Indian spacecraft will try to unravel moon's origin

Sriharikota (Andhra Pradesh): India's lunar explorer, Chandrayaan-1, will try to unravel the moon's origins as it scouts for minerals and water there, says project director M Annadurai.

Chandrayaan, slated for an October 22 launch from Satish Dhawan Space Centre, would bolster international space cooperation by carrying 11 scientific devices — six of them from European and American organisations, while it orbits 100 km above the moon.

One of the lunar orbiter's key missions will be to map the moon. "During the two-year expedition, the 11 devices will be used to prepare a three-dimensional atlas of both near and far side of the moon," Annadurai said.

The maps will have a high resolution of 5 to 10 metres, he added.

Annadurai said the chemical and mineralogical mapping of the entire lunar surface will show where elements such as magnesium, aluminium, silicon, calcium, iron and titanium are to be found.

"Simultaneous photo, geological and chemical mapping will enable indentification of the different geological units, which will test the early evolutionary history of the moon," he said. They will also help determine the nature of the lunar crust, he said.

The lunar probe will also look for water-ice in the permanently dark polar regions of the moon which may be as cold as 50 to 70 degrees Kelvin (about minus 223 to minus 203 degrees Centigrade) , he said.

These are the European Space Agency devices or payloads that will fly on the Chandrayaan:

• Imaging x-ray spectrometer (C1XS), developed by the Rutherford Appleton Laboratory in Britain with the ISRO satellite centre, will map the lunar surface, using x-ray fluorescence technique for measuring the elements. It will also observe the moon during the rising phase of the solar cycle when x-ray signals are expected to be enhanced.
• Sub-kiloelectronvolt (keV) atom reflecting analyser (SARA), built jointly by the Swedish Institute of Space Physics and the Space Physics Laboratory of the Vikram Sarabhai Space Centre (VKSC) at Thiruvananthapuram, will study the composition of the moon, the way its surface reacts to solar wind, how its materials change and the magnetic anomalies.
PAGE_BREAK The following are the two US instruments packages:
• The 6.5-kg mini synthetic aperture radar (MiniSAR), developed by the Johns Hopkins University applied physics laboratory and the naval air warfare centre, will detect water-ice in the permanently shadowed regions of the lunar poles by digging a few metres into the surface.
• Moon mineralogy mapper (M3), an imaging spectrometer built by Brown University and the Jet Propulsion Laboratory (JPL) of NASA, will assess and map lunar mineral resources at high spatial and spectral resolution for future targeted missions.

"The seven kg M3 will also help in characterising and mapping lunar minerals for knowing the moon's early geological evolution," Annadurai said. "Its compositional maps will improve our understanding of the early evolution of a differentiated planetary body and provide a high-resolution assessment of lunar resources."

The Bulgarian Academy of Sciences' radiation dose monitor (RADOM) will characterise the radiation environment in a region of space near the moon. Its data will be used to evaluate the radiation environment and radiation shielding requirements on future manned moon missions.

The five Indian payloads are:

• The seven-kg terrain mapping camera (TMC) will map moon's topography and prepare the three-dimensional atlas.
• The four-kg hyper spectral imager (HySI) will gather spectroscopic data for mapping minerals.
• The 10-kg lunar laser ranging instrument (LLRI) will provide data for determining the height of lunar surface features and moon's gravity field.
• The 16-kg high energy x-ray spectrometer (HEX) will explore the moon's polar regions (north-south) that may be covered by thick water-ice deposits.
• The 29-kg moon impact probe (MIP) that will descend on to the lunar surface in about 20 minutes from an altitude of 100 km on a specific location at a pre-determined time to explore the moon from a close range.