Lunar Triumph: Chandrayaan-3’s Quest for Safe Landing, Exploration and Global Impact
Examining Chandrayaan’s Odyssey and its Achievements.
An article by the collective effort of Abhinav and Avipsa, members of the Astronomy Club, IIT BHU.
Introduction:
Chandrayaan-3, India’s ambitious lunar mission, emerges as a resolute sequel to Chandrayaan-2, driven by a determination to overcome past setbacks. In a departure from its predecessor, this mission embraces a failure-based strategy, omitting the orbiter and extending the landing area. Equipped with an enhanced fuel supply, the Lander-Rover configuration is poised to demonstrate a triumphant end-to-end capability, encompassing a safe lunar landing and rover exploration. Launched by the formidable LVM3 from the SDSC SHAR in Sriharikota, Chandrayaan-3 promises to rectify past challenges and accomplish a successful soft landing on the lunar surface while housing the Spectro-polarimetry of Habitable Planet Earth (SHAPE) payload for studying Earth from the lunar orbit. Join us as we embark on a thrilling journey to explore this remarkable mission.
History:
Chandrayaan-1, India’s maiden lunar mission, marked a historic milestone in the nation’s space exploration journey. Launched on October 22,2008, it was the first Indian spacecraft to reach the Moon, orbit it, and discover water molecules on the lunar surface. Chandrayaan-1 carried 11 scientific instruments, including an impactor that significantly impacted the lunar surface to analyse the ejected materials.Unfortunately, Chandrayaan-1’s mission was cut short when it lost communication with ground control in August 2009.
Chandrayaan-2, India’s second lunar mission, was a highly ambitious endeavour that aimed to build upon the success of Chandrayaan-1 and further India’s progress in space exploration. Launched on July 22, 2019, by the Indian Space Research Organisation (ISRO), Chandrayaan-2 was a multi-component mission consisting of an orbiter, a lander named Vikram, and a rover named Pragyan. The orbiter was designed to study the Moon from lunar orbit, providing valuable data on its surface composition, minerals, and exosphere. The lander, Vikram, carried the rover Pragyan, and their primary mission was to execute a soft landing on the Moon’s south polar region — a challenging task due to the rugged terrain and the Moon’s low gravity. Unfortunately, Vikram’s landing attempt faced difficulties during its descent, resulting in a loss of communication and the its failure to make a successful soft landing.
Objectives:
The primary objectives of Chandrayaan-3, the latest lunar exploration mission by the Indian Space Research Organisation (ISRO), build upon the experiences of its predecessors, Chandrayaan-1 and Chandrayaan-2. This mission aims to demonstrate India’s end-to-end capability in achieving a safe and soft landing on the lunar surface, utilising the lander named Vikram, and conducting rover operations with Pragyaan. Chandrayaan-3’s mission objectives include -
- Showcasing the proficiency in executing a successful soft landing
- Enabling rover exploration on the Moon’s surface
- Conducting in-situ scientific experiments to advance our understanding of lunar geology and its potential resources.
Components:
Chandrayaan-3 comprises three main components: a Propulsion Module, a Lander, and a Rover.
Propulsion Module:
The propulsion module is a box-like structure with a large solar panel mounted on one side and a cylindrical mounting structure for the lander on top. As the lander begins its operations on the Moon, the propulsion module will transform into a relay satellite. The lander is equipped with several different payloads, each serving a specific function. All signals transmitted by these payloads will be received by this relay satellite. Subsequently, it will decipher these signals and transmit them to ISRO’s control centre. Thus, the propulsion module will act as a vital intermediary link between the lander and ISRO. It carries the payload of Spectro-polarimetry of the Habitable Planet Earth (SHAPE). It will study spectral and polarimetric measurements of Earth from the lunar orbit in the near-infrared wavelength range. Its objective is future discoveries of smaller planets in reflected light that would allow us to probe into the variety of Exo-planets, which would qualify for habitability or for presence of life.
Lander:
The lander of Chandrayaan-3 is named as the Vikram lander to honour the late Vikram Sarabhai, father of the Indian space program. Vikram has a box-shaped design and is equipped with four landing legs and four landing thrusters, each capable of generating 800 Newtons of thrust. It is made of Aluminium alloy and carbon fibre to withstand harsh conditions. It has a high-gain antenna to communicate with the ground station and a low-gain antenna to communicate with the rover system.It serves as a carrier for the rover and is equipped with a range of scientific instruments for conducting on-site analysis.This sophisticated lander is equipped with diverse scientific instruments, including cameras, spectrometers for soil analysis, a soil sampling drill, a magnetometer, seismic sensors, a thermal conductivity probe, and a near-surface plasma detector. These instruments aim to unlock the Moon’s geological secrets and understand its unique properties.
The lander carries a total of four payloads.
- The Radio Anatomy of Moon Bound Hypersensitive ionosphere and Atmosphere (RAMBHA) measures the near surface plasma density and its changes with time.
- The Chandra’s Surface Thermo Physical Experiment (ChaSTE) measures the lunar surface's thermal properties near the polar region.
- The Instrument for Lunar Seismic Activity (ILSA) measures the seismicity around the landing site and sketches the lunar crust and mantle structure.
- LASER Retroreflector Array (LRA) is a passive experiment to understand the dynamics of the Moon system.
Rover :
The rover associated with the Chandrayaan-3 mission is the Pragyan Rover. It is a six-wheeled vehicle with a mass of 26 kilograms. Its roger-bogie system allows it to climb heights exceeding its own stature. Its navigational cameras help it view the surrounding terrain and help in path-planning by generating a digital elevation model of the terrain. ISRO’s control system can send direct instructions to Pragyan to make large course corrections. Pragyan is expected to have a working duration of one lunar day which is equal to roughly 14 Earth days. It has a limited operational period because its electronics are not engineered to withstand the harsh cold of lunar night. Its solar-powered sleep and wake-up cycle might potentially extend its initial work period.
