Chandrayaan Missions: India's Path To The Moon
Background of Chandrayaan: The Chandrayaan mission began its early planning in the early 2000s, with the formal announcement made by Prime Minister Atal Bihari Vajpayee on August 15, 2003. This initiative marked a significant step in India's space exploration efforts and aimed to explore the Moon through scientific research and technological development. K. Kasturirangan, who was the Chairman of ISRO at the time, played a crucial role in the program's establishment and development.
The mission led to subsequent Chandrayaan missions, with each iteration advancing India's capabilities in space research and technology. Chandrayaan-1 is India's first moon project and was developed by Indian space agency ISRO, Bengaluru, India. This mission challenges our scientific capability and India's space program. Chandrayaan (Hindi) meaning in English is "MoonCraft".The Chandrayaan-1 mission strengthened U.S.-India space ties, with a MOU (Memorandum of Understanding) signed on May 9, 2006, including two NASA instruments. A 2004 conference led to a Joint Working Group, which first met in June 2005.
About the Moon: Here I will give basic information about the moon, The Moon, the fifth largest natural satellite in the solar system, shines as the brightest object in our night sky and ranks second only to the Sun in brightness. It maintains an orbit around Earth at an average distance of approximately 384,400 kilometers and possesses a diameter of 3,476 kilometers. Despite its substantial size, the Moon's mass is relatively small, measuring 7.35x10^22 kilograms, and its mean density is just 3.35 grams per cubic centimeter, contrasting with Earth's denser 5.52 grams per cubic centimeter. Notably, the Moon lacks an atmosphere and minimal surface outgassing. Due to its weaker gravitational force, which is only one-sixth that of Earth, the Moon cannot retain an atmosphere.
Chandrayaan-01:Chandrayaan-1 was launched on October 22, 2008, using a PSLV-C11 rocket from the Satish Dhawan Space Center in Sriharikota, India. It had an initial mass of 1050 kg and entered a quasi-GTO (Geosynchronous Transfer Orbit) with dimensions of 240 km x 24,000 km and an inclination of 18º.
Subsequently, the spacecraft used its propulsion system over 5.5 days to execute the lunar transfer trajectory (LTT). After cruising to the moon, it entered an initial lunar insertion orbit at 1000 km altitude, which was later lowered to a 200 km orbit for checkout purposes, and eventually settled into a circular polar orbit at 100 km altitude for lunar scientific operations. The spacecraft's lunar orbital mass was 550 kg, with a payload mass of 55 kg.
Chandrayaan-1, on November 12, 2008, successfully achieved its ultimate operational lunar orbit, orbiting at an altitude of roughly 100 km. Following its capture into lunar orbit on November 8, the spacecraft executed three orbit reduction maneuvers. The spacecraft effectively entered lunar orbit on November 8, 2008, by employing engine firings to reduce its velocity and allow the moon's gravity to capture it. These engines were engaged for 817 seconds when Chandrayaan-1 was positioned approximately 500 km away from the moon, resulting in its current orbit of 504 km x 7502 km, which completes an orbit approximately every 11 hours.
Originally slated for a two-year mission duration, the Chandrayaan-1 mission encountered an unexpected loss of communication with the spacecraft around 20:00 UTC on August 28, 2009. Despite this, the probe had a productive 312-day operational period, during which it meticulously mapped around 95 percent of the moon's surface. While the spacecraft was initially anticipated to remain in orbit for another 1000 days and ultimately impact the lunar surface in late 2012, it was later discovered in 2016 that it was still in orbit.
Facts about Chandrayaan-1: Chandrayaan-1 gathered X-ray data revealing aluminum, magnesium, and silicon signatures, captured by the C1XS X-ray camera. On March 25, 2009, it transmitted its initial complete Earth images, courtesy of the Terrain Mapping Camera (TMC).
During its mission, Chandrayaan-1 completed over 3400 lunar orbits and set a remarkable record by capturing 70,000 lunar surface images, surpassing the achievements of previous lunar missions from other countries. In its first 75 days alone, it transmitted over 40,000 images.
The project's estimated cost was ₹386 crores (US$56 million). Chandrayaan-1's objectives included high-resolution remote sensing of the moon across various spectra, detection of a hydrogen-oxygen chemical bond in lunar water, and examination of surface radioactive elements. Unfortunately, it eventually crashed due to excessive radiation and power supply failures.
ISRO generously carried scientific payloads from other nations without charge. At launch, Chandrayaan-1 weighed 1,380 kg (3,042 lb), reducing to 675 kg (1,488 lb) in lunar orbit and 523 kg (1,153 lb) after releasing the impactor. The scientific payload had a mass of 90 kg (198 lb), and the terrain mapping camera on board even recorded images of the landing site of the U.S. Apollo 15 spacecraft.
Chandrayaan-02: The second spacecraft in India's lunar exploration series led by K Sivan, consists of an Orbiter, a Lander named Vikram, and a Rover named Pragyan, all aimed at investigating the previously uncharted South Polar region of the Moon. Launched on July 22, 2019, from the Indian Space Port in Sriharikota using GSLV Mk-III, this mission represents a highly intricate endeavor featuring numerous cutting-edge technological advancements. Its primary objective is to enhance our scientific understanding of the Moon by conducting comprehensive investigations into the topography, mineral distribution and identification, surface chemical composition, mapping, seismology, topsoil characterization, and compositional analysis of the Moon's faint atmosphere, ultimately contributing to a fresh perspective on the Moon's origins and evolution.
