China’s robotic lunar exploration probes, including orbiters, landers, and sample return missions.
Date of creation: 2004. Agency: SASTIND/CNSA. First mission: 2007-10-24. Last mission: 2014-10-24. Missions: 7 planned, 5 launched.
When China launched its first artificial Earth satellite into orbit in 1970, Chinese space professionals envisaged that ambitious missions to explore the Moon and other planets in the solar system would soon follow. However, by the mid-1970s the country was on the verge of being bankrupt following a decade of political chaos brought by the so-called Cultural Revolution movement. The political leadership in the post-Mao era decided to focus on economic development. As a result, the Chinese space programme was scaled back to a new, more moderate objective of developing applications satellites.
In 1990, Japan became the third country to place an object in orbit around the Moon with its Hiten spacecraft. In 1994, NASA also launched its Clementine lunar exploration mission. Other space-fairing nations were also planning similar missions. In a fear that China may fall behind other nations in the new round of race to the Moon, the topic of lunar exploration re-emerged within the Chinese space community. In 1992, a mission was proposed by the scientific community to use a spare CZ-3 launcher to send a metal emblem to the Moon surface, as a celebration for the return of Hong Kong from the British colony in 1997. However, the idea was rejected due to a lack of funding.
Not put off but he setback, the Chinese scientific community continued pursue of a lunar exploration mission. A feasibility study was published by three scholars in 1995, detailing the concept of a lunar orbiter based on the DFH-3 communications satellite bus. This was followed by a report titled “Suggestions for Developing China’s Lunar Exploration Technology” to the political leadership in April 1997. the Committee of Science, Technology, and industries for National Defence (COSTIND) initiated a preliminary study on the lunar exploration mission in 1998.
In his speech titled “China’s Space Exploration in the 21st Century” during the first International Space Week in May 2000, Luan Enjie, Director of the China National Space Administration (CNSA), revealed for the first time that the country was planning to explore the Moon. The Chinese government white paper titled “China’s Space Activities” published in November of the same year outlined three key areas in the country’s future space programme development: application satellites, human spaceflight, and deep space exploration. Lunar exploration was defined as the first step in China’s deep space exploration effort.
COSTIND initiated a series of research projects to develop necessary technologies and techniques required for lunar exploration, including the lunar orbiting spacecraft and its onboard application payload. It also developed a three-step strategy to explore the Moon:
Phase-I: To send one or more unmanned missions to orbit the Moon to carry out survey and map the lunar surface.
Phase-II: To send 1 to 2 missions to land on the Moon surface, where they will deploy robotic lunar rovers to explore areas around the landing spot.
Phase-III: To send 1 to 2 missions to land on the Moon to collect samples of lunar soil samples and return them to Earth.
The China Lunar Exploration Programme (CLEP) was officially given a go-ahead by the Chinese political leadership in 2004. COSTIND was responsible for leading the project and organising and coordinating relevant development programmes. The lunar exploration programme consisted of five main systems:
– Lunar exploration spacecraft named Chang’e after the Moon god in ancient Chinese mythology
– Launch vehicle
– Telemetry, tracking and control (TT&C) system
– Launch site
– Ground application system
In order to support the lunar probing missions, the old Launch Complex 3 at the Xichang Satellite Launch Centre (XSLC) was demolished and rebuilt to allow the launch of heavier launch vehicles. A new Mission Command and Control Centre was built in Xichang city, about 60 km southeast of the launch site. A deep space tracking network was constructed, with a 50 m radio antenna in Beijing, and 40 m antennas in Kunming, Shanghai, and Ürümqi, forming a 3,000 km very long baseline interferometry (VLBI) network. The ground application system was developed for downlink data reception.
China’s first robotic probe to orbit the Moon, the Chang’e 1 mission was launched on 24 October 2007 and reached the lunar orbit in November. The spacecraft stayed in the lunar orbit for 16 months before carried out a controlled crash into the Moon surface on 1 March 2009. Objectives of the mission were: obtaining three-dimensional images of lunar surface and making outline graphs of lunar geology and structures; probing useful elements on the lunar surface and analysing the elements and materials; probing the features and depth of the lunar soil; probing the space environment between 40,000 km and 400,000 km from the Earth.
The second lunar orbiting mission was launched on 1 October 2010. Objective of the mission is to test six key techniques: the direct injection of the spacecraft onto the lunar-transfer path without first settling into an Earth orbit; the insertion of the spacecraft on the 100 km lunar orbit; the flight on the 100 x 15 km lunar orbit; the control of the spacecraft by X-band communications; the high-speed (12mbps download) Lunar-Earth data transmission; The capture of high-definition images of the landing area in the Sinus Iridum (Bay of Rainbows, 43°N 31°W). The mission officially ended in June 2011, but the probe continued flying in space, leaving the lunar orbit to explore Lagrangian point (L2) of the Earth-Moon system and Near Earth Asteroid 4179 Toutatis.
The third robotic lunar probe mission was launched in December 2013. The mission saw the robotic spacecraft making a soft-landing on the lunar surface, the first of its kind in nearly three decades since the Soviet Union’s Luna 24 mission in 1976. The probe also deployed a lunar rover to explore the surrounding areas of the landing spot. The mission was intended to demonstrate and perfect a range of new technologies, including lunar soft-landing, lunar surface exploring, lunar-night survival, and deep-space communications, which are critical for subsequent lunar exploration missions.
The technology demonstration mission launched in October 2014 was a precursor mission to the Chang’e 5 robotic lunar sample return mission. The primary objective of the mission is to validate the design of Chang’e 5’s return capsule and to demonstrate high-speed atmospheric re-entry from the translunar flight.
The first lunar sample return mission was scheduled for launch in late 2017, but now postponed to 2018 due to the ongoing issues with the CZ-5 launch vehicle. The robotic spacecraft will first fly to lunar orbit and then deploy a lander to make a soft-landing on the Moon surface. After collecting the lunar soil samples, the ascent module of the lunar lander will take off to fly back to lunar orbit, where it will perform a lunar orbit rendezvous (LOR) to dock with the re-entry module. The re-entry module carrying the lunar soil samples to fly back to Earth orbit, and return the samples inside a re-entry capsule to land on Earth.
A proposed robotic lunar probing mission in 2018 to soft-land on the far side of the Moon – first in the history of human space exploration. The mission will include the launch of a communications relay satellite to Lagrangian Point (L2) of the Earth-Moon system, followed by the launch of a lunar lander six months later.
A proposed second lunar sample return missions to return lunar soil samples collected from the far side of the Moon in 2023.