Editing Rocket engine (section)

===Modern rocketry===
Slow development of this technology continued up to the later 19th century, when Russian [[Konstantin Tsiolkovsky]] first wrote about [[liquid-propellant rocket|liquid-fuelled rocket engines]]. He was the first to develop the [[Tsiolkovsky rocket equation]], though it was not published widely for some years.

The modern solid- and liquid-fuelled engines became realities early in the 20th century, thanks to the American physicist [[Robert Goddard (scientist)|Robert Goddard]]. Goddard was the first to use a [[De Laval nozzle]] on a solid-propellant (gunpowder) rocket engine, doubling the thrust and increasing the efficiency by a factor of about twenty-five. This was the birth of the modern rocket engine. He calculated from his independently derived rocket equation that a reasonably sized rocket, using solid fuel, could place a one-pound payload on the Moon.