Successful return to Earth is a multi-step process, not a direct return to Earth. It is understood that from the separation of the Shenzhou XIII spacecraft from the core module of the space station to the final return to the ground, the journey of the space trio to go home has gone through more than 390 kilometers and took more than 9 hours.
The process of the return capsule returning to earth.
Fast return needs to meet stricter parameter conditions. It is precisely because of the existence of the space station that the state of the spacecraft can be set and adjusted in advance, and Shenzhou XIII has the ability to return quickly.
After the flight around, the return capsule of Shenzhou XIII officially entered the "speed of life and death" lasting about 48 minutes: before descending the orbit, Shenzhou XIII first separated the orbital module from the return capsule. Then start the engine, and the spacecraft will gradually descend in altitude. Before entering the atmosphere, the propulsion module will separate, and the return module will enter the return orbit.
When the spacecraft's return capsule descends to about 0/00 km from the ground, it will enter the atmosphere, causing fierce friction with the air, the temperature at the bottom will rise to thousands of degrees Celsius, surrounded by flames, and vibration and noise overload will occur in the capsule.
When it is 80 kilometers from the ground, the return capsule will also enter the "black barrier area" and temporarily lose contact with the ground within 4-6 minutes.
Finally, at a height of about 10 km from the ground, the return cabin opens the guide umbrella, the deceleration umbrella and the main umbrella in turn, and throws away the heat-proof outsole. At about 1 m from the ground, the four thrust motors at the bottom of the return capsule ignited, and the descending speed dropped to about 2 meters per second, and finally landed safely.