Tsinghua-1 & SNAP-1, the two latest satellites built at SSTL, have been
shipped from the UK to the launch site at Plesetsk, Northern Russia. They
are being readied for launch at midday Wednesday June 28 onboard a
COSMOS rocket as secondary payloads alongside the Russian Nadezhda
COSPAS-SARSAT satellite.

The Tsinghua-1 microsatellite, a collaborative project between Tsinghua
University in Beijing, China, and SSTL, UK, has been designed and built
by a joint Tsinghua/SSTL team at the Surrey Space Centre, Guildford,
UK. Tsinghua-1 carries multispectral Earth imaging cameras, as a
demonstrator for the upcoming Disaster Monitoring Constellation of
microsatellites being developed by SSTL, as well as experimental
communications payloads.

SNAP-1, the UK’s first nanosatellite, has been designed and built by SSTL
as a Company-funded research project and will be launched on the same
rocket into a similar orbit. SNAP-1 is a research spacecraft for evaluating
the use of commercial micro-miniature technologies for highly advanced,
yet tiny, satellites. Both missions are experimental and, using an inter-
satellite link, it is planned that the SNAP-1 and Tsinghua-1 spacecraft
will attempt to rendezvous in-orbit and demonstrate formation flying of
nano-microsatellites for the first time.

The satellites will be launched into a 650km sun-synchronous orbit. This
will be the first time a sun-synchronous orbit has been used from Plesetsk.

– end –

Further information from:

Audrey Nice

(Press & Publicity)

Email: a.nice@ee.surrey.ac.uk

Dr Wei Sun

(Marketing)

Email: s.wei@ee.surrey.ac.uk

Surrey Satellite Technology Ltd

Surrey Space Centre

University of Surrey

Guildford

United Kingdom GU2 5XH

Tel +44 (0)1483 259 278

Fax +44 (0)1483 259 503

http://www.sstl.co.uk/

Notes for Editors:

Tsinghua-1 Microsatellite for China

As an international collaborative microsatellite project, Tsinghua-1, was
built under a Know-How Transfer and Training programme between the UK &
China. The project marks the first achievement of a 25-year collaborative
joint venture company formed between SSTL & Tsinghua University which
was inaugurated by the UK Space Minister Lord Sainsbury and witnessed
by the British Prime Minister Tony Blair during their respective visits to
Beijing in 1998. Tsinghua University in Beijing is renown as one of China’s
foremost universities.

Ten engineers and scientists from Tsinghua University have spent 12
months during 1998-99 at the Surrey Space Centre — working alongside
SSTL engineers on the design, construction and test of the advanced
microsatellite. Currently, a combined SSTL/Tsinghua team are at the
Plesetsk cosmodrome completing final preparations of the satellite prior
to integration onto the Nadezhda COSPAS-SARSAT satellite and the
COSMOS launcher.

Tsinghua-1 will form the first demonstrator for the Disaster Monitoring
Constellation and carries multi-spectral Earth imaging cameras providing
39-metre nadir ground resolution in 3 spectral bands. The Disaster
Monitoring Constellation, being lead by Surrey for launch in early 2002,
will comprise five microsatellites able to provide daily world-wide high
resolution imaging for the monitoring and mitigation of natural and
man-made disasters. The Chinese Tsinghua-1 satellite will also carry
out research in low Earth orbit using digital store-and-forward
communications, a digital signal processing (DSP) experiment, a
Surrey-built GPS space receiver and a new 3-axis microsatellite attitude
control experiment.

SSTL’s space GPS receiver (SGR-10) is a spacecraft orbit/attitude
determination subsystem specifically designed for small satellite
operations. Tsinghua-1 will make use of the SGR-10, with 12 channels
and equipped with two receive antennas, to investigate the use of GPS
signals in microsatellite on-board attitude as well as orbit determination.
Tsinghua-1 will utilise three reaction wheels to provide full 3-axis
agility on a microsatellite platform. This design is based upon 3-axis
control systems flown successfully on SSTL’s UoSAT-12 minisatellite in
1999 and will be the first demonstration of its use on SSTL’s standard
microsatellite platform.

SNAP-1 – the World’s Most Advanced Nanosatellite

A highly-integrated and sophisticated spacecraft, SNAP-1 weighs just
6.5kg and carries advanced micro-miniature GPS navigation, camera
technology, onboard computing, propulsion and attitude control
technologies — all developed in the UK by SSTL.

SNAP-1’s primary payload is a machine vision system (MVS) which will
enable the inspection of other spacecraft in orbit. The MVS consists of
three ultra-miniature wide-angle CMOS video cameras and one narrow-
angle CMOS video camera, together with sophisticated image processing
electronics. The MVS will also be used to provide medium resolution
images of the Earth from SNAP-1’s 650km altitude, near-polar orbit.
The near infra-red filter in the narrow angle camera provides good
discrimination between land, sea and clouds and allows the camera to
produce clear images through the otherwise hazy atmosphere at 500m
ground resolution.

Using its miniature propulsion, navigation and inter-satellite link
systems, SNAP-1 will attempt to rendezvous in orbit with its sister
spacecraft, Tsinghua-1, to demonstrate satellite formation flying
for the first time, leading the way to the development of the
micro/nanosatellite constellations that are set to revolutionise space
exploration in the 21st Century.

SNAP-1 was designed and built by SSTL with its own funds in under one
year and at an overall mission cost, including development, launch and
commissioning, of less then $1.5 million. Already a world leader in
innovative spacecraft engineering, SSTL’s philosophy of Œaffordable
access to space’ has taken a significant step forward, delivering
micro-miniature satellites which can be constructed within very short
time frames and at extremely low cost — thus opening up many new
possibilities for space exploration to a wider community of users.

Earlier this month, SSTL celebrated its 15th anniversary of the Company’s
founding in 1985 — since when it has built and launched 16 satellites
(with 4 more due this year) and secured contracts to a total value of
£64M. With over 100 orbit-years of flight heritage, SSTL now offers
a range of small satellites from 6kg nanosatellites; 50-130kg
microsatellites and 400kg minisatellites carrying communications,
Earth observation and science payloads.