Chandrayaan-2

Chandrayaan-2 was India’s second lunar exploration mission developed by the Indian Space Research Organisation (ISRO). It was designed as a more advanced successor to Chandrayaan-1, with the ambitious objective of achieving a soft landing on the Moon’s surface — a first for India. Launched in 2019, the mission sought to deepen scientific understanding of the Moon, focusing especially on its unexplored south polar region, while also showcasing India’s growing technological and engineering capabilities in space exploration.

Background and Development

Following the resounding success of Chandrayaan-1 in 2008, ISRO proposed a follow-up mission to further investigate the Moon’s surface and mineral composition. Initially, Chandrayaan-2 was conceived as a joint venture between ISRO and the Russian space agency Roscosmos, with Russia providing the lander module. However, due to delays in the Russian component’s development, India decided to pursue an entirely indigenous mission. Consequently, the spacecraft — including the orbiter, lander, and rover — was fully developed in India.
The mission’s key goals included:

• Demonstrating soft-landing capability on the lunar surface.
• Conducting in-situ scientific experiments on the Moon.
• Mapping the lunar surface for minerals, topography, and elemental composition.
• Exploring the Moon’s south polar region, believed to contain water ice and ancient rock formations.

Launch and Spacecraft Configuration

Chandrayaan-2 was launched on 22 July 2019 from the Satish Dhawan Space Centre, Sriharikota, aboard the Geosynchronous Satellite Launch Vehicle Mark III (GSLV Mk III-M1), India’s most powerful launch vehicle. The spacecraft had a total mass of 3,877 kilograms, comprising three main components:

1. Orbiter – Designed to orbit the Moon at an altitude of about 100 km, equipped with eight advanced instruments for remote sensing, imaging, and mineralogical analysis.
2. Vikram Lander – Named after Dr. Vikram Sarabhai, the founder of India’s space programme, the lander was tasked with achieving a soft landing and deploying the rover.
3. Pragyan Rover – A six-wheeled robotic vehicle designed to traverse the lunar surface, analyse soil and rock samples, and transmit data to the lander.

Scientific Instruments and Payloads

Chandrayaan-2 carried 14 scientific payloads — eight on the orbiter, four on the lander, and two on the rover. These instruments were built to study the Moon’s topography, exosphere, mineralogy, and surface composition.
Key payloads included:

• Terrain Mapping Camera-2 (TMC-2) – Provided detailed 3D maps of the Moon’s surface.
• Imaging IR Spectrometer (IIRS) – Analysed mineral composition and water presence.
• Dual Frequency Synthetic Aperture Radar (DFSAR) – Penetrated lunar soil to detect water ice and map polar regions.
• Chandrayaan-2 Large Area Soft X-ray Spectrometer (CLASS) – Identified major rock-forming elements such as magnesium, aluminium, and silicon.
• Solar X-ray Monitor (XSM) – Measured solar X-rays that affect lunar surface radiation.

The Vikram Lander carried instruments such as the Instrument for Lunar Seismic Activity (ILSA), Chandra’s Surface Thermophysical Experiment (ChaSTE), and Langmuir Probe (LP) to study thermal and plasma conditions. The Pragyan Rover was equipped with the Alpha Particle X-ray Spectrometer (APXS) and Laser Induced Breakdown Spectroscope (LIBS) for analysing elemental composition.

Lunar Journey and Orbital Operations

After launch, Chandrayaan-2 followed a series of orbit-raising manoeuvres around Earth before performing a lunar orbit insertion on 20 August 2019. The spacecraft successfully entered the Moon’s orbit and began detailed mapping operations. Over the next few days, the orbiter and lander separated, preparing for the critical landing phase.

Vikram Lander Descent and Partial Mission Failure

On 6 September 2019, the Vikram lander began its descent towards the lunar surface near the south polar region, specifically targeting a site between two craters — Manzinus C and Simpelius N. The descent phase proceeded smoothly until the lander reached approximately 2.1 kilometres above the surface. At this point, communication with the lander was abruptly lost.
Later analysis indicated that a software or hardware anomaly caused the lander to deviate from its trajectory, resulting in a hard landing. Although the lander and rover were lost, the orbiter remained fully operational and continued to perform its scientific functions.

Scientific Outcomes and Achievements

Despite the setback in the landing attempt, Chandrayaan-2 has been regarded as a major scientific and technological success. The orbiter, equipped with high-resolution cameras and sensors, has continued to transmit valuable data well beyond its intended lifespan.
Key outcomes include:

• High-resolution imaging of the lunar surface, with the Orbiter High-Resolution Camera (OHRC) achieving a resolution of 0.25 metres — the highest from any lunar orbiter to date.
• Confirmation of water ice distribution in permanently shadowed craters near the south pole.
• Detailed mapping of lunar minerals, including magnesium, calcium, and iron.
• Study of the Moon’s exosphere and radiation environment, providing crucial information for future missions.

The orbiter remains operational as of recent reports, continuing to support both national and international lunar research.

Significance and Legacy

Chandrayaan-2 holds immense significance in India’s space history. It demonstrated the nation’s capability to design complex interplanetary systems, including precision landing mechanisms, autonomous rovers, and advanced communication networks. Although the lander’s failure was a moment of disappointment, it provided ISRO with valuable engineering lessons that directly influenced the success of Chandrayaan-3 in 2023, which achieved a perfect soft landing on the Moon’s south pole.
Furthermore, Chandrayaan-2 elevated India’s global status in space exploration, being only the fourth nation to attempt a lunar soft landing after the United States, the Soviet Union, and China. The mission showcased India’s ability to conduct high-value scientific research at a fraction of the cost of other spacefaring nations — approximately ₹978 crore (about US$140 million).

Global Recognition and Future Implications

The Chandrayaan-2 mission received international acclaim for its scientific potential and cost-effectiveness. The data collected continues to be shared with global research communities, contributing to studies on lunar geology, surface temperature variation, and water ice distribution. The mission also inspired cooperation between ISRO and other space agencies for future lunar and planetary projects.
Most importantly, Chandrayaan-2 served as a vital precursor to Chandrayaan-3, refining critical systems such as terrain navigation, altimetry, propulsion control, and autonomous landing algorithms. The persistence shown by ISRO in learning from the mission’s challenges became emblematic of India’s scientific resilience.