Q: How many steps are required for an astronaut to complete a space walk?

Audit expert: Qian Hang

Aerospace science expert of the First Academy of China Aerospace Science and Technology Corporation

"I'm out of the cabin and feeling fine."

——Zhai Zhigang, the first Chinese astronaut to complete an extravehicular mission

Source | China Aerospace Science and Technology Corporation

Human curiosity about the stars is the source of the development of space technology. In 2008, Chinese astronauts completed their first spacewalk . With the continuous advancement of space technology, spacewalks have become a "compulsory course" for every space crew.

How to break through gravity and enter the vast space is a difficult problem, but now that we have entered space, shouldn’t leaving the cabin be as easy as walking out of your home?

This is not as simple as you think.

1

The exit is the hatch, the focus is on the "window"

Every time you go out of the spacecraft, it is necessary to ensure the safety of the astronauts and the successful completion of the mission . Therefore, two "windows" are important factors to consider, namely the "macro time window" and the "specific extravehicular time window."

Source | Xinhua News Agency

What is the basis for determining the specific time window for extravehicular activities? It depends on four factors: energy constraints, space environment, meteorological conditions, and the daily routine of the earth and the sky:

The first is energy constraints . During the single-cabin flight of the Tianhe core module and the in-line flight of the core module and the Wentian experimental module, in order not to interfere with the work of the robotic arm, the solar panels temporarily stop rotating with the sun. Energy supply can only be guaranteed within a suitable range of solar incidence angles, thus creating constraints on the choice of windows for extravehicular activities.

Solar panels in the Wentian Experimental Module

Source | CCTV News

The second is the space environment . According to the characteristics of the South Atlantic Anomaly and the actual shielding capabilities of China's extravehicular space suits, combined with the predicted results of the probability of solar proton events and geomagnetic storms, we avoid space weather events and further analyze the extravehicular activity window based on the operating orbit of the space station complex and make recommendations.

Source | Sina

The third is meteorological conditions . Whether the extravehicular mission in space can be successfully completed is also closely related to the meteorological factors on the earth. During the extravehicular activities, the control center and the astronauts are supported by relay satellites for measurement, control and communication. Since the amount of data transmitted by the relay is large, it is necessary to avoid the influence of rain attenuation during the transmission process, which may cause interference to the ground-to-space communication.

Source: People's Daily

Fourthly , the space station experiences a cycle of day and night approximately every 90 minutes. To ensure that the astronauts are in a full mental state, it is best to choose daytime Beijing time to conduct extravehicular activities.

Source | CCTV13

2

Extravehicular space suits are unisex?

Now that we know the various factors that affect astronauts' extravehicular missions, let's take a look at the essential equipment for astronauts when they go out of the cabin - the extravehicular spacesuit .

Source | CCTV.com

Looking around the world, extravehicular space suits are probably the "ceiling" of work clothes , but extravehicular space suits are not tailor-made for each person, that would be too luxurious.

The service life of the new generation of extravehicular space suits is about 3 years and 15 times, each time supporting 8 hours of work . In order to save space in the space station and transportation costs, the extravehicular space suit adopts the "one-to-many" fitness principle: the upper torso is a hard structure with a fixed structure of a single parameter; the lower torso and upper limbs adopt active fitness design, the parameter range is determined according to the astronaut's body parameters, and local size adjustment is achieved by adjusting the structure; the gloves also adopt passive and active fitness coupling design, according to the astronaut group hand parameter classification, the astronaut wearing the suit can choose according to their own hand parameters, and the palm circumference can be adjusted to obtain better operability.

Source | Sohu

At present, there are three sets of extravehicular space suits in the Chinese space station, with red (A), blue (B), and yellow (C) stripes. In line with the principle of extending the service life in orbit, the frequency of use of the three sets of extravehicular space suits is balanced as much as possible during each extravehicular mission .

Space suit users with different colored ribbons

Source: People's Daily

Nowadays, Chinese astronauts are going out of the spacecraft more and more frequently. Many people are already imagining the moment when Chinese astronauts land on the moon. What do you think the first thing the Chinese astronauts will say after they leave the spacecraft? Welcome to share your thoughts in the background!