Chapter 444: The Battle for Manned Spaceflight Technology
Liu Tao pondered for a moment.
In terms of China's manned space flight, there are two technical routes for the preliminary preparation and demonstration work.
In the past, the Soviet Union and the United States achieved manned space flight through spacecraft, so the mainstream of manned space technology at that time was spacecraft.
Spacecraft flying along the geocentric orbit are called satellite-type spacecraft, which are disposable spacecraft.
Spacecraft flying to other celestial bodies are called interstellar spacecraft or expedition spacecraft.
According to the different transportation targets, they are divided into manned spacecraft and cargo spacecraft. Among them, spacecraft that transport personnel are called manned spacecraft, and spacecraft that transport materials and equipment are called cargo spacecraft.
However, after the successful development of the space shuttle in the United States, manned space flight has an additional option, and the space shuttle has become the most advanced technology for manned space flight and the best choice.
The space shuttle is a reusable spacecraft that travels between space, the universe and the ground, combining the properties of aircraft and spacecraft. This is a manned reusable spacecraft that can take off vertically like a rocket, run on orbit like a spaceship, and land horizontally like an airplane.
Moreover, a space shuttle can usually carry 7 astronauts, including 3 crew members and 4 scientific and technological experts.
When the space shuttle is in orbit, it can complete a variety of tasks such as releasing satellites, recovering and repairing satellites, and conducting various microgravity scientific experiments.
The space shuttle also affects China's aerospace field. Many scientists believe that since the United States has successfully developed a space shuttle, it means that the space shuttle route is feasible and correct. If we want to carry out manned space flight, we naturally want the most advanced, not backward.
The dispute over the manned space technology route began from then on.
Liu Tao pondered for a moment, and then said: "Space shuttles and space shuttles are just tools to realize the round-trip of people and objects between the earth and space. There is no difference between space shuttles and space shuttles in essence."
"Now space shuttles will be more suitable for China's manned space flight, but in 20 or 30 years, when the national strength is improved and there is enough funds, we can also develop space shuttles."
In Liu Tao's eyes, space shuttles and space shuttles are essentially the same, nothing more than tools, and he has a system to achieve both.
To say the difference between the two, the biggest difference is the way to return. Spacecraft return to the ground in a ballistic or ballistic-lift hybrid trajectory, while the space shuttle reenters the atmosphere in a lift-type trajectory.
What is ballistic reentry? Simply put, it is like a cannonball falling in an arc under the influence of inertia and gravity. This method is technically simple, but the disadvantages are large overload and inaccurate landing point control, which makes it difficult for the recovery and rescue team.
What is ballistic-lift hybrid reentry? The flat bottom of the manned spacecraft's return capsule reenters the atmosphere at a suitable angle of attack, which can generate a certain amount of lift like a stone skipping on water. Although the lift is not large, it is still based on ballistic mechanics rather than aerodynamic lift, but it can more or less control the reentry trajectory, making the landing point more accurate, while the deceleration overload is relatively small.
Lift-type reentry is the return method of the space shuttle. The advantages of gliding reentry are low overload, accurate landing on the airport runway, and the ability to withstand a large landing weight without being limited by the parachute capacity, and there will be no parachute entanglement and crash, and there is no need to wait for the rescue team's helicopter in the wilderness or blindly in the ocean. The disadvantage is that the technology is very difficult, and the requirements for aerodynamic design, thermal protection materials, flight control, etc. are relatively high.
Liu Tao believes that the space shuttle is more suitable for China now, not because the technology cannot be overcome, but mainly because of money.
The space shuttle is much more expensive than the space shuttle!
Based on the experience of the United States, it costs about 450 million US dollars to launch a space shuttle!
And how much funding does China's entire space system have in a year?
Even if the space system is funded for a whole year to the space shuttle, it can't afford to launch once.
Not to mention the cost, the cost of the space shuttle is much higher than that of the space shuttle.
Taking the United States as an example, the cost of a single space shuttle is about 3 billion US dollars, which is more than 10 times higher than that of the space shuttle!
China can't afford the space shuttle now.
Even if Liu Tao makes a space shuttle, China can't afford it.
On the contrary, the space shuttle is good quality and cheap.
Qian Lao smiled, "I feel relieved if you can say that."
"After the reform and opening up, our country has developed very fast, and the economy has obviously improved, but our foundation is still very weak. We scientists must be cautious and not waste." Qian Lao said: "I heard that you are going to launch a satellite for positioning and navigation?"
"Yes, I will name it 'Beidou Satellite', and build a 'Beidou Satellite Navigation System' through multiple satellites to establish a global positioning system." Liu Tao said: "Whether it is military or civilian, it will have a great effect."
The navigation system is not taken too seriously now, but Liu Tao knows how big the market is.
For missiles, precision-guided missiles can have an additional option of satellite navigation guidance in the future, thereby improving the accuracy of precision-guided missiles.
For the military, then they can have a clear understanding of the entire battlefield terrain, without worrying about getting lost.
For aircraft, satellite navigation can provide route navigation services.
For ships, there is a vast ocean, and satellite navigation does not worry about getting lost on the sea.
"If you can achieve this goal, it will be of great benefit to the country and the world." Mr. Qian nodded.
In theory, it is feasible to provide navigation through satellites and build a global satellite navigation system through multiple satellites.
After checking the time, Liu Tao said goodbye and left.
Then, he visited some people, all of whom were famous scientists. These people were either already famous throughout the country, or were currently unknown among ordinary people, but actually made outstanding achievements.
Liu Tao either invited them to serve as deans or professors.
In addition, he went to meet Wang Yongzhi. In order to let Wang Yongzhi serve as the vice dean and professor of the School of Aeronautics and Astronautics, he first had to ask for his consent, and then through organizational transfer.
Of course, such talents cannot stay in the college all the time. They all have multiple positions and are very busy.
In addition to visiting these scientists and scholars, Liu Tao visited Tsinghua University and Peking University. If he wanted to put "Southwest Associated University" on the fast track, he could not do without the help of these two universities.
Although part of the campus may not be built next year, it does not mean that he will not be able to enroll students in the college entrance examination next year.
Because the original Yunnan Normal College can be fully utilized.
However, Tsinghua University, Peking University and other universities also need to help and build to continue the friendship.
When Tsinghua University and Peking University learned that they were going to rebuild the Southwest Associated University, they were very surprised. Then, facing Liu Tao's proposal for cooperation, Tsinghua University and Peking University both gladly accepted it.
First, the two sides have a deep relationship, which is a friendship; second, Tsinghua University and Peking University have various cooperation with Panshan Group, and the cooperation between the two sides is very close.