Race to the moon: Chandrayaan 3 sets up lunar date; Luna-25 crashes

Bengaluru: Russia has bowed out of the race to the moon with India after its robot lander crashed on the lunar surface, setting Chandrayaan-3 on an easier course while ISRO scientists achieved yet another successful maneouver to take the spacecraft closer to the moon in its soft-landing attempt on August 23.

ISRO on Sunday said it has successfully reduced the orbit of Chandrayaan-3 mission's Lander Module (LM), and it is now expected to touch down on the surface of the Moon at 6.04 PM on Wednesday.

This came even as Russian lander Luna-25 crashed into the moon after going into uncontrolled orbit.

"The apparatus moved into an unpredictable orbit and ceased to exist as a result of a collision with the surface of the moon," Russian space agency Roscosmos said in a statement.

Roscosmos said it lost contact with the spacecraft on Saturday after it ran into trouble while preparing for its pre-landing orbit after reporting an "abnormal situation" that its specialists were analysing. The Luna-25 was launched from the Vostochny Cosmodrome in Russia's Far East on August 10.

Incidentally, the ambitious Chandrayaan-2 had also crashed into the lunar surface four years ago, but its successor has ticked all the orbit-related boxes so far as part of its journey towards the Moon.

Chandrayaan's LM, comprising the lander 'Vikram' and rover 'Pragyan', is expected to touch down on the lunar surface on Wednesday, August 23 at 6.04 pm, added ISRO, which had earlier said the soft landing would take place at 5.47 pm that day.

Having took off on August 11, Luna-25 was supposed to touch the moon surface on August 21, two days before Vikram's scheduled landing.

ISRO said the second and final deboosting (slowing down) operation has successfully reduced the LM orbit to 25 km x 134 km. The module would undergo internal checks and await the sunrise at the designated landing site. The powered descent is expected to commence on August 23, 2023, around 5.45 pm, ISRO said in a post on 'X', formerly Twitter.

The Russian setback brought back memories of ISRO's Chandrayaan-2 with the lander 'Vikram' along with its rover 'Pragyan' crash landing on September 6, 2019, while attempting a touch down in the south pole of the moon.

Russia’s space agency Roscosmos said in accordance with the flight programme of the automation station Luna-25, on August 19, it was planned to issue an impulse to form its pre-landing elliptical orbit.

However, the communication was interrupted and the measures taken to get in touch with Luna-25 did not produce any results.

According to ISRO, India's pursuit of space exploration will reach a remarkable milestone with the Chandrayaan-3 mission poised to achieve a soft landing on the surface of the Moon.

This achievement marks a significant step forward for Indian Science, Engineering, Technology, and Industry, symbolising our nation's progress in space exploration, it said.

This eagerly anticipated event will be broadcast live on August 23, starting from 5.27 pm IST on multiple platforms, including the ISRO Website, its YouTube channel, the agency's Facebook page, and DD National TV channel.

"The soft landing of Chandrayaan-3 is a monumental moment that not only fuels curiosity but also sparks a passion for exploration within the minds of our youth," ISRO said.

"It generates a profound sense of pride and unity as we collectively celebrate the prowess of Indian science and technology. It will contribute to fostering an environment of scientific inquiry and innovation," it said.

In light of this, all schools and educational institutions across the nation are invited to actively publicise this event among students and faculty, and organise a live streaming of the Chandrayaan-3 soft landing on campuses, ISRO said.

On Thursday, 35 days after the mission was launched on July 14, the lander module of Chandrayaan-3 had successfully separated from the propulsion module.

ISRO sources earlier said that after the separation, the lander would undergo "deboost" (the process of slowing down) operations to place it in an orbit where when it's at a point closest to the Moon (Perilune) it would be at a distance of 30 km and at its farthest point (Apolune) it would be 100 km away.

At this point, the soft landing on the south polar region of the Moon will be attempted.

At around 30 km altitude, the lander enters the powered braking phase and begins to use its thrusters to reach the surface of the Moon, they said. At an altitude of about 100 m, the lander would scan the surface to check whether there are any obstacles and then start descending to make a soft landing.

Post its launch on July 14, Chandrayaan-3 entered into lunar orbit on August 5, following which orbit reduction manoeuvres were carried out on the spacecraft on August 6, 9, 14 and 16, ahead of the separation of both its modules on August 17, in the runup to the landing on August 23.

Earlier, over five moves in the three weeks since the July 14 launch, ISRO had lifted the Chandrayaan-3 spacecraft into orbits farther and farther away from Earth.

Then, on August 1 in a key manoeuvre -- a slingshot move -- the spacecraft was sent successfully towards the Moon from Earth's orbit. Following this trans-lunar injection, the Chandrayaan-3 spacecraft escaped from orbiting the Earth and began following a path that would take it to the vicinity of the Moon.

The current mission is a follow-on to Chandrayaan-2 and seeks to demonstrate end-to-end capability in safe landing and roving on the lunar surface.

The mission objectives of Chandrayaan-3 are to achieve safe and soft landing on the lunar surface, to demonstrate the rover's mobility on the Moon, and to conduct in-situ scientific experiments.

The lander has the capability to soft land at a specified lunar site and deploy the rover that will carry out in-situ chemical analysis of the Moon's surface during the course of its movements.

The lander and the rover are carrying scientific payloads to carry out experiments on the lunar surface.

Only three countries-- the erstwhile Soviet Union, the US and China have achieved successful moon landings, a but not on the moon's south pole. India and Russia were racing to create history by becoming the first countries to do so.