Nation's space journey continues apace

Spectators observe the retrieval of a lunar soil sample on the Chang'e 6 mission, displayed at the 15th China International Aviation and Aerospace Exhibition in Zhuhai, Guangdong province, last month. (Hong Zehua/Xinhua)

The first-ever samples retrieved from the moon's far side, an iconic feat achieved by China's most recent lunar expedition, Chang'e 6, were on display at the 15th China International Aviation and Aerospace Exhibition, which took place in Zhuhai, Guangdong province, from Nov 12 to 17.

This was the first time the valuable lunar substances had been shown to the public since they were brought back to Earth in June.

The Chang'e 6 mission, representing the world's first attempt to bring back samples from the far side of the moon, was launched on May 3 from the Wenchang Space Launch Center in Hainan province.

After a series of complex maneuvers, the lander of the Chang'e 6 probe touched down at the South Pole-Aitken Basin on the lunar far side on June 2, and then began to collect surface and underground samples.

It was the second-ever landing of a spacecraft on the lunar far side. The vast region had never been reached by any spacecraft until January 2019, when the Chang'e 4 probe landed in the South Pole-Aitken Basin. Chang'e 4 surveyed areas surrounding its landing site, but did not collect samples.

The lander worked for 49 hours on the far side, using a mechanical arm and a drill to collect surface and underground materials.

The unmanned mission successfully concluded on June 25 with a total of 1,935.3 grams of samples from the far side retrieved.

The returner of the Chang'e 6 mission, containing lunar soil samples, successfully lands in Siziwang Banner, Inner Mongolia autonomous region, on June 25. (Photo/Xinhua)

The samples have unique scientific value and will further expand knowledge about the moon's history and help to gear up the exploration and exploitation of lunar resources, according to the China National Space Administration.

Previously, 10 lunar sample-return missions were undertaken by the United States, the former Soviet Union, and China, but all these samples were collected from the moon's near side.

Before Chang'e 6, China had fulfilled a lunar sample-return mission — the Chang'e 5 in the winter of 2020, which landed on the moon's near side and recovered 1,731 grams of samples, the first lunar substances obtained since the Apollo era. It made China the third nation, after the US and the former Soviet Union, to have retrieved lunar samples.

So far, Chang'e 5 samples have enabled Chinese researchers to make a number of academic advancements, including the discovery of the sixth new lunar mineral, named Changesite-(Y).

Changesite-(Y), which falls in the category of lunar merrillite, is the first lunar mineral discovered and identified by Chinese scientists.

So far, China has conducted six robotic missions to explore the moon.

Besides the sample-collection endeavors, China has also deployed two rovers on the moon through the Chang'e 3 and Chang'e 4 missions.

The Yutu 2 rover, the central part of the Chang'e 4 mission, has worked on the moon for nearly six years, far exceeding its designed life of three months, and has traveled more than 1,600 meters, continuing to extend its lead as the longest-working robot on the moon.

In the coming years, China plans to continue to send unmanned probes to the moon and use the next two missions — Chang'e 7 and Chang'e 8 — to establish a prototype for the International Lunar Research Station, an ambitious multinational science project initiated by China.

Guan Feng, director of the Lunar Exploration and Space Engineering Center of the China National Space Administration, introduces the Chang'e 6 mission and research development associated with the lunar soil sample the mission had retrieved from the far side of the moon during the 75th International Astronautical Congress in Milan, Italy, in October. (Photo/China News Service)

Crew landing roadmap

Having gathered rich experience through robotic adventures, China is moving progressively toward its goal of sending astronauts to the moon before the end of this decade, according to a key figure in this ambitious endeavor.

Zhou Jianping, chief designer of China's manned space program, told a crewed spaceflight forum in late November in Shenzhen, Guangdong province, that all of the preparatory research work for the nation's first manned lunar mission has finished, with essential technologies and implementation plans already in place.

Mission planners, scientists, and engineers have started to design and build prototypes of necessary hardware, he said.

