Thursday, November 29, 2007

space shuttle

NASA's Space Shuttle, officially called Space Transportation System (STS), is the United States government's present manned launch vehicle. At launch, it consists of a rust-colored outer tank, two white, slender solid rocket boosters (SRBs), and a winged orbiter. The orbiter carries astronauts and payload such as satellites or space location parts into low earth orbit. Normally, five to seven astronauts ride in the orbiter, with two pilots, eight have been carried, and eleven could be accommodated in an urgent situation landing.
When the orbiter's work is complete, it fires its orbital maneuvering thrusters to drop out of orbit and re-enters the Earth's atmosphere. During the descent and landing, the shuttle orbiter acts as a glider and makes a completely unpowered landing. Five spaceworthy orbiters were build, of which three remain.

The Shuttle is the first orbital spacecraft considered for partial reusability. It carries large payloads to various orbits, provides crew rotary motion for the International Space Station (ISS), and performs servicing missions. The orbiter can also recover satellites and other payloads from orbit and return them to Earth, but this capability has not been used often. However, it has been used to return large payloads from the ISS to Earth, as the Russian Soyuz spacecraft has limited capacity for return payloads. Each Shuttle was designed for a expected lifespan of 100 launches or 10 years' operational life.

Thursday, November 22, 2007

Entertainment

Entertainment is an occasion, piece, or movement designed to give enjoyment or leisure to an audience. The audience may join in the entertainment passively as in actively as in computer games. The playing of sports and reading of journalism are usually included in entertainment, but these are regularly called activity more specifically, because they involve some energetic participation past mere leisure.

While people have laughing themselves since the beginning of time, the entertainment industry first became a leading force in culture in the 20th century with the development of latest electronic technologies of recording and spreading. Western peoples, tired of serious purposes and gathering massacre, turned to popular culture following the two world wars. The financial basis of this new culture was advertising of free or inexpensive entertainment program. In their peak, television networks were great selling machines which, besides entertaining people, prohibited both commercial and political markets by providing direct access to the group of customers. This "territory" is now in danger by the explosion and segmentation of media and especially by the growing importance of communication by computer which allows the consumer to look for out the informational message as an alternative of having it broadcast to him or her. A new system of world history sees Americans in changeover between a fourth, entertainment-based "society" and a future fifth evolution based on computer communication.