Chandrayaan 3 Launch: Isro set to launch Chandrayaan-3: Key points | India News

NEW DELHI: All eyes are on Isro‘s Chandrayaan-3, the country’s ambitious lunar mission. Scientists are keen to taste success with a soft landing on lunar surface which will put India in an elite club of nations that have accomplished the challenging task.
A success would make India only the fourth country to achieve the feat after the United States, China and the former Soviet Union.
Chandrayaan-3 is the third lunar exploration mission ready for take off in the fourth operational mission (M4) of LVM3 launcher.
The Indian Space Research Organisation will be launching the hugely anticipated mission from this spaceport at 2.35 pm on Friday. The soft landing on the moon’s surface is planned for late August.
Here’s all you need to know ahead of the launch:
The specifics
The largest and heaviest LVM3 rocket (formerly GSLV MkIII), fondly called as ‘fat boy’ by ISRO scientists for its heavylift capability, has completed six consecutive successful missions.
Today’s mission is the fourth operational flight of LVM3 which aims to launch the Chandrayaan-3 spacecraft into a Geo Transfer Orbit.
Chandrayaan-3 is a follow-on mission to Chandrayaan-2. Unlike its predecessor, which carried an orbiter along with Vikram & Pragyan (the rover), Chandrayaan-3 is a composite of 3 modules: Propulsion, lander and rover.
The spacecraft will weigh 3,900kg – the propulsion module weighs 2,148kg, while the lander module, including the rover, weighs 1,752 kg.
Unlike Chandrayaan-2, when the landing was tracked through a Madrid (NASA-JPL) station, this time tracking of the lander will happen from Isro Telemetry, Tracking and Command Network (Istrac) station in Bengaluru.
Chandrayaan-3 is not just a vast improvement on the Indian Space Research Organisation’s second Moon mission, it also carries a payload to “look at Earth from Moon to study its habitable planet-like features and use this information to explore exoplanets in future”.
Three major objectives
One is to demonstrate safe and soft landing on the surface of the moon. The second is to demonstrate rover operations on the moon. And the third objective is to conduct in-situ scientific experiments on the lunar surface.
According to the ISRO, “the Lander will have the capability to soft land at a specified lunar site and deploy the Rover which will carry out in-situ chemical analysis of the lunar surface during the course of its mobility.” If the launch and moon landing are a success, the data collected by Chandrayaan-3 will prove to be crucial in the larger scheme of lunar exploration initiatives in future.
The lander is expected to land around 40 days after the launch, on August 23 or 24.
After the launch from the earth’s surface, the module would enter the lunar orbit, from where the lander would then separate and attempt to manoeuvre a soft landing on the surface of the moon.
Vikram
Vikram carries four payloads: One to look for moonquakes, the second to study how the surface allows heat to flow through it, the third to understand the plasma environment, and the last to help measure the distance between Earth and Moon more accurately.
The two payloads on Pragyan (rover) will study the composition of Moon’s surface using X Ray and laser. Isro has selected the region near the south pole for the landing. This region is of great scientific interest since it houses permanently shadowed craters that have the potential of holding water molecules in observable quantity.
How is it different from Chandrayaan-2?
After its failed landing attempt in September 2019, Isro has carried out several changes on the lander.
This time around, Vikram will have stronger legs than in its previous avatar to enable withstanding landing at greater velocities than earlier, while Isro has also made several other changes learning from the failures of Chandrayaan-2.
Changes include increasing the velocity tolerance level, adding new sensors to measure velocity and changes to the solar panels.
Isro has also improved the software to have more tolerance to failures like engine disruptions, thrust disruptions, sensor failures, etc, while also removing the central or fifth engine, which was added last minute during Chandrayaan-2.
More fuel & new sensor
Another change is the addition of more fuel to Vikram to handle more disruptions and have the “ability to come back” so there’s more cushion to handle the mission.
Central engine & software
Isro has also improved the software to have more tolerance to failures like engine disruptions, thrust disruptions, sensor failures, etc, while also removing the central or fifth engine, which was added last minute during Chandrayaan-2.
Solar panels & antennas
The space agency has extended solar panels and more panel area to generate power. Vikram will be able to generate power even if it lands in a different orientation and is not facing the Sun. It also has additional TTC (tracking, telemetry and command) antennas for redundancy.
Learning from past mistakes
Earlier, Isro chairman S Somanath said that LVM3 will place Chandrayaan-3 in an apogee (farthest point from Earth) of 36,500km as against 45,475km during Chandrayaan-2. The perigee (closest point to Earth) will be around 170km, nearly the same as last time. “This is being done to get more stability,” he said.
In Chandrayaan-2, Isro took the ‘burn to depletion’ — use the last drop of fuel — approach with the cryogenic upper stage to achieve high altitude. This time, Isro has decided to go to a definitive orbit (36,500km), making initial tracking and operations that follow more efficient.
The process
Isro will then conduct multiple Earth-bound manoeuvres to increase Chandrayaan-3’s orbit before commands for trans-lunar insertion (TLI) that will kick off the spacecraft’s journey towards Moon are given.
If all goes as planned, TLI will be done on July 31. Chandrayaan-3 will then travel towards Moon for about five-and-a-half days and lunar orbit insertion is expected around August 5. These are estimations for nominal performance.
After Chandrayaan-3 reaches 100km X 100km orbit, the lander module (Vikram & Pragyan) will separate from the propulsion module and be eventually brought to a 100km X 30km orbit, from where commands for deboost and final descent is expected on August 23.
Upon successful landing, Pragyan will slide down from Vikram, which will be captured by cameras on the lander, and begin to move on the lunar surface using its wheels. Pragyan is also equipped with cameras for obstacle avoidance.
While the scope of the scientific instruments on the lander and the rover would fit in the theme of ‘Science of the Moon’, another experimental instrument will study the spectro-polarimetric signatures of the Earth from the lunar orbit, which would fit in the theme of ‘Science from the Moon’.
Desi startups get ready to move into space
Meanwhile, with scores of homegrown firms in tow, India is looking to up its share of the $400 million global space market from the current 2-3% to double digits.
Till June, IN-SPACe – the agency responsible for authorising and promoting private firms and entities in the space sector – had more than 1,550 NGE registrations, including 493 startups and more than 300 other units with many hundreds more seeking to join the domestic space bandwagon.
A key development in this area was the contract bagged by the HAL-L&T consortium to manufacture five PSLV rockets, the formal contract – worth around Rs 860 crore – for which was signed in September last year. Already, there are propitious signs.
Moreover, days ahead of the launch, IN-SPACe announced on June 11 that it was ready to share the technology for SSLV rockets with private players.
From ToT deals to new patents in critical technologies, Indian startups are involved in various projects, not to mention indigenous product development and innovative solutions using space data.Companies like Bellatrix and Pixxel had signed MoUs with Isro in 2021 while also working closely with IN-SPACe.