The use of liquid fuel for rocket engines was considered as early as the beginning of 20th century. The Russian K.E.Ziolkowsky, the American H.Goddard and the German-Romanian H.Oberth worked independently on the problems of spaceflight and soon discovered that in order to succeed, rockets with high mass-flow were mandatory. Already then the combustion of liquid fuels seemed the most promising method of generating thrust.
However it was not later until these pioneers made their attempts, the first big liquid powered rocket the German A-4 became reality in the mid-forties. This rocket became successful as the V-2 weapon. Liquid oxygen was used as the oxidizer and ethyl alcohol as the fuel which gave the rocket more than 300KN of thrust. It`s range was 300km.
As the development of rocket engines continued, higher thrust levels were achieved when liquid oxygen and liquid hydrocarbon were used as fuel. This allowed the construction of the first intercontinental rocket with a range of more than 10,000km.
Cryogenics is the study of the production of extremely cold temperatures. This field of science also looks at what happens to a wide variety of materials from metals to gases when they are exposed to these temperatures. Cryogenics is a branch of physics concerned with the production of very low temperatures and the effects of these temperatures on different substances and materials. The temperatures studied in cryogenics are those below -243.67 degrees Fahrenheit (120 Kelvin); such low temperatures do not occur in nature.
These low temperatures have been used to liquefy atmospheric gases like oxygen, hydrogen, nitrogen, methane, argon, helium, and neon. The gases are condensed, collected, distilled and separated. Methane is used in liquid natural gas (LNG), and oxygen, hydrogen and nitrogen are used in rocket fuels and other aerospace and defence applications, in metallurgy and in various chemical processes. Helium is used in diving decompression chambers and to maintain suitably low temperatures for superconducting magnets, and neon is used in lighting.