roccoschili Page 519
Page 519
Re-entry into the atmosphere is also the time for the gliding body nicknamed the "water drift bomb" to show its power.
Generally speaking, the flight trajectory of a ballistic missile is similar to a parabola. After launching, it flies into space for more than 100 kilometers or even hundreds of kilometers, and then plunges down.
If the conical warhead is changed to an acute-angled triangular gliding body, which has the conditions to generate lift, when it plunges down from space, it will not plunge straight down in the atmosphere of 20-100 kilometers, but will be "supported" by the atmosphere , Slowly glide down from 100 kilometers.If the support is particularly strong, the gliding body rises back to the space of more than 100 kilometers, which is a variant of Qian Xuesen's ballistic "Sanger ballistic".The gliding body is from an altitude of 100 kilometers to a height of 20 kilometers, and its speed is from Mach 6~7 to Mach 3. At Mach 20 at 3 kilometers, the missile-borne radar can be turned on. Of course, it can also be directly pierced to the ground.
This is the first advantage of the water drift bomb, the range of the missile is increased by one gear.The near guide changes to the medium guide, the medium guide changes to the far guide, and the far guide changes to the intercontinental guide.
The second advantage of the water drift bomb is that the ballistic trajectory is unpredictable when it re-enters the atmosphere.
But this is also a shortcoming sometimes - if it is not good, the own people will not be able to predict where the floating bomb will fly.
This is how the missile test on December 12 overturned.
From Urad Zhongqi to Hechudaba, the tracking radar station showed that the ballistic of the missile was normal.Near Hechudaba, the missile re-entered the atmosphere and was lifted up.The herdsmen around here saw the miraculous light in the sky that night.
But just this time, the Chudaba and Jiuquan tracking radar stations found that the lifted missile glider flew crookedly.
The gliding body descends from 100 kilometers to 50 kilometers, and enters the top of the stratosphere. At this time, the flight trajectory is even more crooked.The radar continued to track and scan. When the gliding body went from 50 kilometers to 20 kilometers in height, even the naked eye could see that the direction of the gliding body was off.It finally fell to the ground, 43 kilometers away from the point of impact.It took search forces two hours to find the wreckage of the missile on the ground.
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"Obviously, when the boost-glide trajectory is adopted, the inertial guidance system cannot effectively locate the position of the missile itself, neither the electromechanical gyro nor the laser gyro," Tang Hua said. Even if the inertial navigation system does not strike, the frequent direction changes will greatly exceed the cumulative error of the inertial navigation system."
"This test was too aggressive," Qian Xuesen said. "Not only was the inertial guidance system unable to withstand it, but I guess the aerodynamic control surface of the gliding body failed when it hit the water for the first time."
"The boost-glide trajectory can be put into practical use, but the prerequisite is to abandon the inertial navigation system during the reentry phase and adopt another guidance method."
Tang Hua found a piece of paper, drew a circular horizon, and marked a few points in the sky as well as the missiles flying in space, and then connected the missiles with a few points with a line, "Satellite navigation system."
"When the missile is at an altitude of 20 to 50 kilometers in the atmosphere, there is an ionospheric black barrier on the surface, and it cannot send and receive electromagnetic waves. However, in a short period of time before and after that, it can use satellite triangulation to determine its position and speed, and then use the computer on the missile to Compare the scheduled track, determine the error range, and calculate the aerodynamic rudder angle required to correct the course. If the control command is correct, the course can be corrected.”
"This involves the second prerequisite. Not only must the missile be equipped with a computer, but it must also be equipped with an ultra-high-speed digital processing chip, so that the gliding body can complete its own positioning during the short period of space-atmosphere flight. , track comparison and control command calculation functions.”
Qian Xuesen: "It seems that these two prerequisites are not easy to meet. The satellite navigation system is especially difficult."
