Rockets: Engines, Vehicles and Newton's Third Law

• A rocket can be a type of engine or a vehicle that uses a rocket engine.

How Rocket Engines Work

• Rocket engines produce thrust by burning fuel, typically turning it into hot gas.
• The expulsion of hot gas from the back of the engine propels the rocket forward.
• Unlike jet engines, rocket engines carry their own oxygen supply, enabling them to function in the vacuum of space.
• Liquid fuel rocket engines are used in the space shuttle orbiter and the Russian Soyuz.
• Solid-fuel rockets are used for the space shuttle's solid rocket boosters, fireworks, and model rockets.

Why Rockets Work: Newton's Third Law of Motion

• Rockets operate in space due to Newton's third law of motion: For every action, there is an equal and opposite reaction.
• The rocket expels exhaust backward, resulting in the exhaust pushing the rocket forward.
• As an example, when a person on a skateboard throws a bowling ball, the person and the ball move in opposite directions.

History of Rockets

• Rockets were first used in China in the 1200s for fireworks and warfare.
• They spread throughout Asia and Europe in the 1300s for similar purposes.
• Konstantin Tsiolkovsky described liquid-fuel rockets in 1903.
• Robert Goddard flew the first liquid-fuel rocket in 1926.
• German scientists, including Hermann Oberth, further developed liquid-fuel rockets.
• During World War II, Germany used rockets as missiles.
• In 1957, the Soviet Union launched the first satellite using a rocket.
• In 1961, Soviet cosmonaut Yuri Gagarin became the first person in space via a rocket.
• In 1969, the United States used a Saturn V rocket to land Neil Armstrong and Buzz Aldrin on the moon.

How NASA Uses Rockets

• Early NASA missions used rockets developed by the military, such as the Redstone for Alan Shepard's flight and the Atlas for John Glenn's orbit.
• Gemini missions used the Titan II missile to launch astronauts.
• NASA's first astronaut-launching rockets were the Saturn I, Saturn IB, and Saturn V, used in the Apollo missions to the moon and for launching the Skylab space station.
• The space shuttle utilizes rocket engines to transport astronauts into space.
• NASA employs rockets to launch satellites, send probes to other planets, and for scientific research using "sounding rockets" that ascend and descend without orbiting.
• NASA uses rockets such as the Atlas V, Delta II, Pegasus and Taurus to launch satellites and probes.

NASA's Future Rocket Plans

• New rockets are under development that resemble earlier rockets in shape.
• These rockets will ferry astronauts and supplies to the International Space Station.
• NASA is developing a heavy lift vehicle to carry substantial equipment into space for exploring other worlds, potentially sending humans to Mars.