The Indian Space Research Organisation (ISRO) has successfully launched its second mission to moon, named Chandrayaan-2, abroad a Geosynchronous Satellite Launch Vehicle (GSLV) MkIII-M1 rocket on July 22.
The GSLV MkIII-M1 vehicle lifted off from the Second Launch Pad at the Satish Dhawan Space Centre SHAR (SDSC SHAR), Sriharikota at the scheduled launch time of 1443 Hrs Indian Standard Time with the ignition of its two S200 solid strap-on motors. The flight marks the first operational flight of the GSLV Mk III.
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 automatically got deployed and ISRO Telemetry, Tracking and Command Network (ISTRAC), Bengaluru successfully took control of the spacecraft.
The spacecraft is now revolving round the earth with a perigee (nearest point to Earth) of 169.7 km and an apogee (farthest point to Earth) of 45,475 km.
Launch of Chandrayaan-2 was originally scheduled for 15 July 2019 2:51 IST but was called off due to a technical snag noticed at around one hour before launch.
ISRO Chairman Dr. K Sivan congratulated the launch vehicle and satellite teams involved in this challenging mission. “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.”
Chandrayaan-2 is India’s second mission to the Moon and comprises a fully indigenous Orbiter, a Lander (Vikram) and Rover (Pragyan). India’s first mission to Moon, named Chandrayaan-1, only had an orbiter, and an impactor – Moon Impact Probe (MIP) – which conducted controlled impact on the Moon’s surface.
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 and relies on electric power generated by its solar panel for functioning. The Pragyan rover is housed inside Vikram lander.
The mission objective of Chandrayaan-2 is to develop and demonstrate the key technologies for end-to-end lunar mission capability, including soft-landing and roving on the lunar surface. On the science front, 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.
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 remote-sensing observations from a 100 km orbit while the Lander and Rover payloads will perform in-situ measurements near the landing site.
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.
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 100 km height from the lunar surface.
Subsequently, the lander will separate from the Orbiter and enters into a 100 km X 30 km orbit around the Moon. It will then perform a series of complex maneuvers comprising of rough braking and fine braking. Imaging of the landing site region prior to landing will be done for finding safe and hazard-free zones. Vikram will attempt to make a soft landing in a high plain between two craters — Manzinus C and Simpelius N — at a latitude of about 70° 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.
GSLV Mk III is a three-stage launch vehicle developed by ISRO. The vehicle has two solid strap-on boosters, 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 Orbit (LEO).