Last month, the Chinese space agency successfully launched its first and largest module of its upcoming Tiangong-3 space station into orbit. The module, called Tianhe, is now floating in orbit, where it awaits the next ten rocket launches that will ferry the space station’s remaining pieces for eventual construction. Chinese state media has since released video footage of the module reaching into orbit, which is available on its CGTN YouTube channel.
After being effectively blocked from joining the International Space Station by the United States, China has moved ahead with its own, much smaller facility. While the ISS is around 420 metric tons, the T-shaped CSS will be around 66 tons, making it more comparable to Russia’s Mir space station.
This module replaces conventional thrusters with four ion thrusters (also known as Hall effect thrusters), which use electrical charges to create a thrust by accelerating ions. When fired up, the ion drive produces bluish fumes and halo rings that are caused by extremely hot, electrically charged particles leaving the engine running at 30-plus times the speed of sound. These charged particles can degrade engine components, reducing satellite longevity and possibly putting astronauts at risk. Moreover, the thrust is usually fairly low.
However, the Chinese Academy of Sciences says they have found a way to make this approach work. The scientists put the thrusters through rigorous testing to make sure the engines could resist the damage caused by the particles. By putting a magnetic field over the engine’s inner wall to repel damaging particles, they were able to protect the engine from erosion. They also developed a unique ceramic material designed to withstand severe heat or radiation for an extended period of time.
Futurism reports that the module could soon become the first spacecraft in history to transport humans using this technology. Ion drives are orders of magnitude more efficient compared to chemical propulsion. To keep the International Space Station in orbit for a year, the thrusters consume four tons of rocket fuel. With ion thrusters, it would need just 400 kilograms to stay in orbit for the same amount of time, according to the Chinese Academy of Sciences.
China is betting big on ion thrusters, hoping to use them not just for its space station but also for upcoming satellite constellations and nuclear-powered spacecraft capable of carrying astronauts to Mars as well, according to South China Morning Post.
With existing rocket technology, a crewed trip to Mars would take more than eight months and would need a spaceship large enough to carry sufficient fuel and other supplies. However, some researchers calculate that a craft powered by a 200-megawatt ion drive array could shorten the journey time to just 39 days and allow the mission to use smaller vessels or carry more supplies.
The space station will provide China with a wealth of human spaceflight experience over the next decade. At the same time, the country is engaging in robotic lunar exploration. The two projects seem likely to converge to allow China to send astronauts to the moon in the 2030s.