India’s lunar explorer Chandrayaan-2 had to maneuver to avoid collision with South Korea’s Danuri probe. This was reported by the Indian Space Research Organization (ISRO).
A report published by ISRO said the maneuver was carried out on September 19. It avoided a dangerous approach with the Danuri, which would have occurred two weeks later if Chandrayaan-2’s trajectory had not changed. Already on October 1, Chandrayaan-2 performed a new evasive maneuver. It will avoid potential collisions with other vehicles around the Moon, including the U.S. LRO.
Although the Moon’s surroundings are nearly empty compared to Earth, such collision avoidance maneuvers have long been uncommon. The fact is Chandrayaan-2, Danuri and LRO are in polar orbit. This causes them to regularly approach and even photograph each other around the lunar poles, where the risk of collision is very high. For example, in 2021, Chandrayaan-2 changed its orbit to avoid a predicted approach with LRO over the moon’s north pole. Without this maneuver, the two spacecraft would have crossed within only 3 km of each other.
As for Danuri, the Korea Aerospace Research Institute (KARI), which operates it, has received 40 warnings of possible collisions with LRO and Chandrayaan-2 in the past year and a half alone. The vehicle maneuvered at least three times. One time to evade the LRO, a second time to avoid a collision with Chandrayaan-2, and a third time to avoid an encounter with Japan’s SLIM, which was preparing to land on the Moon in January this year.
Currently, there is no agreed international protocol for resolving collision risks. The three space agencies (NASA, KARI and ISRO) voluntarily share data on the trajectories of their lunar landers via e-mail and teleconferences. They usually use a platform created by NASA’s Jet Propulsion Laboratory called MADCAP, which calculates collision risk and generates warnings.
However, due to the lack of a common protocol for information exchange, sometimes there are overlaps when one party does not have the contacts of the responsible person of the other party. And emails may not reach the recipient due to network security issues. As numerous new missions to the Moon are expected to be launched in the coming years, this once again emphasizes the need for an internationally agreed mechanism aimed at preventing near-lunar hazards.
Provided by Space.com
