China says its space station – seen in new photos – is preparing for growth – Ars Technica

China released new photos of the Tiangong space station on Tuesday, as Chinese astronauts and space officials made a public relations visit to Hong Kong. These photos, taken about a month ago, show the Tiangong complex in its fully assembled configuration with three modules manned by three crew members.

A departing crew of three astronauts captured new panoramic views of the Tiangong station in low Earth orbit on October 30, shortly after leaving the outpost to head to Earth at the end of a six-month mission. These are the first scenes showing the Tiangong station after China completed the assembly of its three main units last year.

The basic Tianhe unit is located in the center of the complex. It was launched in April 2021 with crew accommodation and life support systems for the astronauts. Two experiment modules, Wentian and Mingtian, were launched in 2022. The first team of Chinese astronauts arrived at the station in June 2021, and Tiangong has been permanently staffed with rotating three-person crews since June 2022.

One of these crews completed its six-month mission at Tiangong Station on 30 October. The Shenzhou 16 ferry ship backed away from Tiangong, then flew autonomously in a circle around the outpost while the astronauts floated near the windows of their camera-equipped spacecraft to “check it out.” The Chinese Manned Space Agency said: “A panoramic image of the space station assembly with Earth as the background.”

Power-generating solar arrays at Tiangong dominate the views captured by the Shenzhou 16 astronauts. These solar panels span more than half the length of a football field, from end to end.

It turns out that China may not have finished building the Tiangong station. In statements last month, officials outlined plans to add three more pressurized compartments to expand the Chinese space station in the coming years.

Tiangong, which means “Heavenly Palace”, will become a center for experiments, technology demonstrations, spacecraft assembly and satellite service, said Zhang Qiao, a researcher with the China Academy of Space Technology. CAST is part of a network of state-owned contractors that build rockets and spacecraft for China’s space program.

“We will build a batch of six 180-ton modules in the future,” Zhang said at the International Astronautical Congress last month.

Tiangong twice

In its current configuration, the mass of Tiangong is approximately 69 metric tons, not including the visiting crew and cargo vehicles. This is equivalent to about one-sixth the mass of the larger International Space Station, which was built in a partnership between the United States, Russia, Europe, Japan and Canada. Chinese officials claim that their space station, although much smaller than the International Space Station, has the capacity to conduct almost all scientific experiments.

“This indicates that the Tiangong Space Station has high efficiency in supporting applications,” Chinese aerospace engineers wrote in an article. A paper published earlier this year in Space: science and technologyan open access journal and sister publication of Science.

Now China is making a long-term commitment to the Tiangong programme, as part of a plan to double the size of the space station. Chinese space officials originally said the space station would operate for 10 years. Last month, officials said the age will now extend to 15 years or more.

This means that the Tiangong Space Station will continue to operate until at least the mid-2030s, several years after the ISS’s planned decommissioning in 2030, and more than 30 years after the launch of the ISS’s oldest module. NASA’s strategy is to partner with commercial industry to develop a smaller space station to replace the International Space Station in low Earth orbit. The idea is that operating a commercial space station would be cheaper than the International Space Station, and NASA and other government space agencies could buy access to the privately owned site for astronauts and scientific experiments.

NASA is not sure that commercial space stations will be ready by the time the International Space Station is scheduled to be retired. There will likely be a gap between the end of the International Space Station and the arrival of a commercial site in low Earth orbit, a senior NASA official said recently. “Personally, I don’t think it would be the end of the world,” said Phil McAllister, director of the Commercial Spaceflight Division at NASA Headquarters.

Like the United States, China is moving forward with its plans to send astronauts to the moon by 2030. The US space agency wants to free itself from the cost – more than $3 billion annually – of operating the International Space Station in low Earth orbit. To provide funds for missions to the Moon, and eventually to Mars.

China appears to want to keep its government-owned space station in low Earth orbit at the same time as it carries out an ambitious lunar exploration programme. As the United States and China race to reach the moon, China may be the only country with a continuing human presence in orbit closer to Earth.

Tiangong is already equipped with an airlock to allow astronauts to head outside the station on spacewalks, robotic arms to move equipment around the exoskeleton, and experiment racks to support research in human physiology, microgravity physics, astronomy, Earth sciences, and technology demonstrations . . It also has electric propulsion motors to maintain its altitude in a more fuel-efficient manner than if it used traditional rocket engines.

China’s plans for the station and a new telescope

China is building a large astronomical observatory similar in size to the Hubble Space Telescope for launch in 2025. This new telescope, called Xuntian, will fly in orbit close to the Tiangong station, allowing it to dock periodically with the complex for servicing and refueling. . Zhang said more spacecraft “will likely fly in co-orbit” with the Chinese space station in the future.

Then, perhaps around 2027, China plans to launch an “expansion module” to be installed on the forward end of the space station’s core module. This expansion module will bring more docking ports to the station, opening it up for further expansion to about a third of the ISS’s mass. The six-module final station could include an inflatable habitat for more volume, and serve as a test bed for a future inflatable habitat on the moon, according to Zhang.

He said: “The Chinese space station will operate in orbit for a long time, more than 15 years.”

Liu Congming, who helps supervise scientific research at Tiangong, said more than 100 research projects have been started on the space station. He said at the International Astronautical Congress in early October that 65 of them have been implemented, and 48 are still in progress.

Chinese officials have issued a call for international cooperation on the Tiangong Space Station. China has 10 cooperative research projects with the European Space Agency, according to Liu, and there are opportunities for other countries to provide individual experiments, new technologies such as robotic weapons or life support, and even entire international units to join the Tiangong complex.

Long walk

The launch of the Xuntian telescope and the potential addition of three new modules to the Tiangong station will require more flights of China’s Long March 5B rocket, a heavy lifter that is unique among launch vehicles because it does not need an upper stage for placement. Payload to orbit. This means that the massive core stage of Long March 5B enters the same orbit. In previous launches that carried large portions of the Tiangong station, the Long March 5B rocket’s core stage remained in orbit for several days to several weeks until atmospheric drag naturally pulled the rocket back to Earth.

Most of the rocket burned up during reentry, but this booster stage is so massive that large fragments fell to land or into the sea intact. This sparked protests from US officials, including NASA Administrator Bill Nelson, who cited the risk of injury, death, or property damage from falling metal from Long March 5B.

Unless China redesigns parts of the Long March 5B core stage, we may see the skies again as expansion modules ascend to the Tiangong station.