A fire-arrow was a tube of gunpowder capped at one end and tied to a long stick. Burning powder made gas that rushed out the open end as a push, and the stick acted as a simple guidance system that kept it pointed one way. In 1232, Chinese defenders drove back Mongol invaders with "arrows of flying fire", simple rockets. NASA gives that date for the first use of true rockets. In the 1500s a German fireworks maker, Johann Schmidlap, invented the step rocket. A big rocket carried a smaller one that kept climbing after the big one burned out. In 1687, Isaac Newton published a book, usually called the Principia, that began the science of rocketry.

A rocket burns fuel to make hot gas. Rockets work by Newton's third law. The rocket pushes its exhaust backward, and the exhaust pushes the rocket forward. A rocket engine works in space, where there is no air, because the rocket carries its own oxygen. At liftoff, a rocket's push, called thrust, is stronger than its weight, so it rises off the launch pad. A rocket starts off slowly and goes faster and faster as it climbs. Most of a rocket's mass before launch is fuel and oxidizer, which together are called propellant.

Rockets must carry fuel for the fuel they lift. The heavier the cargo, the more fuel a launcher needs, and more fuel means bigger tanks and more weight. That is why most launchers use stages: pieces that fall away once they are used up. Rockets burn two kinds of fuel, liquid or solid. A solid rocket cannot be shut off once it is lit, but a liquid rocket's thrust can be controlled with valves.

A rocket that flew straight up would fall back to Earth when it ran out of fuel, so rockets tilt to the side as they climb. A rocket launched toward the east gets a boost from the speed of Earth's spin. To reach Earth orbit, a rocket must go about 8 km (5 miles) per second. A spacecraft in low Earth orbit travels about 17,500 miles per hour. To leave Earth for good, a spacecraft must reach escape velocity, about 11.2 km per second (7 miles per second). Scientists often say space begins at the Karman line, 100 km (62 miles) above sea level.

In 1914, Robert Goddard received two patents, one for a liquid-fuel rocket and one for a multistage rocket. In 1915 he proved by experiment that a rocket can make thrust in a vacuum. On March 16, 1926, he launched the world's first liquid-fueled rocket in Auburn, Massachusetts. It rose only 41 feet. As his rockets got bigger, Goddard moved his tests to Roswell, New Mexico. In 1949 the "Bumper-WAC", a small WAC Corporal missile riding on a German-made V-2, became the first human-made object to enter space, climbing to 393 kilometers (244 miles).

Sputnik was launched on an R-7 rocket that Soviet designer Sergei Korolev's team had built as an intercontinental ballistic missile, to put a scientific satellite into orbit before the end of 1957. On October 4, 1957, the Soviet Union launched Sputnik, the first human-made satellite. Sputnik sent out a radio "beep-beep" signal that people around the world could hear. It fell back into Earth's atmosphere and burned up on January 4, 1958. Reactions in the United States to Sputnik included shock and amazement and led to Congressional hearings that ultimately created NASA in 1958.

In April 1961, Yuri Gagarin of the Soviet Union was the first person in space. From the start, the plan was that Gagarin would not land inside his Vostok spacecraft after his April 12, 1961 orbit. On July 16, 1969, a Saturn V rocket launched the Apollo 11 astronauts on their way to the Moon. Two hours, 44 minutes after Apollo 11 launched, the Saturn V's third stage fired a second time for five minutes, 48 seconds. The burn sent the spacecraft toward the Moon.

The Saturn V stood 363 feet tall, taller than the Statue of Liberty. At launch it was the largest and most powerful launch vehicle the United States had ever built. The Space Shuttle had three major parts: the Orbiter that carried the crew, a large External Tank holding fuel for the main engines, and two Solid Rocket Boosters that gave most of the lift in the first two minutes of flight. The Space Shuttle was reusable. Its orbiter landed on a runway, and its solid rocket boosters were recovered from the sea.

As of November 2026, NASA's Space Launch System (SLS) first flew on November 16, 2022, on the uncrewed Artemis I test flight, making it the most powerful rocket NASA had launched. The SLS Block 1 stands 322 feet tall and weighs 5.75 million pounds fueled. At launch it makes 8.8 million pounds of thrust, 15% more than the Saturn V. NASA's launch pad sound suppression system dampens the sound and vibration of liftoff to keep the rocket and pad safe. 450,000 gallons of water are released onto the mobile launcher and flame deflector.

As of November 2026, Ariane 6, Europe's rocket, comes in two versions: Ariane 62 with two boosters, which can launch about 10.3 tonnes into low Earth orbit, and Ariane 64 with four boosters. Also as of November 2026, the Falcon 9 medium-lift rocket can carry payloads of up to 22,800 kg (about 50,000 pounds) into low Earth orbit. Its first stage can land upright after launch, so it can be flown again: SpaceX landed one on a landing pad near its Florida launch site while the second stage went on to launch communications satellites.

Words to know

• thrust: a rocket's push
• propellant: fuel and oxidizer
• stages: used-up rocket parts
• satellite: goes around Earth