Chang'e 4 (Chinese: 嫦娥四号; pinyin: Cháng'é sìhào) is a Chinese lunar exploration mission, planned for launch late in 2018, that will incorporate an orbiter, a robotic lander and rover. Chang'e 4 will be China's second lunar lander and rover. It was built as a backup to Chang'e 3, as Chang'e 2 was to Chang'e 1. Following the successful landing of the Chang'e 3 mission, the configuration of Chang'e 4 will be adjusted to meet new scientific objectives. Like its predecessors, the spacecraft is named after the Chinese Moon goddess.
|Mission type||Lander, Lunar rover|
|Mission duration||12 months|
|Launch mass||Orbiter: 425 kg|
|Start of mission|
|Launch date||Orbiter: June 2018
Lander & rover: late 2018
|Rocket||Long March 4C |
|Landing date||End of 2018|
|Landing site||Crater Von Kármán in
the South Pole-Aitken Basin
The mission was first scheduled for launch in 2015 as part of the second phase of the Chinese Lunar Exploration Program but the adjusted objectives and design of the mission imposed delays, and it is currently scheduled for launch by the end of 2018.
Since Chang'e 4 is planned to land on the far side of the Moon, CNSA will first launch a communication relay satellite to Earth–Moon L2 point in June 2018 as a communication relay station to relay the signals between the lander/rover and the Earth station. The lander and rover will follow 6 months later. It will be the first ever landing on the lunar far side, an unexplored region of the Moon called South Pole-Aitken Basin, a vast basin in the southern hemisphere of the far side which extends from the South Pole to Aitken crater.
The Chinese Lunar Exploration Program has started to incorporate private investment from individuals and enterprises for the first time, a move aimed at accelerating aerospace innovation, cutting production costs, and promoting military-civilian relationships. After Chang'e 4, China will follow with a series of other robotic lunar missions that will build towards an attempted human landing in about 15 years.
The proposed landing site is the Von Kármán crater (180 km diameter) in the South Pole-Aitken Basin on the far side of the Moon. The crater is thought to be the oldest impact feature on the Moon. Regarding its composition, it contains about 10% by weight iron oxide (FeO) and 4-5 parts per million of thorium, which has been used as a replacement for uranium as nuclear fuel on several thorium reactors.
While the orbiter will provide communications relay, the lander and rover will carry scientific payloads to study the geophysics of the landing zone, with a very limited chemical analysis capability. In addition, Chang'e 4 will also carry international payloads from Sweden, Germany, the Netherlands and Saudi Arabia.
In addition, the lander will carry a container with seeds and insect eggs to test whether plants and insects could hatch and grow together. The experiment includes seeds of potatoes and Arabidopsis, as well as silkworm eggs. If the eggs hatch, the larvae would produce carbon dioxide, while the germinated plants would release oxygen through photosynthesis. It is hoped that together, the plants and silkworms can establish a simple synergy within the container. In 1982, the crew of the Soviet Salyut 7 space station grew some Arabidopsis, thus becoming the first plants to flower and produce seeds in space. They had a life span of 40 days.