Sunday Reading

New Delhi, 11 October 2008

Chandrayaan-1 Mission

EYES ON WEATHERGODS FOR TIMELY LAUNCH

By Radhakrishna Rao

Everything is going as planned. India’s first lunar probe Chandrayaan-1, with a lift-off mass of 1300-kg will be launched before October-end this year. Even as the countdown for its launch has been signaled with the stacking of the stages of an augmented version of the space workhorse, the Polar Satellite Launch Vehicle (PSLV), the take off is subject to prevalence of clear weather. Normally, the Indian space port in Sriharikota Island on the eastern coast, Satish Dhawan Space Centre (SDSC), is subject to seasonal cyclonic lash during the last quarter of the year.

On its part the Bangalore-based Satellite Centre of the Indian Space Research Organisation (ISRO), which has designed and developed Chandryaan-1, has completed a gamut of checks. These include vibration and acoustic tests to prepare the lunar probe for its 400,000-km long rigorous journey to the moon. After its integration with the four-stage PSLV at SDSC, Chandrayaan-1 will again be subjected to a further series of checks so that there are no hitches during its upcoming cosmic journey.

As things stand now, ISRO is looking at a launch window between October 20 and 28. If for reasons beyond its control, it misses this launch target, Chandrayaan-1 will then get underway sometime in November. On the other hand, if Chandrayaan-1 launch takes place as planned, it will be stabilized in the lunar orbit of 100 km by the first week of November.

In order to monitor and support the Chandrayaan-mission, ISRO has set up a Deep Space Station (DSN) at Byalalu village on the outskirts of Bangalore. According to ISRO sources, the DSN, made up of an 18-m antenna system and a 32-metre antenna system will also be pressed into service for monitoring and supporting the country’s futuristic deep space missions, including Chandrayaan-1 and Astrosat astronomy research satellites.

As pointed out by ISRO, the mission objectives of Chandrayaan-1 include preparation of a three-dimensional atlas of both the near and far side of the moon and to carry out chemical and mineralogical mapping of the entire lunar surface for identifying the distribution of minerals and chemical elements. On another front, Chandrayaan-1 designed for a lifespan of two years, shall   look for signs of water and Helium-3 in lunar topography.

Helium-3 is considered a rich and environmentally friendly source of energy .Mining and transportation of Helium-3 to earth is already on the agenda of advanced space-faring countries. There has been a renewal and resurgence of interest in exploring the moon from a fresh prospective on account of the possibility of water and Helium-3 available on it. The wealth of data being made available by Chandrayaan-1 will also throw fresh light on the evolution and early history of our spaceship earth, as also the dynamics of the formation of moon.

 Incidentally, China launched its first lunar probe Chang’e-2 last year. And the launch of Chandrayaan-1 will make India the fifth country in the world to send a probe to earth’s satellite. Chandrayaan-1 features five Indian payloads and six international scientific probes. The Indian payloads include a terrain mapping stereo camera, a hyper spectral imaging camera, a lunar ranging instrument, a high energy x-ray spectrometer as well as a Moon Impact Probe (MIP).

Significantly, MIP was not envisaged as a part of the original Chandrayaan-1 mission. Its inclusion as a piggy back payload on the main orbiter of Chandryaan-1 spacecraft was prompted by plans to build and launch futuristic robotic landing missions to moon. Evidently, MIP has been designed to impact on the surface of the moon carrying a CCD camera, a radar altimeter and high sensitivity mass spectrometer providing continuous data till the point of impact.

While China has hinted that it was planning to go in for a manned mission to the moon, India is yet to firm up a plan for the human exploration of the earth’s neighbor. Sometime back ISRO Chairman G Madhavan Nair had stated that at the moment, a manned mission to the moon was not on the radar of the space agency. He, of course, also made it clear that before India decides to take up this ambitious project, there would be a need to study the available technological options other than novel technologies that would need to be developed for such a mission to the moon.

Once Chandraayan-1 is stabilized in orbit, ISRO will focus its attention on preparing the ground for the first manned mission slated for a take off sometime during mid next decade. The programme envisages the development of a fully autonomous orbital vehicle carrying two or three crew members to 400-km low earth orbit and their safe return.

In a significant development, the Union Government has approved the proposal for India’s second lunar probe Chandrayaan-II which will feature a robotic rover designed to land on the lunar surface. Chandrayaan-II, which will be developed in association with Russia, is planned to be launched by means of the three-stage GSLV (Geosynchronous Satellite Launch Vehicle) from SDSC. The rover will move on wheels on the lunar surface, pick up samples of soil or rocks, do a chemical analysis and send the data to the mother spacecraft orbiting around the moon.

While ISRO will develop the main orbiter, the Russian Federal Space Agency will build the landing platform along with the rover. Though the exact landing site of the rover onboard Chandrayaan-II is yet to be identified, Aitkan basin near the South Pole of the moon is one of the potential candidates. The Government has already sanctioned Rs.4250-million for the Chandrayaan-II, which is planned to be launched during 2011-12.

The main Chandrayaan-II spacecraft will carry remote sensing instruments, a terrain mapping camera and a nano meter hyper-spectral imager, capable of viewing in the visible, ultra violet and infrared regions. In addition, Chandrayaan-II will feature a low-energy spectrometer with charge coupled device (CCD) arrays, which are likely to be accommodated in Chandrayaan-II.

In a related development, the US’ National Aeronautics and Space Administration (NASA) has hit upon the idea of building what has been described as the biggest-ever telescope on the lunar surface with a mixture of carbon and  lunar dust. “We would make huge telescopes on the moon relatively easily and avoid the large expenses of transporting a large mirror from the earth” being NASA’s idea. This telescope will be capable of taking images of the earth with a high degree of precision and great details. Till then all eyes would be on the launch of Chandrayaan-1---INFA

(Copyright, India News and Feature Alliance)