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

126 escape energy
Organisation). ESA instigates and manages space activities
on behalf of its 15 member states: Austria, Belgium,
Denmark, Finland, France, Germany, the Republic of Ireland,
Italy, the Netherlands, Norway, Portugal, Spain,
Sweden, Switzerland, and the United Kingdom. Canada
has a cooperative relationship with the agency. While
developing an independent capability for Europe in
space technology, ESA also works closely with other
space agencies, including NASA and RKA (the Russian
Space Agency).
ESA has its headquarters in Paris and four major facilities
in other countries: ESTEC (European Space Research
and Technology Centre), at Noordwijk, the Netherlands,
the main center for research and management of satellite
projects; ESOC (European Space Operations Centre), at
Darmstadt, Germany, responsible for satellite control,
monitoring, and data retrieval; ESRIN (European Space
Research Institute), at Frascati, Italy, which supports the
ESA documentation service and manages the data collected
by remote sensing satellites; and EAC (European
Astronaut Center), at Cologne, Germany, responsible for
selecting and training astronauts for space station missions.
In addition, ESA operates the Guiana Space Centre
for launching Ariane rockets, sounding rocket launch
stations in Norway and Sweden, a meteorological program
office at Toulon, France, and satellite tracking stations
in Belgium, Germany, Italy, and Spain. Ariane
rockets are developed, built, and managed by Arianespace,
which is a division of ESA. See individual entries
Major ESA Space Missions and Programs
of the major ESA space missions and programs listed in
the table (“Major ESA Space Missions and Programs”). 176
escape energy
The energy required per unit mass of a spacecraft for it to
escape Earth’s gravity.
escape tower
A tower, mounted on top of the Command Module of
the Apollo spacecraft, that contained a cluster of small
rockets to jettison the spacecraft from the booster in the
event of an aborted mission.
escape trajectory
The path a body must follow to escape a central force
field, such as Earth’s gravity.
escape velocity
The minimum velocity that a body, such as a rocket,
must have in order to escape completely from the gravitational
influence of another, such as a planet or a star,
without being given any extra impetus. It is given by:
2GM
νesc =��
�
R
where G is the gravitational constant and R is the distance
from the center of the gravitating body of mass M.
This is equal to, but in the opposite direction of, the
velocity the body would have acquired if it had been
Past Present Under Development/Study
Space science COS-B Cluster Bepi Colombo
Exosat COROT Darwin
Giotto Huygens (see Cassini) Eddington
Hipparcos SOHO GAIA
ISO Ulysses (with NASA) Herschel
IUE XMM-Newton INTEGRAL
Spacelab LISA
Mars Express
Planck
Rosetta
SMART
Solar Orbiter
XEUS
Earth observation ERS-1 Envisat
ERS-2
Meteosat
MetOp
Communication and MARECS Artemis EGNOS
navigation Olympus Galileo