Jiao Weixin, professor of the School of Earth and Space Sciences, Peking University:

Experts interpret the launch time of Shenzhou 12 to be accurate to the second

  On June 17, the Shenzhou 12 manned spacecraft was launched into space and successfully docked with the space station's Tianhe core module. Astronauts Nie Haisheng, Liu Boming, and Tang Hongbo entered the Tianhe core module successively, and the Chinese astronauts entered their own space station.

  Jiao Weixin, a professor at the School of Earth and Space Sciences of Peking University, accepted an exclusive interview with a reporter from the Beijing News on the same day to fully explain the mission.

  In addition, when talking about the International Space Station, Jiao Weixin said that whether the International Space Station will be decommissioned after three years depends on whether the participating countries are willing to continue to invest funds to maintain it.

  The launch time is accurate to the second, and the missed energy consumption is greater

  Beijing News: Shenzhou XII chose to fire and launch at 9:22:27 on the 17th, Beijing time. The launch time has been accurate to the second. How is this time determined?

  Jiao Weixin: The launch time was chosen because this time is conducive to the rapid rendezvous and docking of the manned spacecraft and the core module of Tianhe.

The Tianhe core module is about 390km high and revolves around the earth at an orbital inclination of 42 degrees.

The earth itself also rotates from west to east, rotating 360 degrees a day, and 15 degrees east in an hour.

  When the orbit of the core module of the space station just passed the Jiuquan Satellite Launch Center, it was the culmination of the rocket launch countdown.

Ignition at this time can ensure that the orbital inclination and orbital plane of the newly launched spacecraft are very close to the data of the sky and core modules.

If the two spacecraft are on the same orbital plane, but the altitude is different, the correction is easier.

If you turn on different circles and adjust to the same orbital plane, it will take a lot of fuel and time.

So now there is basically a zero launch window, which is on time.

It's not that you can't launch if you miss this point in time, but it does cause greater consumption.

  Beijing News: The Shenzhou 12 manned spacecraft completed the rendezvous and docking with the core module of Tianhe in more than 6 hours. How did my country's rapid docking technology develop?

  Jiao Weixin: It used to take about two days, but now it can achieve automatic and rapid rendezvous and docking in 6 to 8 hours.

The substantial reduction in time depends on the development of technology, especially the networking of Beidou satellites.

In the past, when two aircraft were interactively docked, ground measurement and control were required. When the spacecraft arrives near the target aircraft, the ground will monitor and control the orbit of the spacecraft and the orbit of the aircraft, and then command them little by little, which consumes a long time.

Now we don’t need to conduct command on the ground. The orbit of the spacecraft and the orbit data of the space station are provided by Beidou satellites in real time.

  Currently in the beginning stage of site construction

  Beijing News: Now everyone is proud of our own space station. How long will it take to build it?

  Jiao Weixin: From the launch of the core module to the completion of the space station, there will be a total of eleven launches. It takes two years. So far, we have only launched three times, so we are still in the beginning stage of station construction.

If all the preparations are done this time, and the equipment in the core module is inspected to be intact, then every time a manned spacecraft can be launched every time it is launched.

  Beijing News: What kind of pattern will the Chinese space station built in the future look like?

  Jiao Weixin: On the whole, it is a T-shape with a core cabin. There are two experimental cabins at both ends of the core cabin.

  One cabin is about 20 tons, and three cabins are about 60 tons. Although my country's 60-ton space station is incomparable to the size of the International Space Station, a single cabin is the largest in the world.

Each cabin is comprehensive in content, not like the International Space Station, where a cabin is equipped with many other accessories.

  In addition, as long as our space station has people, there will always be manned spacecraft docking with it.

Another point is that we have already deployed. In the unlikely event that the space station malfunctions, threatening the safety of the astronauts, the docking spacecraft can pick up the astronauts.

  Beijing News: At present, only the International Space Station and the Chinese Space Station are in orbit, but the service life of the International Space Station is about to come. Will there be a situation where only the Chinese Space Station is in orbit in the future?

  Jiao Weixin: This situation will definitely appear.

Because according to the plan, the International Space Station will be decommissioned by 2024.

