Chandrayaan-3 highlights: Vikram lander to attempt landing at 6:04pm on Aug 23, says ISRO

Space strategist P K Ghosh said on Sunday that one of the "biggest" challenges in the landing of Chandrayaan 3 on the lunar surface is to get the spacecraft from a horizontal to a vertical position.

"One of the biggest things is that it has got to get the spacecraft from a horizontal position to a vertical position. That is difficult. All these aspects have to be looked into," P K Ghosh told ANI.

Chandrayaan 3 underwent the second and final deboosting operation in the early hours of Sunday and is scheduled to land on the moon on Wednesday around 18:04 IST, the Indian Space Research Organisation (ISRO) announced on Sunday.

On the Chandrayaan 3 mission and Russia Luna-25 crash, Space strategist P K Ghosh told ANI, "I think Chandrayaan 3 will make a good landing on August 23. The crashing of Russia's Luna-25 is an unfortunate event. After about 47 years Russia had taken off Luna-25. This shows that you should never take anything for granted in space exploration...Chandrayaan-3 is just 25 km away from the moon's nearest elliptical orbit."

Business magnate Anand Mahindra on Sunday expressed his excitement for India's third moon mission, Chandrayaan-3, as it inches closer to land on the lunar surface on Wednesday. The chairman of Mahindra Group said he will be watching, praying and cheering on the Chandrayaan-3 mission during its landing. Read the detailed story on Anand Mahindra's enthusiasm for Chandrayaan-3

The rear wheels of the rover, named Pragyan, leave imprints of the ISRO and the national emblem, depicting the Lion Capital of Ashoka at Sarnath, on the lunar surface – symbolising its presence and leaving India’s mark behind.

Read the detailed story on Chandrayaan-3 Pragyan rover

On Chandrayaan 3 mission, Director, ISRO Inertial Systems Unit (IISU) Padmakumar ES told ANI, "...It is very crucial to follow the exact trajectory for this descent because the margins of errors are quite low...That's why this soft landing is considered to be a very difficult job to achieve..."

China is pursuing plans to send a crewed mission to the Moon by 2030 and build a base there, AFP reported.

The world's second-largest economy has invested billions of dollars in its military-run space programme in a push to catch up with the United States and Russia.

China was the third country to place humans in orbit in 2003 and its Tiangong rocket is the crown jewel of its space programme, which has also landed rovers on Mars and the Moon.

The unmanned Chang'e-4 rocket landed on the far side of the Moon in 2019. Another robot mission to the near side raised the Chinese flag there in 2020.

That Moon landing brought rock and soil samples back to Earth, the first time that has been done in more than four decades.

“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. 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,” said ISRO in its special message on Sunday. 

• Safe and soft landing demonstration on the lunar surface

• Rover roving demonstration on the moon

• Execution of in-situ scientific experiments

Luna 25, Russian spacecraft collided with the moon's surface days before the planned lunar soft landing scheduled for August 21.

Follow Luna 25 crash news live

A recent post by the Canadian Space Agency on social media platform X (formerly Twitter) sharing an image of what it called 108 million-year-old Tycho Crater in the Moon's southern hemisphere, caused quite a stir. The picture gained attention as users highlighted roads and buildings alongside the supposed crater. Read more

As part of its series of quiz on Chandrayaan-3, ISRO recently asked to guess to total mass of of the spacecraft. The correct answer is 3895 Kgs. 

Aditya-L1, the first space-based Indian observatory to study the Sun, is getting ready for the launch. The satellite realised at the U R Rao Satellite Centre (URSC), Bengaluru has arrived at SDSC-SHAR, Sriharikota, the Indian Space Research Organisation (ISRO) informed.

Read our detailed report on ISRO's Aditya-L1 mission

Luna 25 news 

Unverified Russian-language Telegram channels reported that communication with the craft had been lost and Russia's Moskovsky Komsomolets newspaper cited an unidentified specialist as saying that the craft may have been lost, reported Reuters.

The landing area of the Chandrayaan 3 spacecraft on the darker side of the moon on the south pole has been enlarged to 4km x 2.5 km. The Chandrayaan-2's landing site was small- within a 500mx500m area.

Chandrayaan 3 soft landing

A soft landing for the lunar module involves slowing down from a speed of 6,000 km/hour to a complete stop. In this process, the Vikram lander will adjust itself to a 90-degree angle to ensure a safe landing on the Moon's surface. When the lander reaches an altitude of about 100 meters, it will assess the surroundings. If no obstacles are detected, it will then gradually lower itself while using its thrusters until it touches down.

