Lewis was an American satellite which was to have been operated by
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research.
NASA was established in 1958, succeeding t ...
as part of the
Small Satellite Technology Initiative
Small may refer to:
Science and technology
* SMALL, an ALGOL-like programming language
* Small (anatomy), the lumbar region of the back
* ''Small'' (journal), a nano-science publication
* <small>, an HTML element that defines smaller text
...
. It carried two experimental Earth imaging instruments, and an
ultraviolet astronomy
Ultraviolet astronomy is the observation of electromagnetic radiation at ultraviolet wavelengths between approximately 10 and 320 nanometres; shorter wavelengths—higher energy photons—are studied by X-ray astronomy and gamma-ray astr ...
payload. Due to a
design flaw A product defect is any characteristic of a product which hinders its usability for the purpose for which it was designed and manufactured.
Product defects arise most prominently in legal contexts regarding product safety, where the term is appl ...
it failed within three days of reaching orbit, before it became operational.
Lewis was a 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
Hyperspectral imaging collects and processes information from across the electromagnetic spectrum. The goal of hyperspectral imaging is to obtain the spectrum for each pixel in the image of a scene, with the purpose of finding objects, identifyi ...
, the
Linear Etalon Imaging Spectral Array and the
Ultraviolet Cosmic Background experiment.
A number of technology demonstration payloads were also flown.
Launch
Lewis was launched by a
LMLV-1 (Athena I) rocket flying from
Space Launch Complex 6 at the
Vandenberg Air Force Base Vandenberg may refer to:
* Vandenberg (surname), including a list of people with the name
* USS General Harry Taylor (AP-145), USNS ''General Hoyt S. Vandenberg'' (T-AGM-10), transport ship in the United States Navy, sank as an artificial reef in K ...
.
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
An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion.
General description
There are two apsides in any ellip ...
of , a
perigee
An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion.
General description
There are two apsides in any ell ...
of , and 97.5 degrees of
inclination
Orbital inclination measures the tilt of an object's orbit around a celestial body. It is expressed as the angle between a Plane of reference, reference plane and the orbital plane or Axis of rotation, axis of direction of the orbiting object ...
. Lewis was to have raised itself into a higher orbit, at an altitude of .
Mission failure
On 26 August, the satellite began spinning out of control at a rate of 2
rpm
Revolutions per minute (abbreviated rpm, RPM, rev/min, r/min, or with the notation min−1) is a unit of rotational speed or rotational frequency for rotating machines.
Standards
ISO 80000-3:2019 defines a unit of rotation as the dimensionl ...
, which led to a loss of communications with ground controllers, and affected the ability of its
solar array
A photovoltaic system, also PV system or solar power system, is an electric power system designed to supply usable solar power by means of photovoltaics. It consists of an arrangement of several components, including solar panels to absorb and ...
s 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
The Total Ozone Mapping Spectrometer (TOMS) was a NASA satellite instrument, specifically a spectrometer, for measuring the ozone layer. Of the five TOMS instruments which were built, four entered successful orbit. The satellites carrying TOMS ins ...
spacecraft and was not sufficiently modified to be compatible with Lewis.
See also
*
1997 in spaceflight
References
{{DEFAULTSORT:Lewis (Satellite)
Spacecraft launched in 1997