Bangalore. The abrupt termination of the Rs 3860-million maiden Indian probe to moon Chandrayaan-1 was not an unexpected development.

Once the radio contact was lost on August 29, there was nothing much one could do to control or direct the spacecraft. Nonetheless, leading scientists from the US National Aeronautics and Space Administration (NASA), European Space Agency (ESA) and other countries have endorsed the Indian Space Research Organisation (ISRO) view that within its lifespan of 10 months, Chandrayaan-1 has provided “excellent” data.

The scientists met in Bangalore early September to consider the performance of this mission, and according to an ISRO statement, they feel that the “data obtained by some of the payloads is of exceptional quality and the initial analysis of it has already resulted in a notable shift in understanding the working of the planetary system.”

Construed as an attempt at building India’s position as a leading space faring nation, this first ever deep space probe of ISRO was under the clouds of uncertainty ever since the loss of its vital star sensor in April this year. The backup orientation system was apparently not enough, and high radiation from the sun eventually killed its onboard computers.

But ISRO says that although it had planned a life of two years for Chandrayaan-1, the spacecraft has already given 90 to 95 per cent of the data that was expected to have been collected from it. The one primary lesson now is to strengthen the heat shield of Chandrayaan-2 when it is launched, and even the Bhabha Atomic Research Centre (BARC) is helping out in this process.

First announced by the then Indian Prime Minister Atal Bihari Vajpayee on Aug 15, 2003 and launched on Oct 22, 2008, Chandrayaan-1 was carried 11 payloads – five Indian and six international. It completed 3400 orbits in its lifespan of 312 days around the moon before its mission was called off.

It’s expected to fall off on the moon’s surface in a year or two, gradually coming down from its height of 200 km above the moon’s surface at present.

One of its major scientific aims was to prepare a three-dimensional map of the lunar surface showing distribution of chemicals and minerals in addition to looking for signs of water and presence of Helium-3, an eco friendly energy source. ISRO says that while most of the lunar probes launched so far focussed on equatorial region, Chandryaan-1 had as its target the polar region of the moon believed to harbour water ice.

Though in public perception, the premature end of Chandrayaan-1 comes as a disappointment, space scientists point out that the fact that it could survive for more than 300 days in the high radiation environment and provide a wealth of data on various aspects of earth’s celestial neighbour is a “stupendous achievement.” Many of the lunar missions launched by other countries have burnt out even in a couple of months after they were put into orbit.

After the meeting of the international panel of scientists, ISRO said that four of the 11 payloads, Terrain Mapping Camera (TMC), Moon Mineralogy Mapper (M3), Hyper Spectral Imager (HySI) and Smart near-Infrared Spectrometer (SIR-2), had given extensive and extremely useful data on the moon’s topography, mineralogy and chemistry. “TMC and HySI covered about 70 per cent of the lunar surface while M3 covered more than 95 per cent. SIR-2 has provided high resolution spectral data on the mineralogy of the moon.”

Notably, manoeuvring a lunar spacecraft and positioning it around the moon is a very complex operation that can be jeopardized by “hostile space environment”.

A third of the moon probes have met with premature end while getting inserted into the lunar orbit. In this context, the former Indian President and well known space and defence scientist Dr A P J Abdul Kalam says, ”We have got images and data from ten instruments onboard the spacecraft in the last ten months. This means the mission is completed.” On another front, Chandrayaan-1 has also helped ISRO realize a deep space tracking network and implement the operational procedures for travel into deep space.

On his part, ISRO Chairman G Madhavan Nair has driven home the point that Chandrayaan-1 has completed 95% of its objectives, and that this is reason enough for satisfaction.

He is of the view that since it was India’s first foray into deep space, the radiation protection and thermal management has fallen short of the real requirements. Though the circumstances leading to the termination of Chandrayaan-1 probe are yet to be convincingly established, excessive radiation seems to be the reason for the failure of the onboard power supply units feeding the two computers meant to sustain the command and control links.

Electronic devices onboard the orbiting spacecraft are known to be susceptible to radiation and violent temperature fluctuations.

Meanwhile, ISRO is in the process of setting up a panel of experts to come out with a post mortem of what actually went wrong with the Chandrayaan-1 mission.

Chandrayaan-1 project director M Annadurai has said that lessons learnt from Chandrayaan-1 will be applied to improve the performance of the systems forming part of Chandrayaan-II mission slated for launch during 2012-13.

Nair has clarified that the termination of Chandrayaan-1 mission in less than a year of its launch does not in any way affect the Chandrayaan-II. Stating that “valuable lessons learnt from Chandrayaan-1 will come in handy for Chandryaan-11”, he says that ISRO has now a detailed understanding and knowledge of the environment it is working with.

Throwing light on Chandrayaan-1, Nair noted that it will take from six months to two years to analyze the data gathered by the Indian moon mission. He also revealed that a detailed analyses of the images was needed to arrive at the nature of the moon and what it was made of.

“From the launch pad and reaching its precise orbit around the moon and landing the MIP on the lunar surface and gathering data, we have crossed all the milestones,” he observed.

