India Moon Mission - Chandrayaan2

India Moon Mission - Chandrayaan2

CHANDRAYAAN, which means “Moon Vehicle” in Sanskrit is a typical example of increased interest in space.
One thing has been in a discussion from so many days and that is Chandrayaan 2. What is exactly this Chandrayaan 2 this is a big question but it will be wrong to talk about it till we get the right answer. So now let’s find out what is Chandrayaan 2 but before it will explain you in short about Chandrayaan 1.

Chandrayaan 1 
It was the first mission of India to the moon which was launched successfully on 22nd October 2008 from Satish Dhawan Space Centre, at Sriharikota, Andhra Pradesh.  The spacecraft weighing 1,380kg along with 11 scientific payloads built in India, UK, USA, Germany, Bulgaria and Sweden. The spacecraft was orbiting around the Moon at a height of 100 km from the lunar surface for chemical, mineralogical and photo-geologic mapping of the Moon.  India launched the spacecraft using a PSLV-XL rocket, serial number C11. Mission life was 2 years but it was operated for 312 days against the plan and was succeeded by achieving 95% of its planned objectives and finally on 29th August 2009, ISRO (Indian Space Research Organization) officially declared that Chandrayaan 1 mission over.

Chandrayaan 2 
Now after small information of Chandrayaan 1, we can talk about 2. Chandrayaan 2 is India’s second moon mission which was launched from a second launch pad on 22nd July 2019 at 2.43 PM from Satish Dhawan Space Centre, at Sriharikota, Andhra Pradesh. A new history is created in India. It is a proud moment for all of us.  People will be able to see the darker side of the Moon. The Chandrayaan-2 mission comes nearly 11 years after India's first expedition to the moon in October 2008. Therefore, the space agency said it is better to be delayed rather than any complications.

The journey of Chandrayaan-2 is around 3.84 lakh km to Moon. It will be injected into an earth parking 170 x 40400 km orbit. It will collect data on water, minerals and formations of rock. 

The primary objective of ISRO to launch Chandrayaan-2 is to demonstrate the ability to soft-land on the lunar surface and operate a robotic rover on the surface. Scientific goals are to study lunar topography, mineralogy, elemental abundance, the lunar exosphere and signatures of hydroxyl and water ice.

The spacecraft weighing 3,840kg was launched on Geosynchronous Satellite Launch Vehicle, GSLV MkIII-M1.  The important thing about Chandrayaan 2 is that all the payloads were developed in India itself. It consists of a lunar orbiter, the Vikram lander, and the Pragyan lunar rover.

Orbiter (Lunar Payloads) - This carries 8 scientific instruments. This structure is manufactured by Hindustan Aeronautics Limited. Orbiter will be capable of communicating with Indian Deep Space Network (IDSN) at Byalalu as well as the Vikram Lander. The mission life of the Orbiter is one year and it will be placed in a 100X100 km lunar polar orbit.

Weight of orbiter – 2,379kg
Electric Power Generation Capability – 1,000 W

Terrain Mapping Camera 2 (TMC-2) – It is a miniature version of the Terrain Mapping Camera used onboard the Chandrayaan 1 mission. Its primary objective is mapping the lunar surface in the panchromatic spectral band (0.5-0.8 microns) with a high spatial resolution of 5 m and a swath of 20 km from 100 km lunar polar orbit. The data collected by TMC 2 will give us clues about the Moon's evolution and help us prepare 3D maps of the lunar surface.

Chandrayaan 2 Large Area Soft X-ray Spectrometer (CLASS) - CLASS measures the Moon's X-ray Fluorescence (XRF) spectra to examine the presence of major elements such as Magnesium, Aluminum, Silicon, Calcium, Titanium, Iron, and Sodium. The XRF technique will detect these elements by measuring the characteristic X-rays they emit when excited by the Sun's rays.

Solar X-ray Monitor (XSM) - XSM observes the X-rays emitted by the Sun and its corona, measures the intensity of solar radiation in these rays, and supports CLASS. The primary objective of this payload is to provide solar X-ray spectrum in the energy range of 1-15 keV. XSM will provide high-energy resolution and high-cadence measurements (full spectrum every second) of solar X-ray spectra as input for analysis of data from CLASS.

Orbiter High-Resolution Camera (OHRC) - OHRC provides high-resolution images of the landing site — ensuring the Lander's safe touchdown by detecting any craters or boulders prior to separation. The images it captures, taken from two different look angles, serve dual purposes. Firstly, they are used to generate DEMs (Digital Elevation Models) of the landing site. Secondly, they are used for scientific research, post-lander separation. OHRC's images will be captured over the course of two orbits, covering an area of 12 km x 3 km with a ground resolution of 0.32 m.

Imaging IR Spectrometer (IIRS) - IIRS has two primary objectives:
Global mineralogical and volatile mapping of the Moon in the spectral range of ~0.8-5.0 µm for the first time, at the high resolution of ~20 nm
Complete characterization of water/hydroxyl feature near 3.0 µm for the first time at high spatial (~80 m) and spectral (~20 nm) resolutions
IIRS will also measure the solar radiation reflected off the Moon's surface in 256 contiguous spectral bands from 100 km lunar orbit.

Dual Frequency Synthetic Aperture Radar (DFSAR) - The main scientific objectives of this payload are:

  • High-resolution lunar mapping in the Polar Regions.
  • Quantitative estimation of water-ice in the Polar Regions.
  • Estimation of regolith thickness and its distribution.

