Leonard David's INSIDE OUTER SPACE

Departure of new Moon relay spacecraft. Image credit: CCTV/Inside Outer Space screengrab

All seems good to go with China’s en route to the Moon Queqiao-2 relay satellite – an essential element of the country’s expanding lunar exploration agenda.

Riding atop a Long March-8 Y3 carrier rocket departing on Wednesday (Beijing Time) from the Wenchang Spacecraft Launch Site, the relay craft entered a planned Earth-Moon transfer orbit.

Queqiao-2’s solar panels and communication antennas were unfolded, according to reports.

Image credit: CNSA

“It will undergo mid-course corrections and near-moon braking to a capture orbit, adjust and finally settle into the lunar orbit,” according to the China Global Television Network (CGTN).

Relay services

The satellite is an upgraded version of Queqiao, the relay satellite used for China’s Chang’e-4 lunar lander/rover.

Tiandu-1 and Tiandu-2 subsatellites are to trial-run lunar communications technology.
Image credit: Deep Space Exploration Laboratory (DSEL)

According to China Central Television (CCTV), as the designed lifespan of the first Queqiao is about to end, Queqiao-2 will continue to provide relay communication services for the Chang’e-4 lander/rover already on the Moon.

Chang’e-4 farside lander and Yutu-2 rover.
Image credit: CNSA/CLEP

Furthermore, this new relay satellite, also named Magpie Bridge 2, will provide relay support for the upcoming Chang’e-6 farside lander and follow-on Chang’e-7 and Chang’e-8 Moon missions.

Queqiao-2 is more powerful and has a longer lifespan for more missions.

The Long March-8 Y3 booster also carried two experiment satellites for trial-running lunar communications technology – the Tiandu-1 and Tiandu-2.

Step-by-step

In December 2021, the fourth phase of the lunar project was approved and put in motion, including the Chang’e-4, Chang’e-6, Chang’e-7 and Chang’e-8 missions.

Photo taking during Chang’e-5 surface sampling.
Credit: CCTV/Inside Outer Space screengrab

The Chang’e-4 was launched in December 2018, making the first soft-landing on the farside of the Moon. The Chang’e-4 mission began its survey of the Von Karman Crater in the South Pole-Aitken Basin on the farside of the Moon on January 3, 2019.

In December 2020, the Chang’e-5 lunar spacecraft hauled back to Earth 1,731 grams of samples from the Moon, marking the completion of China’s three-step lunar exploration program of orbiting, landing and return.

China’s Chang’e-6 lunar sample return mission elements.
Credit: CNSA

Upcoming, reportedly in May, sendoff of the Chang’e-6 mission to attempt a touch down on the Moon’s farside, then grab, stash, and return lunar specimens for return to Earth.

The follow-on Chang’e-7 and Chang’e-8 are planned to form the basic structure of a lunar research station.

Braking operation

China media reports that Queqiao 2 was developed by the China Academy of Space Technology, based on the CAST2000 satellite framework. It weighs about 1.2 metric tons and has two major payloads: a 4.2-meter parabolic antenna for communications with lunar probes and a 0.6-meter parabolic antenna used to transmit data to ground control.

Over the next few days, Queqiao 2 is to perform a series of maneuvers such as a mid-course trajectory correction and a braking operation before it enters an “elliptical frozen orbit” around the Moon.

Once arrived at its predetermined orbital position, Queqiao 2 will conduct two-way communication tests with the Chang’e-4 lander/rover mission now on the lunar surface as well as the soon-to-be-launched Chang’e-6, now being readied for flight to the Moon atop a Long March 5 heavy-lift rocket.

Change’6 lunar sample return scenario. Image credit: CNSA

Fourth phase

Due to the Moon’s perpetual one-side facing away from Earth, probes landing on the farside are obstructed by the Moon itself, hindering direct measurement, control communication, and data transmission with Earth.

“As the fourth phase of China’s lunar exploration project focuses on landing exploration and sampling sites primarily situated in the Moon’s south pole and farside areas, the need arises for more versatile and robust relay satellites. And these satellites will serve as a new relay communication station on the Moon for communication,” explains CCTV.

China’s fourth phase of lunar exploration has the goal of scientific investigation of the Moon’s south pole and set up a fundamental type of lunar scientific research station. Known as the International Lunar Research Station, this facility is to be constructed in the 2030s.

Artist’s view of International Lunar Research Station to be completed by 2035. Credit: CNSA

The fourth phase will be carried out in three steps, with the Chang’e-6, Chang’e-7 and Chang’e-8 probes being launched before 2030, CCTV notes. The Chang’e-8 will constitute, together with Chang’e-7, the basic model of a lunar research station.

Multi-level, multi-type cooperation

Ge Ping, deputy director of the Center of Lunar Exploration and Space Engineering of the China National Space Administration (CNSA) told CGTN that China is willing to carry out Moon exploration-related multi-level and multi-type cooperation with other countries and international organizations.

“China has opened up applications for Chang’e-5’s moon soil samples for the international science community. It’s also looking for cooperation in the lunar program’s fourth step and other planetary exploration projects,” Ge said.

Chang’e-5 return capsule holding lunar specimens.
Credit: National Astronomical Observatories, CAS

The CNSA opened applications for access to the returned cache of Chang’e-5 lunar samples to international scientists in late 2023.

Late last year, NASA worked with Congress to allow NASA-funded researchers to apply to CNSA for access to the Chang’e-5 samples. Subsequently, CNSA received nearly a dozen applications from U.S. proposers.

Still to come is NASA guidance on how space agency funding may be used to support research efforts on Chang’e-5 samples, according to Lori Glaze, director of NASA’s Science Mission Directorate’s Planetary Science Division.