With just one day left to go before the launch of India’s second mission to the moon from the Satish Dhawan Space Centre in Sriharikota, Andhra Pradesh, scientists at the Indian Space Research Organisation (ISRO) have completed the launch rehearsal for Chandrayaan-2.
Chandrayaan-2, due for launch at 02:51 am on Monday by the Geosynchronous Satellite Launch Vehicle — Mark III, will be India’s first space mission that will land on another celestial body and the world’s first to explore the South Pole of the moon.
The event will l take place on the eve of the 50th anniversary of the launch of Apollo 11, the US space mission that made Neil Armstrong the first human to land on the moon.
The mission will have an orbiter that will go around the moon 100 km from the lunar surface. The spacecraft will be placed in a 170*40,400-km orbit and raised until it enters the moon’s sphere of influence.
The lander and rover will soft-land two months later on September 6 at the South Pole of the moon between two craters, Manzinus C and Simpelius N, where it will conduct experiments on the mineralogical composition of the lunar rocks and soil and lunar quakes for 14 days.
Through Chandrayaan 2, scientists at ISRO hops to demystify the origins of the moon.
“Our moon is believed to have formed from the remnants of a giant impact of Mars-sized solar system object with Earth more than 4.4 billion years ago. Evidence of the early solar system environment in Earth’s vicinity is well preserved on the moon. Knowing the early history of the solar system and the Earth is an important step towards understanding planet formation and evolution around other stars,” said P Sreekumar, director of the Space Science Programme Office at ISRO.
The mission’s predecessor, Chandrayaan 1, had conclusively discovered traces of water on the moon in 2008. This mission will build on it and look for water ice on the South Pole.
“The discovery of water on the moon by Chandrayaan 1 in 2008 and further re-examination of retrieved samples for trapped water in lunar rocks was an important finding. The very thin atmosphere of the moon also showed water content. Chandrayaan 2 mission is designed to provide new and unique observations using spectrometers and high-resolution cameras. The advanced synthetic aperture will look for water below the surface, an important input towards sustaining a future human presence on the moon,” Sreekumar said.
The South Pole is ideal for the mission because the craters have shadowy regions hidden from the sun. “Water in the other regions, open to the sun, cannot last long; it evaporates. In the cold areas in the shadowy region Chandrayaan 2 will look for water below the surface. It is also where there are cold traps that conserve the history of the solar system,” said Dr M Annadurai, former director of the ISRO Satellite Centre in Bengaluru.
The mission was first scheduled for March 2018 and delayed four times for making changes in the design of the lander and the orbit in which it would reach the surface of the moon.
The original lander was stumbling on impact, which prompted researchers to go back to the drawing board to incorporate changes in its design and add a fifth central engine to ensure proper descent even with the upward draft of lunar dust. Lunar dust is negatively charged and sticks to almost all surfaces, which can impact the landing and deployment of solar panels and sensors.
After the design change, the liftoff mass of the satellite went up from 3,250 kg to 3,850 kg, making it difficult for the GSLV Mk II launch vehicle to carry it. So, the space agency had to work on carrying out the development flights and operationalise the GSLV Mk III launch vehicle that can carry up to 4 tonnes of mass.
The Chandrayaan 2 mission was approved by the cabinet in 2008, just after the first moon mission. Initially, Russia’s Roscosmos was supposed to develop the lander and ISRO the rover and the orbiter.
The mission had to be postponed as Russia was unable to develop the lander on time and later withdrew after the failure of its mission to Phobos, the moon of Mars, prompting India to develop the entire mission on its own.
Jul 13, 2019 23:35 IST
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