Sailing ship

A modern sailing ship is any large wind-powered vessel. Traditionally a sailing ship (or simply ship) is a sailing vessel that carries three or more masts with square sails on each. Large sailing vessels that are not ship-rigged may be more precisely referred to by their sail rig, such as schooner, barque (also spelled "bark"), brig, barkentine, brigantine or sloop.

Characteristics

There are many different types of sailing ships, but they all have certain basic things in common. Every sailing ship has a hull, rigging and at least one mast to hold up the sails that use the wind to power the ship.

The crew who sail a ship are called sailors or hands. They take turns to take the watch, the active managers of the ship and her performance for a period. Watches are traditionally four hours long. Some sailing ships use traditional ship's bells to tell the time and regulate the watch system, with the bell being rung once for every half hour into the watch and rung eight times at watch end (a four-hour watch).

List of Latin phrases (S)

This page lists English translations of notable Latin phrases, such as veni vidi vici and et cetera. Some of the phrases are themselves translations of Greek phrases, as Greek rhetoric and literature reached its peak centuries before the rise of ancient Rome.

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Notes

References

Centaur (rocket stage)

Centaur is a rocket stage designed for use as the upper stage of space launch vehicles and is currently used on the Atlas V. Centaur boosts its satellite payload to geosynchronous orbit or, in the case of an interplanetary space probe, to or near to escape velocity. Centaur was the world's first high-energy upper stage, burning liquid hydrogen (LH2) and liquid oxygen (LOX), and has enabled the launch of some of NASA's most important scientific missions over its 50-year history.

Centaur was the brainchild of Karel J. "Charlie" Bossart (the man behind the Atlas ICBM) and Dr. Krafft A. Ehricke, both Convair employees. Their design was essentially a smaller version of the Atlas, with its concept of using lightweight "stainless steel balloon" tanks whose structural rigidity was provided solely by the pressure of the propellants within. To keep the tanks from collapsing prior to propellant loading, they were either kept in "stretch" or pressurized with nitrogen gas.

Centaur uses a common double-bulkhead to separate the LOX and LH2 tanks. The two stainless steel skins are separated by a 0.25 inch (6.4 mm) layer of fiberglass honeycomb. The extreme cold of the LH2 on one side creates a vacuum within the fiberglass layer, giving the bulkhead a low thermal conductivity, and thus preventing heat transfer from the relatively warm LOX to the super cold LH2. It is powered by one or two RL10 rocket engines (SEC and DEC variants respectively).