An illustration of Chandrayaan-3’s Pragyan rover roaming on the lunar surface. Photo: X/@chandrayaan_3 via PTI

Chandrayaan-3’s Pragyan rover has confirmed the presence of sulphur on the moon’s surface, near its south pole, and is still searching for hydrogen, the Indian Space Research Organisation said on Tuesday.

The Laser-Induced Breakdown Spectroscopy (LIBS) instrument onboard the Chandrayaan-3’s rover has made the first-ever in-situ measurements on the elemental composition of the lunar surface near the south pole. “These in-situ measurements confirm the presence of Sulphur (S) in the region unambiguously, something that was not feasible by the instruments onboard the orbiters,” ISRO said. “Search for Hydrogen (H) is underway,” it posted on X (formerly Twitter).

Laser pulse technique

The LIBS is a scientific technique that analyses the composition of materials by exposing them to intense laser pulses. A high-energy laser pulse is focussed onto the surface of a material, such as a rock or soil, and generates an extremely hot and localised plasma. The collected plasma light is spectrally resolved and detected by charge coupled devices. Since each element emits a characteristic set of wavelengths of light when in a plasma state, the elemental composition of the material can be determined in this way.

“Preliminary analyses, graphically represented, have unveiled the presence of Aluminum (Al), Sulphur (S), Calcium (Ca), Iron (Fe), Chromium (Cr), and Titanium (Ti) on the lunar surface. Further measurements have revealed the presence of manganese (Mn), silicon (Si), and oxygen (O). Thorough investigation regarding the presence of Hydrogen is underway,” ISRO said.

The LIBS payload was developed at ISRO’s Laboratory for Electro-Optics Systems in Bengaluru.

The graph of temperature variation on lunar surface. Twitter/@isro

ISRO on August 27 released a graph of the temperature variation on lunar surface with increase in depth measured by the ChaSTE payload onboard Chandrayaan-3’s Vikram lander module.

According to the space agency, Chandra’s Surface Thermophysical Experiment (ChaSTE) measured the temperature profile of the lunar topsoil around the south pole, to understand the thermal behaviour of the Moon’s surface.

“Here are the first observations from the ChaSTE payload onboard Vikram Lander. ChaSTE measures the temperature profile of the lunar topsoil around the pole, to understand the thermal behaviour of the moon’s surface,” ISRO said in an update on ‘X’, formerly Twitter.

The payload has a temperature probe equipped with a controlled penetration mechanism capable of reaching a depth of 10 cm beneath the surface.

“The probe is fitted with 10 individual temperature sensors. The presented graph illustrates the temperature variations of the lunar surface/near-surface at various depths, as recorded during the probe’s penetration. This is the first such profile for the lunar south pole. Detailed observations are underway,” it said.

The payload was developed by a team led by the Space Physics Laboratory (SPL) of ISRO’s Vikram Sarabhai Space Centre (VSSC) in collaboration with Physical Research Laboratory (PRL), Ahmedabad.

India on Wednesday scripted history as ISRO’s ambitious third Moon mission Chandrayaan-3’s Lander Module (LM) touched down on the lunar surface, making it only the fourth country to accomplish the feat, and first to reach the uncharted south pole of Earth’s only natural satellite.

The indigenous rover’s exploration of the lunar surface began a day after India became the fourth country to successfully land on the moon, spurring euphoric celebrations at ISRO and around the country. Photo: ISRO

Hours after the Pragyan lunar rover rolled out from the Vikram lander and took its first “walk on the moon” in the early hours of Thursday, the Indian Space Research Organisation (ISRO) said that the historic Chandrayaan-3 Mission was running on schedule, with all systems working normally. Instruments aboard the lander and rover will now study the moon’s mineral composition and the seismic activities in its atmosphere, according to ISRO chairman S. Somanath.

The indigenous rover’s exploration of the lunar surface began a day after India became the fourth country to successfully land on the moon, spurring euphoric celebrations at ISRO and around the country.

