Iron Cross

"The propellant uses ethanol (alcohol) and liquid oxygen as fuel. They will be introduced into the combustion chamber through pipelines at a certain ratio to burn violently and provide power for the rocket. Since they are extremely dangerous, we usually only inject them before launch." Blau En pointed at the sergeant wearing a full protective suit in the distance, "Once the rocket fails to ignite successfully during launch, the liquid needs to be emptied by professional sergeants as soon as possible, otherwise it will easily explode."

Hoffman frowned: "It sounds very troublesome and dangerous. Is there a better way?"

Braun shook his head: "We have tested a lot of fuels. The formula currently used is the most stable and efficient, and it is easy to obtain. The disadvantage is that it is less safe. Maybe we can find a better formula in the future, but this It takes time.”

"There's no rush."

Major General Dornberger added: "Rocket propellants can be divided into two types: liquid fuel and solid fuel. The A-4 rocket is a typical liquid fuel, and Rheinmetall-Bosch has undertaken a multi-stage solid fuel rocket development project. According to the technical parameters, its overall weight is about 1,700 kilograms, and it can carry a warhead of about 1,200 kilograms. The maximum range is more than 200 kilometers. We call it the "Rhine Messenger" internally. Compared with liquid fuel, solid fuel can make the missile body more dense. It is small and can store fuel for a long time in advance, but the technology is more difficult and the overall progress is currently inferior to the A-4 project.”

Hoffman nodded. He knew the trend of rocket development: solid fuels later mostly became missiles, while liquid fuels switched to the task of satellite launches.

"Three minutes to prepare." Hoffman and others were introduced to a special observation trench. From this distance, they can not only fully observe the status of the rocket, but also avoid danger-even if the rocket explodes on the spot, they can still guarantee it in this trench. Safety. Hoffmann thought of the launch sites and monitoring centers seen on TV screens in later generations, and was deeply moved by the power of scientific and technological development, but now the Peenemünde base is the pioneer of the rocket industry for all mankind.

"One minute to prepare."

"Ready, launch!" The last 10-second countdown has not yet been introduced. After the time is up, the technical sergeant next to Braun presses the button hard to activate the radio signal, and the huge A-4 rocket immediately erupts from the tail. Fierce flames erupted, turning half of the sky red. Following an earth-shaking roar, the rocket soared into the sky and soared upwards, getting faster and faster. It drew a track in the sky and then gradually disappeared from the crowd. within the field of vision.

"A metal plate called a gas rudder is placed at the rear end of the rocket. It can change the airflow to induce the rocket to move in the right direction, and it can also be used to change the forward path." Braun said, "There are some gas rudders near the rocket's intended landing point. Our observers, they will pass the data over.”

"How do you guide the rocket? In other words, how do you make the rocket hit the target accurately?"

Braun drew a schematic diagram and explained it in the simplest terms: "The rocket uses inertial guidance. After launch, it climbs at a vertical or nearly vertical angle. When the fuel is burned, the propeller will push the rocket to a certain height. and speed, at this time it is about 80-100 kilometers above the ground - that means that it has rushed out of the atmosphere, and the rocket that has lost power will continue to shoot toward the target along a parabola according to inertia and the influence of gravity at this altitude. Due to wind direction and other factors, the torque the rocket receives during launch is not uniform and constant, so it is difficult to ensure that the actual range is consistent with the designed range. We installed a gyroscope on it to adjust the attitude to ensure that the landing point does not deviate too much to improve Accuracy - we call it the circular probability deviation. The current deviation is still about 5 kilometers. We are trying to install the radio guidance method used on aircraft on the rocket, hoping to help reduce the hit error..."

Gerhard Degenkobe was Speer's right-hand man in the Ministry of Armaments. He once oversaw the locomotive production of Krupp and Henschel. He spent half a year more than tripling the output of the two companies. Now coordinating the production of tank armaments for the Third Reich, he was unusually sensitive to the producibility and cost of military equipment, so he casually asked about the price of rockets.

"If the development costs are not amortized, the current cost of each one is about 150,000 marks. After mass production, the cost can be reduced to 120,000 marks or less." Braun couldn't answer this question, Dornber Major General Ge answered for him.

Hoffmann gave a noncommittal "hmm", but he was actually thinking: 120,000 marks is equivalent to one Panzer IV tank. Considering that more than 8,000 V2s were manufactured, if it were replaced with Panzer IV tanks, I'm afraid the Third Reich would have more. With tens of thousands of tanks, it seems clear how the effectiveness of the two compares.

