How astronauts and command centers can achieve space to earth communication in space

There is bathing, drinking water, going to the toilet, sleeping.

In our country,The communication between the space station and the ground mainly relies on the ground tracking and control station, the data transmission receiving station and the Skylink relay satellite, in which the Skylink relay satellite can ensure uninterrupted communication. To put it simply, to realize the interconnection of the space station with the ground, it needs to rely on artificial satellites and other auxiliary equipment.

Methods of communication for out-of-cabin activities of the Chinese space station

On July 4, 2021, under the watchful eye, the astronauts ushered in an important part of the space journey of the Tianhe core module of the "Space Home" space station - out-of-cabin activities and carried out the established space test activities.

Out-of-cabin activities are a general term for astronauts wearing extravehicular spacesuits to perform spacewalks and operations outside spacecraft. During the space station mission, astronauts will carry out multiple out-of-cabin activities to complete the repair, maintenance and construction of the space station. It is particularly important to establish high-speed and timely communication with the ground during the out-of-cabin activities, which are not only an all-round test for the astronauts, but also a major test for the communication capabilities between the space station's Tianhe core module and the ground TT&C station.

The third-generation relay terminal product developed by the Fifth Academy of Aerospace Science and Technology Group realizes relay communication by establishing relay links with relay satellites Tianlian-1 and Tianlian-2 to ensure real-time and smooth communication between astronauts and the ground. This is like building a "sky road" between the ground and the relay satellite, and between the relay satellite and the astronaut in space.

In addition, the biggest difference between the design of the space station relay terminal and other models is that it needs to have on-orbit maintainability in order to ensure a long life in orbit. The relay terminal of the space station adopts an integrated and modular design idea, which is convenient for astronauts to maintain and replace while ensuring the quality of transmitted signals.

In this astronaut out-of-cabin activity, the TT&C communication products and controller products developed by the Fifth Academy of Aerospace Science and Technology Group were successfully applied to the voice communication and robotic arm control work of the Shenzhou-12 astronauts out of the capsule.

The out-of-cabin communication subsystem realizes full-duplex voice communication between astronauts inside and outside the cabin, between astronauts inside and outside the cabin and ground personnel, and between astronauts outside the cabin, and realizes full coverage of wireless communication within the scope of astronauts' extravehicular activities. Compared with the previous generation of out-of-cabin communication system, the product has the characteristics of longer communication distance, higher communication rate and longer working life, and at the same time, due to the use of power control, anti-multipath and other measures, the product has a stronger anti-electromagnetic interference ability in the space environment, and supports the call function of multiple astronauts when they go out of the capsule at the same time.

The extravehicular image transmission subsystem provides wireless network coverage for the extravehicular area, and transmits the image through the "hot spot" provided by the out-of-cabin wireless transceiver equipment, which realizes the functions of real-time display and real-time recording of astronauts' out-of-cabin activities, as well as the data transmission function for the solar wing circumnavigation measurement test.

How do we communicate with space?

1. There is air inside the spacecraft, which can speak directly; During a spacewalk or when there is no air on the moon, radio can be used to communicate;

2. The ratio of the space capsule to the earth's atmosphere is about the same, and the slag will not prove the normal call system of the astronauts, there is air transmission, and speaking is not a problem, and there is not much difference from the ground. If it talks to the ground, the satellite has a dedicated transmission facility, which can be transmitted directly to the ground command system;

3. It is necessary to distinguish between being in space and being in a space capsule, there is no air in space, there is air in the space capsule, and there is air in the spacesuit. In space, astronauts cannot communicate information with each other by mechanical waves alone, but can use light and radio waves;

4. Astronauts in space are sharp beams and rolls.

When we talk face to face, we can hear each other, because the air contains a medium for sound propagation, and there is no medium in a vacuum, so how do astronauts communicate in space or on the moon?

Astronauts in space use radio to talk to the ground control center and rely on radio waves to propagate.

Astronauts use radio to talk to the ground control center in space, and rely on radio waves to propagate, so the picture and sound will be so smooth and clear.

It turned out that in order to achieve a direct dialogue between the command center and the astronauts, it was necessary to create a secondary communication network. Each surface station is connected with the command center through a synchronous communication satellite located over the Pacific Ocean, and at the same time, a backup route is built through the ground communication network or other communication means to connect with the command center, and a star network between the ground station and the command center is built. In this way, a secondary communication network is formed from the spacecraft to the ground station, and then from the ground station to the command center through the satellite; Similarly, the command center transmits information to the ground station through satellite communications, which in turn transmits it to the spacecraft.

This is a three-dimensional communication network of land, sea and sky.