Tianwen 1 has completed the second mid orbit correction, why does it need to be corrected mid track?

During the flight, the aircraft will deviate from the orbit due to various factors, so it is necessary to make corrections at this time to make it closer to the predetermined orbit.

China's Tianwen-1 successfully completed the second correction, this time with the assistance of four engines. At present, the data of Tianwen-1 is normal, and the data communication with the ground is normal. <>

During the flight in outer space, the aircraft will be disturbed by various factors, such as the gravitational attraction of the sun in outer space and the gravitational attraction of some other planets, etc., which will change the flight orbit and speed of Sky One. At this time, if you continue to fly, you will deviate from the place where it needs to be detected, and you will not be able to complete the mission, so it needs to be corrected in advance to make it fly according to the predetermined trajectory.

The staff on the ground controls the relevant parameters, carries out accurate data positioning, and controls the parameters at all times to ensure accurate positioning. <>

The second halfway correction is a supplement to the first one, because the first correction will also cause some errors, at this time it is necessary to carry out the second correction, in the second correction will be the biggest error to reduce or even completely eliminate the error, to ensure that Tianwen-1 flies in the determined orbit.

Subsequent corrections may also be carried out, because gravity is constant, so there will be subsequent corrections.

Tianwen-1 is a Mars probe independently developed by China, which mainly undertakes the task of orbiting Mars, then landing on the surface of Mars, and finally carrying out Mars patrol and exploration. <>

With the continuous progress of science and technology, the abundant resources and environment of outer space, as well as unknown advantages, are waiting for us to survey and excavate, but because Mars is relatively far away from the earth, and it is only about two years before there is a chance to launch a satellite, so this exploration is not only an opportunity for China's extraterrestrial exploration, but also a great challenge. Finally, I believe that the relevant scientific research teams in my country will complete the task excellently and bring us unexpected surprises.

The mid-course correction should correct the orbit deviation caused by various reasons, so that the probe can fly closer to the theoretical orbit. The accuracy of Tianwen-1's launch into orbit and the first mid-course correction is very high, so the amount of correction this time is very small.

Because there is a certain deviation in the data calculated before this, in order to ensure that it is safer in the subsequent operation, it will be revised in the middle of the process.

Tianwen-1 deviated from the track during driving. Tianwen-1 deviated from orbit due to other drags in space during its drive in space, so it needed to be corrected midway.

Corrections are required due to deviations due to various reasons. Bringing the vehicle closer to orbit.

Because the probe will deviate from orbit for various reasons during flight. Therefore, corrections should be made to make the probe fly closer to the theoretical orbit.

The flight of Tianwen-1 to Mars is likened to driving by car, and it has a planned route, which is called a predetermined orbit. It's going to go off track, so you'll need to fine-tune the steering wheel occasionally to keep it in the middle of the lane – that's a track correction, it's a minor fix.

Although Mars is the Earth's neighbor, the distance between Mars and the Earth varies between 55 million and 400 million kilometers, which is far more than the average distance of 380,000 kilometers between the Earth and the Moon. When choosing a Mars exploration window, it is necessary to take advantage of the opportunity of each close approach of Earth and Mars to launch a few months in advance, and such opportunities will only appear every 26 months.

The orbit of the probe may be as long as 5-700 million kilometers and take 6-11 months, depending on the detection window. Distance and time pose a huge challenge: due to the extreme complexity of the actual flight conditions, the theoretical orbit cannot be fully realized, and it must be approached as close as possible by orbit correction and deep space maneuvering.

At 22:00 on October 28, 2020, under the control of the flight control team of China's first Mars exploration mission, the eight 25N engines of the Tianwen-1 probe were ignited at the same time for 41 seconds, successfully completing the third orbit mid-course correction, and the purpose of the mid-track correction of Tianwen-1 orbit is to make the Mars rover rendezvous with Mars according to the scheduled time.

One: What is Tianwen-1

Tianwen-1 is China's first Mars probe, which was launched by the Long March 5 Yao-4 long-range carrier rocket at the Wenchang Cosmodrome in China on July 23, 2020, and successfully entered the predetermined orbit. Tianwen-1 will fly to Mars in about 7 months, and it is mainly used to carry out scientific exploration of Mars' surface topography, water, ice, ionosphere, etc., so as to achieve China's technological leap in the field of deep space exploration.

