A Long March-7 rocket carrying the cargo spacecraft Tianzhou-1, China's first cargo spacecraft, takes off from Wenchang Spacecraft Launch Site in Wenchang, South China's Hainan province, on Thursday. Photo: IC
China's first cargo spacecraft, Tianzhou-1, was launched successfully at 7:41 pm Beijing Time Thursday, a crucial step for the country to build a space station by approximately 2022.
Lifted by a Long March-7 Y2 carrier rocket, Tianzhou-1 roared into space from Wenchang Space Launch Center in Hainan Province on Thursday evening.
The cargo ship will dock with the orbiting Tiangong-2 space lab, provide fuel and other supplies, and conduct space experiments before falling back to Earth. The launch of Tianzhou-1 was a "zero-window" mission, which means it had to be launched at precisely 7:41:28 pm, with no room for error, China Central Television reported.
The cargo ship is 10.6 meters long and has a maximum diameter of 3.35 meters. Its maximum takeoff weight is 13.5 tons, allowing it to carry over 6 tons of supplies. Tianzhou-1 is larger and heavier than Tiangong-2, which is 10.4 meters in length and has a maximum diameter of 3.35 meters, weighing 8.6 tons, the Xinhua News Agency reported.
"Tianzhou-1's cargo usually includes space food, medicine, water and so on, for three people's use for 30 days, but this time it is a unmanned flight, so we put simulated cargo that weighs the same in the spacecraft," Huang Weifen, deputy chief designer of China's manned space project astronaut system, told the Global Times.
The biggest challenge of this mission is that new spacecraft, new rockets and the new launch site need to match each other, Xu said. When Tianzhou-1 completes its mission, it will make an automatic destructive re-entry into Earth's atmosphere.
"This shows that China's environmental awareness of space has improved, and this is a good attempt to reduce space junk. Tianzhou-1 will fall into the South Pacific under our control when its mission ends," Xu said.
Bai Mingsheng, chief designer of the cargo ship, told Xinhua that the cargo aboard the spacecraft weighs almost the same as the ship, exceeding the load capacity of Russian cargo ships in active service. If the Tianzhou-1 mission is successful, China will become the third country besides Russia and the US to master the technique of refueling in space.
"In general, Tianzhou-1's technology is definitely in the first-class around the globe, at the same stage as Russia and the US. Although Europe and Japan also have their own cargo spacecraft and their payload capacity is bigger than Tianzhou-1, they heavily rely on US and Russian technological support in various aspects," Song Zhongping, a military expert who served in the Second Artillery Corps (now known as the PLA Rocket Force), told the Global Times on Thursday.
From launch to automatic destruction, China's Tianzhou-1 doesn't need to rely on any other country's facilities or technology, and compared to the US' Cygnus and Dragon, its payload capacity is bigger and technologically more reliable and advanced in general, Song said.
China aims to build a permanent space station that is expected to orbit for at least 10 years, and the maiden voyage of the cargo ship is important as it will be a courier to help maintain the space station. Without a cargo transportation system, the station would run out of power and basic necessities, causing it to fall back to Earth before the designated time, Xinhua reported.
Currently, the only space station is the International Space Station (ISS), which was mainly pushed by the US and Russia and was launched in 1998. It should reach the end of its mission in 2020, but the US and Russia might decide to extend its lifetime a little bit, Song said.
According to previous reports in the Global Times, in order to prevent China from sharing in advanced space technology, the US always refused any attempt from China to join the ISS program, despite efforts China made in 2000.
"But we are going to have our own space station very soon. After 2020, China's Tiangong will very likely become the only space station in service, and will provide services to more developing countries so more countries can benefit from humanity's achievements in space technology," Song said.