the team behind the launch .PM Modi said, "Special moments that will be etched in the annals of our glorious history. The launch of Chandrayaan-2 illustrates the prowess of our scientists and the determination of 130 crore Indians to scale new frontiers of science. Every Indian is immensely proud today."
"Efforts such as Chandrayaan-2 will further encourage our bright youngsters towards science,top quality research and innovation. Thanks to Chandrayaan, India’s Lunar Programme will get a substantial boost. Our existing knowledge of the Moon will be significantly enhanced," PM Modi added.

PM Modi also congratulated ISRO chairman K Sivan on the successful launch of Chandrayaan-2, and said, " Last week due to technical snag, launch of Chandrayaan-2 was postponed. But after that within a week, the ISRO team found out the fault promptly & took the necessary steps to resolve it. The ISRO team deserves special compliments for this."

Rajya Sabha Chairman & Vice President Venkaiah Naidu also said, "Chandrayaan-2 has been successfully launched. I extend my heartiest congratulations to our countrymen on this momentous achievement. Our scientists deserve a special compliment, their achievement has enhanced country's pride."

Defence Minister Rajnath Singh also lauded the efforts, " Congratulations to ISRO scientists on flawless launching of Chandrayaan-2. Team ISRO scripted a new chapter in India’s space history with launch of this ambitious & indigenous Mission to Moon. Nation is extremely proud of its scientists and Team ISRO."

Laudable women team

Vanitha Muthayya Ritu Karidhal All credit should go to ISRO's two women directors in charge of the Chandrayaan-2 mission.
Vanitha Muthayya is the project director and Ritu Karidhal the mission director. The Chandrayaan -2 team comprises of 30% women. Vanitha and Ritu have both worked in space research for over 20 years. Vanitha, who will be the first female project director at ISRO, is an electronics system engineer, and known to be a problem solver and data cruncher. She’s been responsible for data handling systems of India’s remote sensing satellites.
Ritu Karidhal is popularly known as rocket woman of India . She is responsible for the spacecraft's outward autonomy system. In 2013, she was associated with the Mars Orbiter Mission (MOM). “MOM was a big challenge. We had to be ready for it in 18 months. This was the first Indian satellite to have full-scale, on-board autonomy, which had the capability to rectify its own problems. And, most importantly, female scientists worked shoulder to shoulder along with male scientists to make this mission a success,” she revealed in her TEDx talk.