"Currently, prototypes of the Long March 10 heavy-lift carrier rocket, the Mengzhou crew spaceship, the Lanyue lunar lander, as well as the crew rover and other hardware needed in a manned mission to the moon are under research and development. Some of their components have been made and are being tested," Zhou said at the forum, hosted by the China Manned Space Agency.

China's roadmap for its first manned lunar expedition involves two Long March 10 launches from the Wenchang Space Launch Center in Hainan province to transport a Lanyue lunar lander and a Mengzhou manned spacecraft to lunar orbit.

After reaching their preset orbital positions, the Lanyue lander and the Mengzhou vessel will rendezvous and dock with each other. Two crew members will enter the lander, which will then undock and descend toward the lunar surface for an engine-assisted soft landing.

The lander-ascender of the Chang’e 6 mission. (Photo/Xinhua)

On the moon, the astronauts will drive a rover to carry out scientific tasks and collect samples. Upon completion of their assignments, they will return to the Lanyue module, which will fly them back to their spaceship waiting in lunar orbit.

Finally, the astronauts will carry the samples into their Mengzhou spacecraft, which will then undock and carry the crew back to Earth.

To prepare for the challenging adventure, China has selected its fourth group of astronauts, who are learning knowledge and skills to be used in lunar operations.

If everything goes according to plan, China will become the second nation in the world, after the US, to have sent humans to the moon. The US made six Apollo crewed missions in the 1960s and 1970s, taking 12 Americans to the silver celestial neighbor.

In the long term, the country intends to construct a lunar scientific outpost to conduct extended explorations and technology demonstration operations, according to Zhang Hailian, deputy chief planner at the China Manned Space Agency.

"The moon is the nearest extraterrestrial body that humans can reach based on current technologies. Manned missions to the moon will be a realistic and practical step... to start with (in order) to expand our exploration endeavors in deep space. Meanwhile, it is scientifically meaningful for us to continue to explore the moon because it will help scientists better understand the origin and the evolution of the solar system as well as the composition of planets," he said.

Deep-space adventures

Beyond the moon, China has left its mark on another extraterrestrial body in the solar system — Mars — via the Tianwen 1 mission, which was launched in July 2020 as the country's first independent interplanetary expedition.

The landing craft of Tianwen 1 touched down on the Martian surface in May 2021 after traveling more than 470 million kilometers and going through an extremely challenging landing process. Soon after landing, it released a rover named Zhurong to perform scientific tasks.

Before Tianwen 1, no country had ever tried to send an orbiter, a lander, and a rover in one single flight to Mars.

Zhurong, the sixth rover deployed on the Red Planet, following five predecessors from the US, traveled more than 1,900 meters in its yearlong journey and obtained much data and many images en route to its destination — an ancient coastal area on Utopia Planitia, a vast Martian plain.

China plans to collect Martian samples and bring them back to Earth in around 2028 via another historic mission named Tianwen 3.

The main scientific goal of this mission is to look for traces of life on Mars, according to Liu Jizhong, chief planner of the Martian soil-return project.

He said in September that Chinese researchers "are working on essential technologies to be used in the robotic expedition such as sampling and liftoff on the Martian surface".

Chinese scientists have also placed two solar observation satellites in orbit. The spacecraft has achieved major scientific and technological feats that have helped scientists to deepen their knowledge of our nearest star.

The Chinese H-Alpha Solar Explorer, known as Xihe, was launched in October 2021 from the Taiyuan Satellite Launch Center in Shanxi province to become the nation's first space-based solar telescope. Its scientific payload is an H-Alpha imaging spectrograph that can, for the first time, acquire full-disk spectroscopic solar observations in the H-Alpha waveband.

Its primary task is to investigate the dynamics of solar activity in the lower atmosphere, namely the photosphere, and chromosphere, and to understand the physical mechanisms of solar eruptions. The mission is very meaningful to the nation's space exploration and satellite technology, mission planners said.

