Chandrayaan-3 highlights: Vikram Lander undergoes first deboosting move, health normal says ISRO

Chandrayaan 3 Live Updates: The former ISRO scientist and Padma Shri awardee Mylswamy Annadurai said that the Vikram lander now has to take its own action and further it has to separate after which the major event comes. "Now Vikram has to take its own course of action. Further, it has to separate. So even after separating, then the major event comes. A major event is the 4800 Newton thrusters. They have to fire to take it to the lower orbit. That will also be done in two steps 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-kilometer orbit... that's very very vital. But when it's going very closer, closer to the Earth," he said while speaking to ANI.

Chandrayaan 3 Live Updates: Chandrayaan-3 is just days away from its final destination, the moon. On August 23 the Vikram Lander of Chandrayaan 3 is expected to make a soft landing on the south pole of the moon. ISRO on Friday released images of the moon as captured by the position detection camera attached to the lander right after the successful separation of the lander from the propulsion module.

Chandrayaan 3 Live Updates: Announcing that the health of Chandrayaan-3's Lander Module is normal, ISRO on Friday said that the module has successfully undergone a deboosting (slowing down) operation taking it closer to the Moon. The Lander Module comprising the lander (Vikram) and the rover (Pragyan), will undergo its second deboosting operation on August 20. 

The former ISRO scientist and Padma Shri awardee Mylswamy Annadurai explained that the major event is the 4800 Newton thrusters of the Vikram lander fired to take it to the lower orbit in two steps, placing it in a 30-kilometre orbit.

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 fire, what orientation to fire, and how to reduce the velocity in the horizontal and vertical direction. “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,” Annadurai told ANI.

Read Chandrayaan-3 mission detailed timeline

ISRO released a video captured by Chandrayaan-3's Vikram Lander's camera. The images were captured by the Lander Position Detection Camera (LPDC) on August 15. The images were captured when LDPC was attached to its propulsion module. Meanwhile, Vikram Lander carried out its first deboosting successfully. The second deboosting operation is scheduled for August 20, 2023. ISRO's most ambitious mission, Chandrayaan-3, has reached the final stage.

The automatic station continues its flight in the orbit of an artificial satellite of the Moon. Today at 09:20 Moscow time, the propulsion system of the automatic station performed an orbit correction for 40 seconds. Its goal is to provide the best conditions for the subsequent construction of a pre-landing orbit, Roscosmos said in a post on the social media platform Telegram.

The correction went through normally, all the onboard systems of Luna-25 are working normally, communication with it is stable, the Russian space agency added.

Chandrayaan-3 mission detailed timeline

• July 6: ISRO announces Mission Chandrayaan-3 launch date of July 14 from Sriharikota's second pad.

• July 7: Successful vehicle electrical tests completed.

• July 11: Comprehensive 24-hour 'Launch Rehearsal' simulating the entire launch process concludes.

• July 14: LVM3 M4 vehicle launches Chandrayaan-3 into designated orbit.

• July 15: First orbit-raising manoeuvre successful, reaching 41762 km x 173 km orbit.

• July 17: Second orbit-raising manoeuvre places Chandrayaan-3 at 41603 km x 226 km orbit.

• July 22: Fourth orbit-raising manoeuvre establishes spacecraft in 71351 km x 233 km orbit.

• July 25: Another successful orbit-raising manoeuvre.

• August 1: Chandrayaan-3 inserted into translunar orbit (288 km x 369328 km).

• August 5: Successful lunar orbit insertion (164 km x 18074 km).

• August 6: Lunar orbit lowered to 170 km x 4,313 km.

• August 9: ISRO carefully moves the spacecraft's path lower in its orbit around the moon. It has achieved a lunar orbit of 174 km x 1437 km

• August 14: Chandrayaan-3 gets closer to the moon's surface in another controlled bringing it in a orbit of 150 km x 177 km

• August 16: The Indian spacecraft performs the fifth and final Moon-bound manoeuvre positioning itself in a near circular Lunar orbit of 163*153 km.

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

• August 18: The Chandrayaan-3 will make the final orbit adjustment by reducing it to be around 100*30 km, the farthest and nearest point from the moon respectively.

• August 23: If everything goes well, planned lunar touchdown attempt at 5:47pm where the spacecraft will travel the last 30km distance.

ISRO on Friday said that Chandrayaan-3's Lander Module has successfully undergone a deboosting (slowing down) operation taking it closer to the Moon, and that its health is normal. 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. 

Chandrayaan-3 Mission:

The Lander Module (LM) health is normal.

LM successfully underwent a deboosting operation that reduced its orbit to 113 km x 157 km.

The second deboosting operation is scheduled for August 20, around 2am, said ISRO.

ISRO on Friday shared videos captured by Chandrayaan 3's Vikram lander's Lander. In one video recorded by Lander Position Detection Camera (LPDC) on August 15, when it was attached to its propulsion module, Moon craters can be clearly seen. In another video, taken by Lander Imager (LI) Camera-1, Earth can be seen, although minutely.

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

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

(i) 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.

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

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

(iv) 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.

After separation from the propulsion module yesterday, the Vikram Lander will:

• Undergo "deboost" (the process of slowing down) to lower the lunar orbit.

• A couple of deboosting manoeuvres will place it in an orbit where the Perilune (closest point to the Moon) is 30 kilometres and Apolune (farthest point from the Moon) is 100 km.

• From this orbit, the soft landing on the south polar region of the Moon will be attempted on August 23.

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.

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

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.

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 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.

At around 4pm today, the Lander Module will undergo the process of ‘deboosting’ , following its successful seperation from the Propulsion Module on Thurdsay. What is deboosting?

• 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.
• “The next Lander Module (Deorbit 1) manoeuvre is scheduled for tomorrow (August 18, 2023) around 1600 hrs IST,” ISRO posted yesterday on X.

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.

"Now I think I'm quite confident, more than 100% it's going to be a safe landing (Chandrayaan 3 landing). I was watching with slightly caution the moment when Chandrayaan was to move out of Earth's orbit and move to Moon's orbit because that a critical situation. Most of the critical stages are over now," says Union minister Dr Jitendra Singh on Chandrayaan-3 mission.

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.

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? 

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.

“No one's childhood is complete without stories of the Moon! Tell us what your favourite childhood Moon memory is and stand a chance to be featured on our X handle,” Chandrayaan 3 mission's official X (formerly Twitter) page posted on Thursday.