In September 2008, the Chandrayaan-2 mission was approved by the government for a cost of Rs 425 crore. It is India’s second mission to the moon. It aims to explore the Moon’s south polar region. It was launched onboard India’s most powerful launcher – GSLV MK-III.
GSLV Mk-III:
- Developed by ISRO, the Geosynchronous Satellite Launch Vehicle Mark-III is a three-stage vehicle.
- Primarily designed to launch communication satellites into geostationary orbit.
- It has a mass of 640 tonnes that can accommodate up to 8,000 kg payload to LEO and 4000 kg payload to GTO.
- GSLV Mk-III vehicle is powered by two solid motor strap-ons (S200), a liquid propellant core stage (L110) and a cryogenic stage (C25), that has been designed for carrying the four-tonne class satellites.
- The C25 is powered by CE-20, India’s largest cryogenic engine, designed and developed by the Liquid Propulsion Systems Centre
Timeline
- July 22: Chandrayaan 2 launched
- August 14: Successfully enters Lunar Transfer Trajectory
- August 20: Successfully enters Lunar orbit
- September 2: Vikram successfully separates from orbitor
- September 7: India attempted to make a soft landing on to the lunar surface. Communication from Vikram lander was lost
The mission payloads
Terrain Mapping Camera which will generate a Digital Elevation Model (DEM) of the entire moon, Chandrayaan 2 Large Area Soft X-ray Spectrometer which will test the elemental composition of the Moon’s surface Solar X-Ray Monitor which will provide solar X-ray spectrum inputs for CLASS.
Components
Chandrayaan-2 to have 3 components — Orbiter, Lander and Rover
The lander, rover and orbiter will perform mineralogical and elemental studies of the lunar surface
Orbiter
- Orbiter, with scientific payloads, would orbit around the moon
- The orbiter is deployed at an altitude of 100 kilometers above the surface of the Moon.
- Orbiter will have a lifespan of 7.5 years not just 1 year as said earlier as there is lot of fuel left in it.
Lander (Vikram):
- This was first time that ISRO attempted to soft-land a module in extra-terrestrial Space.
- Once the Lander and Rover, enter the Moon’s gravity, they would be in a state of free fall. That could end up in crash-landing and destruction of instrument.
- Because of lack of air to provide drag, these instruments cannot make use of parachute like technologies.
- To enable a smooth landing, the speed of the Lander just ahead of touchdown should be 6 kilometres per hour or less.
Rover (Pragyan):
- The Rover, a six-wheeled solar-powered vehicle, will detach itself and slowly crawl on the surface, making observations and collecting data.
- It will be equipped with two instruments, the primary objective is to study the composition of the surface near the lunar landing site, and determine its abundance of various elements.
- It is designed in such a way that it will have power to spend a lunar day or 14 Earth days on Moon’s surface.
Outcome
Lander Vikram lost all communication with the ground station during the last two minutes when it was just 2.1 km above the lunar surface.All simulations, testing and verification were done several times on earth. But there were uncertainties involved in executing it on the moon. The moon has no atmosphere and the gravity is one-sixth of that of earth, and actions have to be performed accordingly. It could not control the velocity during the last two minutes and could not achieve a soft landing on the moon.
The orbiter, however, continues to revolve around the moon at an altitude of 100 km above the surface and would continue the Chandrayaan-2’s exploration.
Orbiter will do the following
- Terrain Mapping camera 2 will map lunar surface
- Look for presence of major elements on the moon
- Solar X-ray monitor will observe X-rays emitted by Sun and its corona
- Orbiter’s high resolution camera will provides high resolution images
- Imaging IR spectrometer will map for mineralogical data.
- Duel Frequency synthetic aperture radar will map polar regions, estimate water ice in poles.
- Atmospheric compositional explorer 2 will study composition of lunar neutral exosphere.
Positives of Chandrayaan 2
- Successful initiation of operational service of GSLV MK III
- GSLV MK III has carrying capacity of 4000 kgs; can be commercialized.
- Precise placement into orbit saved fuel, giving orbiter prolonged life around moon.
- Orbiter earlier predicted to have one year life span could now go on for 7.5 years.
- Orbiter carries 7 of 13 major payloads of the mission.
- Camera, spectrometers can offer insights into origin and evolution of moon.
- Will generate 3D terrain map, study mineral distribution.
- Orbiter has already sent images.
- Data generated by such missions yield results for long time.
- Vikram got extremely close (i.e 2.1 kms) to realizing soft landing, providing many lessons.
ISRO’s future plans
ISRO’s next priority is the $1.4 billion Gaganyaan mission, which aims to put three Indian “gaganauts” — at least one of which will be a woman — into orbit.
