Press Release

Three SSTL spacecraft complete pre-flight tests at RAL for DMC

By SpaceRef Editor
May 30, 2003
Filed under , ,

British spacecraft manufacturers, Surrey Satellite Technology Ltd (SSTL), have
completed thermal vacuum tests on three spacecraft, UK-DMC, NigeriaSat-1 and
BILSAT-1. The 100kg enhanced microsatellites will form part of the international
Disaster Monitoring Constellation (DMC).

The tests were conducted using the large Space Test Chamber at the Rutherford
Appleton Laboratory in Oxfordshire where each spacecraft was subjected to hot
and cold cycles within a temperature range of +60 C to -20 C. In addition,
vacuum tests replicated the ‘non-atmospheric’ environment in which the
satellites will operate in-orbit some 686km above the Earth. Thermal vacuum
tests ran over a 5-day, 24-hour period with each subsystem tested individually
within the extremes of environment.

All three satellites will be launched in July, completing the first
constellation of microsatellites providing daily earth imaging dedicated to
disaster mitigation and monitoring. AlSAT-1, the first satellite of the
constellation, was launched last November and is fully operational.

Two of the satellites carry space technology experiments as well as their DMC
remote sensing payloads. UK-DMC hosts a high capacity 1-Gbyte solid data
recorder, a micropropulsion experiment that will qualify an ultra-low cost
system for future nanosatellites and a GPS reflectometry payload to look for
reflections of GPS signals from the sea surface.

BILSAT experiments include two payloads designed and built by SSTL’s Turkish
customer, TUBITAK-ODTU-BILTEN. The first, named COBAN, is a nine-band low
resolution multi-spectral imager. The second, named GEZGIN, is a DSP based image
processing module that uses the JPEG2000 algorithm to compress images taken by
BILSAT-1’s on board cameras.

Both of these payloads were designed and built by BILTEN engineers in the
context of the KHTT (Know How Training and Transfer) programme that ran in
parallel with the BILSAT project.

About the DMC:

The Disaster Monitoring Constellation (DMC) is a novel international
co-operation in space, led by SSTL bringing together organisations from seven
countries: Algeria, China, Nigeria, Thailand, Turkey, the United Kingdom and
Vietnam. The DMC Consortium is forming the first-ever microsatellite
constellation bringing remarkable Earth observation capabilities both nationally
to the individual satellite owners, and internationally to benefit world-wide
humanitarian aid efforts.

The first satellite in the DMC, AlSAT-1 for Algeria, was launched on 28 November
2002 and is fully operational in orbit, delivering outstanding Earth observation
imagery. AlSAT-1 will be joined in orbit by a further three satellites for
Nigeria, Turkey and the UK in July 2003 — all built at the Surrey Space Centre
in Guildford. The spacecraft for Algeria, Nigeria and Turkey were built under
know-how transfer and training programmes, whereby a team of engineers from each
country spent 18 months at Surrey working alongside SSTL engineers.

Each satellite, weighing some 90kg, will provide 32-metre multispectral Earth
observation imaging, covering a vast 600 x 600km area anywhere on the Earth’s
surface. The images cover ten times more area, compared with images of less than
200 x 200km currently available from other civilian Earth observation
satellites. Also unique is the ability to re-image anywhere on the Earth’s
surface within 24-hours — something not achievable by any other satellite
currently in-orbit. These powerful resources place the DMC in a distinctive
position to provide Earth observation images to the international disaster
relief community in partnership with Reuters AlertNet.

The International Disaster Monitoring Constellation is a further example of a
new generation of advanced small satellites pioneered by SSTL — providing
outstanding capability at low cost. The DMC will demonstrate how a network of
small satellites can work together to provide valuable operational services at
exceptionally low cost.

About SSTL:

SSTL specialises in the design, manufacture and operation of high-performance
yet low-cost small satellites provided on rapid timescales to meet both civil
and military Earth observation, communications and space science applications.
During 22 years SSTL have launched 21 small satellite missions into low Earth
orbit for international customers, pioneering use of ‘commercial-of-the-shelf’
(COTS) technologies and resulting in an experience and heritage of missions and
in-orbit operations unmatched by any other professional satellite manufacturer.

Four spacecraft are currently under construction at SSTL’s purpose-built
facilities at the Surrey Space Centre in England: three satellites for the
international disaster monitoring constellation (DMC), plus an enhanced, agile
microsatellite to demonstrate 2.5-metre resolution Earth imaging for the UK MoD.
The DMC is a collaboration between organisations in six countries: Algeria,
China, Nigeria, Thailand, Turkey, and UK to launch an Earth observation
constellation of small satellites providing daily imaging revisit worldwide to
assist in disaster monitoring.

SSTL employs 150 staff at Guildford, currently working on LEO, geostationary and
interplanetary platforms — exploiting the cost-effective technology and
techniques that are the hallmarks of Surrey’s work.

About CCLRC:

The CCLRC Rutherford Appleton Laboratory in Oxfordshire is the largest of the
three sites of the Council for the Central Laboratory of the Research Councils.
The CCLRC is one of the UK’s seven research councils and is one of the UK’s
leading science research organisations.

Its Space Science and Technology Department is one of the largest in Europe,
with expertise in a broad range of space science subjects including solar
physics, planetary science and space technology. The Space Test Chamber is a 5.5
metre long thermal vacuum chamber where small satellites and instruments are
tested under vacuum and at the extreme temperatures they will encounter in space.

Picture available at:
http://www.sstl.co.uk/primages/NigeriaSATUKDMC_RAL.jpg (68KB)

SpaceRef staff editor.