East Meets West on “Double Star”, a Joint Mission to Explore Earth’s Magnetic Field

A new phase in ESA-China scientific collaboration was officially given the
green light today at ESA Headquarters in Paris with an historic agreement
between ESA and the Chinese National Space Administration (CNSA) to
develop a joint project known as “Double Star”.

ESA Director General Antonio Rodotý and Luan Enjie, Administrator of the
CNSA, signed an official agreement that will enable European experiments
to be flown on Chinese satellites for the first time.

“This agreement marks a significant advance for international cooperation
in the exploration and peaceful use of outer space,” said Mr. Rodotý. “It
is one of the most important landmarks in scientific collaboration since
ESA and the People’s Republic of China first agreed to exchange scientific
information more than 20 years ago.”

“The Double Star programme will be just the first step in substantial
cooperation between the Chinese National Space Administration and ESA”
said Mr Luan Enjie. “The signing of today’s agreement paves the way not
only for reciprocal cooperation between scientists, but for the
establishment of comprehensive cooperation between the two agencies”.

Double Star will follow in the footsteps of ESA’s groundbreaking Cluster
mission by studying the effects of the Sun on the Earth’s environment.
Conducting joint studies with Cluster and Double Star should increase the
overall scientific return from both missions.

A key aspect of ESA’s participation in the Double Star project is the
inclusion of 10 instruments that are identical to those currently flying
on the four Cluster spacecraft. A further eight experiments will be
provided by Chinese institutes.

“We hope it will be possible to make coordinated measurements with both
Cluster and Double Star.” said Cluster Project Scientist Philippe
Escoubet. “For example, we would hope to carry out a joint exploration of
the magnetotail, a region where storms of high energy particles are
generated. When these particles reach Earth, they can cause power cuts,
damage satellites and disrupt communications.”

Six of the eleven Cluster principal investigators have agreed to provide
flight spares or duplicates of the experiments that are currently
revolutionising our understanding of near-Earth space. This reuse of
Cluster instruments has a number of advantages for both European and
Chinese scientists.

“By flying experiments identical to those on Cluster, we can reduce costs
and development time,” explained Alberto Gianolio, ESA Project Manager for
Double Star. “This will minimise risk and help us to ensure that we are
able to meet the spacecraft development schedule.”

ESA has agreed to contribute 8 million euros to the Double Star programme.
This funding will be used for refurbishment and pre-integration of the
European instruments, acquisition of data for 4 hours per day and
coordination of scientific operations.

Notes for Editors:

Double Star will be the first mission launched by China to explore the
Earth’s magnetosphere – the magnetic bubble that surrounds our planet. As
its name suggests, Double Star will involve two satellites – each
designed, developed, launched and operated by the CNSA – flying in
complementary orbits around the Earth.

This orbital configuration will enable scientists to obtain simultaneous
data on the changing magnetic field and population of electrified
particles in different regions of the magnetosphere.

The duo is expected to be launched by Chinese Long March 2C rockets in
December 2002 and March 2003. This schedule may enable them to operate
alongside ESA’s Cluster mission – a mini-flotilla of four identical
spacecraft launched into elliptical orbits around the Earth last summer.

The “equatorial” spacecraft (DSP-1) will be launched into an elliptical
orbit of 550 x 60,000 km, inclined at 28.5 degrees to the equator. This
will enable it to investigate the Earth’s huge magnetic tail, the region
where particles are accelerated towards the planet’s magnetic poles by a
process known as reconnection.

The “polar” satellite (DSP-2) will concentrate on physical processes
taking place over the magnetic poles and the development of aurorae. It
will have a 350 x 25,000 km orbit taking it round the Earth once every 7.3
hours.

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For more information on the ESA Science Programme, visit the ESA Science
website at: http://sci.esa.int