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RSTV: IN DEPTH- CHANDRAYAAN 2- BIG TAKEAWAYS


RSTV: IN DEPTH- CHANDRAYAAN 2- BIG TAKEAWAYS


Introduction:

It’s been over six days that Chandrayaan -2’s lander Vikram lost contact with its ground stations. But the Indian Space Research Organisation has not lost hope. The space agency’s team is making all efforts to restore communication with the lander at ISRO Telemetry, Tracking and Command Network in Bengaluru. Hope revived for crores of Indians after the lander was spotted by the on-board cameras on the orbiter. Images showed the lander is intact, lying in a tilted position, with rover Pragyan possibly still confined inside. But despite what happened to the lander, Chandrayaan-2 mission achieved 90 to 95 per cent of its objectives. The orbiter is healthy, safe and in Lunar orbit. It is expected to provide extensive information about the Moon, and also what minerals and water it has.

 

Chandrayaan-2 mission:

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.
  • The mission is an important step in India’s plans for planetary exploration, a program known as Planetary Science and Exploration (PLANEX).
  • There are three components of the mission, an orbiter, a lander and a rover.
  • The mission payloads include — 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. 
  • The orbiter is deployed at an altitude of 100 kilometers above the surface of the Moon. The lander is separated from the orbiter, and execute a soft landing(but could not is what is said) on the surface of the Moon, unlike the previous mission which crash landed near the lunar south pole.
  • The lander, rover and orbiter will perform mineralogical and elemental studies of the lunar surface. The rover is named Pragyan.
  • The mission’s lander is named Vikram after Dr Vikram A Sarabhai, the Father of the Indian Space Programme.
  • If ISRO achieves the feat in its first attempt, it will make India only the fourth country to soft-land on the lunar surface. The erstwhile Soviet Union, the U.S. and China are the only countries to have achieved lunar landings.

 

Chandrayaan 2: The Journey

  • 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
  • Two de-orbiting maneuvers performed successfully.
  • Sept 7: Successfully completes rough braking phase

 

Soft landing:

  • A soft-landing protects the object from impact while a hard landing doesn’t.
  • Soft-landing ensures that the object is able to carry out further experimentation on the target planet or satellite, mostly with the help of a rover vehicle.
  • Soft-landing on any planetary surface is complicated. Vikram was to use five thrusters — four at the corners and one at the centre to make its final descent.
  • Maintaining the required velocity with such thrusters is difficult as a fine balance among them needs to be maintained.
  • Then there is the issue of moon dust which could wreck the engines of the thrusters.

 

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

 

Chandrayaan-2 to have 3 components — Orbiter, Lander and Rover:

  • Chandrayaan 2 is India’s second lunar mission with three modules: the Orbiter, Lander (Vikram) and Rover (Pragyan).
  • The Orbiter and Lander are mechanically interfaced and stacked together as an integrated module inside the launch vehicle, GSLV MK-III.
  • Rover is housed inside Lander.
  • After the launch into an earth-bound orbit by GSLV MK-III, the integrated module reached the moon orbit using the orbiter propulsion module.
  • Chandrayaan spacecraft, with a mass of 3.8 tonne, has three modules comprising of the Orbiter, Lander (Vikram) and Rover (Pragyan).

 

Lander (Vikram):

  • This was first time that ISRO is attempting 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.
  • The mission cost of Chandrayaan-2 with regard to the satellite was Rs 603 crore. Cost of GSLV MK III is Rs 375 crore.

According to the ISRO, Orbiter, with scientific payloads, would orbit around the moon. Lander would soft land on the moon at a predetermined site and deploy Rover.

The scientific payloads on board Orbiter, Lander and Rover are expected to perform mineralogical and elemental studies of the lunar surface.

            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.

 

What the Orbiter will do?

  • 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.

 

Space experts and media across the globe have also called the loss of moon lander Vikram as nothing more than a partial loss but now that the kinder has been spotted lying in the single piece, ISRP scientists are holding out hope and continuing efforts to revive communication with it.

 

Chandrayaan 2: The positives

  • 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 missions:

  • Aditya-L1
    • First planned probe to study Sun’s corana
    • Launch proposed in 2019-2020
  • Astrostat 2
    • 2020= Plan to launch second observatory in space
    • To replace Astrosat 1
    • Discover new planets
    • Decode origins of the universe
  • Gaganyaan
    • Plan to send 3 Indians to space by 2022
    • By GSLV MK III
  • Second mission to Mars
    • 2022-23: Mars orbiter mission 2
    • Will have orbiter.
    • May also include lander and rover
  • Shukrayaan 1
    • To study atmosphere of planet Venus
    • Fly-by mission over Venus
    • Planned for 2023
  • Chandrayaan 3
    • ISRO’S joint mission with Japan
    • 2024: Explore moon’s south pole
  • India’s own space station
    • Proposed space station to weigh 20 tonnes
    • Astronauts can stay for 15-20 days
    • Orbit 400 kms above Earth
    • Launch planned 5-7 years after Gaganyaan.

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