|
The Space Shuttle ''Enterprise'' (NASA Orbiter Vehicle Designation: OV-101) was the first Space Shuttle. It was built for NASA as part of the Space Shuttle program to perform test flights in the atmosphere, aided by a modified Boeing 747. It was constructed without engines or a functional heat shield, and was therefore not capable of spaceflight. It was rolled out on September 17, 1976. Originally, ''Enterprise'' had been intended to be refitted for orbital flight to become the second space-rated orbiter in service.〔 However, during the construction of ''Columbia'', details of the final design changed, particularly with regard to the weight of the fuselage and wings. Refitting ''Enterprise'' for spaceflight would have involved dismantling the orbiter and returning the sections to subcontractors across the country. As this was an expensive proposition, it was determined to be less costly to build ''Challenger'' around a body frame (STA-099) that had been built as a test article.〔 Similarly, ''Enterprise'' was considered for refit to replace ''Challenger'' after the latter was destroyed, but ''Endeavour'' was built from structural spares instead.〔〔 ''Enterprise'' was restored and placed on display in 2003 at the Smithsonian's new Steven F. Udvar-Hazy Center in Virginia. Following the retirement of the Space Shuttle fleet, ''Discovery'' replaced ''Enterprise'' at the Udvar-Hazy Center, and ''Enterprise'' was transferred to the Intrepid Sea, Air & Space Museum in New York City, where it has been on display since July 2012. ==Differences between ''Enterprise'' and future shuttles== The design of OV-101 was not the same as that planned for OV-102, the first flight model; the aft fuselage was constructed differently, and it did not have the interfaces to mount OMS pods. A large number of subsystems—ranging from main engines to radar equipment—were not installed on ''Enterprise'', but the capacity to add them in the future was retained, as NASA originally intended to refit the orbiter for spaceflight at the conclusion of its testing. Instead of a thermal protection system, its surface was primarily covered with simulated tiles made from polyurethane foam. Fiberglass was used for the leading edge panels in place of the reinforced carbon–carbon ones of spaceflight-worthy orbiters. Only a few sample thermal tiles and some Nomex blankets were real. ''Enterprise'' used fuel cells to generate its electrical power, but these were not sufficient to power the orbiter for spaceflight. ''Enterprise'' also lacked RCS thrusters (which were useless in atmospheric flight) and hydraulic mechanisms for the landing gear; the landing gear doors were simply opened through the use of explosive bolts and the gear dropped down solely by gravity.〔 As it was only used for atmospheric testing, ''Enterprise'' featured a large nose probe mounted on its nose cap, common on test aircraft because the location provides the most accurate readings for the test instruments, being mounted out in front of the disturbed airflow. ''Enterprise'' was equipped with Lockheed-manufactured zero-zero ejection seats like those its sister ''Columbia'' had carried on its first four missions.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Space Shuttle Enterprise」の詳細全文を読む スポンサード リンク
|