Chapter 2889 The fifteen-kilometer landing journey
The hall of the Xinyuehu Aerospace Command and Control Center in Haoyu Science and Technology Park is already brightly lit at this time, and everyone is in their seats, waiting for the important moment to arrive. On the big screen in front of the hall, there is a 3D model image of the moon. In this slowly rotating
On the moon, there are green lines surrounding this circle. The end point of the green line shows a strange-looking aircraft. This is the lander of the Lunar Cargo 2 spacecraft launched five days ago. These green lines are exactly
Its previous flight path around the moon.
In front of the lander, there are several circles of red lines, which are the routes the lander is expected to travel. At the end of the red line, there is a flashing dot, which is the final landing point of the Zhesu lander. Zhihai
The aircraft landing site of the lunar scientific research station.
In fact, many people have confused a concept. In everyone's impression, it seems that the moon does not rotate, because in our impression, the moon always faces the earth, and the back side can never be seen, so we think that the moon does not rotate.
It will rotate on its own.
In fact, the moon rotates, but its rotation period is relatively long. Because of the "tidal locking" effect, the moon rotates while revolving around the earth, which is 27 days, 7 hours, 43 minutes, and 11.47 seconds. Therefore,
The moon we see from the earth is always the front side, and we can never see the back side.
Ten hours ago, the lander successfully separated from the orbiter and is now gradually descending to the altitude of the lunar orbit in preparation for landing.
Therefore, today's landing process also attracted a lot of attention, and the guest auditorium in the command and control hall was also filled with many reporters and invited guests.
Wu Hao and others also came to the scene and accompanied several important guests to witness the entire landing process with their own eyes.
In fact, in addition to some experts and professors, these guests also included some leaders, including local leaders from Anxi and provincial leaders who came to watch the entire launch process.
After all, this can be regarded as a grand event in the scientific and aerospace fields of Anxi and even the whole province, so the leaders are also very concerned about it. They have made several phone calls before to inquire about the details and are concerned about the progress of the entire project.
Now at this most critical moment, they came in person, which made Wu Hao and the others very grateful, and they felt the leaders' support and concern for them.
As the general person in charge of the entire project, Yu Chengwu also acted as the host and commentator, personally helping them and introducing some important guests who came this time.
"Xiao Wu, when will we land?" The leader sitting next to Wu Hao looked at the big screen and asked Wu Hao with a smile.
Seeing the leader's inquiry, Wu Hao glanced at the time and replied with a smile: "There are about forty minutes left. Our lander is currently flying around the moon, gradually lowering the orbital altitude, adjusting the orbital angle, and waiting until the entire landing.
After the vehicle reaches the predetermined height and position, it can implement orbit change and descent.
You see, those red lines on the big screen are its next trajectory. We have to wait until it descends to an altitude of about fifteen kilometers and reaches the sky above the Zhima Basin in the southern hemisphere of the moon. That is the red dot flashing on the screen.
position, and then begin the official landing. The entire descent and landing process takes about fourteen minutes, which is also the most dangerous fourteen minutes from the launch of the rocket to the final landing. It is related to the success or failure of the entire mission."
"Fifteen kilometers, is it so low?" This altitude on Earth is almost the same as the altitude of our civil aviation aircraft. Another leader said in surprise.
Hearing the leader's words, Wu Hao smiled and nodded: "Yes, the international flights of our current civil aviation aircraft are generally around 13,000 to 16,000, and the final track may not be as high as the aircraft."
"So low!"
After Wu Hao finished speaking, the leaders next to him all showed expressions of surprise. They did not expect that the altitude of the lunar orbit would be so low.
Seeing this, Wu Hao smiled and explained: "The moon's volume is only one-eighth of the Earth's, its radius is one-fourth of the Earth's, and its weight is only one-eighty-one of the Earth's.
So compared to the Earth, it is very small overall and its mass is very light, so its own gravity will be very small, only one-sixth of our Earth.
If the gravity on our earth is '1', then the gravity on the moon is only '0.17', which is very small.
In this way, we can calculate that the Kármán line of our earth, which is the dividing line between our earth's atmosphere and space, and also the dividing line of gravity, is one hundred kilometers.
If you are above this 100 kilometers, you can float weightlessly, and if you are below this height, you will feel gravity.
Then convert this height to the moon, 0.17 is 17 kilometers, so we can conclude that the Kármán line on the moon is 17 kilometers.
Of course, this number is not an exact number, it is just an approximate value, which may be higher or lower. Also affected by the lack of atmosphere on the moon and the speed of flying around the moon, the altitude of this landing orbit is lower.
These are all carefully calculated, so there will be no problems."
Finally, Wu Hao added something, which was a reassurance to the leaders and made them feel at ease.
Sure enough, after hearing Wu Hao's introduction, the leaders couldn't help but nodded, and they had a general understanding of the entire landing process.
"The altitude of fifteen kilometers shouldn't be too high. Why is it so dangerous?" Another leader who accompanied us immediately raised such a question.
The leaders all laughed at this. Indeed, on Earth, the altitude of fifteen kilometers is the flight altitude of international flights, which is still far from space.
It may also be because of our country's excellent achievements and strong strength in the aerospace field, so in the eyes of the leaders, it seems that there is no difficulty at such a height.
In this regard, Wu Hao was also very helpless, but who should let the other party be the leader? He could only explain with a smile: "On our earth, this height is indeed nothing. Even many extreme skydivers can reach from 10,000 to 10,000.
Skydive at an altitude of more than 20,000 kilometers and then land safely.
But this is the moon, another planet 380,000 kilometers away from us. Things that are very easy on the earth will be difficult on the moon.
It seems that these fifteen kilometers are very simple, but we have to reduce the lander's flight speed from 1.7 kilometers per second to zero during the landing process of about fourteen minutes.
In other words, during the entire descent process, the engine on the lander must continuously work to slow down the lander. This process is very important.
