At 9 a.m. on April 24, 2024, the press conference of the Shenzhou-18 manned mission was held at the Jiuquan Satellite Launch Center, at which some information about the mission was announced, including the status of the mission and the astronaut crew.
When the Shenzhou 17 spacecraft was launched, the Shenzhou 18 spacecraft had already begun to become one of the focuses of everyone's attention. Because when the Shenzhou 17 spacecraft was launched, the Shenzhou 18 spacecraft and rocket began to be on standby to escort the three astronauts of Shenzhou 17.
With the smooth development of the Shenzhou 17 mission, everyone began to pay attention to the astronaut crew of the Shenzhou 18 mission, such as speculating whether there will be female astronauts, female commanders or foreign astronauts participating in this mission. Now the official announcement of the list of astronauts and the specific launch time of this mission, this mission has no female commander, and no female astronauts participated.
According to the news at the press conference, the mission is still carried out by three astronauts, and the flight crew is composed of astronauts Ye Guangfu, Li Cong, and Li Guangsu, of which Ye Guangfu serves as the commander of the mission.
The Shenzhou-18 spacecraft is expected to be launched on the evening of April 25, and preparations for the launch site are progressing steadily, and the Long March-2F Yao-18 rocket that carries out the launch of the Shenzhou-18 spacecraft is also ready to start propellant filling.
According to the plan, the Shenzhou-18 spacecraft will continue to use the autonomous fast rendezvous and docking method, and will arrive at the Chinese space station about 6.5 hours after launch, and take the radial docking method to rendezvous and dock with the space station, that is, the radial port docked in the core module of the space station Tianhe.
There are many ways to rendezvous and dock a spacecraft and space station assembly, each of which will have a different level of difficulty. For example, the Shenzhou-17 spacecraft, which is currently on a mission on the Chinese space station, is a forward port to connect to the core module of Tianhe, which should be relatively less difficult. The Shenzhou 18 spacecraft is a radial port connected to the core module of Tianhe, which will be more difficult.
The previous Shenzhou-14 manned spacecraft also used radial docking to dock at the space station, but at that time, China's space station had not yet completed the construction in orbit, and the docking space station assembly of the Shenzhou-14 spacecraft was 47 tons. With the completion of the in-orbit construction of China's space station, the tonnage of the space station assembly has also been increased to 90 tons.
The Shenzhou-16 spacecraft is also the radial port of the rendezvous and the core module of the Tianhe, which is the first radial rendezvous and docking mission carried out under the "T" configuration of the third module of the Chinese space station. Compared to the radial docking of Shenzhou-14, Shenzhou-16 is much more difficult, because its docking target weighs 90 tons, and now the Shenzhou-18 spacecraft will carry out the second radial rendezvous and docking under the "T" configuration of the Chinese space station.
When the Shenzhou-18 spacecraft successfully rendezvous and dock with the Chinese space station assembly, the astronauts will open the hatch of the return capsule and enter the orbital module of the spacecraft. After entering the orbital module, the astronauts will take off their spacesuits, change into cabin overalls, and then enter the Chinese space station through the interface channel. The Shenzhou-17 astronauts in China's space station greeted the arrival of the Shenzhou-18 astronauts.
The Chinese space station is once again full of 6 people
The Shenzhou-18 spacecraft is about to arrive! When the hatch is opened and we enter the space station, our space station will be even more lively, because the number of astronauts in orbit at the same time has increased from three to six, and our space station is once again full of six people.
Although there are 3 more astronauts than usual, our space station still meets the requirements, and the materials are enough for so many astronauts to live and work in orbit for a period of time at the same time, because our space station was designed and built with the requirements of 2 astronaut crews in orbit handover and rotation. In the Tianhe core module and the Wentian experimental module, there are three sleeping areas respectively, so when these spacecraft are in orbit at the same time, each astronaut can be guaranteed to have their own independent sleeping area and can rest after work.
Countdown to the return of Shenzhou 17
It's already late April, and according to the plan, the Shenzhou-17 spacecraft will return to Earth at the end of this month, so now the Shenzhou-17 mission is about to end. As with previous missions, Shenzhou-17 will also use fast return technology, that is, to reduce the number of orbits around the Earth after the spacecraft is evacuated from the Chinese space station assembly to shorten the return time to Earth. It took almost 28 hours for the Shenzhou-12 spacecraft to land from the Chinese space station complex, and now it only takes a few hours for the spacecraft to return to the surface with fast return technology.
In the first step, when the spacecraft is evacuated from the space station assembly, it will fly around the Earth, and it will take about 1.5 hours to orbit the Earth every time, and during the flight, the flight attitude will be adjusted to brake and slow down, so as to gradually reduce the orbital altitude, and at the same time, it will also separate from the orbital module.
In the second step, the engine of the propulsion module is activated to reduce the flight speed and descend from an orbit of about 400 kilometers, and when it is about 145 kilometers above the ground, the spacecraft's return capsule and propulsion module are separated, leaving only the return capsule, and the astronauts are returning to Earth in the return capsule.
In the third step, after the separation of the propulsion module is completed, the spacecraft return module becomes a single-cabin state, and the return module also needs to adjust the flight state, and when the return module descends to 100 kilometers, it will begin to re-enter the earth's atmosphere. Due to the high speed of the spacecraft return capsule and the dense atmosphere of the earth, when the spacecraft return capsule quickly returns to the earth, the aerodynamic heating effect is very strong, and the outside temperature is quite high, reaching one or two thousand °C, and the outside of the entire spacecraft return capsule is like being surrounded by raging fire.
This process is actually very thrilling, because ordinary materials are unbearable, such as those satellites, rocket wreckage, and probes will burn violently in the atmosphere and turn into ashes, but the spacecraft return capsule will not be burned out, so you don't need to worry.
In the fourth step, open the parachute to decelerate further. After passing through the atmosphere, the speed of the spacecraft's return capsule drops from nearly 7.9 kilometers per second to about 200 meters per second, but this speed is still very fast, so when the return capsule descends to 10 kilometers above the ground, it will open the parachute for the next step of reduction, which can reduce the speed of the return capsule to about 3.5 meters. When the spacecraft's return capsule is still 1 meter above the ground, the four thrust reversers installed at the bottom of the return capsule will be activated to further reduce the speed of the spacecraft's landing and successfully complete the landing.