At 19:41:361 Beijing time on April 20, 2017, China's first cargo spacecraft, Tianzhou-1, was launched from the Wenchang Space Launch Center in Hainan province on the Long March 7 Yao-2 carrier rocket, and the mission was a complete success.
After liftoff, Tianzhou-1 will rendezvous and dock with space laboratory Tiangong-2 three times and test "space refueling" three times, that is, propellant replenishment experiments.
The first time was two days after Tianzhou-1 was launched, it docked with Tiangong-2 to complete the replenishment of propellant and clear the technical obstacles in energy supply for the construction and long-term operation of China's space station.
This process is through the pressure difference between the two spacecraft fuel tanks, and the propellant is automatically delivered from Tianzhou-1 to Tiangong-2.
After the first addition of the thruster, the combination will be a two-month flight, after which Tianzhou-1 will evacuate Tiangong-2 and dock with Tiangong-2 from the other side, because in the future, after the space station is in orbit, it will have several pairs, so this time it will have an autonomous flight.
The last meeting will test the rapid rendezvous and docking, the general rendezvous and docking takes two days, and the rapid docking only takes 6 hours, in preparation for the rapid rendezvous and docking of the space station in the future.
In the complex space environment, these behaviors are not easy to achieve, such as "space refueling" docking to be tightly sewn together, but also to be able to separate.
To this end, the design team added a controllable damper for buffering the impact energy to the second-generation docking mechanism, which not only did not affect its original capture performance, but also realized the large tonnage energy consumption requirements after the docking mechanism was captured.
The Shenzhou spacecraft and the Tiangong aircraft are both 8-ton spacecraft, and the rendezvous and docking of the two is already a difficult action.
The 13-ton "big man" Tianzhou-1 flew on orbit at 8 times the speed of the bullet flight, and it was difficult to "embrace" the same high-speed Tiangong-2 as gently as possible.
To measure whether the technology of cargo spacecraft is advanced, one of the main indicators is the "load-to-load ratio", that is, the proportion of cargo weight to the total weight of the entire spacecraft. The higher this value, the higher the carrying efficiency of the cargo spacecraft.
As the largest and heaviest spacecraft in China, Tianzhou-1 can send more than 6 tons of cargo to the space laboratory.
Even compared with the world's advanced active cargo ships such as Russia's Progress and the United States' Cygnus, tianzhou-1's material uplink capability is not inferior.
At the same time, it is also an application platform for space payloads, and has reached the international advanced level in many technologies such as refueling, flying around, rapid docking, and remote operation.