"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.Following this, a hiatus of about one and a half-decade followed. 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.

At Sriharikota, Chandrayaan will be put through its paces on the ground. Indian Satellite Research Organisation (Isro) scientists will check how its solar panels will deploy. It will also undergo electrical and mechanical tests. Chandrayaan had earlier undergone preliminary thermal and vibration tests at Isro Satellite Centre (ISAC) in Bangalore.

For security threats arising from Naxalites and other possible extremist attacks, the exact location of Chandrayaan is being kept under wraps even as it is being provided tightest possible security, according to sources in Isro. Chandrayaan is expected to reach SHAR in a day or two.

The upgraded version of PSLV, PSLV-C11, which has a lift-off weight of 316 tonnes, will be used to inject the 1,304-kg mass spacecraft into a 240 x 24,000 km orbit.
The main objective of Chandrayaan-I is investigation of the distribution of various minerals and chemical elements and high-resolution three-dimensional mapping of the entire lunar surface. ISRO’s Polar Satellite Launch Vehicle (PSLV) will launch Chandrayaan-I into a 240 km x 24,000 km earth orbit. Subsequently, the spacecraft’s own propulsion system will be used to place it in a 100-km polar orbit around the moon.
Scientific Objectives The Chandrayaan-1 mission is aimed at high-resolution remote sensing of the moon in visible, near infrared (NIR), low energy X-rays and high-energy X-ray regions. Specifically the objectives will be

Mission Objectives

• To prepare a three-dimensional atlas (with a high spatial and altitude resolution of 5-10m) of both near and far side of the moon

• To conduct chemical and mineralogical mapping of the entire lunar surface for distribution of elements such as Magnesium, Aluminum, Silicon, Calcium, Iron and Titanium with a spatial resolution of about 25 km and high atomic number elements such as Radon, Uranium & Thorium with a spatial resolution of about 20 km.

• Simultaneous photo geological and chemical mapping will enable identification of different geological units, which will test the early evolutionary history of the moon and help in determining the nature and stratigraphy of the lunar crust.

• To realise the mission goal of harnessing the science payloads, lunar craft and the launch vehicle with suitable ground support systems including DSN station.

• To realise the integration and testing, launching and achieving lunar polar orbit of about 100 km, in-orbit operation of experiments, communication/ telecommand, telemetry data reception, quick look data and archival for scientific utilization by identified group of scientists.

• Simultaneous photo geological and chemical mapping will enable identification of different geological units, which will test the early evolutionary history of the moon and help in determining the nature and stratigraphy of the lunar crust.

• To realise the mission goal of harnessing the science payloads, lunar craft and the launch vehicle with suitable ground support systems including DSN station.

• To realise the integration and testing, launching and achieving lunar polar orbit of about 100 km, in-orbit operation of experiments, communication/ telecommand, telemetry data reception, quick look data and archival for scientific utilization by identified group of scientists.

• Simultaneous photo geological and chemical mapping will enable identification of different geological units, which will test the early evolutionary history of the moon and help in determining the nature and stratigraphy of the lunar crust.

• To realise the mission goal of harnessing the science payloads, lunar craft and the launch vehicle with suitable ground support systems including DSN station.

• To realise the integration and testing, launching and achieving lunar polar orbit of about 100 km, in-orbit operation of experiments, communication/ telecommand, telemetry data reception, quick look data and archival for scientific utilization by identified group of scientists.

Polar Satellite Launch Vehicle

The Indian Space Research Organisation (ISRO) built its Polar Satellite Launch Vehicle (PSLV) in the early 90s. The 45 m tall PSLV with a lift-off mass of 295 tonne, had its maiden success on October 15, 1994 when it launched India’s IRS-P2 remote sensing satellite into a Polar Sun Synchronous Orbit (SSO) of 820 km. Between 1996 and 2005, it has launched six more Indian Remote Sensing satellites as well as HAMSAT, a micro satellite built by ISRO for amateur radio communications into polar SSOs, one Indian meteorological satellite into Geosynchronous Transfer Orbit (GTO). During this period, PSLV has also launched four satellites from abroad (TUBSAT and DLR-Bird from Germany, Proba from Belgium and KITSAT from Republic of Korea) as piggyback payloads into polar SSOs. Thus, PSLV has emerged as ISRO’s workhorse launch vehicle and proved its reliability and versatility by scoring eight consecutive successes between 1994-2005 periods in launching multiple payloads to both SSO as well as GTO.

The first Indian moon mission is proposed to be a lunar polar orbiter at an altitude of about 100 km from the lunar surface. Considering the maturity of Polar Satellite Launch Vehicle (PSLV) demonstrated through PSLV-C4/KALPANA-1 mission, PSLV is chosen for the first lunar mission. The upgraded version of PSLV viz., PSLV-C11 which has a liftoff weight of 316 tonnes, will be used to inject 1304 kg mass spacecraft at 240 x 24,000 km orbit and the corresponding spacecraft mass is 590kg when the target lunar orbit of 100 km is achieved.