Chandrayaan-2 one step closer to Moon landing

On its own after separating from Chandrayaan-2’s Orbiter, the Lander Vikram is now just four days away from that final, defining moment: a soft-landing on the Moon’s South pole on September 7.

Preparing for that terrifying descent, the Indian Space Research Organisation (Isro) on Tuesday morning performed the first de-orbit manoeuvre on Vikram. The operation began at 8.50 am as planned using the Lander’s onboard propulsion system.

The entire manoeuvre lasted only four seconds. But this was adequate to place Vikram in an orbit of 104 km X 128 km. “Chandrayaan-2 Orbiter continues to orbit the Moon in the existing orbit and both the Orbiter and Lander are healthy,” the space agency confirmed.

The next de-orbiting manoeuvre has been scheduled between 3.30 am and 4.30 am on September 4. For Isro, the successful Orbiter-Lander separation has injected a sense of great confidence barely four days away from a game-changing lunar-landing.

Incidentally, it was for the first time in Isro’s history that two models were separated in space. The operation was meticulous, according to Isro Chairman K Sivan.

The health of the Orbiter and Lander is being constantly tracked from the Mission Operations Complex (MOX) at ISRO Telemetry, Tracking and Command Network (ISTRAC) in Bengaluru. This is supported by the Indian Deep Space Network (IDSN) antennas at Bylalu, near Bengaluru.

Chandrayaan-2 was launched aboard the GSLV-Mk III launcher from the Satish Dhawan Space Centre in Sriharikota on July 22. Till date, the spacecraft has undertaken all its manoeuvres with high precision. The final soft-landing in the Moon’s south polar region will be the icing on the cake.

Once the Lander touches down anytime between 1.30 am and 2.30 am the Rover, Pragyaan will roll out within three to four hours. Pragyaan is expected to probe the lunar surface for an entire lunar day equivalent to 14 Earth days.

One of its many critical tasks will be to probe deeper for water, the presence of which was first indicated by the Chandrayaan-1 mission in 2008. The Rover will also explore the chemicals and other surface material towards a better understanding of the origins of the solar system.

Most complex operation

While Sivan is on record dubbing the final descent as '15 minutes of terror,' former Isro Chairman G Madhavan Nair has called the operation the most complex to be attempted in the space agency's history. Nair had spearheaded the Chandrayaan-1 mission over a decade ago.

The complexity of the manoeuvre, according to Nair, lies in the onboard cameras of the Orbiter mapping the terrain to identify the best location for the Lander to touch down. The Lander will be virtually on autonomous mode once the landing site is decided.