Tang Hua: "Actually, the latter condition is equally difficult. To complete such a large amount of calculation in a short period of time, the main frequency of the digital processing chip may reach G Hz, or at least 800 MHz. It must also be resistant to high temperature and Radiation professionally packaged chips...It would be great if the electronic information industry can achieve this step within 20 to 25 years.”
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In view of the fact that the first round of water drift bombs was fired far away from the topic, the project was frozen first.
When the satellite navigation system is formed, the water drift bomb can also carry out nuclear strikes on fixed targets on the ground.Of course, the trajectory of the water drift bomb is not generally erratic, and the end is repeatedly corrected, with amazing accuracy, which can accurately feed the nuclear bomb to the top of the opponent's hard target.
To achieve accurate hitting of moving targets, that is T-ASBM. I don’t know when this large system will be completed.
"How is the progress of the rocket engine of the DF-2 missile?" Tang Hua thinks it is better to pay attention to the ballistic missile of the traditional route.
"A concept prototype has been built, and it may be sent to Chengde for testing at the end of January and early February," Qian Xuesen said. "Actually, I am not very satisfied with the theoretical parameters of this concept prototype. If possible, the engine team will do a redesign next year." .” Tang Hua: “It will be 1 in three days.”
Qian Xuesen: "According to the plan, in July 1957, Dongfeng-7 will be tested in a full state, and there is a margin of time. Now I am mainly considering the first-stage engines of Dongfeng-2 and Dongfeng-2. In a certain period of time, it may Development and testing should be carried out at the same time. The technical specifications of Dongfeng-3 have been improved by a bit, and the technical span is large. If the work is done in advance, there will be plenty of time to overcome the bottleneck if it encounters a bottleneck in the middle.”
Tang Hua: "That's true. Dongfeng-3 is a long-range guided missile, and it may also be used as the prototype of the first launch vehicle. If the development progress of this is delayed, the overall plan for aerospace and missiles will be delayed."
DF-2 is a two-stage liquid rocket, the second stage borrows DF-1's 42-ton thrust rocket engine, and the first stage is a newly developed 65-ton thrust engine. The general outline of DF-3 has also been planned, two-stage liquid rocket, because the weight of the whole bomb has increased sharply, the first-stage rocket engine may reach 100 or even 120 tons, and it is still a "one" engine with one pump and four jets.
In view of the fact that the progress of the missile/rocket line is slightly faster now, the DF-3 was probably already in service when the atomic bomb exploded, and the DF-2 became a true transitional model.In the end, what Tang Hua wanted to mass-produce and deploy was not the DF-2, but a second-generation intermediate missile with a range of 1500 to 2000 kilometers, solid propellant, mobile launch, and high precision.
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On December 12, after Qian Xuesen returned to Beijing with the DF-27 gliding body that had been broken into eight petals, the Wuliangsuhai missile test base was temporarily occupied by the Air Force Air Defense First Brigade.For the next three months, this will be the testing and training ground for the First Air Defense Brigade.
According to the division of equipment established during the War to Resist US Aggression and Aid Korea, the field mobile short-range and medium-range air defense systems belong to the Army/Marine Corps, and are mixed with small-caliber anti-aircraft artillery in the form of an anti-aircraft artillery division; the long-range air defense system belongs to the Air Force, and the Air Force The air defense brigade is organized as a unit.
A long military column stopped at Wuliangsuhai Railway Station, and the heavy trucks and trailers loaded on the flatbed drove off one after another.Finally, the trailer and S75 anti-aircraft missiles were also lowered and combined with the heavy trailer.
The S75 is a little shorter than the S25 air defense missile, but it has a total length of 10.6 meters, which is much thinner.
The pointed and long missile is equipped with 4 sets of wings from the head to the end of the booster, which makes the S75 missile look particularly energetic-of course, the 4 sets of wings are just for sale. From the perspective of practicality, So many wings indicate that the stability of the missile in the initial stage of flight is inherently insufficient, so heavy and large-area wings have to be used to make up for it.
