National Space Day: Learn about the Moon through Chandrayaan-3 – it landed, hoped and slept but its journey will continue | Mint

India celebrated its first National Space Day on Friday, August 23. Exactly a year ago, on this day, India made history by becoming the first country to soft land on the south pole of the Moon, thanks to the Chandrayaan 3 mission and the Indian Space Research Organisation (ISRO). To commemorate this historic achievement, India will now celebrate National Space Day on August 23 every year.

Remembering India’s Chandrayaan mission

Five years ago, in 2019, the crash of the Chandrayaan 2 mission’s lander shattered millions of hopes. It was heartbreaking to see the then ISRO chief K Sivan crying. But the Chandrayaan 2 mission was a setback and not a complete failure.

In August 2023, all eyes were on the Chandrayaan 3 mission. The LVM3 M4 spacecraft successfully launched Chandrayaan-3 into orbit on 14 July 2023.

ISRO, led by S Somanath, launched Chandrayaan-3 by taking some lessons from the Chandrayaan-2 mission. Somanath had earlier said that the images taken by the Chandrayaan-2 orbiter were used to “better identify locations” on the lunar surface. The agency had also analysed failure scenarios, among other strategies, to soft-land the Chandrayaan-3 mission’s lander and rover on the moon’s south pole.

The Indian space agency achieved this feat on August 23. “I reached my destination and so do you!” The Chandrayaan 3 rover descended from the lander and India set foot on the moon on August 24, 2023.

Since then, the Chandrayaan-3 mission has conducted unprecedented experiments and made significant discoveries through three payloads on the Vikram lander and two payloads on the Pragyan rover.

The major discoveries of the mission so far are as follows:

1. 70 degrees on the moon: The first observation was received on August 27 from CHAAST (Chandra Surface Thermophysical Experiment). The payload on board the Vikram lander measured the temperature of the lunar topsoil around the poles to understand the thermal behaviour of the lunar surface.

The CHEST payload has a temperature probe equipped with a controlled entry mechanism, capable of reaching a depth of 10 cm below the surface. “We all believed that the temperature at the surface might be around 20 degrees Centigrade to 30 degrees Centigrade, but it is 70 degrees Centigrade. It is surprisingly higher than our expectation,” ISRO scientist BHM Darukesha told PTI.

2. Confirmation of sulphur on the moon: On August 28, ISRO said that the Laser-Induced Breakdown Spectroscopy (LIBS) instrument on board the rover made the first real-time measurements on the elemental composition of the lunar surface near the south pole.

“These in-situ measurements clearly confirm the presence of sulphur in the region, which was not possible using instruments on board the orbiter,” the space agency said. It said the presence of hydrogen on the moon is under investigation.

According to ISRO, initial analyses revealed the presence of aluminium (Al), sulphur (S), calcium (Ca), iron (Fe), chromium (Cr) and titanium (Ti) on the lunar surface. Further measurements revealed the presence of manganese (Mn), silicon (Si) and oxygen (O).

3. Minor elements on the Moon: ISRO announced on August 30, 2023 that the Alpha Particle X-ray Spectrometer (APXS) on board the rover “has also discovered the presence of interesting minor elements including sulphur in addition to the expected major elements like aluminium, silicon, calcium, iron.”

4. Rarefied plasma: ISRO informed on August 31, 2023 that the Radio Anatomy of Moon Bound Hypersensitive Ionosphere and Atmosphere – Langmuir Probe (RAMBHA-LP) payload on Chandrayaan-3 lander carried out the first in-situ measurement of the surface-bound lunar plasma environment over the south polar region of the Moon.

ISRO said, “Initial assessments indicate that the plasma present on the lunar surface is relatively sparse, with a density of about 5 to 30 million electrons per cubic metre.”

5. Recorded Vibrations: The Instrument for Lunar Seismic Activity (ILSA) payload mounted on the Chandrayaan 3 lander recorded vibrations caused by the movements of the rover and other payloads. Vibrations were recorded during the rover’s navigation on August 25, 2023.

6. Moonquake? The payload also recorded “a natural event on August 26, 2023”. ISRO said the source of the event is being investigated. ILSA’s purpose is to measure ground vibrations caused by natural earthquakes (or lunar earthquakes), impacts and artificial events.

7. Unplanned ‘Hop Experiment’: Vikram lander surprised ISRO with its successful ‘hop experiment’. What is its significance? The ‘hop experiment’ or ‘kick-start’ “excites future sample return and human missions.”

ISRO said, “Vikram made a soft landing again on 🌖!” It added, “On receiving the command, it started the engines, lifted itself up about 40 cm as expected and landed safely at a distance of 30-40 cm.”

8. Is there a magma ocean on the Moon? The Chandrayaan-3 lunar mission has recently obtained data that supports the theory that Earth’s satellite was once covered by an ocean of magma.

Chandrayaan 3’s lander and rover are now in sleep mode but…

…the journey will continue

India on Friday celebrated its first National Space Day under the theme “Touching Lives by Touching the Moon: India’s Space Story”.

Speaking at an event in New Delhi to mark the first National Space Day, Somnath said, “The journey of Chandrayaan-3 will continue… The model for Chandrayaan-4 is ready. We have proved how to reach the moon. But now we have to prove how to come back from there.”