3. The purpose of the third mid-orbit correction of Tianwen-1

Many people are very curious about this, why did the third orbit of Tianwen-1 be corrected halfway? What is its purpose? In fact, the implementation of the third mid-orbit correction is to adjust the transfer orbit again after the deep space maneuver, so that the Mars rover can rendezvous with Mars at the scheduled time, and the actual performance of the 25N engine is calibrated in orbit.

As of October 28, 2020, Tianwen-1 has flown for 97 days, tens of millions of meters away from the earth, the state of all systems is very good, the ground TT&C communication centers and stations are tracking normally, presumably it will be able to reach Mars smoothly in a few months, let us wait and see.

3. The degree to which China attaches importance to aerospace science and technology

As early as the 90s of the 20th century, China's aerospace science and technology experts discussed issues such as Mars exploration, and China attaches great importance to the development of aerospace industry as an important part of the country's overall development strategy. Since January 2016, China's independent Mars exploration mission has begun, which will be launched between July and August 2020, and is expected to land on Mars in 2021, which will allow for the exploration of all aspects of Mars and make important contributions to China's development.

It is to adjust the transfer orbit again after maneuvering in deep space, so that the Mars rover can rendezvous with Mars at a predetermined time.

The purpose is to be able to make the Mars rover rendezvous with Mars at the scheduled time after maneuvering in deep space.

In physics, when the satellite orbits the planet, the mutual attraction between the planet and the satellite will become less and less, and if the orbit of the artificial satellite is not corrected, it will deviate from the predetermined orbit over time, so as to escape the shackles of the planet, so the orbit of Tianwen-1 should be corrected so that it can always orbit the earth.

The third mid-orbit correction was implemented in order to make minor adjustments to the transfer orbit again after the deep space maneuver, so that the Mars rover could rendezvous with Mars at the scheduled time.

After orbit correction, the Tianwen-1 probe will continue to follow the predetermined orbit to Mars, otherwise, it will sail to a place that we cannot predict.

The purpose of the correction is to compensate for the deviations that occur during the flight of the probe, and to fine-tune the flight trajectory of the probe in order to fly according to the predetermined orbit. For example, when driving, you always have to constantly adjust the steering wheel and drive along the road, and this subtle adjustment is called correction.

daysQ-1 will eventually need to be corrected about 4-5 times. In fact, the purpose of the correction is very simple, that is, to reduce the error, and finally make Tianwen-1 reach Mars. So as to complete the difficult exploration mission of Mars.

1. Tianwen-1 has completed two correctionsSince its successful launch, Tianwen-1 has completed two corrections on August 2, 2020 and September 20, 2020. Judging from the corrections that have been completed, the correction method of Tianwen-1 is also different.

2. Tianwen-1 has the ability to change orbitsTianwen-1 not only needs to have the ability to change orbit in the starry sky, but also needs different orbit change capabilities. After all, there will be a big difference in what Tianwen-1 needs to change orbit in space.

3. The number of corrections that need to be made is not fixed, because Tianwen-1 is carrying out China's first mission to send a probe to Mars, and in front of it is an unknown starry sky. In this unknown star field, the difficulties that Tianwen-1 needs to overcome are also unknown. Therefore, our scientists do not know how many corrections Tianwen-1 needs to make.

Judging from the actual situation, Tianwen-1 will need to be corrected no less than 4 times.

We believe that no matter how many corrections Tianwen-1 needs to make, it will definitely be able to complete the corresponding task excellently.

Tianwen-1 will eventually need several corrections, and this is uncertain. The correction is to correct the flight trajectory and reduce the error.

It has to be corrected countless times until it is possible, and the purpose of the correction is to ensure that the data is more accurate.

Eventually, a correction is required. The purpose of the correction is to put the aircraft into the correct orbit for operation, so that the aircraft can work normally in the correct orbit.

It's hard to say. What is the correct direction of operation, and how fast should it be run, so that Tianwen-1 can run in the predetermined orbit and successfully reach Mars to complete the exploration mission.

Tianwen-1 still needs to be corrected several times.

Why make a mid-course correction:As China's first Mars probe, Tianwen-1 has been in a state of unpowered flight for a long time in the process of flying to Mars, in this case, even a very small error will gradually accumulate and amplify during the flight, and eventually cause serious consequences, which is why Tianwen-1 should make corrections in the middle. In fact, the Mars rover not only has to correct the single parameter of flight direction, but also has to correct several variables, including flight speed, so that it can reach Mars smoothly.

