The Complete Book of Spaceflight: From Apollo 1 to Zero Gravity

124 Eole
Envisat Envisat being prepared for launch. European Space
Agency
advanced land imaging (ALI) instruments that would
reduce the costs of future Landsatmissions. These instruments
range from a hyperspectral imager (a camera that
views Earth’s surface with unprecedented spectral discrimination)
to an X-band phased array antenna that
sends back high volumes of data in a unique pencil-beam
pattern. The spacecraft was in an orbit that allowed it to
fly in formation with Landsat 7 and take a series of the
same images. Comparison of these “paired scene” images
was one way of evaluating EO-1’s instruments. Future use
of ALI technology will cut the mass and power consumption
by a factor of seven compared to the Landsat 7
imager. EO-1 is also the first spacecraft to use a new generation
of pulsed-plasma thrusters developed at the
Glenn Research Center. EO-1 is a component of NASA’s
EOS (Earth Observing System).
EO-1 FACTS
Launch
Date: November 21, 2000
Vehicle: Delta 7320
Site: Vandenberg Air Force Base
Orbit (circular, sun-synchronous): 705 km × 98.7°
Eole
A French weather microsatellite, also known as CAS
(Cooperative Applications Satellite) and, before launch,
as FR-2. Eole, named after the god of the wind, interrogated
and returned data from over 500 instrumented
weather balloons released from Argentina and drifting at
heights of 12 km to help study southern-hemisphere
winds, temperatures, and pressures.
Launch
Date: August 16, 1971
Vehicle: Scout B
Site: Wallops Island
Orbit: 678 × 903 km × 50.2°
Mass: 84 kg
EORSAT (ELINT Ocean Reconnaissance Satellite)
A system of specialized Russian/Soviet ELINT (electronic
intelligence) satellites that has been in operation
since 1974. It monitors and locates enemy naval forces by
detecting and triangulating on their radio and radar emissions.
EOS (Earth Observing System)
A series of polar-orbiting and low-inclination satellites
for conducting long-term global observations of Earth’s
land surface, atmosphere, oceans, and biosphere. EOS is
the centerpiece of NASA’s Earth Science Enterprise program
(formerly called Mission to Planet Earth), and
together with other missions from NOAA (National
Oceanic and Atmospheric Administration), Europe, and
Japan forms the comprehensive International Earth
Observing System (IEOS). Current and future EOS missions
include: SeaStar/SeaWiFS, TRMM, Landsat-7,
QuikScat, Terra (EOS AM-1), ACRIMSAT, EO-1,
SAGE III, Jason-1, Aqua (EOS PM-1), ICESAT (EOS
Laser Alt-1), ADEOS-2, SORCE, and Aura (EOS
Chem).
EOS Chem (Earth Observing System Chemistry)
See Aura.
EOS PM (Earth Observing System PM)
See Aqua.
ephemeris
A set of numbers that specifies the location of a celestial
body or satellite in space.
equatorial orbit
An orbit in the same plane as Earth’s equator.