And how astronauts work in weightlessness

In the case of weightlessness in space, how do astronauts eat, drink, and sleep? This doesn't increase knowledge!

Astronauts are weightless in space because there is almost no gravitational pull in space.

Space spacecraft will be far away from Earth and other planets as they orbit the Earth or in interstellar space orbit, so they will lose their gravity, and so will the astronauts.

Weightlessness is not the result of the disappearance or drastic reduction of gravity (in fact, at an altitude of 100 km, the Earth's gravity is only about 3% less than the Earth's surface). The phenomenon of weightlessness mainly occurs in orbit or in space, or in aircraft that performs parabolic flights, or in some other abnormal conditions (far from the planet or heavy objects) of objects or people. The phenomenon that the pressure of an object on a support is less than the gravitational force experienced by an object is called weightlessness.

Pang Zhihao, chief science communication expert of the national space exploration technology, said that it must be exercised in space, because in the case of weightlessness, there is very little force, and the muscles will atrophy after a long time. The method of exercising in space is different from that on the ground, so you must fix yourself, the treadmill can't run directly, people will float up, and they have to fix themselves first. Hold your waist and chest in place with a rope, and your legs can still move

In the past, the former Soviet Union's Salyut spacecraft, the astronauts stayed in space for a long time, and they did not pay special attention when they came back, and later the astronauts' ability to live was very difficult. Since the Mir space station, this training of astronauts has begun to intensify. This is also the experience that human beings have gradually accumulated.

Later, the fitness function became the standard for long-term life on the space station.

The three astronauts will complete four main aspects of work during their time in orbit

According to the overall arrangement of the Shenzhou-12 manned mission, the three astronauts will mainly complete four aspects of work during their time in orbit, and plan to carry out two out-of-cabin activities and extravehicular operations.

Ji Qiming, assistant director of the China Manned Space Engineering Office, said that the four main tasks include:

Carry out the daily management of the core module assembly.

Carry out out-of-cabin activities and extravehicular operations.

Space science experiments and technical experiments were carried out.

Carry out the health management of the astronauts themselves.

The above content refers to Xinhuanet-Astronauts also need to exercise in space, and eating for 5 days is not the same.

In order to maintain the normal "functioning" of various organs and tissues in space, the astronauts of the International Space Station must perform daily physical exercises, such as riding bicycles or pedaling on "moving carpets". Without the constraints of Earth's gravity, astronauts do not move as freely in space as they do on Earth. They need to attach themselves to the station's equipment with ropes and wear special pants to circulate blood from head to toe in order to achieve the same physiological effect as exercising on Earth.

These exercises can basically maintain the normal "operation" of the heart, arteries and other organs, but they cannot prevent bone atrophy. According to statistics, astronauts lose 1% to 10% of their skeleton during a space trip, and this part of the bone usually regenerates on Earth for much longer than in space. Under normal circumstances, astronauts should insist on at least two hours of exercise every day.

The long-term weightlessness of astronauts in space can lead to bone deterioration.

In weightlessness, human bones do not need to perform the basic function of supporting weight, but this is not good for the human body, so astronauts are prone to osteoporosis. Astronauts on the International Space Station must take into account their daily physical activity, and astronauts usually participate in at least two hours of exercise a day.

The space station consists mainly of bicycles, treadmills and other equipment that help keep the body in shape, and this treadmill must have a rope to pull the astronaut in the direction of the conveyor belt, so that the astronaut can move as if he were on Earth. Hope!

Caused by weightlessness and radiation.

And inertia.

Weightlessness is the absence of weight, and weight is the manifestation of gravity. Astronauts are not affected by gravity in space (in fact, gravity still exists, but it is too weak), so there is no weight.

But inertia is mass-generated and has nothing to do with gravity (gravitational force). In the language of physics textbooks, inertia is the ability of an object to maintain its original state of motion and is a fundamental property of matter. An object with mass has inertia.

Whether an astronaut is in space or not, and whether or not he is affected by gravity (gravity), mass is still there, so there is still inertia.

For the understanding of inertia, we should pay attention to the following three points:

1.Everything has inertia.

2.Inertia is an intrinsic property of an object.

3.Mass is the only measure of the magnitude of inertia.

No matter where you are, there is inertia, a weightless astronaut, in the space shuttle, if the plane suddenly stops, he will rush out.

Not just "astronauts", not just "in space", any person in any position, as long as the acceleration he experiences can cancel out or partially cancel out the acceleration of gravity, he will experience weightlessness. It's just that the clump is noisy on the ground or in the area close to the ground, and the space for such movement is narrow, and weightlessness is difficult to maintain for a long time.

As long as the astronaut is in an unpowered state, the acceleration of the motion he makes will be subject to the gravitational pull of nearby celestial bodies at all times, and its acceleration will be exactly equal to the acceleration produced by these gravitational forces, so there will be no interaction force between him and the spacecraft due to external gravity - complete weightlessness. Of course, if the astronaut is located outside the spacecraft, then there is at least a mutual gravitational pull between him and the spacecraft due to the sum of their masses. This force is so small that the human body cannot feel it.

The so-called weightlessness is nothing more than the phenomenon that the supporting force between the body (such as a person) and other objects (such as an elevator) carrying it is less than the gravitational force, or even reduced to 0. This is a very local and one-sided phenomenon that does not even need to be specifically discussed as an effect in the mechanics system. Many people find this phenomenon novel and mysterious, simply because the feeling habit of being supported smoothly by the ground is deeply ingrained.

It's a difficult problem to explain, and it's not that, as some have claimed, astronauts are weightless because of Earth's gravity.

It can be said that it is the gravitational pull of the earth that causes weightlessness.

For example, the International Space Station, if a human mass m1 = 60kg, about r = 6500km from the center of the earth, the mass of the earth is about m2 = 6 * 10 24 kg, the gravitational constant is about g = 7 * 10 -11nm2 kg2, and the gravitational formula is f = g * m1 * m2 r 2 It is obvious that there is almost a human gravitational force between them.

So why is there still weightlessness?

Centrifugal force can be described here, like throwing a small ball with a rope on it, you will feel that the ball is going to fly out, and the faster you shake it, the more obvious this feeling is.

The spacecraft will have a velocity that causes the gravitational force to be equal to the centrifugal force, resulting in weightlessness (only the force is not felt, but it is a two-force balance), and this velocity is called the "first cosmic velocity" (approx.

But in reality, centrifugal force does not exist, so special attention should be paid to it.