We can use the analogy of driving, and as we all know, many cars now have a lane-keeping feature that automatically reorients the car if it deviates from its lane. To some extent, the orbit correction of the Mars rover is similar to that of the car, but the orbit correction is more complicated, not only to fix the flight direction, but also to fix multiple parameters such as flight speed. And in space, the Mars rover also has no reference, so it is much more difficult.

Moreover, Tianwen-1 is not all right after one correction, and will also experience deep space maneuvers and multiple mid-course corrections in the subsequent journey to Mars. It is also very easy to understand that the Mars rover flying to Mars is a very long journey, and there will be no more than one orbit deviation in the middle. Therefore, in order to successfully complete the mission, we need to keep monitoring Tianwen-1 at all times to ensure that it can react quickly after it deviates from orbit, so as to make corrections in the middle of the course.

So we need to make corrections several times.

After reading the news, many people think that everything will be fine after China's successful launch of the Mars rover, but this is not the case, the Mars rover will not be able to land on Mars until next year, and we are also facing many challenges on the way. However, I also believe that the Chinese astronauts, the Mars exploration mission will be a complete success, come on, China's aerospace!

Tianwen-1 has completed its first mid-orbit correction, and on its way to Mars, it will have to go through many attitude adjustments in the future, which means that it may need to be revised many times in the middle.

It needs to be corrected many times, because Tianwen-1 will deviate from orbit due to some external forces during its flight in space.

Many times, there are many variable factors in the satellite's space flight, such as the influence of planetary gravity, its own attitude adjustment, etc., which need to be corrected many times in order to accurately enter the predetermined orbit.

Normally, this track has to be modified many times in order to find the best position.

At 23:00 on September 20, 2020Under the control of the flight control team of China's first Mars exploration mission, the four 120N engines of the Tianwen-1 probe were ignited for 20 seconds at the same time, and the second mid-orbit correction was successfully completed.

Up to now, Tianwen-1 has been in orbit for 60 days, about 19 million kilometers away from the earth, with a flight distance of about 100 million kilometers.

Mid-course correction generally refers to the correction of orbit deviation caused by various reasons during the flight of the probe, so that the probe can fly closer to the theoretical orbit. The accuracy of Tianwen-1's launch into orbit and the first mid-course correction is very high, and the amount of correction this time is very small.

Ensure the accuracy of the trajectory and ensure that it can reach Mars.

Like many cars nowadays, if the car deviates from its lane, it will automatically correct the direction and return the car to its original lane.

The orbit correction of the Mars rover is similar, but the difference is that the Mars rover has to correct not only the direction of flight, but also multiple variables such as flight speed. In the vast space of space, the probe does not have road markings as a reference, so it is very difficult.

During the flight of the earth-fire transfer orbit, the detector will be affected by factors such as orbit entry deviation and control accuracy deviation. Because the probe is in unpowered flight for a long time, the small position velocity error will gradually accumulate and amplify, and if it is not corrected, the probe will miss Mars, resulting in the serious consequences of "a small difference, a thousand miles".

Therefore, when performing the flight mission, it is necessary to formulate a mid-course correction control strategy for the ground-fire transfer trajectory, including the timing of each correction, the size of the velocity increment of each correction, and the direction of the velocity increment. Zhu Qinghua said that in the actual mission, researchers need to complete the corresponding detector attitude and orbit control according to the mid-course correction strategy to ensure that the probe always flies in the predetermined orbit.

Experts say that the key to mid-course track correction lies in the choice of correction timing and the precision with which each correction is implemented. The researchers comprehensively consider the current actual trajectory deviation, navigation deviation and thrust deviation to determine the correction time, and at the same time use the on-orbit calibration technology to ensure the control accuracy of each mid-course correction.

According to the follow-up plan, the "Tianwen-1" probe will also undergo deep space maneuvers and several mid-course corrections, arrive near Mars after more than six months of flying to the fire, and be captured by Martian gravity through braking to enter the orbit of the ring of fire, and carry out preparations for landing on Mars and scientific exploration.

Tianwen-1 was launched by a Long March 5 rocket, starting the journey of Mars exploration and taking the first step in China's independent planetary exploration. It is believed that in the future, China's exploration of the universe will continue to deepen and gradually uncover the mysteries of the universe.