How rockets work: A complete guide
How rockets lift off Writers and inventors have dreamt of exploring the universe beyond Earth for centuries, but the real challenges of traveling into space only became clear in the 19th century. Experimental balloon flights showed that Earth’s atmosphere thins out rapidly at high altitudes, and so even before powered flight became a reality, engineers knew that devices that create a forward or upward force by pushing against a surrounding medium like air — such as wings and propellers — would be of no use in space. Another problem was that combustion engines — machines such as steam or gasoline engines that generate power by burning fuel in the oxygen from Earth’s atmosphere — would also fail in airless space. Research From Nasa Fortunately, a device that solved the problem of generating force without a surrounding medium had already been invented — the rocket. Initially used as weapons of war or in fireworks, rockets generate a force in one direction, called thrust, by the principle of action and reaction: exhaust fumes released by explosive chemicals are pushed out of the back of the rocket at high speed, and as a result the rocket is pushed in the other direction, regardless of any surrounding medium, NASA explains in this primer (pdf). The key to using rockets in space is to carry a chemical called an oxidant that can perform the same role as oxygen in Earth’s air and enable the fuel to combust.