China’s Queqiao-2 relay satellite enters lunar orbit

The far side of the moon and distant Earth, imaged by the Chang’e-5 T1 mission service module. Credit: Chinese Academy of Sciences

HELSINKI — China’s Queqiao-2 communications relay satellite entered lunar orbit March 24, paving the way for a lunar far side sample return mission.

Queqiao-2 began a 19-minute-long braking burn at 12:46 p.m. Eastern Sunday (1646 UTC), allowing the spacecraft to be captured by the moon’s gravity, the China National Space Administration (CNSA) announced early March 25.

The spacecraft is expected to have entered an initial 200 by 100,000-kilometer lunar orbit. Operators will further alter its orbit and inclination to bring Queqiao-2 into a 200 by 16,000-km, highly-elliptical “frozen” orbit.

Queqiao-2 will have simultaneous direct line-of-sight with both ground stations on Earth and the lunar far side for large portions of this 24-hour-period orbit. This frozen orbit is intended to be highly stable and require little maintenance, boosting mission longevity.

China intends to launch its Chang’e-6 spacecraft in May to attempt to collect samples from the far side of the moon. The far side of the moon never faces the Earth, as the planet’s gravity has slowed the rotation of the moon over time. Queqiao-2 is thus required for communications for the mission.