Chang'e 3

Did You Know?

• The landing site of Chang'e 3 has been named 'Guang Han Gong' (Moon Palace) by the International Astronomical Union.
• Three nearby impact craters were given the names Zi Wei, Tian Shi and Tai Wei, after constellations in traditional Chinese astrology.
• The Yutu rover ceased to transmit data in March 2015, but status checks of the lander in 2018, 2020, and 2025 indicate it is still operational, roughly twelve years after landing.

History

China's lunar orbiter project was formally established in January 2004. The first orbiter, Chang'e 1, launched on 24 October 2007 and entered lunar orbit on 5 November, operating until it was intentionally crashed into the Moon on 1 March 2009. Its data created a high-resolution 3D map used for Chang'e 3 site selection. Chang'e 2, approved in October 2008 and launched on 1 October 2010, conducted research from a 100-km orbit with improved instruments, providing higher-resolution imagery for Chang'e 3 planning. In 2012, Chang'e 2 was sent on an extended mission to asteroid 4179 Toutatis.

Objectives

The official objective is to achieve China's first soft-landing and roving exploration on the Moon, demonstrating key technologies for future missions. Scientific goals include surveying lunar surface topography, geology, material composition, and resources; detecting the Sun-Earth-Moon space environment; and performing lunar-based astronomical observation. Chang'e 3 aims to directly measure lunar soil structure and depth down to 30 m and investigate crust structure down to several hundred meters.

Mission profile

Chang'e 3 launched at 17:30 UTC on 1 December 2013 atop a Long March 3B rocket from Launch Complex 2 at Xichang Satellite Launch Centre. Spent rocket wreckage fell on a village in Suining County, Hunan province, damaging homes; 160,000 people had been moved to safety in the county, and over 20,000 near the launch site were relocated. The spacecraft entered a 100 km-high circular lunar orbit on 6 December 2013 at 9:53 UTC after 361 seconds of engine braking.

It later adopted a 15 km elliptic orbit. Landing occurred on 14 December after a 12-minute sequence: variable thrusters fired at periapsis to reduce velocity, descending to 100 m altitude, then hovering and moving horizontally to avoid obstacles, descending to 4 m, where the engine shut down for free-fall. Topographic data from Chang'e 1 and 2 guided site selection; the planned site was Sinus Iridum, but the lander touched down on Mare Imbrium, about 40 km south of crater Laplace F, at 44.1214°N, 19.5116°W and 2640 m elevation, at 13:11 UTC.

The lander massed 1200 kg and carried a 140 kg rover. It serves as a technology demonstrator for future sample-return missions. The lander uses a radioisotope heater unit and solar panels for its planned one-year mission, with seven instruments and cameras. During 14-day lunar nights, both lander and rover enter sleep mode.

Monitoring by other lunar missions

The descent of Chang'e 3 was expected to increase lunar dust in the exosphere and introduce gases from engine firings. Although no formal cooperation exists between NASA and CNSA, NASA's Lunar Atmosphere and Dust Environment Explorer (LADEE) examined possible changes to baseline exosphere readings, studying how dust and propellant gases settle after a landing. One combustion byproduct is water vapor, which LADEE may observe depositing in cold traps near the poles. NASA's Lunar Reconnaissance Orbiter (LRO) photographed the landing site on 25 December 2013, showing the lander and rover, and attempted further imaging on 22 January and 18 February 2014.