While waiting for the experimental data to come in, Dornberg took Hoffman and others to visit the next project. This is also a rocket project. The internal development number is Fischler Fi-103 (V1 missile precursor). It was designed by a design team led by engineer Robert Rüssel of Gerhard Fessler GmbH in the Kassel area. The rocket body is spindle-shaped and adopts a mid-wing design. The front main wing and tail wing are both rectangular straight wings. The maximum diameter of the missile body is 0.82 meters, the wingspan of the missile is 5.3 meters, and the length is about 8 meters. From the appearance, it looks like an ordinary aircraft, except that a tubular engine nacelle is installed on the upper part of the vertical tail and connected to the fuselage, and a ramjet engine is installed in the cabin.

Pointing to the chimney-like thing at the rear of the projectile, Dornberg said: "This is the Argus thrust device. It is launched from an inclined rail. It is equipped with a predetermined guidance device and guides the rocket to fly in the specified direction, all the way in the atmosphere. It is also not very high above the ground, which is significantly different from the A-4 rocket. The total weight of the rocket is expected to exceed 2,000 kilograms, and the warhead is designed to install about 800 kilograms of Amato high-energy explosives. Its advantages and disadvantages are equally outstanding. The engine can only operate at lower altitudes and is difficult to repair and maintain. At the same time, the air inlet valve will soon be worn and penetrated, but from the perspective of a single-use weapon, this seemingly simple engine has its own merits. "It has great advantages: it has a simple structure, low cost, and high thrust (can reach more than 270 kilograms). In addition, it uses low-grade gasoline as fuel instead of using precious high-octane aviation fuel."

"What about its speed and range?" Hoffman pointed at the missile body and said, "It looks like a small unmanned aircraft. I wonder what its advantages are compared to an airplane?"

"It does not require a pilot to fly, it is faster than conventional bombers, and it is cheaper to build - these are the three main advantages. Its stable cruising speed after launch is about 650 kilometers per hour, and its range is more than 240 kilometers. If it is launched from the French coastline, It’s more than enough to reach the south of England, and it may be no problem to reach London. It’s not that we don’t install more fuel, it’s because this engine can only work for so long,” Major General Dornberg said with a smile, “The progress of this project is faster than A. The -4 rocket wants to be faster and is almost successful. Basically, this is an unmanned jet aircraft. It also relies on a set of gyroscopes to maintain flight stability, controls the orientation through a magnetic compass, and attaches a barometric altimeter to control its flight. Altitude. The current problem is to improve the stability of the flight attitude and the accuracy of the attack target.”

Speer asked: "How safe is it?"

"It's more reliable and safer than the A-4 rocket. After all, it only contains gasoline." Dornberg explained, "This one has been filled with fuel. We will demonstrate it directly to the head of state later. Its disadvantage is its speed during flight. It’s not fast, and the landing accuracy and flight attitude stability are poor. We are still working hard to improve it.”

At this time, news came that the A-4 rocket was successfully launched: the rocket reached a flight altitude of 96.5 kilometers and flew for a total of 296 seconds. During this period, it flew a total of 201 kilometers. It exploded when it was 4 kilometers away from the intended target. It was the highest before the explosion. The speed reached 5280 kilometers per hour (about 4.8 times the speed of sound), exceeding the speed of any known aircraft or even artillery shells. Everyone began to applaud and was full of curiosity about the launch test of the second project.

Under the watchful eye of the observers, the test rocket, which was fully fueled and all systems had been carefully checked, lay quietly on a specially designed rail-wheeled launcher, waiting for the final launch command. This is a 48-meter-long wooden slope-shaped launcher that uses a steam ejection system. There is a piston groove on the launcher. A dumbbell-shaped piston is placed in the groove during launch. The rocket is placed in the piston groove by a trolley. And secure it with safety pins to prevent it from sliding out. The entire system includes a reaction chamber and two chemical tanks: the chemical tanks are respectively equipped with hydrogen peroxide (HO) and (KMnO4) particle catalysts. The reaction chamber is connected to the rear end of the piston groove at the bottom of the launcher through a pipe. During launch, hydrogen peroxide is extracted and a chemical reaction occurs in the reaction chamber to generate a large amount of hot steam. After neatly accumulating to a certain pressure, the dumbbell-shaped piston is pushed to make the trolley move forward quickly to ensure that the rocket gains a valuable initial speed.

The interesting launch process is about to begin.