‘Walk on the moon’

“Chandrayaan-3 ROVER: Made in India Made for the MOON! The Ch-3 Rover ramped down from the Lander and India took a walk on the moon!” ISRO posted on social media platform X, on Thursday morning.

President Draupadi Murmu had made the first announcement of the rover’s successful deployment at 7 a.m. “Its rolling out a few hours after the landing of Vikram marked the success of yet another stage of Chandrayan 3. I look forward with excitement, alongside my fellow citizens and scientists to the information and analyses that Pragyan will acquire and enrich our understanding of the moon,” she posted.

‘All systems are normal’

Later in the evening, ISRO added an update on mission operations and the payloads aboard the lander. “Chandrayaan-3 Mission: All activities are on schedule. All systems are normal. Lander Module payloads ILSA, RAMBHA and ChaSTE are turned ON today. Rover mobility operations have commenced. SHAPE payload on the Propulsion Module was turned ON on Sunday,” it posted.

Dr. Somanath confirmed that the rover movement is happening and working very well. He told the Press Trust of India that there are two instruments in the rover and three instruments on board the lander, and all of them have been switched on sequentially.

“They will study basically the mineral composition of the moon, as well as the atmosphere of the Moon and the seismic activities there,” he added.

‘Perfect landing’

Dr. Somanath also said that the Chandrayaan-3 spacecraft’s lander Vikram had touched down on the moon’s surface well within the area identified for the purpose.

“(The lander landed) perfectly in the intended site. The landing location was marked as 4.5 km x 2.5 km — I think on that space, and the exact centre of that was identified as the location of landing. It landed within 300 metres of that point. That means it is well within the area identified for landing,” he said.

(with PTI inputs)

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A dish antenna is seen inside the ISRO Telemetry Tracking and Command Network (ISTRAC) facility on August 23, 2023 in Bengaluru.
| Photo Credit: Getty Images

With Vikram, the lander module of Chandrayaan-3, successfully landing on the surface of moon on August 23, the focus has now moved to the rover in its belly, Pragyan.

The officials at the Mission Operations Complex (MOX) at ISRO Telemetry, Tracking, and Command Network (ISTRAC) are readying to roll out the rover, which will carry out in-situ chemical analysis of the lunar surface during the course of its mobility.

“The Pragyan rover may come out in the next few hours or it may take one day also to come out depending on the conditions,” ISRO Chairman S. Somanath said.

He said that once out, the rover would carry out two important experiments. It has two payloads — the LASER Induced Breakdown Spectroscope (LIBS) and the Alpha Particle X-ray Spectrometer (APXS). The objectives of the LIBS are to conduct qualitative and quantitative elemental analysis and to derive the chemical composition and infer mineralogical composition to further our understanding of the lunar surface.

The APXS will determine the elemental composition of lunar soil and rocks around the landing site.

The team behind Chandrayan-3’s success

Soon after the ISRO achieved the historic feat of landing on the lunar south pole, Mr. Somanth introduced the key members who enabled India to achieve the task flawlessly.

P. Veeramuthuvel, Project Director, Chandrayaan-3, said, “It is a great moment of happiness, it gives me immense satisfaction on achieving this goal as Project Director of this mission. The entire mission operations from launch till landing happened flawlessly as per the timeline and we have become the fourth country to demonstrate the soft landing on the moon and the first country to go to the south pole of the moon.”

Sreekanth, Mission Director, Chandrayaan-3, said, “It gives me immense pleasure to be part of Chandrayaan-3 and as Mission Director, I would like to thank each and every team member who has supported in carrying out all the mission operations flawlessly.”

Calling it a memorable moment, Kalpana K., Associate Project Director, Chandrayaan-3 said, “We have achieved our goal flawlessly after rebuilding our spacecraft. It has been breath in and out for our team.”

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M. Sankaran, Director of U.R. Rao Satellite Centre, said, “Today we have achieved what we set out to achieve in 2019. It was delayed by four years but we have done it.” He was referring to the failed landing of Chandrayaan-2 in 2019.