Cracking the Lunar Code: Chandrayaan 3 and India’s Space Ambitions
A remarkable day in the history of India was July 14th when the whole nation witnessed the launch of Chandrayaan 3, a recent lunar exploration mission by the Indian Space Research Organisation (ISRO)
Chandrayaan-3, following the experience gained from Chandrayaan-2, represents India’s determined pursuit of lunar redemption. It is designed with a lander and the Pragyan rover, similar to its predecessor, Chandrayaan-3 forgoes an orbiter and employs a unique propulsion module that serves as a communication relay satellite. This propulsion module carries the lander and rover configuration until the spacecraft achieves a 100 km lunar orbit. The mission aims to address the last-minute glitch in the landing guidance software that led to the crash of the Chandrayaan-2 lander after entering lunar orbit. On 14th July 2023, at 2:35 pm IST, Chandrayaan-3 was successfully launched, marking the mission’s first phase. The spacecraft’s lunar injection into a 100 km circular polar orbit was completed, setting the stage for the next milestone. The anticipated landing of the lander and rover near the lunar south pole region is scheduled for 23rd August 2023. Chandrayaan-3 is a stepping stone towards ISRO’s future interplanetary missions, showcasing India’s commitment to advancing its space exploration capabilities.
Background
As part of the Chandrayaan programme, the Indian Space Research Organisation (ISRO) launched Chandrayaan-2 with the objective of demonstrating a soft landing on the Moon. The mission was carried out using the Launch Vehicle Mark-3 (LVM 3) launch vehicle and consisted of an orbiter, a lander, and a rover.
The planned timeline envisioned the lander touching down on the lunar surface in September 2019, where it would deploy the Pragyan rover for further exploration. In a significant collaboration, the European Space Tracking (ESTRACK) operated by the European Space Agency (ESA) entered into a contract to support the Chandrayaan-2 mission.
This partnership established a cross-support arrangement, allowing ESA to provide tracking support for upcoming ISRO missions, including India’s first human spaceflight programme, Gaganyaan, the lunar lander mission Chandrayaan-3, and the solar research mission Aditya-L1. In return, ISRO’s tracking stations will offer similar support to future ESA missions, fostering mutual cooperation and advancement in space exploration.
In December 2019, reports emerged regarding ISRO’s request for initial funding for the Chandrayaan-3 project. The requested funding amounted to ₹75 crores (approximately US$9.4 million). Out of this sum, ₹60 crores (around US$7.5 million) was allocated for machinery, equipment, and other capital expenses, while the remaining ₹15 crores (approximately US$1.9 million) was sought under the revenue expenditure category.
Confirming the existence of the project, K. Sivan, the former chairman of ISRO, stated that the estimated cost for Chandrayaan-3 would be around ₹615 crores. Considering the inflation rate, this amount would be equivalent to ₹721 crore or approximately US$90 million in 2023.
Objective of Chandryaan 3
ISRO has set three main objectives for the Chandrayaan-3 mission, which include:
- Getting a lander to land safely and softly on the surface of the Moon.
- Observing and demonstrating the rover’s loitering capabilities on the Moon.
- In-site observation & conducting experiments on the materials available on the lunar surface to better understand the composition of the Moon.
Decoding Chandrayaan 3
Chandrayaan-3 consists of three main components:
Propulsion Module
This module serves the purpose of carrying the lander and rover configuration until it reaches the 100 km lunar orbit. It is designed as a box-like structure featuring a large solar panel mounted on one side. On top of the module, there is a prominent cylindrical structure known as the Intermodular Adapter Cone, which serves as a mounting structure for the lander. In addition to the lander and rover, the propulsion module also carries a payload called Spectro-polarimetry of Habitable Planet Earth (SHAPE). This payload is designed to conduct spectral and polarimetric measurements of Earth from the lunar orbit, specifically in the near-infrared (NIR) wavelength range of 1–1.7 μm.
