Shenzhou 13 3 astronauts "home" is imminent!
According to the original plan, the three astronauts of Shenzhou 13 will work and live in orbit on the mainland space station for about 180 days, and now they have been working and living for more than 5 months, and now it is time to go home, and this week the astronauts have also begun to prepare for "going home"!
Like Shenzhou 12, the return landing site of the 3 astronauts of Shenzhou 13 still chose the Dongfeng landing site, in order to successfully welcome back the 3 astronauts, the search and rescue team has begun to carry out a targeted exercise at the Dongfeng landing site, and further improve the search and rescue plan in different complex terrain environments.
It should be known that the Dongfeng landing field has 20,000 square kilometers, and the terrain of the Dongfeng landing field is complex and diverse, with desert, Gobi, mountain and other environments.
The Siziwangqi landing field is different, its area is only more than 2,000 square kilometers, which is 1/10 of the Dongfeng landing field, and the area is smaller, which means that the search area is smaller and the search work is simpler.
And the Landing Site of the Four Sons King Banner is flat and open, there is no large river and lake, it belongs to the grassland environment, there is vegetation cover, from the geographical point of view, the Four Sons King Banner landing site is obviously easier to search and rescue, so why does Shenzhou Thirteen choose a more difficult Dongfeng landing field?
Dongfeng landing field
In fact, in the past, the mainland has always used the Siziwangqi landing field as the main landing field, the Dongfeng landing field as a backup landing field, in the process of the development of the mainland's aerospace industry, the Siziwangqi landing field has played an important role, for example: the mainland aerospace hero Yang Liwei landed in the Siziwangqi landing field, and the moon soil carried by Chang'e 5 also landed on the Siziwangqi landing field.
However, in the era of the continental space station, the Four Sons Wang Banner landing field lost its advantage, and the advantage of the larger Dongfeng landing field was very obvious.
First, the Dongfeng landing field is larger, which means more opportunities to return. During the orbital flight of the Continental Space Station, the orbital altitude of the space station changes with different times.
In order to save the consumption of propellant from the space station, when the Shenzhou spacecraft returns, it will no longer adjust the orbit of the space station, so when the Shenzhou spacecraft re-enters the atmosphere from the continental space station, the re-entry point is no longer fixed, and the smaller Siziwangqi landing field will be difficult to bear the heavy responsibility of returning, while the east-west span is larger, and the landing area is 10 times larger than the Siziwangqi Dongfeng landing field has obvious advantages.
Secondly, the design life of the continental space station is 10 years, and from the perspective of the operation of the International Space Station, it is not ruled out that the operation time will be extended in the later stage. During the operation of the continental space station, it is planned that each batch of astronauts will work and live in orbit for 6 months, which means that the mainland will launch 2 manned launch missions per year, and will also usher in the demand for 2 batches of spacecraft to return to land every year.
Because of the large demand for continental spacecraft to return, at least 2 batches of spacecraft return every year for 10 years, so a normalized emergency standby search and rescue force is needed.
Compared with the Siziwangqi landing site, the Dongfeng landing site is closer to the Jiuquan Satellite Launch Base, and the facilities of the Jiuquan Satellite Launch Base are very perfect, and it is not difficult to form a high-level and normalized search and rescue team.
In addition, the Dongfeng landing field is sparsely populated, there is less precipitation throughout the year, there is no snow on the ground of more than half a meter, the visibility is high, the wind speed is not large, there is no hail throughout the year, and it is also very suitable for the spacecraft to return to land.
Dongfeng landing field 20,000 square kilometers, the search for astronauts?
After the landing process and landing of the spacecraft, the spacecraft return module needs the ground search and rescue team to quickly locate the return capsule, and at present, the mainland search and rescue team can already achieve the degree that as soon as the return capsule lands, the search and rescue team is already waiting nearby.
This is not because the continental return capsule can accurately land at the destination, but the continental aircraft and radar have been continuously observing, locking its approximate position, and will give the search range of the first forecast according to the forecast data, and the ground convoy is equipped with the Beidou navigation system, according to the search range of the first forecast, quickly assemble near the approximate landing point.
Similar forecast landing range will be many times, each time according to the existing position of the spacecraft, as well as scientific simulation of the forecast out of the approximate location, reported to the ground search and rescue team, the ground search and rescue team can continue to move towards the forecast landing site nearby, as the forecast is more and more accurate, so that in the end the spacecraft has not landed, but the search and rescue team has been guarded nearby, can find the spacecraft return module at the first time.
In the process of simulating the search and rescue for many times, the search and rescue team has a more direct understanding of the local terrain and landform, and the communication is more closely linked, the degree of mutual cooperation is more perfect, and the search and rescue task can be ensured to be successfully completed.
Secondly, the parachute of the spacecraft return capsule is very large, and the color is designed with red and white stripes, which has the advantage of making the spacecraft return capsule more conspicuous.
Dongfeng landing site for the desert, Gobi environment, the blue sky and white clouds here and the color of ground vegetation are completely inconsistent with the color of the parachute, coupled with the day of the spacecraft landing, the local area does not allow unauthorized flight activities, parachuting activities, etc., so after the spacecraft return capsule Parachute is opened, the ground personnel can quickly identify the approximate location of the spacecraft according to the color of the parachute.
In addition, the local terrain is relatively flat, the field of view is open, and there is no vegetation to block, which also makes people even visual, as long as they are within the field of vision, they can see the position of the return capsule in the air, and be prepared for search and rescue of the return capsule.
Finally, when the return capsule is about to land, the reverse thrust engine on the return capsule will start, playing a reverse propulsion, so that the return capsule can achieve a soft landing, as far as possible to reduce the damage caused to the astronauts at the moment of landing.
Others are worried about what happens if the Shenzhou XIII return capsule hits people or buildings during the return process.
There is no need to worry about this, because the Dongfeng landing field is sparsely populated, and the possibility of hitting people or buildings is very small. In addition, the spacecraft will be pulled by the parachute in the process of approaching the ground, the speed is not fast, and the parachute is very large, and very conspicuous, people can see when they look up, there is plenty of time to dodge, the possibility of hitting people is not large.
In fact, there are still some residents living in the Siziwangqi landing field, and when the spaceship returned to the Siziwangqi landing field at that time, the local residents were very welcome to land the spaceship near their home or their own grassland, thinking that whoever the spaceship landed was glorious.
The Dongfeng landing field is less than the Four Sons King Banner landing field, here are deserts, Gobi, not suitable for human survival, so the probability of hitting people or buildings is really too low.