India's Journey to the Moon
Photo Credit: Indian Space Research Organization via CNN
On Aug. 23, 2023, India became the fourth country in the world to land a spacecraft on the moon. Chandrayaan-3 — meaning “moon craft” in Sanskrit — took off from a launchpad on July 14, 2023 in Sriharikota, an island in southern India.
The Indian Space Research Organization (ISRO) spacecraft also became the first spacecraft to land near the south pole of the moon, which is believed to be home to deposits of water and ice. The successful mission is expected to both boost the country’s growing private space sector and provide more research opportunities. The ISRO stated the three objectives of the Chandrayaan-3’s mission were “to demonstrate a safe and soft moon landing, to demonstrate rover roving on the moon, and to conduct in-situ scientific experiments”.
This year’s moon landing followed a previous failed mission, Chandrayaan-2. The Chandrayaan-2 spacecraft launched on July 22, 2019 from Sriharikota on a Geosynchronous Satellite Launch Vehicle Mark III. It was planned to land on the moon on Sept. 7 of the same year. The craft consisted of an orbiter, lander, and rover. The mission was planned to have a lifetime of seven and a half years, but the ISRO lost contact with it at an altitude of 2 km — just before the lander was about to make contact with the moon’s surface.
“From the day we started rebuilding our spacecraft after the Chandrayaan-2 experience, it has been breathe in, breathe out Chandrayaan-3 for our team,” said the mission’s associate project director, Kalpana Kalahasti.
The historic landing came after the launch of Russia’s robotic Luna-25 spacecraft, which left for the moon on Aug. 11, also with the goal to be the first spacecraft to land near the south pole of the moon. The mission was unsuccessful, however. On Aug. 19, the craft crashed into the moon, and was destroyed.
The Chandrayaan-3 consists of an indigenous lander module named Vikram and a propulsion module. It also comprises a rover named Pragyan with the objective to develop and demonstrate new technologies in preparation for interplanetary travel. The propulsion module carried the lander module from launch vehicle injection until its final lunar 100 km circular polar orbit, before separating. The lander module then safely landed on the south pole of the moon. It deployed the rover, which was filled with almost a dozen scientific instruments. One of these instruments included a laser that could analyze the chemical composition of the moon’s regolith. Its purpose was to aid in the search for water and ice.
In India, the Chandrayaan-3 mission was considered a point of national pride. Over 70 million people watched online coverage of the historic landing. Countless others watched in auditoriums and viewing parties throughout the country.
The ISRO shared mission updates on social media, posting information and data that the rover and lander collected. The rover managed to travel over 100 meters across the moon’s surface and take photos of the lander.
One of the experiments conducted during the mission was ChaSTE (Chandra’s Surface Thermophysical Experiment). The purpose of the experiment was to understand the thermal behavior of the moon’s surface by measuring the temperature profile of the lunar topsoil around the south pole. The rover has a temperature probe equipped with ten individual temperature sensors, as well as a controlled penetration mechanism capable of reaching 10 cm beneath the moon’s surface.
After the experiment was conducted, ISRO scientist BHM Darukesha told a local news outlet, Press Trust of India, that the surface was hotter than they had expected. “We all believed that the temperature could be somewhere around 20 degrees centigrade to 30 degrees centigrade on the surface but it is 70 degrees centigrade,” said Darukesha.
Additionally, using a spectroscope, the rover confirmed the presence of sulfur near the south pole of the moon. This discovery now compels scientists to investigate how the element got there, and whether it naturally exists on the surface or was sent there by volcanic activity or a meteor. The rover also found other elements near the south pole of the moon, including iron and oxygen.
On Sept. 2, the Chandrayaan-3 was set to sleep for 14 days before mission controllers attempted to wake up the spacecraft. The lander and rover was put into “sleep mode” in order to protect the electrical parts during the two week lunar night that sees temperatures on the moon drop to -250 degrees Celsius. ISRO scientists have not been able to make contact with the lander or rover since putting it to sleep.
Despite not being able to wake up the lander and rover, the mission was still considered a success, since all of the Chandrayaan’s primary objectives were completed. The prime minister of India, Narendra Modi, hailed the mission as “a victory cry of a new India.”