The Pragyan carries two payloads.
- LASER Induced Breakdown Spectroscope (LIBS)- Its objective is to perform qualitative and quantitative elemental analysis, to derive the chemical composition and infer mineralogical composition of the Lunar-surface.
- Alpha Particle X-ray Spectrometer (APXS)- Its objective is to determine the elemental composition (Mg, Al, Si, K, Ca,Ti, Fe) of Lunar soil and rocks around the lunar landing site.
Timeline:
July 14, 2023: Chandrayaan-3 spacecraft launched with LVM3 M4 vehicle, achieving designated orbit.
July 15, 2023: First orbit-raising maneuver to 41,762 km x 173 km.
July 17, 2023: Second maneuver to 41,603 km x 226 km.
July 22, 2023: Fourth maneuver(Earth-bound perigee firing) to 71,351 km x 233 km.
July 25, 2023: Additional orbit-raising maneuver.
August 1, 2023: Chandrayaan-3 inserted into translunar orbit (288 km x 369,328 km).
August 5, 2023: Lunar orbit achieved at 164 km x 18,074 km.
August 6, 2023: Lunar orbit adjusted to 170 km x 4,313 km.
August 9, 2023: Chandrayaan-3’s trajectory adjusted to maintain lunar orbit of 174 km x 1,437 km.
August 14, 2023: Orbit further adjusted to 150 km x 177 km.
August 16, 2023: The spacecraft is in an orbit of 153 km x 163 km after the firing
August 17, 2023: Separation of landing module (Vikram lander and Pragyan rover) from the propulsion system.
August 19, 2023: “Deboosting” operation lowers landing module’s orbit to 113 km x 157 km.
August 20, 2023: Orbit set at 134 km x 25 km, representing farthest and nearest lunar points.
August 23, 2023: Anticipated lunar touchdown initiation at 5:47 pm IST, with soft landing planned for 6:04 pm IST.
September 2, 2023: Pragyan has completed its assignments, is safely parked, and is set into sleep mode.The battery is reported to be fully charged. APXS and LIBS payloads are turned off.
September 22, 2023: The solar panel is oriented to receive light at the next sunrise, expected
Discoveries:
Ionosphere Insights:
- Chandrayaan-3’s lander, Vikram, analyzed the Moon’s ionosphere, measuring density and temperature.
- It discovered ion and electron concentrations with densities ranging from 5 million to 30 million electrons per cubic meter.
- Variations in density during the lunar day were observed.
- It was found that low electron density in the Moon’s ionosphere facilitates faster radio signal transmission, crucial for future lunar settlements.
Lunar Soil Properties:
- Vikram’s observations included lunar soil properties like temperature and conductivity.
- It recorded temperatures 8 centimetres below the surface, which were approximately 60 degrees Celsius lower than at the surface.
- Surface temperatures were found to be warmer than previously recorded in 2009 by NASA’s Lunar Reconnaissance Orbiter.
- Vital data for planning future lunar settlements was collected.
Detection of “Moonquakes”:
- The lander featured a seismograph capable of detecting slight seismic activity.
- It recorded a brief seismic event lasting about 4 seconds, likely a minor “Moonquake” or a result of a small meteorite impact.
- Moonquakes are expected due to small impacts and local tectonic adjustments on the Moon.
Confirmation of Sulphur’s Presence:
- Vikram rover confirmed the presence of sulphur on the Moon, particularly near the South Pole.
- It detected elements like aluminium, silicon, calcium, and iron on the Moon’s surface.
- Sulphur’s presence provides insights into the Moon’s formation, possibly from asteroid impacts or as a component of molten rock.
- It contributes to a better understanding of the Moon’s geochemistry, complementing data from US Apollo missions.
Impact:
The Chandrayaan-3 mission’s triumphant landing and rover deployment marks a significant milestone for India’s space program and offers promising prospects for the nation’s future. From a technological perspective, the mission showcases India’s growing expertise in space technology and its capacity to execute complex lunar exploration missions. This accomplishment positions India as a prominent player in the global space exploration arena, elevating its status and reputation.
Scientifically, Chandrayaan-3 contributes valuable data and insights into lunar research, enhancing India’s capabilities in the field and offering opportunities for further scientific discovery. Beyond the realm of science, the mission holds the potential to boost India’s economy significantly. With the global space economy experiencing exponential growth, India’s participation in this industry could result in substantial economic benefits.
Moreover, the mission inspires the Indian populace, particularly the younger generation, encouraging them to pursue careers in science, technology, engineering, and mathematics (STEM). This increased interest in STEM fields can potentially drive innovation and technological advancements within the country.
Internationally, Chandrayaan-3’s success aligns with the broader trends in the global space economy. It underscores the growing demand for satellite imaging, navigation, and data services, presenting opportunities for international collaboration and commercial ventures. The mission also demonstrates the importance of collaboration and shared learning among spacefaring nations.
Furthermore, Chandrayaan-3’s achievements underscore the significance of technological progress in space exploration. It highlights the importance of redundancy, systems engineering, and change management in modern spaceflight, exploring the south pole of the moon which is not explored till now and valuable lessons not only for India but for the entire global space community. Lastly, India’s active participation in international space initiatives, like the Artemis Accords, strengthens diplomatic relations with other spacefaring nations, positioning India as a valuable partner in global space exploration endeavours.
In conclusion, Chandrayaan-3’s successful mission not only advances India’s space program but also contributes to the global space economy and scientific community while inspiring the nation’s youth to engage in the exciting new era of space exploration.