China initiated the launch of a satellite aimed at establishing a communications link between terrestrial operations on Earth and an upcoming expedition to the far side of the moon.
On March 19th, the Long March 8 rocket embarks on its journey from the Wenchang spaceport in the Eastern region, bearing the Queqiao-2 lunar relay satellite. Credit: CNSA
This Wednesday’s launch marks a significant advancement in China’s extensive lunar exploration initiative.
The Queqiao-2 satellite, weighing 1.2 metric tons and named after a legendary mythical bridge composed of magpies, along with two miniature satellites named Tiandu-1 and -2, were transported into space by a Long March 8 rocket from the southern island province of Hainan.
Since the moon’s near side always remains visible from Earth, direct data transmission from the far side has historically been difficult due to the absence of a direct line of sight. Queqiao-2 is set to circumnavigate the moon, facilitating the relay of signals to and from the forthcoming Chang’e-6 mission, scheduled for launch in May.
The primary objective of the Chang’e-6 mission is to collect and return samples from an ancient basin located on the hidden side of the moon, marking the first instance of lunar material retrieval from this region.
Furthermore, Queqiao-2 will serve as a pivotal relay platform for subsequent lunar expeditions, including the Chang’e-7 mission in 2026 and the Chang’e-8 mission in 2028. By the year 2040, it is anticipated that Queqiao-2 will form part of a network of relay satellites, functioning as a vital communications conduit for manned lunar missions and exploration endeavors on celestial bodies like Mars and Venus. Additionally, the Tiandu-1 and -2 miniature satellites will engage in experimental trials to advance the development of a satellite constellation.
The satellite constellation will additionally provide vital support for China’s planned lunar research station situated at the moon’s south pole. Queqiao-2 will join a fleet of approximately half a dozen orbiters deployed by various nations, including the United States, India, and Japan.
Designed to operate for a minimum of eight years, Queqiao-2 is planned to support lunar missions beyond 2030. This also coincides with China’s projected endeavor to land its first astronauts on the lunar surface. It is anticipated that the satellite will enter a trajectory that closely approaches the moon’s south pole, the designated location for China’s research facility.
Queqiao-2’s orbital path will be elliptical, extending up to 8,600 kilometers above the lunar terrain, thereby establishing a communication link between Earth and the moon for over eight hours. During the remaining duration of its approximately 12-hour orbit, Queqiao-2 will descend to as low as 300 kilometers above the moon’s surface.
Taking over the responsibilities of its predecessor, Queqiao-1, launched in 2018, Queqiao-2 has a triple mass compared to its precursor. Queqiao-1, initially intended to operate for five years, served as the inaugural relay satellite dispatched to the far side of the moon, aiding the Chang’e-4 mission. Despite exceeding its projected lifespan, Queqiao-1 continues to operate, orbiting a point in space approximately 70,000 kilometers beyond the lunar surface.
In 2019, the Chang’e-4 mission achieved a historic milestone by executing a soft landing on the far side of the moon, facilitating the deployment of the robotic rover Yutu-2, also known as Jade Rabbit in Chinese. Yutu-2 remains operational, continuing its scientific exploration endeavors on the lunar terrain.