Chandrayaan-2
Following the success of Chandrayaan-1, the Indian Space Research Organisation (ISRO) launched Chandrayaan-2 on July 22, 2019. It was a highly complex mission that represented a significant technological leap for India’s space program. The spacecraft was launched from the Satish Dhawan Space Centre in Sriharikota using India’s heavy-lift launcher, the GSLV Mk III (now known as LVM3).
Unlike the first mission, which only orbited the Moon and dropped an impact probe, Chandrayaan-2 was designed to perform a “soft landing” (a safe, gentle touchdown) on the Moon’s completely unexplored South Polar region.
Primary Objectives
The main scientific goals of the Chandrayaan-2 mission included:
- Water-Ice Confirmation: To quantify and map the exact amount of water-ice hidden in the extremely cold, permanently dark craters of the lunar South Pole.
- Topographical Mapping: To create highly detailed 3D maps of the lunar surface using high-resolution cameras.
- Chemical Analysis: To study the minerals, rock compositions, and the Moon’s thin outer atmosphere (exosphere) to better understand how the Moon formed and evolved.
The Three Main Components
The Chandrayaan-2 spacecraft was a composite module made up of three distinct parts. All of these components were developed entirely in India:
- The Lunar Orbiter: Designed to orbit the Moon at an altitude of 100 km. It carries eight advanced scientific instruments to map the surface, study the atmosphere, and act as a communication relay between the Earth and the surface modules.
- The Vikram Lander: The lander was named “Vikram” in honor of Dr. Vikram A. Sarabhai, the founding father of the Indian space program. This module was designed to detach from the orbiter and safely lower itself onto the lunar surface using carefully controlled rocket engines. It was designed to function for one lunar day, which is equivalent to about 14 Earth days.
- The Pragyan Rover: “Pragyan” translates to “wisdom” in Sanskrit. It was a small, solar-powered, 6-wheeled robotic vehicle weighing 27 kg. Housed inside the Vikram lander, it was designed to roll out onto the Moon’s surface after landing to conduct direct chemical tests on the lunar soil.
Scientific Payloads on Chandrayaan-2
Module | Name of the Scientific Payload | Abbreviation |
Orbiter | Terrain Mapping Camera 2 | TMC 2 |
Chandrayaan-2 Large Area Soft X-ray Spectrometer | CLASS | |
Solar X-ray Monitor | XSM | |
Orbiter High Resolution Camera | OHRC | |
Imaging IR Spectrometer | IIRS | |
Dual Frequency Synthetic Aperture Radar | DFSAR | |
Chandrayaan 2 Atmospheric Compositional Explorer 2 | CHACE 2 | |
Dual Frequency Radio Science experiment | DFRS | |
Vikram (Lander) | Radio Anatomy of Moon Bound Hypersensitive Ionosphere and Atmosphere | RAMBHA |
Chandra’s Surface Thermo-physical Experiment | CHaSTE | |
Instrument for Lunar Seismic Activity | ILSA | |
Pragyan (Rover) | Alpha Particle X-ray Spectrometer | APXS |
Laser Induced Breakdown Spectroscope | LIBS | |
Passive Experiment | Laser Retroreflector Array | LRA |
The Journey and Landing Attempt
After liftoff, the spacecraft performed a series of calculated orbit-raising maneuvers around the Earth before changing its path toward the Moon. On August 20, 2019, the spacecraft successfully entered the Moon’s orbit.
On September 2, 2019, the Vikram lander successfully separated from the Orbiter to begin its descent. The final landing sequence took place on September 7, 2019. The lander followed its planned trajectory perfectly until it was just 2.1 kilometers above the lunar surface. Unfortunately, at this critical final stage, an unexpected software anomaly caused the lander to lose communication with the ground stations on Earth. This resulted in a “hard landing” (a crash) on the lunar surface, meaning the Pragyan rover could not be deployed.
Mission Outcome and Achievements
Although the surface landing attempt was not successful, the Chandrayaan-2 mission was not a failure.
The Lunar Orbiter was placed perfectly into its intended orbit and continues to operate flawlessly. It is equipped with the highest resolution camera ever sent to the Moon by any space agency (capable of resolving features as small as 30 centimeters). The Orbiter has been consistently transmitting excellent scientific data, identifying new craters, mapping lunar minerals, and finding clear signatures of water-ice.
Due to highly precise launch and fuel management by ISRO, the Orbiter’s expected lifespan increased from just one year to over seven years. Today, it remains a highly valuable asset for global space science and played a crucial role in mapping a safe landing site for India’s subsequent mission, Chandrayaan-3.
