In the run-up to the Chandrayaan-3’s lander’s soft landing on the moon’s surface on August 23, the Indian Space Research Organisation (ISRO) has carried out an assessment of the current space situation around the moon.
The space agency, which released the document on August 9, stated that the moon and Mars are the most explored and also comparatively more crowded planetary bodies at present.
It added that India’s Chandrayaan-3 is the latest entry into lunar orbit and more intensified activities around the moon are foreseen in the next few years due to the renewed interest in lunar exploration, heralded by Artemis missions for return to the moon and preparations for colonisation of Mars.
“While the previous missions were essentially aimed at scientific explorations, upcoming ventures will likely involve multiple actors of diverse interests, including those primarily driven by resource utilisation for commercial purposes. A better understanding of the environment is needed to formulate reasonable mitigation practices to avoid close-approach threats in planetary orbits,” ISRO said.
Current situation around the moon
ISRO said that as of July 2023, there are six active lunar orbiters.
It said that two of the five probes of NASA’s THEMIS mission have been re-purposed under ARTEMIS as ARTEMIS P1 and ARTEMIS P2 and both operate in eccentric orbits of low inclination.
The assessment stated that NASA’s Lunar Reconnaissance Orbiter (LRO) orbits the moon in a nearly polar, slightly elliptical orbit. The Chandrayaan-2, the second lunar mission of ISRO and Korea Pathfinder Lunar Orbiter (KPLO) also operate in polar orbits of 100 km altitude.
Besides, NASA’s Capstone operates in a 9:2 resonant southern L2 NRHO, its perilune passes over the lunar north pole at 1500-1600 km altitude, while the apolune is over the South pole at a distance of nearly 70,000 km.
The Japanese spacecraft Ouna which was placed in lunar orbit as part of Kaguya/SELENE mission in 2009 and Chandrayaan-1 launched in 2008 are the two defunct spacecraft, ISRO said.
It said that all the other orbiters have been either moved out of the moon-bound orbital regime or have landed/impacted the lunar surface, either deliberately or due to failure to land softly. For example, the Chang’e 4 mission’s data relay satellite Queqiao, launched by China in May 2018, was later moved to a halo orbit near the Earth-Moon L2 point.
“Currently, the only operating rover is China’s Yutu-2 rover released by Chang’e 4, which operates on the far side. From the available media sources, it is expected that Luna-25 of Russia with a lander and rover will be in a lunar orbit of 100 km by August 16, 2023, and will be landing on the south pole of the moon by August 21-23, 2023,” ISRO added.
Role of India and way forward
ISRO said that India has pro-actively taken up many initiatives in collaboration with International Organisations like the Inter-Agency Space Debris Coordination Committee (IADC), which include studies related to the future evolution of space object environment in the cislunar and lunar region to bring out specific guidelines and best practices for space operations to be sustainable in these regions.
