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

Equator-S
A German satellite in a near-equatorial orbit that studies
Earth’s equatorial magnetosphere out to distances of
67,000 km. It was designed and built by the Max-Planck-
Institut fur Extraterrestrische Physik.
Launch
Date: December 2, 1997
Vehicle: Ariane 44
Site: Kourou
Orbit: 496 × 67,232 km × 4.0°
ERBE (Earth Radiation Budget Experiment)
A NASA project to study the energy exchanged between
the Sun, Earth, and space. Absorption and re-radiation of
energy from the Sun is one of the main drivers of Earth’s
weather patterns. ERBE was designed around three Earthorbiting
satellites: ERBS and two NOAA (National
Oceanic and Atmospheric Administration) satellites,
NOAA 9 and 10.
ERBS (Earth Radiation Budget Satellite)
Part of NASA’s three-satellite ERBE (Earth Radiation
Budget Experiment). In addition to its ERBE instrumentation,ERBS
also carried a Stratospheric Aerosol and Gas
Experiment (SAGE II), observations of which were used
to assess the effects of human activities (such as burning
fossil fuels and the use of CFCs) and natural occurrences
(such as volcanic eruptions) on Earth’s radiation balance.
Following deployment from the Space Shuttle, astronaut
Sally Ride had to shake the satellite with the remote
manipulator arm in order open its solar array.
Shuttle deployment
Date: October 5, 1984
Mission: STS-41G
Orbit: 576 × 589 km × 57.0°
Size: 4.6 × 3.5 m
Mass: 226 kg
ERS (Earth Resources Satellite)
The first two remote sensing satellites launched by ESA
(European Space Agency). Their primary mission was to
ERS Missions
ESA (European Space Agency) 125
monitor Earth’s oceans, ice caps, and coastal regions. The
satellites provided systematic, repetitive global measurements
of wind speed and direction, wave height, surface
temperature, surface altitude, cloud cover, and atmospheric
water vapor level. Data from ERS-1 were shared
with NASA under a reciprocal agreement for Seasat and
Nimbus 7 data. ERS-2 carries the same suite of instruments
as ERS-1 with the addition of the Global Ozone
Measuring Equipment (GOME), which measures ozone
distribution in the outer atmosphere. Having performed
well for nine years—more than three times its planned
lifetime—the ERS-1 mission was ended on March 10,
2000, by a failure in the onboard attitude control system.
The length of its operation enabled scientists to track several
El Niño episodes through combined observations of
surface currents, topography, temperatures, and winds.
The measurements of sea surface temperatures by the
ERS-1 Along-Track Scanning Radiometer, critical to the
understanding of climate change, were the most accurate
ever made from space. All these important measurements
are being continued by ERS-2 and Envisat. (See table,
“ERS Missions.”)
ERS (Environmental Research Satellite)
Spacecraft designed for piggyback-launching from large
primary mission vehicles. With masses of 0.7 to 45 kg
and payloads of 1 to 14 experiments, the ERS hitchhikers
provided a low-cost, flexible way of making scientific and
engineering measurements in space. One of their major
roles was to act as a test-bed to determine the reliability
of improved components and subsystems destined for
use in later generations of spacecraft. A unique feature of
the system was its ability to function without a battery by
having solar cells fastened to all exterior surfaces. At least
12 satellites were launched from 1962 to 1969 for a variety
of missions and sponsors.
ERTS (Earth Resources Technology Satellites)
A series of spacecraft now known as Landsat.
ESA (European Space Agency)
A multinational agency formed in 1975 through the
merger of ESRO (European Space Research Organisation)
and ELDO (European Launcher Development
Launch vehicle: Ariane 4; launch site: Kourou
Spacecraft Launch Date Orbit Mass (kg)
ERS 1 Jul. 17, 1991 774 × 775 km × 98.5° 2,384
ERS 2 Apr. 21, 1995 783 × 784 km × 98.6° 2,516