The rockets built by Robert Goddard in America, Hermann Oberth in Germany, and other pioneers around the world in the 1920s required complex and dangerous technology. The early rocketeers attacked the problems of this technology with no precedents to guide them and with almost no money. From Goddard's physics shop at Clark University to Oberth's back-lot lab at the UFA film studio and Rudolf Nebel's rundown barracks at the Raketenflugplatz, many of these fundamental problems were solved in workshops that were little more than garages.
At Raketenflugplatz, Rudolph Nebel, Wernher von Braun, and Klaus Riedel tried lining the combustion chambers of their MIRAK rockets with aluminum, beryllium, or molybdenum to prevent the rockets from exploding from internal heat. They also added flanges around the chambers to strengthen as well as cool them. Another major breakthrough in this area was to provide continual cooling by running the liquid oxygen which helped power the rockets through a jacket that surrounded the chamber.
Some of the biggest problems rocketeers faced were aerodynamic. The rockets had to be shaped to minimize wind resistance. Fuel pumps had to be small and light so they wouldn't unbalance the rocket, and yet strong and fast enough to keep it fueled and moving. Weight, most of which came from the rocket's fuel, had to be properly distributed in separate chambers so that the rocket stayed on course at take-off and during its flight. Goddard presented the ultimate solution to this last problem with his design for a "step" or "multiple stage" rocket.
