SSTL congratulates the EU, ESA and Astrium on the successful launch of the two first in-orbit validation (IOV) satellites, which marks a critical step for the Galileo system.

Galileo is the upcoming European satellite navigation system, equivalent to the American Global Positioning System (GPS). Galileo will start operating in 2014 as a free consumer navigation service, with more specialised services to be rolled out until 2020, when it’s planned to be fully operational

Launched by a Russian Soyuz rocket from the base in French Guiana on Friday 21 October 07:30 local time (11:30 BST), the satellites are now in their 23,000km orbit above Earth.



Friday’s launch is the beginning of the deployment of the operational system, with two further satellites of a similar design to be launched next. A further fourteen satellites being manufactured by the OHB / SSTL team will begin launching in 2012.

To find out more on Friday’s launch, read this BBC News online article

Satellite navigation (GNSS) experts from SSTL are contributing remote sensing and satellite know-how to a pioneering UK-led project that aims to improve forecasting of adverse weather conditions at sea.

Using satellite data to measure ocean roughness has been an area of interest for SSTL since an experimental GNSS receiver payload was launched onboard its UK-DMC satellite. During the past few years, the GNSS receivers team has investigated the use of GNSS reflectometry – the use of reflected navigation signals from space to characterise ocean weather – with promising results, and produced a prototype instrument in collaboration with partners in the UK that will be developed into a payload for the TechDemoSat-1 technology demonstration satellite.



Smarter shipping
In addition to shipping, many marine operations such as offshore oil platforms and renewable energy projects depend on high quality information on sea-state (wave height, period, direction, steepness) for economic and safety decision making. However, the information currently available is based on atmospheric/ocean models and lacks sufficient temporal and spatial resolution.

Martin Unwin, Principal Engineer commented,

Wave conditions are always changing and can vary tremendously over just 100km, or over a period of two hours. This also makes modelling and forecasting very difficult, so the most immediate use of this data is more likely to be what we call ‘nowcasting’ – assessing current conditions thoroughly before commencing an operation.

Another problem with conventional methods is that the use of buoys provides good information around the coast and shipping lanes, but is simply not economical nor practical for charting the vast oceans of Earth. This is one area where satellites, with their global view, are ideally equipped.

All hands on deck
Recognising the opportunity for an improved system, the UK’s Technology Strategy Board has provided co-funding for the WaveSentry project. WaveSentry will address shortcomings on two fronts:

• By exploiting new data sources that include SSTL’s novel satellite remote measurements of wave steepness.


• By integrating data from all sources in a single system (including real-time buoy and ship data).

This multi-disciplinary project will bring together partners from all areas to develop and apply techniques to substantially enhance the integration of diverse data sources to offer improved data about adverse sea-states to a number of markets. SSTL and its partner National Oceanographic Centre, Southampton, are investigating the potential for spaceborne GNSS Reflectometry measurements to contribute towards knowledge of sea state in combination with other data sources.

You can keep up to date with the WaveSentry project on the the Marine Southeast website.

SSTL has taken delivery of a Search and Rescue Antenna (SARANT) for use to support the development of the fully operational satellites that will power Europe’s new satellite navigation system.

An important milestone, this is the first payload equipment to be delivered to SSTL since it was selected by the European Space Agency to deliver the navigation payloads for the first 14 satellites in the system just over a year ago. SSTL’s partner OHB-System in Germany is prime contractor, building the satellite bus for these satellites.

As part of a Global navigation satellite systems (GNSS), Europe’s new sat-nav service will provide highly accurate, guaranteed global positioning, including specialised rescue services. Consisting of 30 satellites in 56 degrees inclined circular Medium-Earth-Orbits, the baseline is a constellation with 9 equally spaced satellites (plus one spare) per orbit.

The newly delivered Search & Rescue antenna will be used by SSTL in the full engineering model of the payload.

The Search and Rescue Payload on the satellites will relay distress and co-ordination messages from the COSPAS-SARSAT Search and Rescue service. The diagram below shows a fully operational satellite with the SARANT visible on top.

Continue reading "SSTL receives first payload equipment for European Sat-Nav"

It’s now five years since Space Blog reported on GIOVE-A transmitting its first signals for the European GNSS system. The first validation satellite GIOVE-A, was launched in December 2005 by a Soyuz rocket from Baikonur in Kazakhstan, and is still working well five years after the satellite payload was commanded 'on' from the SSTL Mission Control Centre.

With a design lifetime of 27 months, the five-year-old has exceeded all expectations. Part of its long lifespan can be put down to design margins, though luck comes into it as well, according to GIOVE manager at ESA, Valter Alpe. The satellite has been orbiting through an exceptionally quiet time in the 11-year solar cycle, meaning it has accumulated lower radiation doses than originally anticipated.

GIOVE-A was built by SSTL in just 30 months and carries a prototype rubidium atomic clock designed for the European GNSS constellation. In 2008 GIOVE-A was joined by GIOVE-B, equipped with an ultra-precise passive hydrogen maser design as well as a second rubidium clock. Operational European GNSS satellites will carry both clock designs for maximum reliability.