One year later, the second solar explorer, the Advanced Space-based Solar Observatory, or Kuafu 1, was launched from the Jiuquan Satellite Launch Center in Northwest China.

Carrying cutting-edge apparatus such as a full-disc vector magnetograph and a hard X-ray imager, the Kuafu 1 aims to explore connections among solar magnetic fields, solar flares, and coronal mass ejections.

China's Tiangong space station photographed from above by Shenzhou XVI crew members last year. (Photo/China Daily)

Orbital outpost

In a low-Earth orbit about 400 km above the ground, China's Tiangong space station has been traveling around the mother planet for about three years and seven months.

The origin of China's aspirations to operate its own space station can be traced back to the mid-1980s when a group of distinguished space scientists started calling for government support to open manned space programs so that China would not lag behind in the global arena of space exploration.

In 1986, the government launched what later became known as Project 863. The national high-tech project covered seven major fields, ranging from biology to new energy. It set two major goals for China's space sector: one was to build large carrier rockets and reusable aerospace vehicles; the other was to construct a space station.

In September 1992, a massive plan made by scientists for crewed spaceflights and a permanent space station was approved by the top leadership, officially beginning the nation's manned space program.

Since then, the Chinese space community has made specific plans and taken a systematic approach, advancing patiently from simple, multi-day missions to sophisticated, monthlong flights involving several spacecraft.

(From right) Shenzhou XIX crew members Cai Xuzhe, Song Lingdong and Wang Haoze salute the crowd at the Jiuquan Satellite Launch Center on Oct 30 before the mission. (Photo/Xinhua)

After nearly 30 years of preparations that included five unmanned flights and six crewed missions, China launched the first, and central, component of its space station, the Tianhe core module, in April 2021, and began to send astronauts to fly with it to perform trial operations and prepare for the arrival of other parts.

In the second half of 2022, the Wentian and Mengtian science modules were launched to dock with Tiangong, completing the space station's construction phase.

The Tiangong is one of the largest and most advanced structures ever deployed in Earth's orbit and is the only operating space station independently built by a single nation.

So far, eight crews have been sent to man the space station, including the incumbent Shenzhou XIX team, who arrived at the outpost in late October.

A rocket model is displayed at the Hainan International Commercial Aerospace Launch Center, as a rocket is launched at its adjacent Wenchang Space Launch Center in Hainan province, on June 29. (Photo/Xinhua)

Private power rising

Besides State-funded projects, China's private enterprises have become serious players in the space circle.

So far, five private companies — Space Pioneer, i-Space, LandSpace, Galactic Energy, and Orienspace — have used their own rockets to conduct orbital missions, which refer to powered flights that place satellites or other kinds of payloads in orbit in outer space.

Among the privately developed rocket models, LandSpace's ZQ 2 and Orienspace's Gravity 1 are most known because they set records in the global space sector.

In July last year, the ZQ 2 became the first methane-fueled rocket to successfully complete an orbital mission.

The rocket model's main propulsion system — the TQ 12 — is the first methane engine in China. Before Land-Space, only a handful of companies in the US had developed such engines.

Compared with traditional types of rocket engines that can function only once, a methane engine is reusable and more environmentally friendly.

In January, the Gravity 1 conducted its debut flight from a launch service ship off the coast of Haiyang in Shandong province, becoming the most powerful solid-propellant launch vehicle in the world and also the mightiest of all of Chinese private rocket types.

Private players have also come of age in the satellite field to become a flourishing seedbed for technological innovation and creativity.

GalaxySpace, a leading private satellite maker, built China's first satellite equipped with a flexible solar array and deployed it into space in July last year.

The satellite, Lingxi 03, is a plate-shaped communications satellite. It has a millimeter-wave multibeam digital payload, which features a transmission capacity of tens of gigabits per second.

In May, GalaxySpace cooperated with the Mahanakorn University of Technology in Thailand to establish a ground test station at the Thai university, marking the first trial of a low-orbit broadband internet communication network in the Southeast Asian country.