Whether it will be decommissioned on time depends on the attitude of the main participating countries and whether it will continue to invest to maintain the International Space Station.

  This is just like a human being. Many illnesses will definitely appear after the age of eighty. The space station will naturally age after it has been running for so long. With ultraviolet radiation, the micrometeoroid fragments continue to hit, and the surface is also scarred.

If there is a major repair, it will cost a lot of money, and even if it is repaired, it will only restore the original level.

This requires comprehensive consideration. It is not clear whether to invest in maintenance or to abandon it altogether.

There will be six astronauts at the handover

  Beijing News: Will the three astronauts in space maintain the same schedule as on the ground?

  Jiao Weixin: Yes, there are more than a dozen sunrises and sunsets a day in space. According to this schedule, the rhythm of life will change.

There is a clock in the space station, and the brightness of the lights is automatically adjusted. If the lights dim, you have to rest quickly.

Astronauts must ensure eight hours of sleep a day, so that they have the energy to cope with daily work.

  Beijing News: What are the differences between their lives in space and the ground?

  Jiao Weixin: In the case of microgravity, the way the astronauts brush their teeth is different from that on the ground.

According to foreign reports, there are two kinds of toothbrushes. One is an American toothbrush, which uses a plasticine-like thing to remove all the dirt on the teeth; European astronauts squeeze out edible toothpaste. Drink some water, then swallow the toothpaste with water.

  Washing your face is to wipe it with a wet paper towel. After wiping, the paper should not be thrown around. The remaining water should be squeezed out and stored. In the future, it will be processed into pure water for drinking water.

An important task of our astronauts this time is to test this regenerative life support system.

This includes the collection and regeneration of domestic water, as well as the collection, processing and treatment of astronauts' urine to remove harmful substances and turn it into drinking water.

  Beijing News: This time the three astronauts will stay for three months. After three months, how will the astronaut handover work proceed?

  Jiao Weixin: The next group of astronauts will be sent up. The last group of astronauts cannot get off immediately. It will take a few days for the transition. At this time, there will be six astronauts on the space station.

When the handover is complete, the last group of astronauts can go home.

  This time the three astronauts will inspect all the equipment on the core module.

In the future, astronauts will need to do more things and take care of them. Now it will be a one-bedroom, and it will be a three-bedroom in the future.

Two spacewalk spacesuits are equivalent to small spacecraft

  Beijing News: Is the astronaut’s spacewalk mission different from that of Zhai Zhigang?

  Jiao Weixin: Zhai Zhigang was mainly to verify that my country's extravehicular walking technology can withstand the test. He just hovered outside the cabin and displayed the five-star red flag to complete the task.

This time the astronauts will really go out and have to deal with other tasks, such as checking the condition of equipment outside the space station.

This time the astronauts will perform two spacewalks.

  I have counted it. For so many years, humans have carried out hundreds of spacewalks without major accidents, but minor accidents have not stopped, mainly because of problems with space suits.

For example, once, an astronaut’s gyroscope had a problem. The gyroscope was in balance. If it was not repaired in time, the balance would be lost.

  Beijing News: Space suits are very important to the exit activities. In the design of space suits, what functions must be guaranteed?

  Jiao Weixin: There are so many functions. In a sense, it is a small spacecraft.

The outside of the cabin is a vacuum environment, oxygen must be supplied, gas circulation and constant temperature must be ensured.

In addition, it is necessary to be able to shield ultraviolet rays, because the ultraviolet rays outside the cabin are very strong, and there are particle radiation, which can damage human DNA when hitting people. In addition, it is necessary to prevent micrometeoroids and microorbital fragments. Protective clothing is enough. If it is a large meteoroid or fragment, we have to start filing and change its orbit.

  The spacesuit weighs more than one hundred kilograms, and the earliest spacesuit price was 30 million yuan.

Now there are great improvements, and the future direction of change is to gradually achieve lightness and flexibility, improve comfort, and improve astronauts’ work efficiency while enhancing functionality and reliability.

  Beijing News reporter Li Yukun Jiang Huizi and intern Cui Wanting