Space Scientists

For this one, we'll just take a look at Tsiolkovsky since there's too much ground to cover.

#### Konstantin Tsiolkovsky (1857-1935)

• During his lifetime, Tsiolkovsky was a recluse, and almost a hermit. As a result, he never achieved much.
• However, he proposed many important new ideas that influenced other scientists in their work on space travel.
• His ideas couldn't be brought to fruition mostly because they couldn't with the technology at the time.
• He proposed 3 major ideas:
• The first idea was the principles behind rocket propulsion.
• Originally, people thought rockets could not be used in space as there was no air to "push back on."
• Tsiolkovsky used the Law of Conservation of Momentum and Newton's Third Law to demonstrate that fuel expulsion could in fact be used in space travel.
• He showed that fuel expelled one way will cause the rocket to move the other way (See here)
• Thus, he was the first person to suggest the exploration of Space using rockets.
• The second idea was the use of liquid fuels
• He suggested the use of liquid oxygen and hydrogen fuels as they were the lightest, and would provide the greatest exhaust speed.
• This would produce the most force as $F = \frac{\Delta mass}{\Delta time} \times v_{exhaust}$
• In addition, the use of liquid fuels allows for the exhaust speed to be easily varied and controlled
• This suggestion has had a large impact was it allows for the intermittent firing of rockets and sequential shutdowns.
• Some satellites utilise this heavily to switch orbits.
• The last idea was the concept of multi-staged rockets
• He visualised a 20 staged rocket train that dropped stages when fuel ran out to cut weight and improve efficiency.
• Although he did not build it, and that a rocket train idea was a bit ridiculous, it was vital in launches with large payloads.
• It was used in the manned space missions like Apollo 20.
• Other than that he also made some other developments:
• Developed wind tunnels to study aerodynamics.
• Investigated air friction and its heating effects
• Calculated Earth's escape velocity
• Presented ideas to help with high g-forces and weightlessness.
• ASSESSMENT: Although Tsiolkovsky didn't directly impact space exploration, his ideas are vital to spaceflight today.

#### Robert H. Goddard

• Inspired by Jules Verne, Goddard decided to dedicate his life to rocketry.
• He built and tested the first liquid rocket.
• Unlike Tsiolkovsky, Goddard tested and engineered his own rockets, patenting those that were successful.
• His ideas of liquid fuel rockets in space were initially ridiculed, however his continued success with many technical problems solves such as fuel valving for throttle, start and stop, fuel injection, engine cooling and ignition soon made it apparent that his work was valuable.
• Two wars would boost his research into liquid fuel rockets used in both space exploration and the military.
page revision: 2, last edited: 03 Nov 2011 05:30