Lander
The Chandrayaan-3 lander plays a crucial role in achieving a soft landing on the lunar surface. It features a box-shaped design with four landing legs and four throttle-able engines, each with a thrust of 800 newtons. Unlike the Chandrayaan-2 lander, which had five engines, the Chandrayaan-3 lander has four engines, and it incorporates improved structural rigidity and increased instrumentation redundancy. Furthermore, it is equipped with a Laser Doppler Velocimeter (LDV) to enhance landing accuracy and stability. The lander carries three essential payloads for scientific analysis: Chandra’s Surface Thermophysical Experiment (ChaSTE): This payload is designed to measure the thermal conductivity and temperature of the lunar surface. It will provide valuable data to enhance our understanding of the Moon’s composition and geophysical properties. Instrument for Lunar Seismic Activity (ILSA): ILSA is specifically designed to measure the seismicity or moonquakes around the landing site.
By studying lunar seismic activity, scientists can gain insights into the Moon’s internal structure and geodynamic processes. Langmuir Probe (LP): The LP payload serves the purpose of estimating plasma density and its variations on the lunar surface. This data will contribute to our understanding of the lunar exosphere and the interaction between the Moon and the space environment. Together, these payloads on the Chandrayaan-3 lander aim to enhance our knowledge of the lunar surface, geology, and environment, furthering scientific exploration and research.
Rover
The Chandrayaan-3 rover is a crucial component of the mission, designed to explore the lunar surface and conduct various scientific investigations. Here are the key features and objectives of the rover:
- Design: The rover features a six-wheeled design, enabling it to navigate the challenging lunar terrain effectively. It has a weight of 26 kilograms (57 pounds), making it a compact and versatile exploration vehicle.
- Range and Mobility: The rover has a range of 500 meters (1,600 feet), allowing it to traverse significant distances on the lunar surface. Its mobility enables it to explore different regions and gather diverse samples for analysis.
- Scientific Instruments: Equipped with a range of scientific instruments, including cameras, spectrometers, and a drill, the rover is capable of conducting in-depth analysis of the lunar surface. These instruments provide valuable data on the composition, mineralogy, and elemental characteristics of the lunar soil and rocks.
- Lifespan and Communication: The rover is designed to operate for one lunar day, which is equivalent to approximately 14 Earth days. It establishes communication with the lander and the ground control team in India, enabling the transmission of data and instructions for further exploration.
The rover carries two primary payloads for scientific investigations:
- Alpha Particle X-Ray Spectrometer (APXS): This payload derives the chemical composition and infers the mineralogical composition of the lunar surface. It helps in understanding the geological processes and history of the Moon.
- Laser-Induced Breakdown Spectroscope (LIBS): The LIBS payload determines the elemental composition (Mg, Al, Si, K, Ca, Ti, Fe) of lunar soil and rocks around the landing site. This data contributes to our understanding of lunar geology and the presence of specific elements.
Through these scientific instruments and payloads, the Chandrayaan-3 rover aims to achieve several scientific objectives, including:
- Analysing the composition of the lunar surface to understand its geological characteristics. Investigating the presence of water ice in the lunar soil, providing insights into potential resources for future exploration.
- Studying the history of lunar impacts and the effects of meteorite bombardment on the lunar surface.
- Exploring the evolution of the Moon’s atmosphere contributes to our understanding of its volatile elements and their dynamics.
Updates so far
The manoeuvre was performed by the ISRO Telemetry Tracking and Command Network (ISTRAC) in Bengaluru to place the Chandrayaan 3 spacecraft in the 41,603 km x 226 km orbit. This means that Chandrayaan 3 is now in an orbit, which when closest to Earth is 226 km away and farthest is at a distance of 41,603 km.
Chandrayaan-3 spacecraft has now moved into a new, higher orbit around the Earth after the successful completion of the second orbit-raising manoeuvre, the Indian Space Research Organisation (ISRO) stated on 17th July. The second orbit-raising step took place at around noon on the 17th of July. Before this, the spacecraft was moving in an orbit that was 41,762 at the furthest from Earth and 173 km at its closest. Hoping to make a soft landing on the moon’s surface next month, Chandrayaan-3 is now going around the Earth in an elliptical orbit that is 41,603 km at its furthest and 226 km at the closest from the Earth’s surface, ISRO said in an official statement.
Pointers for the graph
- Successful launch of the Chandrayaan-3 on July 14th at 2:35 PM IST
- ISRO officials addressed the difficulties with the soft landing on the moon calling it “15 minutes of terror”
- Chandrayaan-3 spacecraft has now moved into a new, higher orbit around the Earth after the successful completion of the second orbit-raising manoeuvre
