Europe's first Moon probe prepares for launch (Forwarded)

European Space Agency
Press Release No. 50-2003
Paris, France 8 August 2003

Europe's first Moon probe prepares for launch

Europe's first probe to the Moon, SMART-1, is about to begin a unique
journey that will take it into orbit around our closest neighbour powered
only by an ion engine, which Europe will be testing for the first time as
main spacecraft propulsion.

The European Space Agency's SMART-1 spacecraft was delivered to Kourou,
French Guiana, on July 15 and is currently being prepared for launch atop
an Ariane 5 during the night from August 28 to 29. The launch window will
open at 20:04 local time (01:04 on August 29 morning CEST) and will remain
open for 26 minutes.

The 367 kg spacecraft will share Ariane's V162 launch with two commercial
payloads: the Indian Space Research Organisation's Insat 3E and Eutelsat's
e-Bird communication satellites. The smallest spacecraft in the trio,
SMART-1, will travel in the lower position, inside a cylindrical adapter,
and will be the last to be released.

A generic Ariane 5 will be in charge of placing these three payloads in a
standard geostationary transfer orbit from which each will begin its own
journey towards its final operational orbit. SMART-1, powered by its ion
engine, will reach its destination in about 16 months, having followed a
long spiralling trajectory.

SMART-1's ion engine will be used to accelerate the probe and raise its
orbit until it reaches the vicinity of the Moon, some 350,000 to 400,000
km from Earth. Then, following gravity assists from a series of lunar
swingbys in late September, late October and late November 2004,
SMART-1 will be ìcapturedî by the Moon's gravity in December 2004
and will begin using its engine to slow down and reduce the altitude
of its lunar orbit.

Testing breakthrough technologies and studying the Moon

SMART-1 is not a standard outer space probe. As ESA's first Small Mission
for Advanced Research in Technology, it is primarily designed to
demonstrate innovative and key technologies for future deep space science
missions. However, once it has arrived at its destination, it will also
perform an unprecedented scientific study of the Moon. SMART-1 is a very
small spacecraft (measuring just one cubic metre). Its solar arrays,
spanning 14 metres, will deliver 1.9 kW of power, about 75% of which will
be used for the probe's 'solar electric' propulsion system.

In its role as technological demonstrator, SMART-1's primary goal is to
test this new solar electric propulsion system. This is a form of
continuous low-thrust engine that uses electricity derived from solar
panels to produce a beam of charged particles that pushes the spacecraft
forward. Such engines are commonly called ion engines, and engineers
consider them essential for future, long-range space missions. SMART-1
will also test miniaturised spacecraft equipment and instruments, a
navigation system that, in the future, will allow spacecraft to
autonomously navigate through the solar system, and in addition to a
new short-wavelength communication system, a space communication
technique by means of which SMART-1 will try to establish a link with
the Earth using a laser beam.

Once it enters into a near-polar orbit around the Moon in January 2005,
SMART-1 will also become a science platform for lunar observation.
SMART-1 will search for signs of water-ice in craters near the Moon's
poles, provide data to shed light on the still uncertain origin of the
Moon, and reconstruct its evolution by mapping its topography and
the surface distribution of minerals and key chemical elements.

SMART-1 will be the second ESA-led planetary mission to be launched
in 2003 after Mars Express in June.

For more information please contact:

ESA Communication Department
Media Relations Office
Paris, France
Tel: +33(0)15369 7155
Fax: +33(0)1 5369 7690

For more information about SMART-1 and the ESA Science Programme visit:
http://www.esa.int/science

For more information about ESA visit:
http://www.esa.int

Related articles

* SMART-1: the lunar adventure begins
http://www.esa.int/esaCP/SEMBTIYO4HD_Expanding_0.html
* ESA's SMART-1 ready to fly
http://www.esa.int/esaCP/SEME2GXO4HD_Expanding_0.html
* ESA presents SMART-1: Europe to the Moon, the Moon for Europe
http://www.esa.int/esaCP/SEMKKO8YFDD_Expanding_0.html

More information

* SMART-1 lunar mission
http://www.esa.int/export/esaMI/SMART-1/
* SMART-1 overview
http://www.esa.int/science/smart1
* ESA Science (http://www.esa.int/science

IMAGE CAPTIONS:

[Image 1:
http://www.esa.int/export/esaCP/SEMQ...anding_1.html]
The European Space Agency's Science Programme encompasses,
in addition to the ambitious 'Cornerstone' and medium-sized
missions, recently dubbed 'flexi-missions', small relatively
low-cost missions. These have been given the generic name
SMART -- 'Small Missions for Advanced Research in Technology'.
Their purpose is to test new technologies that will eventually be
used on bigger projects.

SMART-1 is the first in this programme. Its primary objective
is to flight test Solar Electric Primary Propulsion as the key
technology for future Cornerstones in a mission representative
of a deep-space one. ESA's projected BepiColombo mission to
explore the planet Mercury could be the first to benefit from
SMART-1's demonstration of electric propulsion. Another
objective is to test new technologies for spacecraft and
instruments.

The planetary objective selected for the SMART-1 mission is to
orbit the Moon for a nominal period of six months. It is the first
time that Europe sends a spacecraft to the Moon. The project
aims to have the spacecraft ready early in 2003 for launch
as an Ariane-5 auxiliary payload. In addition to the use of
solar electric primary propulsion to reach Earth's natural
satellite, the spacecraft will carry out a complete programme
of scientific observations in lunar orbit.

Credits: ESA

[Image 2:
http://www.esa.int/export/esaCP/SEMQ...html#subhead1]
A piggyback ride into space, on Europe's Ariane-5 launcher,
will put SMART-1 into orbit around the Earth, from where it
will begin a long, slow journey to the Moon.

Credits: ESA

[Image 3:
http://www.esa.int/export/esaCP/SEMQ...html#subhead3]
Electrons attracted into the discharge chamber collide with
xenon atoms from the propellant gas supply, making charged
atoms (ions). Current-carrying coils, inside and outside the
doughnut-shaped discharge chamber, sustain a magnetic
field oriented like the spokes of a wheel. By the Hall effect,
ions and electrons swerving in opposite directions in the
magnetic field create an electric field. This expels the xenon
ions in a propulsive jet. Other emitted electrons then neutralize
the xenon, producing the blue jet.

Credits: ESA 2002. Illustration by Medialab.