Chandrayaan-3 highlights: Lander Module to decent on moon on August 23 at 5:45pm

The powered descent of the Lander Module is expected to commence on August 23 around 1745 hours: ISRO.

The second and final deboosting operation has successfully reduced the LM orbit to 25 km x 134 km.

The module would undergo internal checks and await the sun-rise at the designated landing site.

The powered descent is expected to commence on August 23, 2023, around 1745 Hrs. IST

In a stride toward India's lunar exploration goals, Chandrayaan-3, the country's third lunar mission, is progressing smoothly and its anticipated landing on the moon's south pole is on August 23.

Dr Apathukatha Sivathanu Pillai, former Chief Controller (R&D) of the Defence Research and Development Organisation (DRDO), on Saturday expressed confidence in the mission's success and said that the mission will be successful.

"Now nearing 100 km orbit, it came to 30 km and then started descending to the moon. It will be 100 per cent successful," Pillai said while speaking to ANI.

Dr Pillai, who is also the former chief executive officer (CEO) and managing director (MD) of BrahMos Aerospace, further highlighted the significance of Chandrayaan-3 and added that "it will enable the identification of various lunar resources, particularly Helium-3, which holds promise as a future energy source."

An "emergency" was detected on Saturday during a manoeuvre by Russia's Luna-25 probe prior to its Moon landing, Russian space agency Roscosmos said. Read more

Former Chief Controller (R&D) of the Defence Research and Development Organisation (DRDO) Apathukatha Sivathanu Pillai on Saturday expressed confidence in the Chandrayaan-3 mission's success.

"Now nearing 100 km orbit, it came to 30 km and then started descending to the moon. It will be 100 per cent successful," ANI quoted Pillai as saying.

• Safe and soft landing demonstration on the lunar surface

• Rover roving demonstration on the moon

• Execution of in-situ scientific experiments

Chandrayaan 3 mission explained: "A major event is the 4800 N Thrusters. They have to fire to take it to the lower orbit. That will also be done in two steps (first completed yesterday) and ensuring that all the systems are working properly these two steps will go down, put a 100-kilometre orbit. Then from 100 go to the 30-kilometre orbit... that's very very vital," Former Indian Space Research Organisation (ISRO) scientist, Mylswamy Annadurai said while speaking to ANI.

He further said that the position of the module has to be ascertained properly. So then from the 30 kilometre onwards, how to move, how to thrust to fire, what orientation to fire, and whether along it will reduce the velocity in the horizontal. Then it has to composite vertical also it has to vertical fall, also it has to reduce. So that way a lot of manoeuvres to be done. And while doing it, it has to make sure that it is going on the proper path. So already loaded pictures of the lunar terrain will be there. Check against that and try to identify the place where it's supposed to land. It is also supposed to have been already loaded in the system.

"So all these activities will be done by the lander. The lander will start its real action…,” Annadurai added.

Earth with Moon in the background as captured by Chandrayaan 3 Lander Camera as it got separated from the propulsion system.

Moon as captured by Chandrayaan 3 Lander Position Detection Camera (LPDC) on this Independence Day.

Read our detailed story on Chandrayaan 3 moon videos here

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

• Safe and soft landing demonstration on the lunar surface

• Rover roving demonstration on the moon

• Execution of in-situ scientific experiments

Russia's Luna 25 spacecraft is expected to land before Chandrayaan 3, which has set its soft landing attempt for August 23. Former Indian Space Research Organisation (ISRO) Chief, K Sivan, has said that frugal engineering in the country will need to give way to more funding and larger rockets in the future.

"We need bigger rockets and better systems. Frugal engineering is not enough. We need powerful rockets and advanced technology," Sivan told NDTV.

The former ISRO chief added that one positive step by the government is opening up space activities to private industries. He said that the private sector's interest is evident and results are already emerging. "I am sure they will soon be able to take up high-end technology as well. Investment won't be a problem," he told the website.

Read the report on former ISRO Chief K Sivan

Differences between Chandrayaan-3 and its predecessor, Chandrayaan-2:

Orbiter Exclusion:

• Chandrayaan-3 skips carrying an orbiter, unlike Chandrayaan-2.

• Chandrayaan-2's orbiter remains operational, providing valuable data.

Enhanced Launch Capability:

• Launched via LVM3 (previously GSLV Mk III), Chandrayaan-3 gains powerful launch capability.

• Increased fuel capacity allows extra manoeuvres and extended travel.

• Reinforced landing legs ensure a safer and more stable lunar touchdown.

Improved Instrumentation:

• Upgraded sensors and larger solar panels characterize Chandrayaan-3.