Every Indian scientist remembers Chandrayaan-2 because of lunar lander of Chandrayaan 2 is named Vikram in honor of Dr. Vikram A. Sarabhai, often regarded as the Father of the Indian Space Programme. Vikram is engineered to operate throughout one lunar day, approximately equivalent to 14 Earth days, and possesses the capability to establish communication with the IDSN facility located in Byalalu near Bangalore, in addition to maintaining contact with the Orbiter and Pragyan rover. Its design facilitates a gentle touchdown on the lunar surface, achieving a landing velocity of 2 meters per second.
And Chandrayaan 2 features a six-wheeled robotic rover known as Pragyan, a name derived from Sanskrit meaning 'wisdom.' This rover is capable of traversing distances of up to 500 meters (0.5 kilometers) at a slow and steady speed of 1 centimeter per second, relying on solar energy for its operational power. Importantly, Pragyan can establish communication with the lander. Both landers and rovers are used in Chandrayaan-3.
Unfortunately, Chandrayaan-2 is During its descent on September 6, 2019, the lander experienced a deviation from its planned trajectory, starting at an altitude of 2.1 kilometers (1.3 miles), and unfortunately, communication was lost at the point where touchdown confirmation was anticipated. But we consider it is not a failure by mission it helps to The setback of Chandrayaan-2 was transformed into an opportunity for the success of Chandrayaan-3, demonstrating a remarkable accomplishment by ISRO scientists who effectively turned adversity to their advantage.
Chandrayaan-3: It is the third mission in the Chandrayaan program, Chandrayaan-3 comprises an indigenous propulsion module, a lander module, and a rover, with the primary goal of developing and demonstrating new technologies essential for interplanetary missions. The propulsion module's key responsibilities include transporting the lander and rover from the injection orbit to a lunar orbit of approximately 100 kilometers. Additionally, it carries a Spectropolarimetry of Habitable Planetary Earth (SHAPE) payload for analyzing spectral and polarimetric data of Earth from its lunar orbit. Its primary role is to facilitate the journey of the lander module from the launch vehicle's injection orbit until the moment of lander separation.
Chandrayaan-3 is led by S. Somanath, Chandrayaan-3 spacecraft was successfully launched onboard LVM-3 on 14th July, 2023 at 14:35 hrs from the Satish Dhawan Space Centre, SHAR. The spacecraft is currently undergoing a series of orbit maneuvers to reach the moon’s orbit and has two phases namely Earth Bound Phase and Lunar Bound Phase. The spacecraft is currently in the Earthbound phase.
Chandrayaan-3 is composed of an indigenous Lander module (LM), a Propulsion module (PM), and a Rover, all aimed at advancing and demonstrating novel technologies crucial for interplanetary missions. The Lander possesses the capability to perform a gentle touchdown at a specified lunar site and deploy the Rover, which will conduct on-site chemical analysis of the lunar surface while on the move. Both the Lander and the Rover are equipped with scientific payloads to execute experiments on the lunar terrain. The primary role of the PM is to transport the LM from the launch vehicle's injection point to the final lunar orbit, located approximately 100 kilometers above the lunar surface, and then separate from the LM. Additionally, the Propulsion Module includes an added scientific payload for post-separation operations, and the chosen launcher for Chandrayaan-3 is the LVM3 M4, which will position the integrated module in an Elliptic Parking Orbit (EPO) with dimensions of approximately 170 x 36,500 kilometers.
Facts about Chandrayaan-3: The vehicle employed to facilitate the moon lander Vikram's journey is the GSLV (Geosynchronous Satellite Launch Vehicle), commonly referred to as the Launch Vehicle Mark III, boasting a height of approximately 5 meters. The moon lander Vikram will be assisted by the GSLV Mark 3 heavy-lift launch vehicle, often referred to as the Bahubali rocket. This launch vehicle, now designated as Launch Vehicle Mark 3 (LM-3), stands tall at a height of 43.5 meters. The spacecraft's anticipated lunar touchdown is scheduled for August 23, following a voyage spanning over 40 days. The combined weight of the spacecraft is 3,900 kg, with the propulsion system accounting for 2,148 kg, and the lander and rover weighing 1,752 kg together. This overall mass is near the upper limit of the GSLV MK III's capacity, making it India's most robust rocket. Once Chandrayaan-3 successfully touches down on the moon's surface, the Pragyan Rover will be autonomously deployed for lunar exploration. The rover will be gently released from the lander using a ramp. This solar-powered, six-wheeled vehicle equipped with two spectrometers is dedicated to analyzing the composition of the moon's surface. It is expected to traverse the landing site for approximately 14 Earth days, equivalent to one lunar day.
Final Words: "Yesterday (02/09/2023) ISRO announced, that 100% of Rover completed its assignments. The spacecraft is securely in a parked position, having entered Sleep mode. Both the APXS and LIBS payloads have been deactivated, with their collected data being relayed to Earth through the Lander. At present, the battery is fully charged, and the solar panel is correctly aligned to capture the incoming sunlight when the next sunrise occurs, anticipated on September 22, 2023. The receiver remains active. With optimism for a triumphant reawakening to embark on further missions, otherwise, it shall remain as India's enduring lunar envoy."
This moment stands as one of the most significant milestones in India's history, akin to a nationwide celebration and a deeply cherished success. It represents the realization of dreams for every Indian and holds immense emotional value. The entire Chandrayaan mission has touched the hearts of all Indians, and there is profound gratitude towards ISRO scientists and the supportive government. A heartfelt thank you to "ISRO," and a resounding sense of pride in being Indian. Once more, a salute to ISRO.
Content by: Bhagyalaxmi N Bhat
Email: bhagyabhat98@gmail.com
Image Credit: ISRO