Rocket technology

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Under rocketry refers to all knowledge, materials, procedures and processes leading to successful construction, launch and operation of rockets contribute.

history

Main article: Beginnings of rocket construction

The first evidence of the technology of a three-stage rocket from the period between 1529 and 1556 goes back to Conrad Haas . With his work Ars magna artilleriae pars prima from 1650, the weapon designer Casimir Simienowicz left the next known description of three-stage rocket technology.

After the Second World War, the USA and Russia secured large parts of the German missile know-how. The US accelerated its advance towards the end of the war in order to reach certain places before the Russians.

For example, on April 11, 1945, US troops occupied the production facilities in Bleicherode , the Mittelwerk . One hundred A4 missiles were shipped to the United States; they formed a basis for the US missile program there.

A few days earlier, the rocket pioneers around Wernher von Braun and General Walter Dornberger had gathered in hotels and barracks in southern Germany in the vicinity of Oberammergau in order to escape the Soviet occupiers. After the occupation of Upper Bavaria by American troops, the English-speaking brother Magnus von Braun contacted the Americans. During the war, the Operation Overcast campaign was specifically looking for German scientists in order to gain access to their knowledge. On May 2, 1945, von Braun and some scientists from his team surrendered to the US armed forces in Oberjoch .

Wernher von Braun was housed by the Americans in Bad Kissingen in the winter of 1945/1946 , which was the location of Operation Overcast and where many scientists from Peenemünde stayed. The scientists were brought to the USA in the spring of 1946 after more than a hundred rocket developers had been shipped to the USA as part of Operation Overcast ( called Operation Paperclip since March 1946 ). Walter Dornberger from the Heereswaffenamt also found a new sphere of activity there in 1947. Von Braun initially worked in Fort Bliss ( Texas ), under the supervision of US troops, and from 1950 headed a team of more than a hundred developers for the US Army in Huntsville (Alabama) .

In October 1946, more than 2000 engineers and their families were deported from the Soviet occupation zone to the Soviet Union (" Operation Ossawakim ") to work on military developments ( nuclear technology and rocket technology) and to disclose scientific achievements.

Technical requirements in rocket construction

Unlike airplanes, rockets can also be used outside the earth's atmosphere. They need neither the buoyancy of the air nor its oxygen, but carry all the substances necessary for propulsion in solid or liquid form. However, because of the tanks , lines and pumps required , they are also more prone to malfunctions, which means long development times and high costs. The control is more complicated than in aviation.

Rockets work on the principle of recoil by combustion gases , which is stronger, the more and faster the gases escape from the nozzle and the lighter the rocket shell is. On the other hand, it needs a certain strength, which is why favorable mass ratios (starting to empty mass) can only be achieved with an extremely lightweight construction . The outflow speed increases with the temperature in the combustion chamber - which poses further technical problems for the most effective drives.

In summary, this means that as much of the total mass of a rocket as possible should be used for the explosive fuel possible and only a little for the rocket structure. The latter must nevertheless remain stable, reliable and easy to control. These contradicting requirements present rocket science with numerous difficult challenges.

Design and type of missiles

The basic choice of the rocket type (s) depends on the purpose and size. A distinction is made above all:

Design of the rocket shape and propulsion system

Material, durability and operation

Reliability and false starts

The reliability of the individual components for rockets with many thousands of individual parts must be over 99.999 percent. An optimum between many contradicting aspects is to be sought here, among others

  • between risk, costs and development time,
  • between innovation , tried and tested and complex test runs,
  • Structure, durability, weight and fuel consumption,
  • Reserve systems, weight gain and energy consumption, and
  • between error messages, control and autonomy.

The failure rate of various missile types is usually in the range of a few percent. In some cases it can be reduced to 1–2 false starts per 100 starts, as in the Delta series. Numerous variants have been tested and gradually improved over the past 40 years - from the first types (1960) to Delta I, II and III to Delta IV .