• Increased solar panel size generates more energy for onboard systems.

• Introduction of 'Laser Doppler VelociMeter' to accurately measure spacecraft speed.

Enhanced Algorithm and Software:

• Chandrayaan-3 benefits from lessons learned from Chandrayaan-2.

• Algorithm and software refined to mitigate software glitches.

• Landing target area expanded from 500x500m to 4x2.4km for added flexibility.

Propulsion Module and Payload:

• Chandrayaan-3's propulsion module transports lander and rover to a 100km lunar orbit.

• Includes Spectro-polarimetry of Habitable Planet Earth (SHAPE) payload for studying smaller planets.

The Lander Module, which will soon touch the south pole of the Moon, consists of the lander Vikram and the rover Pragyan. The lander has been named ‘Vikram’ after Vikram Sarabhai (1919–1971), who is widely regarded as the father of the Indian space programme and the founder of our country's space agency, the Indian Space Research Organisation (ISRO).

“Chandrayaan 2 was noted active and is known to be part of the landing attempt as it is equipped with advanced communication equipment. It is in a ~7045s period orbit or a nominal altitude of ~96km above the Moon. It is phasing with the PM and could be in phase or 180 deg. out,” said Scott Tilley, a spacecraft tracking expert.

Back on September 7, 2019, the Chandrayaan-2 mission encountered a challenge while attempting to land. The Vikram lander went off course, leading to a loss of communication with the lander carrying the Pragyan rover.

Despite this unexpected turn of events, the Chandrayaan-2 orbiter still works well. It's circling the Moon and collecting important scientific data.

Read: Why did Chandrayaan-2 lander fail?

Chandrayaan-3 Live Updates: The approved cost of Chandrayaan-3 is ₹250 crores (excluding launch vehicle cost). According to LiveMint, citing reports, the launch services cost around ₹365 crore.

Indian Space Research Organisation (ISRO) chairperson 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.

Although the south pole of the Moon has challenging terrain for landing, it is a highly valued target because scientists believe it could contain substantial amounts of ice, potentially useful for extracting fuel, oxygen, and even drinking water.

Roscosmos stated that its Luna 25 spacecraft will take about five days to travel to the Moon after launch on August 11. It will then spend around five to seven days in lunar orbit before descending to one of three potential landing sites near the pole, reported Reuters.

This timeline indicates that Russia's mission could reach the lunar surface around the same time as or shortly before the Indian mission.

Roscosmos, however, assured that the two missions won't interfere with each other, as they have separate landing areas planned. The Russian Space Agency stated, “There is no danger that they interfere with each other or collide. There is enough space for everyone on the moon,” Reuters added.

Read report: Chandrayaan 3 vs Luna 25

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," ISRO chief said.

As of July 2023, six lunar orbiters remain operational, according to Indian Space Research Organisation or ISRO.

• The National Aeronautics and Space Administration or NASA THEMIS mission's two probes, now known as Artemis P1 and Artemis P2, have been repurposed under the Artemis initiative, maintaining eccentric orbits of low inclination.

• NASA's Lunar Reconnaissance Orbiter (LRO) traces a nearly polar, slightly elliptical path around the moon.

• ISRO's Chandrayaan-2 and Korea Pathfinder Lunar Orbiter (KPLO) both navigate polar orbits at an altitude of 100 km.

• NASA's Capstone follows a 9:2 resonant southern L2 NRHO trajectory, flying over the lunar North pole at an altitude of 1500-1600 km and the South pole at approximately 70,000 km away.

• Spacecraft Ouna from Japan's Kaguya/SELENE mission in 2009 and India's Chandrayaan-1 launched in 2008 are no longer functional.

• All the other orbiters have been either moved out of the moon-bound orbital regime or have landed/impacted the lunar surface, either deliberately or due to failure to land softly. China's Queqiao, a data relay satellite for the Chang’e 4 mission, shifted to a halo orbit near the Earth-Moon L2 point after its launch in 2018.

Moon as captured by Chandrayaan 3 Lander Position Detection Camera (LPDC) on this Independence Day.

Read our detailed story on Chandrayaan 3 moon videos here

The Lander Module comprising the lander (Vikram) and the rover (Pragyan), will undergo the second deboosting operation on August 20, to be lowered to an orbit that takes it much closer to the Moon's surface. The soft landing on the Lunar south pole is scheduled on August 23.

Where is Chandrayaan 3

Vikram Lander Module of Chandrayaan 3 successfully completed a 'deboosting' operation that reduced its orbit to 113 km x 157 km, on Friday, announced ISRO.