On Monday, a Long March 4B missile was launched from China’s Taiyuan Satellite Launch Center carrying a remote sensing satellite. This 50-year-old space port is located in north-central China, about 500 kilometers southwest of Beijing.
As often happens with the initial stages of Chinese missile launches from the Taiyuan inland facility, the spent Long March 4B booster fell downstream in the spaceport. In this case, it fell near a school, causing a large cloud of toxic gases to form.
Unlike most space ports in the world, many launch sites in China are located inland rather than near water to avoid such hazards. For security purposes, China built three major launch centers away from water during the Cold War, amid tensions with both America and the Soviet Union.
Some great footage from the return of the first stage of Long March 4B today.
– LaunchStuff (LaunchStuff) 7 September 2020
In recent years, China has begun experimenting with retinal fins to guide its missiles to the ground – and eventually boosters like SpaceX could land its Falcon 9. However, this project appears to be driven by a desire to master the technology of reuse rather than protect its population, where it took off. China has been from Taiyuan since 1968 with little interest in the nearby population.
To compound the problem of launching missiles in the early stages on the surrounding rural areas, China continues to use toxic hydrazine fuel in its early stages. Hydrazine, which is nitrogen bound together by hydrogen atoms, is an efficient and storable fuel. But it is also highly corrosive and toxic.
When the Crew Dragon The spacecraft exploded During a test in April 2019, it produced large clouds of toxic orange gas that could be seen for miles around Florida beaches. These reddish clouds are caused by nitrogen tetroxide, the oxidizer that burns with hydrazine fuel. This spacecraft – and many other vehicles in the past, including the Space Shuttle – used storable fuel for operations in space. NASA Work has been done To find “green” propellants that would avoid the need to use hydrazine even in space operations.
But it is different for missiles. The use of hydrazine as a launch vehicle fuel has been phased out in most parts of the world. The last major US missile to use hydrazine was the United Launch Alliance’s Delta 2 missile, which used toxic fuel in its second stage. This missile was decommissioned in 2018. The Russian backbone Proton missile uses hydrazine in its first and second stages.
However, the majority of the Chinese launch fleet is powered by hydrazine and nitrogen tetroxide. This includes the human-rated Long March 2F missile as well as the widely used Long March 4 family. All of these rockets, with their toxic early stages, are launched above the ground and have caused many accidents over the years. These fuels are inexpensive and relatively easy to use, and China naturally used them in the 1980s and 1990s when these boosters were developed. But today their use continues unabated.
China is changing slowly. Its new family of large missiles, the Long March 5 Fleet, is fueled by liquid oxygen and kerosene, like SpaceX’s Falcon 9 rocket. Ironically, however, Long March 5 rockets are usually launched from the Wenchang spacecraft launch site – over the ocean.