SSTL is celebrating the 4th anniversary of the launch of its historic GIOVE-A satellite today. As the first of the Galileo In Orbit Validation Element satellites, GIOVE-A was the first step in Europe's visionary Galileo satellite navigation programme when it was launched on December 28th 2005.

During the past 4 years, SSTL and GIOVE-A have contributed significantly to the testing and validation of technologies vital to the now imminent operational constellation of satellites. The 660 kg GIOVE-A satellite was built by SSTL for ESA in just 30 months at a cost of just 28m Euros.

SSTL CEO Dr. Matt Perkins commented

SSTL is proud of its involvement with the Galileo programme and the continuing success of GIOVE-A. This mission has clearly demonstrated the effectiveness of SSTL’s small satellite approach for the delivery of operational missions.

GIOVE-A was the first part of the in-orbit validation programme for Galileo, broadcasting the first signal to successfully secure the critical Galileo frequency filing with the International Telecommunications Union (ITU) at 17:25 GMT on the 12th January 2006. This was a significant achievement for SSTL having commissioned the necessary systems to achieve this broadcast in just 3 weeks.



On the 2nd May 2007 GIOVE-A successfully transmitted the first Galileo navigation message from space, containing the information needed by users' receivers to calculate their position using the future Galileo satellite navigation service. These signals have since been used for signal quality testing and for equipment manufacturers and the scientific community to validate prototype Galileo receivers.

Throughout the past 4 years, the satellite has provided valuable data about the Medium Earth Orbit which the Galileo constellation will occupy, helping to characterise the radiation environment and validating subsystems such as an atomic clock and the Galileo signal broadcasting payload.

In July and August this year, GIOVE-A was gradually moved to a higher orbit to ensure that it does not cross the operational Galileo constellation’s orbits when the first operation satellites are launched in 2012. The satellite has been in orbit for 21 months beyond its original 27 month mission design life and continues to provide critical data to all of the ground users experimenting with Galileo navigation signals

SSTL, together with its partner OHB-System of Bremen, Germany form the core team of one of the two consortia bidding for the operational satellites. The final proposal was delivered to ESA in November and the outcome of the evaluation process is awaited. To help improve the overall schedule the team was authorised by the EC and ESA to initiate the procurement of long lead items for the full system earlier this year. The British space pioneer looks forward to continued success supporting the European Space Agency (ESA) and the EC with the expertise it has gained and its cost effective and reliable approach to satellite and subsystem design and manufacture.

SSTL is sponsoring a team of students that have been enrolled in the Engineering Education Scheme (EES) to help solve real and live problems for engineering, applied science and technological companies. The Scheme is set up by the Engineering Development Trust (EDT), with the aim to provide students aged 16 and 17 with experience in engineering, science and technology in order to make informed decisions about their future education and career.

During the 6 month programme, the students who all currently attend Farnborough 6th Form College, will take on the task set by SSTL to “Investigate possible ways of detecting earthquake precursor signals using satellites, to help us move from disaster monitoring to disaster mitigation”. The project will be mentored by SSTL Radio Frequency team member David Sanderson.

David met with the four budding engineers and their school teacher to give them a tour of the SSTL clean rooms, a presentation on small satellite engineering and introduced them to the project, which will end in April or May with a Celebration and Assessment Day by professional engineers.

The aim of the project is to provide SSTL’s Mission Concepts team with carefully calculated information, including mass, volume and power estimates, for a pre-selected list of sensors. These estimates can then be used to determine the size of the mission required to carry them.

The European Space Agency (ESA) Proba-2 mission has entered its 2 month commissioning period following a successful launch. SSTL’s Microsatellite Gas Propulsion System is on-board the 137kg small satellite and was integrated by the satellite’s manufacturer Verhaert Space Systems.

The Microsatellite Gas Propulsion System is based upon SSTL’s heritage xenon resistojet propulsion system. Its highly cost effective design provides an enhancement over conventional cold gas propulsion.

By using the resistojet thruster to heat the exhaust gas to over 300ºC a 30% increase in efficiency is gained. The electronically controlled pressure regulation improves thrust control compared to conventional mechanically regulated propulsion systems for greater positioning control in orbit.

The warm gas propulsion system is simpler, safer and cleaner than chemical propulsion systems. This makes them ideal for launcher injection correction, constellation station keeping and acquisition and orbit height maintenance for small, low cost spacecraft.

Proba-2 is the follow-on to the highly successful Proba-1 satellite launched in 2001 that carried the Compact High Resolution Imaging Sensor (CHRIS) payload manufactured by SSTL’s Optical Payloads Group. Proba-2 will demonstrate 17 advanced satellite technologies – such as miniaturised sensors for ESA's future space probes and a highly sophisticated CCD camera with a wide angle view of about 120 degrees – while carrying a set of four science instruments to observe the Sun and study the plasma environment in orbit.

A datasheet for the SSTL Microsatellite Gas Propulsion System is available on the SSTL Website.

