Chandrayaan-1 is the first collaborative mission between ESA and ISRO, and also the first Indian scientific mission leaving the earth’s vicinity.
 
 
Objectives
 
Chandrayaan-1 will use several electromagnetic wavelengths – visible, near infrared, microwave, X-ray – to map the Moon’s minerals in unprecedented, high resolution, and study lunar geology and geochemistry.

The mission will:

• Analyse geological, mineralogical and topographical aspects of the lunar surface in unprecedented detail
• Study the vertical distribution of crustal material
• Investigate the processes that led to the formation of craters, maria and basins on the Moon
• Explore space weathering processes, that result from the interaction of the solar wind and cosmic rays with the Moon’s surface
• Analyse the magnetic anomalies on the lunar surface
• Search for ices at the poles
• Produce 3D maps of regions of particular scientific interest at high spatial resolution (5-10 m)
• Drop an impact probe on the lunar surface to test near-surface properties and test impact technology

A ‘champion’ in high-quality remote sensing

Although missions have collected lunar samples in the past to analyse later on ground, the role of remote sensing of the lunar surface is gradually increasing. Direct, in-situ exploration of the Moon, particularly by the Apollo, Luna, and Lunar Prospector missions have provided a considerable amount of data of the lunar surface which gave us an insight into the processes responsible for lunar origin and evolution. Nevertheless, there are many aspects, such as the global mineralogical composition, size and structure of the Moon, that require further study from orbit using remote-sensing techniques. Other aspects that require study are the existence of ice and water in the permanently-shadowed lunar polar regions, and the hemispheric asymmetry between the Earth-facing and the far side of the Moon.

Accommodating eleven instruments on board, Chandrayaan-1 will record high-quality visible, near infrared, low- and medium-energy X-ray data of the Moon to help answer these questions from orbit.

Global coverage of the Moon’s surface composition

More than any other question about the Moon, our understanding of the evolution of lunar crust strongly depends on our knowledge of its composition. Chandrayaan-1 will collect global surface composition data to understand the formation and evolution of lunar crust and the processes that have modified it during its history.

ESA and Europe’s fundamental contribution

The experience and know-how ESA gained with SMART-1, Europe’s first mission to the Moon, is benefiting Chandrayaan-1 greatly. ESA is assisting ISRO in operations, data handling, flight dynamics for the mission. ESA is also coordinating the provision of three European instruments for the mission, two of which were already flown on SMART-1:

• The Chandrayaan-1 X-ray Spectrometer (C1XS) is one of the core instruments that will carry out high-quality, low-energy (soft) X-ray spectroscopic mapping of the Moon
• The near infrared spectrometer, SIR-2, a near-infrared spectrometer will study the chemical composition of the Moon’s crust and mantle
• The Sub-keV Atom Reflecting Analyser SARA will be the first-ever lunar experiment dedicated to direct studies of plasma-surface interactions in space.

Precursor for future space missions

Chandrayaan-1’s objectives will be of great value for future missions to the Moon, Mercury (such as ESA’s BepiColombo) and other bodies in the solar system which do not have an atmosphere. For example, a replica of the SARA LENA sensor is also included in BepiColombo’s Mercury Magnetospheric Orbiter. This opens up ample possibilities for comparative planetology studies.
 
 
Spacecraft
 
Chandrayaan-1 is a cuboid of approximately 1.50-m side length. At launch, it will weigh 1304 kg, including 814 kg of fuel needed by the spacecraft for its journey and in-orbit adjustments. A canted, single-sided solar array will provide the electrical power needed during all mission phases. The fully-deployed solar array generates up to 700 Watts of power.

The spacecraft hosts 11 science instruments. They include:

• A Hyper Spectral Imaging camera, HySI, a spectral imager for mineralogical mapping
• The Chandrayaan-1 X-ray Spectrometer (C1XS), an X-ray fluorescence spectrometer for mapping elements
• High-energy X-ray spectrometer, HEX, to map the distribution of radioactive elements
• A near-infrared spectrometer, SIR-2
• Moon Mineralogy mapper (M3)
• Terrain Mapping Camera (TMC)
• Lunar Laser Ranging Instrument (LLRI)
• Miniature Synthetic Aperture Radar (Mini-SAR)
• Radiation Dose Monitor Experiment (Radom)
• Sub KeV Atom Reflecting Analyser (SARA)

The instrument suite also includes a 29-kg landing probe (MIP), to be dropped on the lunar surface at the beginning of the mission for near-surface studies. The probe carries a mass spectrometer, a camera and an altimeter.
 
 
Journey
 
Chandrayaan-1 will be launched on board a Polar Satellite Launch Vehicle (PSLV) from the Satish Dhawan Space Center in Sriharikota, India, in April 2008. After having reached its lunar transfer orbit around the Earth, it will travel for five and a half days to reach the lunar orbit insertion point and enter a nearly circular orbit at a height of about 1000 km over the Moon. After two-weeks of in-orbit manoeuvres, the satellite will reach its final circular, polar orbit at an altitude of 100 km. The mission is planned to operate for at least two years.
 
 
History
 
ISRO announced the Chandrayaan-1 mission in 2003 and in spring 2004, expressed interest in cooperation with ESA. A Cooperative Agreement was signed between two agencies, and entered into force in June 2005.

Partnerships

Chandrayaan-1 is led by ISRO. ESA is coordinating the provision of three European instruments, has provided support in areas such as thermal design and flight dynamics, and is providing support for data archiving and processing. Other partners include Bulgaria and the USA.
 
 


Last update: 8 October 2008