Indian Space Research Organisation (ISRO) chairman S Somanath said that the lander of India’s third lunar mission Chandrayaan-3, Vikram, will be able to make a soft landing on the Moon's surface on August 23 even if all the sensors and two of its engines do not work.

Read ISRO Chief S Somanath on Chandrayaan 3 mission

"There will always be a small non-zero probability that it can go wrong and we cannot eliminate that," Annapurni Subramanian, senior astronomer and director of the Indian Institute of Astrophysics (IIA) told News18 and added, “ I’m quite certain that we will make it this time. A huge amount of preparation has gone into it and Chandrayaan-3 has the highest probability of being successful.”

Despite its challenging terrain, the lunar south pole remains an enticing destination due to its potential reservoirs of ice. Scientists speculate that these ice deposits could hold significant value for future missions, offering resources like fuel, oxygen, and even potable water.

ISRO Chairperson S Somanath has said that the critical part during the soft landing of the Chandrayaan-3 spacecraft would be the direction of the spacecraft. He said the velocity at the start of the landing process is almost 1.68 km per second, but this speed is horizontal to the surface of the moon. The Chandrayaan-3 here is tilted almost 90 degrees, it has to become vertical. "The ability to transfer the spacecraft from horizontal to vertical direction is the 'trick we have to play' here," the ISRO chief said.

"Soyuz rocket with Progress at launch! We share a photo of the removal of the Soyuz-2.1a rocket with the Progress MS-24 cargo ship. After being installed in a vertical position at the launch site of the 31st site, Roscosmos specialists continued to prepare it for launch. Progress MS-24 truck launch — August 23 at 04:08 Moscow time," said the Russian space agency Roscosmos.

Dr Apathukatha Sivathanu Pillai, former Chief Controller (R&D) of the Defence Research and Development Organisation (DRDO), on Saturday said that Chandrayaan 3 mission " will enable the identification of various lunar resources, particularly Helium-3, which holds promise as a future energy source," ANI reported.

Chandrayaan 3's detailed timeline

July 6: The ISRO declared Chandrayaan-3 mission would launch on July 14 from Andhra Pradesh's Sriharikota's second launch pad.

July 7: All vehicle electrical tests were completed successfully.

July 11: A 24-hour ‘Launch Rehearsal’ was done successfully.

July 14: ISRO's LVM3 M4 launched Chandrayaan-3 into its intended orbit.

July 15: The mission's first orbit-raising manoeuvre succeeded in Bengaluru. The spacecraft reached an orbit of 41762 km x 173 km.

July 17: The second orbit-raising manoeuvre put Chandrayaan-3 in an orbit of 41603 km x 226 km.

July 22: The fourth orbit-raising manoeuvre, Earth-bound perigee firing, successfully placed the spacecraft in a 71351 km x 233 km orbit.

July 25: Another orbit-raising manoeuvre was carried out successfully.

August 1: In a significant milestone, Chandrayaan-3 entered the translunar orbit with an orbit of 288 km x 369328 km.

August 5: The spacecraft entered the lunar orbit at 164 km x 18074 km.

August 6: The spacecraft's orbit was lowered to 170 km x 4,313 km around the Moon.

August 9: Another manoeuver was performed that lowered the spacecraft to 174 km x 1437 km.

August 14: The mission entered the orbit circularisation phase of 151 km x 179 km orbit.

August 16: The spacecraft entered the orbit of 153 km x 163 km after the firing.

August 17: The landing module, comprising the Vikram lander and Pragyan rover was separated from its propulsion system.

August 18: The spacecraft successfully completed a 'deboosting' operation that reduced its orbit to 113 km x 157 km. Deboosting is the process of slowing down to position itself in an orbit where the orbit's closest point to the Moon (Perilune) is 30 km and the farthest point (the Apolune) is 100 km.

August 20: Chandrayaan-3 performed the second and final deboosting operation and reduced the LM orbit to 25 km x 134 km.

August 23: If everything goes well and as planned, the spacecraft will land on the lunar surface.

Russia's space agency Roscosmos, in a Telegram post, said, “During the operation, an abnormal situation occurred on board the automatic station, which did not allow the maneuver to be performed with the specified parameters.”

Read our detailed report on Luna-25