Lewis (satellite)
Encyclopedia
Lewis was an American
satellite which was to have been operated by NASA
as part of the Small Satellite Technology Initiative. It carried two experimental Earth imaging instruments, and an ultraviolet astronomy payload. Due to a design flaw it failed within three days of reaching orbit, before it became operational.
Lewis was a 288 kilograms (634.9 lb) spacecraft, which was designed to operate for between one and three years. It was built by TRW
under a contract which was signed on 11 July 1994. Its primary instruments were the Hyperspectral Imager, the Linear Etalon Imaging Spectral Array and the Ultraviolet Cosmic Background experiment. A number of technology demonstration payloads were also flown.
Lewis was launched by a LMLV-1
(Athena I) rocket flying from Space Launch Complex 6
at the Vandenberg Air Force Base
. The launch was originally scheduled to take place in September 1996, but it was delayed due to technical problems affecting the rocket. Launch finally occurred at 06:51:01 GMT on 23 August 1997, and Lewis was successfully placed into a parking orbit with an apogee
of 134 kilometres (83.3 mi), a perigee
of 124 kilometres (77.1 mi), and 97.5 degrees of inclination
. Lewis was to have raised itself into a higher orbit, at an altitude of 523 kilometres (325 mi).
On 26 August, the satellite began spinning out of control at a rate of 2 rpm
, which led to a loss of communications with ground controllers, and affected the ability of its solar arrays to generate power. Controllers were unable to regain contact with the spacecraft, and it was declared a total loss. It reentered the atmosphere at 11:58 GMT on 28 September 1997. The cause of the failure was later established to be a design flaw in the spacecraft's attitude control system, which had been designed for the TOMS-EP spacecraft and was not sufficiently modified to be compatible with Lewis.
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
satellite which was to have been operated by NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
as part of the Small Satellite Technology Initiative. It carried two experimental Earth imaging instruments, and an ultraviolet astronomy payload. Due to a design flaw it failed within three days of reaching orbit, before it became operational.
Lewis was a 288 kilograms (634.9 lb) spacecraft, which was designed to operate for between one and three years. It was built by TRW
TRW
TRW Inc. was an American corporation involved in a variety of businesses, mainly aerospace, automotive, and credit reporting. It was a pioneer in multiple fields including electronic components, integrated circuits, computers, software and systems engineering. TRW built many spacecraft,...
under a contract which was signed on 11 July 1994. Its primary instruments were the Hyperspectral Imager, the Linear Etalon Imaging Spectral Array and the Ultraviolet Cosmic Background experiment. A number of technology demonstration payloads were also flown.
Lewis was launched by a LMLV-1
Athena I
The Athena I, known as the Lockheed Launch Vehicle at the time of its first flight and Lockheed Martin Launch Vehicle at the time of its second flight, is an American small expendable launch system which was used for four launches between 1995 and 2001, and which is scheduled to return to service...
(Athena I) rocket flying from Space Launch Complex 6
Vandenberg AFB Space Launch Complex 6
Space Launch Complex-6 at Vandenberg Air Force Base in California is a launch pad and support area. It was originally designed for the launching of the Titan III in support of the cancelled Manned Orbiting Laboratory, and was later rebuilt for the Space Shuttle, which also never used it due to...
at the Vandenberg Air Force Base
Vandenberg Air Force Base
Vandenberg Air Force Base is a United States Air Force Base, located approximately northwest of Lompoc, California. It is under the jurisdiction of the 30th Space Wing, Air Force Space Command ....
. The launch was originally scheduled to take place in September 1996, but it was delayed due to technical problems affecting the rocket. Launch finally occurred at 06:51:01 GMT on 23 August 1997, and Lewis was successfully placed into a parking orbit with an apogee
Apsis
An apsis , plural apsides , is the point of greatest or least distance of a body from one of the foci of its elliptical orbit. In modern celestial mechanics this focus is also the center of attraction, which is usually the center of mass of the system...
of 134 kilometres (83.3 mi), a perigee
Apsis
An apsis , plural apsides , is the point of greatest or least distance of a body from one of the foci of its elliptical orbit. In modern celestial mechanics this focus is also the center of attraction, which is usually the center of mass of the system...
of 124 kilometres (77.1 mi), and 97.5 degrees of inclination
Inclination
Inclination in general is the angle between a reference plane and another plane or axis of direction.-Orbits:The inclination is one of the six orbital parameters describing the shape and orientation of a celestial orbit...
. Lewis was to have raised itself into a higher orbit, at an altitude of 523 kilometres (325 mi).
On 26 August, the satellite began spinning out of control at a rate of 2 rpm
Revolutions per minute
Revolutions per minute is a measure of the frequency of a rotation. It annotates the number of full rotations completed in one minute around a fixed axis...
, which led to a loss of communications with ground controllers, and affected the ability of its solar arrays to generate power. Controllers were unable to regain contact with the spacecraft, and it was declared a total loss. It reentered the atmosphere at 11:58 GMT on 28 September 1997. The cause of the failure was later established to be a design flaw in the spacecraft's attitude control system, which had been designed for the TOMS-EP spacecraft and was not sufficiently modified to be compatible with Lewis.