"Do you know what Commander Liu called this missile?" Senior Colonel Zhang Fengyi, the commander-in-chief of the base, asked the brigade commander who brought the whole brigade to the test site.
"I don't know, wow, in the past year, it has been Deputy Commander Chang who has been guiding our work."
Lao Zhang: "Commander Liu said that this missile is designed to attack RB57, and it can be called 'Friends of Canberra'."
Chapter 109, U-2 is coming soon
After the first air defense brigade of the Air Force received the Hongqi-3 (S75) missile, the biggest difficulty encountered was: there was no high-altitude target drone.
1950年底空军用拖曳滑翔机当红旗-1的靶机，红旗-2导弹试射时做了一款升限11000米的遥控靶机。红旗-4试射时配用的新靶机升限15000米，这是拿米格-15的涡喷发动机做动力的，价格还比较贵。
The problem is that the maximum interception altitude of Hongqi-3 is 25000 meters.
This is still the basic type. The Soviet Union is making an improved missile called V-750VN. If equipped with this type of missile, the maximum interception altitude can reach 27000 meters.
防空第一旅从1月到3月，训练的科目有导弹系统机动、展开收起、基本操作，实弹打靶就只有三个科目：1500米低空打靶（红旗-3最低拦截高度就是1500米，再低导弹可能打不准）、6000~8000米中高空打靶和15000米高空打靶。
In mid-1956, there were still two 18000-meter target drones, which were ultra-high-altitude target drones imported from the Soviet Union—the Soviet missile force could only use 18000-meter target drones to shoot targets.
鉴于RB-57“堪培拉”的最大平飞高度是18200米，苏联空军和防空军都认为，打18000米的靶是够用了的。至于S75导弹打25000米高度，那只是为了预防万一。甚至防空军还放出这样的话：“这个世界上不可能有飞到20000米的侦察机”。
Even the current mainstream air defense radar in the Soviet Union has a limited beam angle. At a distance of 30 kilometers, an aircraft that detects an altitude of 19800 meters is the upper limit of radar waves, and the upper limit of a distance of 20 kilometers becomes 13200 meters.
As for China, the Hangzhou/Nanjing Radar Institute has never considered 19800 meters as the upper limit. The radar institute is scratching its head for introducing a digital phase shifter to allow the radar to freely reach a large upward shooting angle.
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"Area 51" in Nevada, USA.
The area marked on the map here is Area 51, and its correct name is "U.S. Air Force Nevada Aircraft Test Center".
A black aircraft with a length of 19 meters and a wingspan of 31 meters flew slowly over Area 51.
This is the U-2 of Lockheed Skunk Works. How secret is this aircraft?In order not to attract the attention of the outside world, its design code is CL-282, its nickname is Angel (Angel), and its official name is U-2 (Multipurpose Aircraft-2), all of which have nothing to do with the R of the reconnaissance aircraft.
Although the plane that looked like a "super-large glider" was slowly leveling off, it was not easy for the pilot to control the plane: At this time, the plane's flying altitude had reached 22300 meters, and the ground control center was still calling the pilot on the radio. Fly a little higher.
The pilot already felt a little out of control of this guy.
At 22300 meters, the maximum flight speed of U-2 is 760 km/h, and the stall speed is 748 km/h.That is to say, the pilot must keep the speed of the aircraft within the small range of 748~760, neither fast nor slow.As long as it is lower than 748 km/h, the lift of the aircraft's wings is not enough to counteract the gravity, and the aircraft will fall down.
If the speed exceeds 760, it will rise upwards, but at an altitude of 22 kilometers, even if you step on the accelerator, the speed of the plane will slowly rise at 1 kilometer per hour.
The second thing that pilots feel bad about is that this plane...it's hard to fly straight forward.
An aircraft with a short fuselage and long wings has poor stability. If the airflow encountered by the left and right wings is slightly unbalanced, the aircraft will be crooked.
Under the command of the ground control center, the U-2 prototype took half a day to climb to 22600 meters. After seeing that the remaining fuel was running out, it returned.
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