Shenzhou-20 Crew Completes Second Tiangong Spacewalk, Upgrading Shields and Robotic Arm

Six and a Half Hours of Work Outside Tiangong

China's Shenzhou-20 astronauts completed their second spacewalk on June 26, 2025, installing protective shielding and upgrading equipment outside the Tiangong space station. Among the changes were adapters for its robotic arm platform that are expected to shorten future spacewalks by approximately 40 minutes.

Mission commander Senior Colonel Chen Dong and Colonel Chen Zhongrui carried out the work outside, while Colonel Wang Jie supported them from inside the station. Ground controllers assisted throughout the operation, and Tiangong's robotic arm helped move astronauts and equipment between work sites.

Chen Zhongrui opened the hatch of the Wentian experiment module at 3:04 a.m. Eastern Time, or 0704 UTC. Chen Dong joined him two hours later. Both wore Feitian suits designed for extravehicular activity, or EVA, the technical term for working outside a spacecraft.

The astronauts returned to Wentian at 9:29 a.m. Eastern Time, or 1329 UTC, after an operation lasting approximately six and a half hours. They completed tasks that included installing debris protection, inspecting and upgrading external equipment, and fixing components on the station's exterior.

The work came roughly two months into a planned mission lasting six months. As of June 30, the crew had completed two spacewalks while continuing scientific research, station maintenance and educational activities. The second operation added protection to the station and changed how astronauts will prepare to use its robotic arm during future work outside.

Adapters Aim to Save 40 Minutes

The installation of automated foot restraint adapters and interface adapters on Tiangong's robotic arm platform was one of the spacewalk's main upgrades. Foot restraints hold astronauts in position while they work, and the interfaces connect equipment to the platform.

Li Xuedong, lead designer of the space station system at the China Aerospace Science and Technology Corporation (CASC), described the preparation required during earlier spacewalks:

In the previous spacewalks, astronauts had to install foot limiter and operation platform on the robotic arm's end effector before and after exiting the module, and then rely on the arm to transport them to the work site.

The end effector is the working end of the robotic arm, where equipment attaches. The new adapters automate steps that previously required astronauts to install the foot restraint and operating platform themselves.

The expected saving of approximately 40 minutes would give crews more time for their assigned work during a spacewalk. The changes are also intended to make operations safer, more efficient and less physically demanding.

Tiangong's robotic arm serves as a means of transport as well as a support system. During the June 26 operation, it helped the astronauts reach different locations on the station's exterior and move the equipment needed for their tasks.

Shielding, Inspections and Repairs

Chen Dong and Chen Zhongrui installed additional debris protective shielding to help safeguard Tiangong against micrometeoroids and orbital debris. Micrometeoroids are tiny natural objects in space, while orbital debris refers to material left in orbit.

The astronauts also inspected external equipment and carried out maintenance to keep the station's systems functioning safely. Their assignments included upgrading equipment, repairing or replacing components as needed, and checking the condition of systems exposed outside the station.

The operation combined several kinds of work:

• Installing additional shielding against micrometeoroids and orbital debris.
• Inspecting and maintaining equipment outside the station.
• Fitting automated foot restraint adapters and interface adapters to the robotic arm platform.
• Fixing or replacing components to maintain the station's operation.

Wang Jie coordinated support from inside Tiangong while the two astronauts worked outside. Together with assistance from ground controllers, that division of responsibilities allowed the crew to complete all the assigned tasks.

The shielding and equipment maintenance addressed the station's continuing protection and upkeep. The robotic arm modifications addressed the way later spacewalks will be conducted, reducing the amount of preparation astronauts must complete before concentrating on their work.

A Veteran Commander and Two New Space Travelers

Senior Colonel Chen Dong is on his third spaceflight and serving as mission commander for the second time. With the June 26 operation completed, he had carried out five spacewalks, placing him among China's most experienced astronauts in work outside a spacecraft.

Chen previously commanded Shenzhou-14, the mission that oversaw the arrival of Tiangong's two experiment modules, Wentian and Mengtian. His current assignment brings that experience to the maintenance and operation of the expanded station.

