China's Space Program: Ambitious Achievements Amid Dangerous Designs

China's space program, while marked by impressive achievements, has also been plagued by serious issues stemming from questionable engineering decisions and a lack of transparency. One notable problem is the country’s repeated use of hypergolic fuels, which pose significant health risks to local populations when rocket stages fall back to Earth. In June 2024, a Long March rocket booster crashed near a Chinese village, just one of many incidents where rockets have dangerously re-entered over populated areas, often releasing clouds of toxic gases. These incidents are not accidental. The falling rocket stages are by design due to where China launches many of its rockets. Rather than launching east from its coastline, where rockets could safely land in the Pacific Ocean, China’s most active launch site, the Xi Chang Satellite Launch Center, is located inland in a mountainous region. This location was originally chosen to protect the site from military threats, as it was first a missile testing base. However, the geographical consequence is that every launch risks debris falling on villages east of the site.

The dangers don’t end with the crashes. The early versions of the Long March rockets, which are still in use, burn hypergolic propellants like unsymmetrical dimethyl hydrazine as fuel and nitrogen tetroxide as an oxidizer. These chemicals are extremely toxic. Nitrogen tetroxide turns into nitrogen dioxide at higher temperatures, giving the Long March rockets their distinctive orange hue. When nitrogen dioxide interacts with water, it forms acids that can cause severe damage to lung tissue. Meanwhile, the hydrazine fuel is a carcinogen that is also highly reactive with metals, posing long-term health risks to those exposed. Despite these dangers, China continues to use these fuels, even though safer alternatives exist. The Chinese government takes minimal steps to mitigate the risk, advising villagers in the path of falling debris to “adjust your location quickly.”

China’s approach to space exploration has made them something of an outlier in the international space community. In 1996, a Long March 3B carrying a U.S. telecommunication satellite crashed shortly after launch, tragically hitting a nearby village. The Chinese government reported six casualties, but this number has been widely questioned, with concerns about the true extent of the damage and deaths caused by such incidents. Beyond these tragedies, China’s space program has also been criticized for its recklessness on the global stage. In 2007, China destroyed one of its own satellites with a missile, creating a significant amount of space debris and showcasing its military capabilities. This led the U.S. to pass the Wolf Amendment, which prohibits NASA from collaborating with the Chinese space agency, effectively barring China from participating in the International Space Station (ISS) program.

Despite these challenges, China has made remarkable progress. In response to their exclusion from the ISS, China developed its own space station program. The first step was launching Tiangong 1 in 2011, followed by Tiangong 2 in 2016. These prototypes tested key technologies such as refueling and cargo transfer. By April 2021, China began constructing its own permanently crewed space station, Tiangong, which was completed in 2022. The station, featuring three modules and two robotic arms, represents a significant technological achievement, though it is smaller and lighter than the ISS. Alongside this, China has been developing new rockets, such as the Long March 5, to reduce its reliance on dangerous hypergolic fuels. The Long March 5 uses liquid oxygen and kerosene for its main stage and liquid hydrogen and oxygen for its upper stage, offering a safer alternative. However, the Long March 5B, used for low Earth orbit missions, has its own risks. The 5B’s core stage functions as both the first and upper stages, meaning it reaches orbit and re-enters uncontrollably, posing a risk to populated areas across the globe.

Between 2021 and 2022, three of these uncontrolled re-entries occurred during the construction of the Tiangong space station, with debris landing in countries as far away as the Ivory Coast. This issue is not confined to China, as other nations had to close airspace and issue warnings due to potential falling rocket parts. These re-entries are now among the largest uncontrolled re-entries in history, drawing criticism from international leaders, including NASA’s administrator, who urged spacefaring nations to minimize risks to people and property from space debris.

China’s space ambitions also extend beyond human spaceflight. The nation has built its own global positioning system after the U.S. jammed GPS signals to a Chinese ship in the early 2000s. China initially launched four satellites for regional coverage, and after the European Space Agency withdrew from a partnership fearing military use, China expanded its constellation to 65 satellites, creating the largest global positioning system in orbit. These achievements, alongside their landing of a rover on Mars and plans for lunar exploration, demonstrate China’s determination to establish itself as a dominant force in space. Yet, their rapid progress is often accompanied by controversial practices and designs that continue to raise safety and ethical concerns on the global stage.