ISRO's Chandrayaan-3 confronts cold lunar odds, here's why

ISRO reportedly chose not to equip these robotic pioneers with the commonly used radioisotope heater units.
Rizwan Choudhury
Chandrayan-3 and Pragyan rover.
Chandrayan-3 and Pragyan rover.

Source: ISRO 

In a pioneering two-week mission that captured international attention, India's Chandrayaan-3's lander Vikram and its rover Pragyan have gone into sleep mode, facing the unyielding cold of the moon's south pole region. As they await the next lunar dawn, their survival is a matter of luck, as reported by

Why you ask? On Earth, temperatures in Antarctica can plunge, but nothing compares to the -424°F (-253°C or 20 K) found near the moon's poles. In a surprising move, the Indian Space Research Organization (ISRO), responsible for operating this mission, chose not to equip these robotic pioneers with the commonly used radioisotope heater units (RHUs). These RHUs keep spacecraft warm enough to run by transforming the heat from radioactive decay into electrical power.

Heating systems

Since the 1970s, such heating systems have been standard in moon missions. For instance, the Lunokhod 1, the world's first successful lunar rover, covered over 10 kilometers in 10 months and used solar cells to charge its batteries during the lunar day. Lunokhod 1 relied on the heat generated by a polonium-210 radioisotope heater to survive the lunar night. China's Chang'e-3 lander and its Yutu rovers also incorporated similar technology to ensure survival through the cold lunar nights.

While ISRO has remained silent on why Chandrayaan-3 lacks these heating elements, the mission has been full of accomplishments. Both Vikram and Pragyan successfully touched down on the moon's south pole on August 23, a region that has gained increased focus for potentially harboring reserves of frozen water. They were the first to land on this part of the moon successfully.

The Vikram lander even outperformed expectations when it managed a surprising "hop" on the moon's surface, propelling itself closer to Pragyan by about 16 inches (40 centimeters). At that time, Pragyan had already been put into sleep mode.

ISRO's take

Before starting their lunar night rest, Pragyan's batteries were fully charged, ISRO indicated in a post on X, the social media platform formerly Twitter. Arun Sinha, a former senior scientist at ISRO, explained to that the mission's longevity might receive an unlikely extension if the batteries prove to be extra-efficient. "If the battery charge performs exceptionally well, the mission could have another 14 days," he noted.

The mission has stirred scientific curiosity and national pride as India continues to make strides in space exploration. Yet, whether Vikram and Pragyan awaken with the following lunar dawn remains a high-stakes gamble, ultimately depending on how they weather the frigid conditions of the moon's south pole without the aid of conventional heating mechanisms.

Add Interesting Engineering to your Google News feed.
Add Interesting Engineering to your Google News feed.
message circleSHOW COMMENT (1)chevron
Job Board