skyrocket

A skyrocket is a type of firework that uses a solid-fuel rocket to rise quickly into the sky; a bottle rocket is a small skyrocket. At the apex of its ascent, it is usual for a variety of effects (stars, bangs, crackles, etc.) to be emitted. Skyrockets use various stabilisation techniques to ensure the flight follows a predictable course, often a long stick attached to the side of the motor, but also including spin-stabilisation or fins. These rockets have been made at least since the early decades of the 20th century, and in many countries, including Japan and China. The older type of bottle rocket was typically a black powder skyrocket with an engine about 2 inches (5 cm) long and up to 0.375-inch (9-mm) diameter, mounted on a thin bamboo splint and often having a small report charge. Modern bottle rockets are small and very cheap. They are often sold by the box (but more commonly by the pack, or by the gross, a packet of 144 rockets) for less than US$0.20 each. Construction A bottle rocket consists of three major parts including: The rocket engine will typically use a black powder-type fuel, possibly with additives that produce a decorative spark trail as the rocket ascends, but other chemical reactions have also been used for thrust. The fuel is pressed to form a solid grain inside a cardboard tube, which is sealed at the top but open at the bottom with an air gap. When the fuel is ignited from the bottom, hot gases expand in the air gap and are expelled downward to propel the rocket upward. Other fuels are possible; a common alternative is whistle mix, to produce a whistling rocket. The nose cone, in addition to serving an aerodynamic role, typically contains the rocket's payload. This may include exploding fireworks, colored stars, a parachute, confetti, or other decorative items. The guide stick, in a bottle rocket lacking fins or other stabilizers, provides stability in flight. The stick's length and weight are sized to achieve this. Professional displays A common misconception about professional fireworks displays is that skyrockets are used to propel the pyrotechnic effects into the air. In reality, skyrockets are more widely used as a consumer item. Professional fireworks displays utilize mortars to fire aerial shells into the air, not rockets.