Notes

Konstantin Tsiolkovsky first described life aboard space stations 70 years before the first space flights.
Robert Goddard, the Father of U.S. Rocketry, launched the first liquid-fuel rockets in the 1920s.
Herman Oberth designed the V-1 and V-2 rockets. The V-2s were the first objects launched into space.
Sputnik, the first satellite, was launched by the Soviets in 1957, starting the "Space Race."
The early U.S. space programs, Mercury, Gemini, and Apollo, pioneered manned space flight.
On June 20, 1969, Neil Armstrong was the first man to set foot on the Moon. This was part of the Apollo 11 mission.Once Americans reached the Moon, the next task was to learn how to live in space. From Skylab to the Space Shuttle to the International Space Station, astronauts are living in space for longer and longer periods of time. Where we may go in the future is uncertain. Yet it does seems certain we will go further into space.For rockets, this means that the burning of fuel causes expanding gases to escape rapidly out of the nozzle. This action creates the reaction called thrust, which causes all motion of the rocket.Since there is no air in space, space rockets use propellants. Propellants combine fuel and an oxidizer to create thrust. A solid-fuel rocket, once it's ignited, simply combines the fuel and oxidizer in a dry chemical and usually burns all of this propellant.Liquid-fuel rockets are more complex. The fuel and oxidizer are stored in separate storage tanks, then pumped to the combustion chamber. In this chamber, they're combined and burned to provide the rocket's thrust. Liquid-fuel rockets can be stopped and later reignited.
Two other types of engines are already in use. Nuclear and electric engines don't use a chemical reaction to produce thrust. Instead, by heating liquids they produce expanding gases to create thrust. Future technologies might include a "solar sail" to harness the energy of the Sun and other stars.Thrust is the force that moves a rocket or plane forward through the air. Weight is exerted by the pull of gravity. In a rocket, thrust overcomes weight. In a plane, lift overcomes weight. The force of air against the forward motion of a rocket or plane is called drag. Lift is created by a wing as it moves through the air. Airplane wings are designed for upward lift to overcome the plane's weight. Rocket fins use lift for stability.The Center of Gravity is the point inside an object where all the object's mass is perfectly balanced.

An object's Center of Pressure is that point where there is exactly the same amount of surface area in front of and behind it. The Center of Pressure only exists when the object is moving through the air. For stability, the Center of Pressure must be behind the Center of Gravity. Good rocket design moves the Center of Pressure toward the end of the rocket and the Center of Gravity toward the nose cone. The greater the distance between the two centers, the more stable the rocket will be.When you build a rocket, you make a nose cone, a body tube, and fins, and then you assemble the pieces. At every step of the way, you use good design to reduce the rocket's drag. Before launching a rocket, you must perform a "swing test" to check its stability. Then you can calculate the altitude of the rocket's flight.