Meanwhile, a preliminary analysis of the data made available by Moon Mineralogy Mapper (M3), an American payload onboard Chandrayaan-1, is known to have confirmed the Lunar Magma hypothesis, the widely accepted explanation for the formation of the lunar highlands.

As it is, the hypothesis postulates that a large portion of the moon was once completely molten, forming a lunar magma ocean. “It proves beyond doubt the magma ocean hypothesis. There is no other way, this massive rock type would be formed,” said Carle Pieters, Science Manager at the NASA Spectroscopy facility at the Brown University in the Untied States.

Launched by means of the four-stage trusted workhorse PSLV (Polar Satellite Launch Vehicle) rocket from the Satish Dhawan Space Centre (SDSC) at Sriharikota island on India’s eastern coast, Chandrayaan-1 entered its final orbit of 100-km above the lunar surface on Nov 4 after a series of complex manoeuvres. The PSLV was equipped with an upper trans-lunar stage for its approximately 380,400 km long journey.

On Nov 14, the 30 kg Indian-built Moon Impact Probe (MIP) with the Indian flag etched on it crashed on the lunar surface as planned. This signal achievement catapulted India into elite league of space faring nations which have injected probes around the moon – the USA, Europe, Russia, China and Japan.

As a matter of policy, India has also cooperated in this moon mission with other countries, and valuable data is being shared to the advancement of science.

The loss of star sensor meant to determine the position of the spacecraft has nudged the Indian space scientists to come out with an alternate strategy to keep the lunar probes in a “safe and stable mode”. Hopefully, in future missions, there will be adequate backup.

Indeed, ISRO had activated the onboard backup gyroscope, an electro mechanical device meant to stabilize the orientation of the spacecraft. But it was not enough to sustain the mission. The orbit of Chandrayaan-1 was raised to 200-km from 100-km as that was considered a “more benign environment” and the use of onboard fuel would have been less at that height. But then, there was no answer to the excessive solar radiation at that height.

From its new orbital home, Chandryaan-1 provided clues to the traces of calcium and silicon on the lunar surface.

This significant sighting of the two vital minerals was made possible by CXIS (Chandrayaan-1 Imaging X-ray Spectrometer), a payload contributed by the ESA through the collaboration between Rutherford Appleton Laboratory of the United Kingdom and ISRO Satellite Centre (ISAC) in Bangalore. This happens to be the second sighting of the minerals, nine months into the mission.

Incidentally, the first sighting happened two months into the mission when Moon Mineralogy Mapper revealed clues to the presence of iron traces on the moon.

Overall, Chandrayaan-1 has provided clues to the presence of four mineral elements on the moon. It may be noted that its 11 scientific instruments were built in India, USA, UK, Germany, Sweden and Bulgaria.

According to ISRO sources, data from CIXS and Moon Mineralogy Mapper will help in mapping the lunar minerals in great detail and also in getting an insight into the early history and geological evolution of the moon. Chandrayaan-1 has provided more than 70,000 high quality imageries, some of which provide a breathtaking view of the lunar mountains and craters in its permanently shadowed regions.

In a development of significance, on August 21, Chandrayaan-1 in tandem with American lunar probe Lunar Reconnaissance Orbiter (LRO) successfully carried out what is known as Bistatic Experminet. During this experiment, radar instruments onboard these two lunar spacecraft focused on the same locations from different angles in a permanently shadowed crater near the northern pole of the moon. The objective of the experiment was to gather additional data and more conclusive information on the possibility of water ice existing in the polar region of the moon. The Indian spacecraft took the pictures and the US satellite relayed them.

The Chandrayaan-1 mission was realized by India at a fraction of the cost of the lunar probes launched by other space faring nations.

As per the benchmark set by the International Academy of Astronautics, a deep space or planetary mission could be categorized as low cost if its price tag does not exceed US$ 500million. Even the PSLV rocket used for launching Chadnrayaan-1is a midget compared to the gigantic vehicles used by China and Japan to launch their respective lunar probes.

Meanwhile, ISRO has completed the design phase of Chandrayaan-II which will be an Indo-Russian project.

While ISRO will be responsible for the moon orbiter, Russia will develop lander/rover forming part of the mission. The robotic rover which will make a soft landing on the surface of the moon, will pick up soil and rock samples, subject them to in-situ analyses and send the data instantly to the mother craft orbiting around the moon.

The site for landing the rover will be determined based on an analysis of the data transmitted by Chandrayaan-1.

The biggest hurdle involved in the successful accomplishment of the Chandrayaan-II mission is to find a way to ensure that the robotic rover lands safely on the lunar surface. Due to the absence of atmosphere in the moon’s periphery, the option of parachuting the rover is ruled out.

Chandrayaan-II is planned to be launched by means of the three stage GSLV (Geosynchronous Satellite Launch Vehicle) featuring an upper cryogenic engine stage. However Nair has made it plain that as of now, a manned mission to moon is not on the agenda of ISRO.