In March 2007, SSTL announced that it had signed an order with Federal State Unitary Enterprise - The Russian Research and Production Enterprise Pan-Russian Research Institute for Electromechanics (FSUE NPP VNIIEM) and Radioexport of Russia for the supply for the supply of satellite platform equipment and services for the KANOPUS Low Earth Orbit (LEO) Earth observation spacecraft.

The first satellite, KANOPUS-B will monitor the Earth's surface and support the monitoring of disasters, agricultural planning and the management of water and coastal resources.

The project was to be a highly cooperative effort from the beginning, with great admiration on both sides of the project. The cooperation has also been different in the nature of its deliverables, and for technical, cultural reasons.

First of all, let’s look into the project itself. SSTL is a small satellite manufacturer, that regularly builds and integrates fully-functioning satellites like the recently launched UK-DMC2 or Deimos-1 earth observation missions. It also supplies sub-systems such as high resolution earth imaging payloads, multi-spectral imagers, on-board computers or GPS receivers for third party missions.

For the KANOPUS-B contract, a new approach was adopted where SSTL would build the satellite platform, avionics equipment and software, but then support VNIIEM with their spacecraft assembly and payload integration activities in Russia.

Integration – the moment of truth

During May and June, teams from SSTL visited VNIIEM’s impressive Assembly, integration and test (AIT) facilities in Moscow.

AIT Engineer Rob Gibbings and manufacturing engineer Greg Rouse can be seen to the left cutting a wiring harness to the required length and attaching customer connectors onto the SSTL harness.

More recently, in August, a team from SSTL visited the VNIIEM AIT facilities in Moscow to connect the SSTL equipment with the rest of the satellite equipment, perform tests on hardware and perform initial integration checks before satellite integration.

In the photo Lead AIT engineer Ari Venkatesan is connecting the VNIIEM Solar Array Simulator (SAS) to the SSTL power system, which was one of the integration checks performed.

During the visit in August, SSTL successfully integrated the VNIIEM SAS.

SSTL provided power and pulse-per-second [satellite timing information] to the Mission Hardware (Payload) through our systems, and achieved communication between the SSTL on-board computer and the Mission Hardware over the MIL-1553 data bus.

One of the major technical differences was the Russian’s use of a MIL-1553 data bus, and the compatibility of the SSTL built systems with this.

SSTL’s heritage systems use a CAN (control area network) bus for robust on-board communications between subsystems. VNIIEM wanted SSTL’s CAN-based systems to be able to “talk” to the 1553 bus systems reliably and with no loss of information. This has been achieved by using the OBC (On-Board Computer) as the interface between the SSTL CAN data bus and the VNIIEM MIL-1553 data bus. The OBC in effect performs the translation from MIL-1553 data into CAN data and vice-versa.

The SSTL on-board computer is also using newly developed flight software for this mission. Building the software from the new operating system upwards and accommodating the new and different payload interfaces and modes of operation to what SSTL is accustomed to is no small task. This newly developed software successfully established communications with the Mission Hardware during the testing in Moscow. Further testing is required, but this first step went a long way to build confidence in both teams.

The culture of engineering

Yes, you heard right. Culture and engineering in the same sentence.

The two companies have a very different engineering culture. SSTL has made a name for itself by changing the economics of space – a feat made possible by adopting Commercial Off The Shelf (COTS) technology and applying it to space systems.

Its heritage is built on a “systems engineering” approach which takes advantage of new technologies and tight integration. For example, one of the reasons that SSTL can provide such fast turnaround for missions is that their “off the shelf” platforms comprise tightly integrated subsystems for telemetry, navigation, mission planning and attitude control.

The culture of engineering in Russia is quite different. This is largely because SSTL’s Russian counterparts are more familiar with building larger satellites with stringent specifications and reliability requirements.

SSTL, on the other hand builds complete systems that are integrated with software and (re)programmable electronics. The modules are physically separate and can be tested separately, but the customer benefits from advanced functionality and a more robust system within a lower total cost of ownership (TCO) when the system is treated as a whole.

Project Manager, Alex O’Neill explained,

“The design process is also different. Whereas we would design and allow for margins of error, the Russian approach is more focussed on eliminating errors through thorough, precise and comprehensive analysis and design choices.”

“This meant that our initial meetings could stop and start, with both ourselves and the VNIIEM engineers having different expectations.”

SSTL is a dynamic young company that attracts talented young scientists and engineers, as such the average age of the core team dedicated to the VNIIEM project is 33, even experts in a particular field may not be much older.

Alex O’Neill reflects,

“In the beginning, the age difference was very noticeable. We felt that we were perhaps treated with some fair scepticism by the more mature and very experienced and capable Russian engineers. Initially, our ideas were also difficult for these experienced space veterans to fully appreciate, but I am pleased to say that a strong mutual respect has been earned by both sides."

It is believed that the KANOPUS satellites will be launched either at the end of 2009 and early 2010, and SSTL looks forward to a long a fruitful relationship with VNIIEM in the future.