CHANDRAYAAN-1: India's first mission to
Moon
"THE MOON"with the history of the early solar system etched on it beckons mankind from time immemorial to admire its marvels and discover its secrets. Understanding the moon provides a pathway to unravel the early evolution of the solar system and that of the planet earth.
Through the ages, the Moon, our closest celestial body has aroused curiosity in our mind much more than any other objects in the sky. This led to scientific study of the Moon, driven by human desire and quest for knowledge. This is also reflected in the ancient verse.
Exploration of the moon got a boost with the advent of the space age and the decades of sixties and seventies saw a myriad of successful unmanned and manned missions to moon. This was followed by a hiatus of about one and a half-decade. During this period we refined our knowledge about the origin and evolution of the moon and its place as a link to understand the early history of the Solar System and of the earth.
However, new questions about lunar evolution also emerged and new possibilities of using the moon as a platform for further exploration of the solar system and beyond were formulated. Moon again became the prime target for exploration and a new renaissance of rejuvenated interest dawned. All the major space faring nations of the world started planning missions to explore the moon and also to utilize moon as a potential base for space exploration.
The idea of undertaking an Indian scientific mission to Moon was initially mooted in a meeting of the Indian Academy of Sciences in 1999 that was followed up by discussions in the Astronautical Society of India in 2000. Based on the recommendations made by the learned members of these forums, a National Lunar Mission Task Force was constituted by the Indian Space Research Organisation (ISRO). Leading Indian scientists and technologists participated in the deliberations of the Task Force that provided an assessment on the feasibility of an Indian Mission to the Moon as well as dwelt on the focus of such a mission and its possible configuration.
The task force recommended that given the technical expertise of ISRO it will be extreme worthwhile to plan an Indian Mission to the Moon. It also provided specific inputs such as the primary scientific objectives of such a mission, plausible instruments to meet these objectives, launch and spacecraft technologies that need to be developed and suggested the need for setting up of a Deep Space Network (DSN) station in India for communication with the lunar orbiting spacecraft. The team also provided a provisional budgetary estimate.
The Study Report of the Task Team was discussed in April 2003 by a peer group of about 100 eminent Indian scientists representing various fields of planetary & space sciences, earth sciences, physics, chemistry, astronomy, astrophysics and engineering and communication sciences. After detailed discussions, it was unanimously recommended that India should undertake the Mission to Moon, particularly in view of the renowned international interest on moon with several exciting missions planned for the new millennium. In addition, such a mission will provide the needed thrust to basic science and engineering research in the country including new challenges to ISRO to go beyond the Geostationary orbit. Further, such a project will also help bringing in young talents to the arena of fundamental research. The Academia, in particular, the university scientists would also find participation in such a project intellectually rewarding.
Subsequently, Government of India approved ISRO's proposal for the first Indian Moon Mission, called Chandrayaan-1 in November 2003.
Spacecraft > Description
Description
Spacecraft for lunar mission is :
Cuboid in shape of approximately 1.5 m side.
Weighing 1380 kg at launch and 675 kg at lunar orbit.
Accommodates eleven science payloads.
3-axis stabilized spacecraft using two star sensors, gyros and four reaction wheels.
The power generation would be through a canted single-sided solar array to provide required power during all phases of the mission. This deployable solar array consisting of a single panel generates 750W of peak power. Solar array along with yoke would be stowed on the south deck of the spacecraft in the launch phase. During eclipse, spacecraft will be powered by Lithium ion (Li-Ion) batteries.
After deployment, the solar panel plane is canted by 30º to the spacecraft pitch axis.
The spacecraft employs a X-band, 0.7m diameter parabolic antenna for payload data transmission. The antenna employs a dual gimbal mechanism to track the earth station when the spacecraft is in lunar orbit.
The spacecraft uses a bipropellant integrated propulsion system to reach lunar orbit as well as orbit and attitude maintenance while orbiting the Moon.
The propulsion system carries required propellant for a mission life of 2 years, with adequate margin.
The Telemetry, Tracking & Command (TTC) communication is in S-band frequency.
The scientific payload data transmission is in X-band frequency.
The spacecraft has three Solid State Recorders (SSRs) Onboard to record data from various payloads.
SSR-1 will store science payload data and has capability of storing 32Gb data.
SSR-2 will store science payload data along with spacecraft attitude information (gyro and star sensor), satellite house keeping and other auxiliary data. The storing capacity of SSR-2 is 8Gb.
M3 (Moon Mineralogy Mapper) payload has an independent SSR with 10Gb capacity.
