China has postponed the return of three astronauts from its space station, citing a suspected debris strike on their spacecraft. The decision, announced by the China Manned Space Agency (CMSA) on Wednesday, prioritizes the health and safety of the crew.
The Delayed Mission and Crew Details
The Shenzhou-20 mission, launched from the Jiuquan Satellite Launch Center in northern China’s Gobi Desert on April 24, marked the 35th flight in China’s manned space program. Mission commander Chen Dong, alongside crewmates Chen Zhongrui and Wang Jie, have spent approximately six months in orbit at the Tiangong space station. Their return to the Dongfeng Landing Site in Inner Mongolia had been anticipated for Thursday.
Investigating the Spacecraft Strike
The CMSA is currently conducting an analysis and risk assessment following the suspected strike. A crucial aspect of the investigation is to determine if the impact has compromised any critical systems of the Shenzhou-20 spacecraft, potentially jeopardizing a safe re-entry into Earth’s atmosphere.
Growing Risks of Space Debris
The incident highlights a broader issue: the increasing problem of space debris. As more satellites are launched, the risk of collisions—and the creation of even more debris—increases significantly. Rocket fragments are a primary contributor, often remaining in orbit long after a satellite’s mission is complete. Furthermore, antisatellite tests, which deliberately destroy satellites, generate large volumes of space junk. China’s 2007 destruction of a weather satellite remains a significant example, with scientists still tracking the resulting debris.
“You don’t see them, and they are deadly,” said Christophe Bonnal of the International Academy of Astronautics.
The Threat of Small Debris
While larger objects are tracked to avoid collisions, numerous smaller pieces—micrometeoroids and debris—pose a serious threat. Even an object as small as 1 millimeter can cause substantial damage due to its velocity in space. Traveling at speeds of around 100 kilometers per hour, such a tiny object can have the same impact as a bowling ball. Scientists estimate that approximately 130 million such objects are orbiting the Earth.
Increased Collision Probability
The probability of collisions has risen in recent years, partly due to the deployment of large satellite constellations like SpaceX’s Starlink and China’s Qianfan and Guowang. As Bian Zhigang, vice administrator of China’s National Space Administration, stated, “We can see there are more risks.”
China’s Response to Space Debris
China is actively researching solutions, including “the active removal of space debris on orbit,” as Bian Zhigang noted at the International Astronautical Congress. In extreme scenarios, China’s space agency has indicated the possibility of launching a standby emergency spacecraft to rescue astronauts, potentially sending an unmanned craft to the space station to facilitate the Shenzhou-20 crew’s return.
China’s Rapid Ascent in Space Exploration
After a two-decade period of relative stagnation following its first satellite launch in 1970, China’s space program has experienced a remarkable resurgence. Jonathan McDowell, an astronomer and expert on space exploration, points out that China has risen from fourth to second place globally, rivaling the United States.
“They have now moved to this era of permanent human occupation,” Mr. McDowell said, referring to the fact that the space station always has a Chinese astronaut. “That is a really impressive achievement from a late starter.”
Crew Activities and Station Operations
During their six-month mission, the Shenzhou-20 crew conducted spacewalks, managed cargo deliveries, and performed various scientific experiments. The crew was replaced last week by a relief crew aboard the Shenzhou-21 spacecraft, and both vessels are currently docked at the Tiangong station.
The decision to delay the return of the Shenzhou-20 astronauts underscores the growing challenges posed by space debris and the importance of prioritizing astronaut safety. China’s continued investment in space exploration and its proactive approach to debris mitigation position it as a key player in ensuring the long-term sustainability of space activities.
