If you can't explain it simply,you don't understand it well enough.

-Albert Einstein-

Space Shuttle

Space Shuttle

Space Shuttle

  


The Space Shuttle was a partially reusable low Earth orbital spacecraft system operated by the U.S. National Aeronautics and Space Administration (NASA), as part of the Space Shuttle program. Its official program name was Space Transportation System (STS), taken from a 1969 plan for a system of reusable spacecraft of which it was the only item funded for development.[10] The first of four orbital test flights occurred in 1981, leading to operational flights beginning in 1982. Five complete Shuttle systems were built and used on a total of 135 missions from 1981 to 2011, launched from the Kennedy Space Center (KSC) in Florida. Operational missions launched numerous satellites, interplanetary probes, and the Hubble Space Telescope (HST); conducted science experiments in orbit; and participated in construction and servicing of the International Space Station. The Shuttle fleet's total mission time was 1322 days, 19 hours, 21 minutes and 23 seconds.



Shuttle components included the Orbiter Vehicle (OV), a pair of recoverable solid rocket boosters (SRBs), and the expendable external tank (ET) containing liquid hydrogen and liquid oxygen. The Shuttle was launched vertically, like a conventional rocket, with the two SRBs operating in parallel with the OV's three main engines, which were fueled from the ET. The SRBs were jettisoned before the vehicle reached orbit, and the ET was jettisoned just before orbit insertion, which used the orbiter's two Orbital Maneuvering System (OMS) engines. At the conclusion of the mission, the orbiter fired its OMS to de-orbit and re-enter the atmosphere. The orbiter then glided as a spaceplane to a runway landing, usually at the Shuttle Landing Facility of KSC or Rogers Dry Lake in Edwards Air Force Base, California. After landing at Edwards, the orbiter was flown back to the KSC on the Shuttle Carrier Aircraft, a specially modified Boeing 747.



The first orbiter, Enterprise, was built in 1976 for use in Approach and Landing Tests and had no orbital capability. Four fully operational orbiters were initially built: Columbia, Challenger, Discovery, and Atlantis. Of these, two were lost in mission accidents: Challenger in 1986 and Columbia in 2003, with a total of fourteen astronauts killed. A fifth operational (and sixth in total) orbiter, Endeavour, was built in 1991 to replace Challenger. The Space Shuttle was retired from service upon the conclusion of Atlantis's final flight on July 21, 2011.

eBook Formats

Comparison of

e-book formats

From Wikipedia, the free encyclopedia

The following is a comparison of e-book formats used to create and publish e-books.

eBook files are digital books designed to be viewed on eReaders, such as the Amazon Kindle, Sony Reader, Barnes and Noble Nook, and the iPad. However, they can often be viewed on a PC using eReader software as well. While many eBook formats can be viewed on multiple devices, some proprietary eBook formats can only be viewed using specific hardware or software.

The EPUB format is the most widely supported vendor-independent XML-based (as opposed to PDF) e-book format; that is, it is supported by the largest number of e-Readers, including Amazon Kindle Fire (but not standard Kindle).

Format descriptions

Formats available include, but are not limited to:

Broadband eBooks (BBeB)

Main article: BBeB

Format:         Sony media

Published as:           .lrf; .lrx

The digital book format originally used by Sony Corporation. It is a proprietary format, but some reader software for general-purpose computers, particularly under GNU/Linux (for example, Calibre's internal viewer[2]), have the capability to read it. The LRX file extension represents a DRM encrypted eBook. More recently, Sony has converted its books from BBeB to EPUB and is now issuing new titles in EPUB.