Isro nudges ‘Vikram’ closer to the moon

Bengaluru: All it took Indian space scientists was a four-second manoeuvre to inch closer to history as they nudged “Vikram”, the lander holding rover “Pragyan” in its belly, and part of Mission Chandrayaan-2, closer to the moon on Tuesday.

“Vikram” is now on course to a soft touchdown in a zone hardly explored so far — the south pole region — on earth’s natural satellite. It will descend nearer to the moon, from its orbit of 104 km X 128 km, through another tweak of its cruise on Wednesday afternoon, by firing of mini-rockets onboard.

“Vikram” has been operating independently as of Tuesday morning after it was launched as part of the orbiter-lander-rover mission on July 22. It broke free from the mother ship, Chandrayaan-2, on Monday afternoon, but continued orbiting the moon till the first step of the slide down began Tuesday morning.

The “terrifying 15 minutes” often reiterated by Isro chairman K. Sivan is scheduled to begin at 1.40 am on Saturday, September 7, with Prime Minister Narendra Modi viewing from the Mission Operations Complex (MOX) at ISTRAC (Isro’s Telemetry, Tracking and Command Network) facility in Bengaluru.

The success of the Chandrayaan-2 mission will make India the fourth nation after the United States, Russia and China to accomplish a soft landing on lunar soil.

It, however, will top the list of successful touchdowns in the south pole region with its permanently shadowed craters estimated to hold about 100 million tons of water, and more important, scientific evidence on the birth and evolution of the solar system as these craters have remained untouched by rays of the sun for billions of years. An older Chinese probe landed in the northernmost part, followed by

Russia’s Luna missions. Most of the US lunar landings, including the Apollo missions, were in the moon’s equatorial region.

The space scientists said that a couple of hours after landing, “Pragyan”, the rover, will slide down a ramp between 5.30 am and 6.30 am on September 7, to probe the lunar soil over a period of one lunar day (equal to 14 days on earth). “Vikram” will also be operational for one lunar day.

Most of the instruments on board this Rs 978-crore orbiter-lander-rover mission are made indigenously, the sole exception being one built by Nasa. The orbiter carries eight gadgets to map the lunar surface and study the exosphere (outer atmosphere) of the moon, while “Vikram” is fitted with three instruments to carry out surface and subsurface science experiments.

“Pragyan” has been equipped with two instruments to enhance the understanding of the lunar surface.

Originally scheduled for a pre-dawn launch on July 15, Chandrayaan-2 was launched by GSLV Mk-III rocket a week later, after space scientists fixed a
glitch in the cryogenic engine of the rocket.