Colonel Chen Zhongrui, a former air force pilot, is on his first mission to orbit. His mechanical expertise and piloting skills have contributed to the crew's spacewalk activities as he adapts to working in space.

Colonel Wang Jie is also a member of the three-person crew and previously worked as an engineer at CASC. During the second spacewalk, he managed systems and helped coordinate the operation from inside Tiangong.

The crew launched aboard Shenzhou-20 on April 24, 2025, from the Jiuquan Satellite Launch Center in northwest China. Their spacecraft docked with Tiangong six and a half hours later, beginning a stay planned to last six months and devoted to research, maintenance and international outreach.

From Launch to the Second Spacewalk

The June operation followed the crew's arrival in April and its first spacewalk earlier in the mission. The main dates and times show how the second outing fits into their stay:

• April 24, 2025: Shenzhou-20 launched from Jiuquan with Chen Dong, Chen Zhongrui and Wang Jie aboard.
• Six and a half hours after launch: The spacecraft docked with Tiangong.
• June 26, 2025, at 3:04 a.m. Eastern Time, or 0704 UTC: Chen Zhongrui opened Wentian's hatch for the second spacewalk.
• Two hours later: Chen Dong joined Chen Zhongrui outside the station.
• June 26, 2025, at 9:29 a.m. Eastern Time, or 1329 UTC: The astronauts returned to Wentian after approximately six and a half hours of operations.
• June 30, 2025: The crew was about two months into its planned mission lasting six months, with further research and maintenance ahead.

The two astronauts working outside and Wang Jie working inside had different assignments within the same operation. The robotic arm and ground support connected those activities, helping the crew complete work across the station's exterior.

Three Modules Form the Station

Tiangong, whose name means "Heavenly Palace," orbits Earth at an altitude described as between 217 and 280 miles, or 340 to 450 kilometers. Its three main modules provide the living quarters, control systems and laboratories used by the crew.

Tianhe, the core module, launched in April 2021. It serves as the station's main habitat and control center, with regenerative life support systems, propulsion and docking hubs for visiting spacecraft. Regenerative life support systems recycle resources to help sustain the people aboard.

Wentian, added in July 2022, provides further crew quarters, scientific experiment racks and the airlock used for spacewalks. Its robotic arm, measuring five meters, supports astronauts during EVA operations and assists with module positioning.

Mengtian launched in October 2022, expanding Tiangong's research capabilities and living space. Chen Dong's earlier Shenzhou-14 command included overseeing the arrival of both experiment modules.

The station is designed to remain continuously inhabited by at least three astronauts for a decade or more. It supports research in life sciences, microgravity physics and new space technologies, alongside the regular maintenance needed to keep a permanent workplace operating in orbit.

Tiangong's configuration brings accommodation, laboratories, life support and robotic systems together in a modular structure. China plans to add more modules in the coming years, potentially doubling its size and research capacity.

Experiments on Health, Organisms and Materials

The Shenzhou-20 crew's mission includes nearly 60 experiments and technology demonstrations. Their work ranges from studies of living organisms to investigations of materials, life support systems and cooperation between people and robots.

Life science research includes microbiota, nutrition metabolism and bone health. Microbiota are communities of microorganisms, while nutrition metabolism concerns how living bodies process nutrients. Advanced instruments, including Raman spectrometers, are being used in these studies.

Experiments involving zebra fish and planarians examine regeneration and the effects of microgravity on living organisms. Regeneration means the ability to regrow or repair parts of a body. Microgravity is the condition in orbit in which objects and astronauts appear almost weightless.

The crew is also conducting biotechnology work with streptomyces bacteria. Those experiments assess how microgravity affects microorganisms and prepare samples for further study on Earth.

Microgravity physics investigations examine the behavior of fluids, materials and biological samples in low Earth orbit. Studying them in that environment allows the crew to explore how they behave under conditions different from those on the ground.

Technology testing includes regenerative life support systems, materials with superconducting properties at high temperatures, and intelligent robotics. The astronauts interact with an intelligent spaceflight robot called "Xiao Hang" to explore how humans and robots can work together in space.

