Moon Mission Lays Groundwork For Chinese Manned Landing
The Chang’e 5 mission, launched on Nov. 24 to bring samples back from the Moon, will demonstrate technology needed for later manned exploration. The 3-4-week operation is intended to gather the youngest-ever samples from the Moon’s surface.
The Long March 5 launcher departed the Wenchang space base three years behind the original schedule for the mission, which was repeatedly delayed. It was the fifth launch for the Long March 5 series.
- Lunar ascent and orbital docking will be demonstrated
- This is the third phase of China’s Moon exploration effort
Chang’e 5’s return capsule is set to make its way back to Earth Dec. 16-17 for a landing in Inner Mongolia.
The primary mission objective is to bring back 2.2 kg (5 lb.) of samples from near the volcanic mound Mons Rumker; if successful, it will be the first sample-return mission from the Moon since the 1970s. Some samples could be taken from a depth of 2 m (6.6 ft.). The age of the lunar surface materials at Mons Rumker is estimated at 1.2 billion years, compared with the 3.1-4.4 billion years for the samples from the U.S. Apollo program.
Missions in the Soviet Union’s Luna program returned samples in 1970, 1972 and 1976. The last of those is the most recent sample-return effort before the Chang’e 5 mission.
Chang’e 5 payloads consist of a camera to survey the landing site, a ground-penetrating radar and a spectrometer to assess the surface mineralogy, including how much water is locked in the soil.
In bringing back the soil and rocks, Chang’e 5 will need to demonstrate Chinese technology for two operations that eventual manned lunar missions will need: ascent from the lunar surface and docking in lunar orbit. Lunar docking may be needed for more than moving astronauts between an ascent module and a return capsule. In September, the Chinese manned space program outlined a mission configuration that implied docking by a spacecraft upon arrival in lunar orbit.
Chinese space officials discuss plans for manned landings, and the industry is working on the technology, but the government has not approved such a program.
China has already achieved a return from the Moon, with reentry at the associated high velocity. This occurred in 2014 during the Chang’e 5 T1 demonstration mission, in which a reentry capsule traveled toward the Moon, looped around it and came back.
The first phase of the China Lunar Exploration Program achieved the objective of merely placing an orbiter into lunar orbit, with the Chang’e 1 mission of 2007. The second phase, conducted by Chang’e 3 in 2013 and 2014, achieved a landing.
Whereas the spacecraft of Chang’e 3 and 4 had a launch mass of about 3.8 metric tons, the figure for the Chang’e 5 is 8.2 metric tons. The current mission, therefore, required China’s most powerful launcher, Long March 5, and had to be delayed when the second flight of the rocket failed in 2017.
Chang’e 5 was rescheduled for late 2018, then late 2019, as Long March 5 plans were reshuffled.
The spacecraft consists of four main modules. As mounted for launch, the lowest is a propulsion (or service) module, above which is the reentry capsule. Two more modules form the lander: a descent stage and an ascent stage—just as in the Apollo lunar module. (The Chinese refer to the descent stage as the lander and the ascent stage as the ascender.)
Again using the Apollo approach, the assembly will separate in lunar orbit, and the lander will drop to the Moon’s surface while the propulsion module and reentry capsule (“returner,” to the Chinese) await completion of surface activity, according to official descriptions of the mission.
Back in orbit, the samples will be transferred to the reentry capsule, which the propulsion module will then push back toward the Earth, separating from it on approach.
The operation on the Moon’s surface must be completed within a lunar day (about 14 Earth days) because the equipment is not built to withstand the temperature change that will come with the next lunar night.
The European Space Agency is providing the China National Space Administration mission with ground-station communications support from Kourou, French Guiana, and tracking from Spain.
China’s lunar exploration effort began in 2004. As originally planned, the first phase would comprise Chang’e 1 and 2, the second Chang’e 3 and 4, and the third Chang’e 5 and 6. (In each pair, the second spacecraft was intended as a backup for the first but could be modified for a somewhat different mission.)
But by 2019, Chang’e 5 was described as the only mission of the third phase; a fourth would begin with Chang’e 6, then scheduled to make a landing at the Moon’s south pole in 2023-24.
The fourth phase is intended to prepare for eventually establishing a base on the Moon and is also intended to include Chang’e 7 and 8, to be launched by 2030. A Chang’e 9 has also been mentioned as a possibility.
During this time, China may not have a space launcher more powerful than Long March 5. None has been approved. So a further significant rise in mass hurled toward the Moon cannot be an immediate prospect for the program.