What caused scientists such as robert goddard, konstantin tsiolkovsky, and hermann oberth to experiment with rocket technology in the early twentieth century?

 Many of these men were interested in a way of achieving higher altitudes than were possible for lighter-than-air balloons. Others saw the chance to enhance the military power. Other saw the opportunity to get to see the universe. For example, Robert H. Goddard conducted a variety of practical experiments in rocketry and he published a mathematical analysis of what is today called the meteorological sounding rocket. Konstantin Tsiolkovsky proposed the idea of space exploration by rocket and he suggested the use of liquid propellants for rockets in order to achieve greater range. Because of Oberth's work, many small rocket societies sprang up around the world