Chandrayaan 2 Atmospheric Compositional Explorer 2 (CHACE 2) - It is a Quadrupole Mass Spectrometer (QMA) capable of scanning the lunar neutral exosphere in the mass range of 1 to 300 amu with the mass resolution of ~0.5 amu. CHACE 2's primary objective is to carry out an in-situ study of the composition and distribution of the lunar neutral exosphere and its variability.

Dual Frequency Radio Science (DFRS) experiment - To study the temporal evolution of electron density in the Lunar ionosphere. Two coherent signals at X (8496 MHz) and S (2240 MHz) band are transmitted simultaneously from satellite and received at ground-based deep station network receivers.

Vikram (Lander payloads) - The name “Vikram” to honour the late Dr Vikram Sarabhai, who was the former chairman of ISRO and is widely regarded as the ‘Father of the Indian Space Programme’.

The Vikram Lander is a module that will enable 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.

Weight of Vikram Lander – 1,471 kg
Electric Power Generation Capability – 650 W

Radio Anatomy of Moon Bound Hypersensitive ionosphere and Atmosphere (RAMBHA) - The lunar ionosphere is a highly dynamic plasma environment. Langmuir probes, such as RAMBHA, have proven to be an effective diagnostic tool to gain information in such conditions. Its primary objective is to measure factors such as:

  • Ambient electron density/temperature near the lunar surface
  • Temporal evolution of lunar plasma density for the first time near the surface under varying solar conditions

Chandra’s Surface Thermophysical Experiment (ChaSTE) - ChaSTE measures the vertical temperature gradient and thermal conductivity of the lunar surface. It consists of a thermal probe (sensors and a heater) that is inserted into the lunar regolith down to a depth of ~10 cm. ChaSTE operates in two modes:
Passive mode operation in which continuous in-situ measurements of temperature at different depths are carried out
Active mode operation in which temperature variations in a set period of time, and the regolith's thermal conductivity under contact, are estimated

Instrument for Lunar Seismic Activity (ILSA) - ILSA is a triple-axis, MEMS-based seismometer that can detect minute ground displacement, velocity, or acceleration caused by lunar quakes. Its primary objective is to characterize the seismicity around the landing site. ILSA has been designed to identify acceleration as low as 100 ng /√Hz with a dynamic range of ±0.5 g and a bandwidth of 40 Hz. The dynamic range is met by using two sensors — a coarse-range sensor and a fine-range sensor.

Pragyan (Rover payloads) - Pragyan, which means 'wisdom' in Sanskrit is a rover and the third component of the Chandrayaan 2 mission. It is a robotic vehicle that will travel across the lunar surface on six wheels that are painted in the colours of the Tiranga. It is expected to travel at a speed of one centimetre per second and will hence travel a total distance of half a kilometre. It will help to identify the elements present near the landing site on the moon’s surface.

Weight of Pragyan – 27 kg
Electric Power Generation Capability – 50 W

Alpha Practical X-ray Spectrometer (APXS) - APXS' primary objective is to determine the elemental composition of the Moon's surface near the landing site. It achieves this through X-ray fluorescence spectroscopy technique, where X-ray or alpha particles are used to excite the surface. APXS uses radioactive Curium (244) metal that emits high-energy, alpha particles — as well as X-rays — enabling both X-ray emission spectroscopy and X-ray fluorescence spectroscopy. Through these techniques, APXS can detect all major rock-forming elements such as Sodium, Magnesium, Aluminium, Silica, Calcium, Titanium, Iron, and some trace elements such as Strontium, Yttrium and Zirconium.

Laser-Induced Breakdown Spectroscopy (LIBS) - LIBS' prime objective is to identify and determine the abundance of elements near the landing site. It does this by firing high-powered laser pulses at various locations and analyzing the radiation emitted by the decaying plasma.

Passive Experiment – From NASA

Laser Retroreflector Array (LRA) - To understand the dynamics of Earth's Moon system and also derive clues on the Lunar interior.
Why we are going to the Moon?

Moon is the Earth's natural satellite which was formed around 4.6 billion years ago after the formation of the solar system.  The first spacecraft reached to the moon in September 1959 by the Soviet Union’s Luna 2 and the first successful manned orbital mission was Appolo 11 in 1969. 

The Moon is the closest cosmic body at which space discovery can be attempted and documented. It is also a promising testbed to demonstrate the technologies required for deep-space missions. Chandrayaan-2 will be a new age discovery which will increase our understanding of space.

Scientific objectives of Chandrayaan 2

  • To identify or to find out the minerals and indicators of hydroxyl and water molecules.
  • To study the surface of the moon.
  • To study the density of the electrons in the Moon’s ionosphere that is the uppermost part of the atmosphere that is ionised by radiation.
  • The Orbiter will observe the lunar surface and relay communication between Earth and Chandrayaan 2’s Lander
  • The lander is designed to execute India’s first soft landing on the lunar surface.

What makes Chandrayaan 2 special?

  • 1st space mission to conduct a soft landing on the Moon's South Polar Region
  • 1st Indian expedition to attempt a soft landing on the lunar surface with home-grown technology
  • 1st Indian mission to explore the lunar terrain with home-grown technology
  • 4th country ever to soft-land on the lunar surface

Timeline of the mission

  • 18th September 2008 - Prime Minister Manmohan Singh approves the Chandrayaan2 lunar mission
  • Launch Date – 22nd July 2019
  • Landing on Moon – 7th Sep 2019
  • Scientific Experiment on Moon – 1 Lunar Day (14 earth days)
  • Orbital Experiment – Will be operational for 1 year