The research contributes to scientific knowledge while helping prepare for longer missions, including possible exploration of the moon and deep space. The crew's maintenance duties support that research by keeping Tiangong's equipment and working environment ready for continued use.

Records and International Outreach

China has expanded its human spaceflight operations through regular crewed missions, spacewalks and scientific experiments since the first Tiangong module launched in 2021. The Shenzhou-20 mission continues that effort to establish the country as a major participant in human spaceflight.

The program's records include a Chinese spacewalk lasting 8.5 hours and four EVAs by the Shenzhou-15 crew, the most completed by a single Chinese crew. The second Shenzhou-20 outing lasted approximately 6.5 hours, about two hours less than the longest Chinese spacewalk.

China's approach combines independent operation, technological development and international outreach. Tiangong is the only operational space station independently run by a single nation. China is outside the International Space Station partnership because of U.S. legal restrictions.

International engagement remains part of Tiangong's activities. China recently involved students and scientists from Hungary in a live "Tiangong Classroom" event, extending the station's educational work beyond its own borders.

The Shenzhou-20 crew's planned activities include further educational outreach alongside research and maintenance. Those events make the astronauts' work accessible to audiences on Earth while the station continues to operate as an orbiting laboratory.

A Smaller Station With Plans to Grow

Tiangong has about 20% of the mass of the International Space Station (ISS). Its three modules nevertheless provide living and working space for its crew, supported by advanced life support and robotic systems.

The ISS is a joint project involving the United States, Russia, Europe, Japan and Canada. Tiangong is operated solely by China, allowing the country to set its research agenda and mission schedule while pursuing international partnerships on its own terms.

Continuous occupation and regular crew rotations are central to China's permanent human presence in low Earth orbit. The planned addition of modules would expand the station's size and the amount of research it can support.

China also plans a large space telescope named Xuntian. Rather than remaining attached to the station, it will share Tiangong's orbit and dock for maintenance. That arrangement would allow the station to support the telescope's upkeep.

Xuntian's planned camera has 2.5 billion pixels, and the telescope is intended to survey 40% of the sky over a decade. The project would add astronomical research to the scientific work supported by Tiangong.

The combination of possible module expansion and a telescope able to visit for maintenance extends the station's intended role beyond its current three-module configuration. Its existing laboratories, crew facilities and robotic equipment provide the basis for those plans.

Supplies, More Spacewalks and Lunar Plans

Chen Dong, Chen Zhongrui and Wang Jie will continue their planned stay with further experiments, technology demonstrations, maintenance tasks and spacewalks. Educational outreach also remains on their schedule.

On Earth, preparations are underway for the Tianzhou-9 cargo spacecraft, which will deliver fresh supplies and equipment to Tiangong. No launch date is given for that delivery, and no dates are specified for the crew's next spacewalks.

China's broader plans include expanding Tiangong and training new astronauts, including the first from Hong Kong and Macao. The country is also developing the Mengzhou spacecraft for larger crews and potential missions to the moon.

China aims to land astronauts on the moon before 2030. It also plans to establish a sustained lunar presence through the International Lunar Research Station (ILRS) project.

The immediate work aboard Tiangong remains concrete: maintain the station, carry out nearly 60 experiments and technology demonstrations during the mission, and prepare for continued operations. The June 26 spacewalk contributed by adding debris protection and installing equipment expected to reduce preparation time during future outings.

Key Points

• Shenzhou-20 completed its second spacewalk on June 26, 2025, in approximately six and a half hours.
• Chen Dong and Chen Zhongrui worked outside Tiangong, with Wang Jie supporting them from inside.
• The crew installed debris shielding, inspected external equipment, fitted robotic arm adapters and repaired components.
• The new adapters are expected to shorten future spacewalks by approximately 40 minutes.
• Chen Dong has now completed five spacewalks and is on his third spaceflight and second command.
• The crew launched on April 24 for a planned stay lasting six months, with nearly 60 experiments and technology demonstrations.
• Tianzhou-9 is being prepared to deliver supplies and equipment, while more maintenance, spacewalks and outreach are planned.
• China plans to expand Tiangong, develop the Xuntian telescope and Mengzhou spacecraft, and land astronauts on the moon before 2030.