With the successful separation of the Chandrayaan-3 spacecraft's lander module from the propulsion module, India has surpassed China in having the most active spacecraft around Moon. The lander module, which comprises lander Vikram and rover Pragyan, is scheduled to soft land on the south pole on August 23, and till then it will orbit around the Moon.
The propulsion module too will continue its journey in the current orbit for months or years. The SHAPE (Spectro-polarimetry of Habitable Planet Earth) payload onboard the propulsion module would perform a spectroscopic study of the Earth's atmosphere and measure the variations in polarisation from the clouds on Earth – to accumulate signatures of exoplanets that would qualify for habitability.
Besides propulsion and lander modules, India's Chandrayaan-2 orbiter is still functioning - taking the total number of active spacecraft to 3. With this, the number of active lunar orbiters has jumped to nine from six a month earlier. As of July, there were six active lunar orbiters but India's Chandryaan-3 and Russia's Luna-25 entered the lunar orbit later. Chandryaan-3 entered the lunar orbiter on August 5, while Luna-25 followed it up on August 16.
Also read: Russia's Luna-25 spacecraft enters lunar orbit, touchdown planned two days ahead of Chandrayaan-3
Apart from Chandryaan-3 and Luna-25, six spacecraft orbiting the Moon are US space agency NASA's THEMIS-B, THEMIS-C, LRO, and CAPSTONE; India's Chandrayaan-2; and Korea's KPLO.
Two of the five probes of NASA's THEMIS mission have been re-purposed under ARTEMIS (Acceleration, Reconnection, Turbulence, and Electrodynamics of the Moon's Interaction with the Sun) as ARTEMIS P1 and ARTEMIS P2 - both operate in eccentric orbits of low inclination, the ISRO said in an assessment paper published on July 8.
NASA's Lunar Reconnaissance Orbiter (LRO) orbits the Moon in a nearly polar, slightly elliptical orbit. Chandrayaan-2 and Korea Pathfinder Lunar Orbiter (KPLO) also operate in polar orbits of 100 km altitude.
WATCH: Chandrayaan-3: Pragyan rover, not Vikram lander, is the dark horse of ISRO’s giant leap towards Moon
The Japanese spacecraft Ouna which was placed in lunar orbit as part of the country's moon mission in 2009 and Chandrayaan-1 launched in 2008 are the two defunct spacecraft. 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, the assessment said.
"For example, 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," the Indian space agency said. "Currently, the only operating rover is China's Yutu-2 released by Chang'e 4, which operates on the far side."