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.

Today at 12:30 in Brussels, the EC announced that the SSTL and OHB-System team has been selected by ESA to supply 14 navigation satellites for the deployment phase of the Galileo satellite navigation system in a deal worth 560m Euro.

The two companies agreed to work together as a “core team” on Galileo at the end of 2007, with OHB taking the role of prime contractor and builder of the spacecraft “bus” and SSTL taking full responsibility for the navigation payloads onboard the satellite that will form the heart of the Galileo navigation system.

SSTL Group CEO Dr Matt Perkins is delighted with the news:

The award of this contract is an important step for SSTL. Our satellites are already providing operational services for many government and commercial customers and we are pleased to have a major role within Europe’s flagship Galileo programme. The experience gained on GIOVE-A will help us to ensure the contract will be a success for the EC and ESA. This programme will also help to establish SSTL as a provider of communications and navigation satellites into other markets.

It was champagne all round at SSTL in Guildford as the news was announced, warming spirits despite worst snow for 30 years affecting the local area.

A jubilant SSTL’s Executive Chairman, Sir Martin Sweeting, added

This award is great news for the UK space industry and once again confirms SSTL as a world leader in sophisticated satellites and payloads, building on its 25-year history pioneering small satellites with 34 already launched, truly changing the economics of space.

The first Galileo satellites produced under this contract will be launched from 2013. 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 during 2009 which will enable the team to make a quick start towards an operational Galileo constellation.

Continue reading "Green light for Galileo satellites"

SSTL’s Group Executive Chairman, Sir Martin Sweeting stated in a press release today that he believes the increased competition resulting from the June proposal by the European Commission to fund the Galileo satellite navigation system through the public sector will reduce the cost and risk involved.

”The increased competition will have significant benefits,” stated SSTL’s Group Executive Chairman, Sir Martin Sweeting. “The public sector will soon be in a position to place contracts that give the European taxpayer better value for money and step up the pace of delivering the system”.

SSTL aims to support the European Commission and European Space Agency (ESA) by building on its experience gained through the successful GIOVE-A mission, to provide best value in the operational phase of Galileo. GIOVE-A was developed under a €28M contract signed with ESA in the second half of 2003. The mission’s primary aim was to broadcast Galileo signals from space so that Europe could claim the frequencies filed for Galileo with the International Telecommunications Union (ITU). The satellite was designed, built, tested and launched before the end of 2005 – on-time and on-budget. GIOVE-A has transmitted Galileo signals for over 18 months and remains the only Galileo spacecraft in operation. Following the success of GIOVE-A, ESA placed a further contract with SSTL in March 2007 for a second satellite named GIOVE-A2.

Sir Martin added:

“It’s clear that a second source of operational satellites is needed, both to provide healthy competition and to reduce risk to the schedule of the Galileo system. SSTL has begun discussions with other key European suppliers, with the aim of forming a team capable of supplying a significant portion of Galileo whilst maintaining the winning formula employed on GIOVE-A. We expect these discussions to be finalised in October, in time to provide the public sector with a much needed competitive option”.

Galileo is a joint initiative between ESA and the European Commission. When fully deployed in the early years of the next decade, it will be the first non-military positioning system to offer global coverage.

Technical update - Europe's first Galileo navigation signals were transmitted from space by the GIOVE-A satellite at 17:25 GMT this afternoon 12th January.

























The satellite payload was commanded 'on' from the SSTL Mission Control Centre and the Galileo signals were successfully received using the 25-metre dish antenna at CCLRC Chilbolton Observatory (Andover) and the ESA Station in Redu (Belgium). The Galileo E5 and L1 channel signals were successfully decoded at the SSTL groundstation using a Galileo navigation receiver.

GIOVE-A payload switch-on at Mission Control at SSTl:



















SSTL & ESA team celebrate reception of first Gailileo signals:


















These milestone transmissions from GIOVE-A mark Europe's independent entry into global positioning, navigation and timing services - intended to work alongside the US GPS and provide enhanced performance.

Galileo signal spectrum received in the UK from GIOVE-A:








Gailileo navigation signals decoded alongside GPS at SSTL:












Following launch from Baikonur on 28th December, the GIOVE-A spacecraft in-orbit checkout and commissioning progressed extremely well and had been completed by Friday 6th January. These activities on GIOVE-A involved the co-operation of the ground stations deployed at RAL (UK), Bangalore (India) and Kuala Lumpur (Malaysia), which supported SSTL during the upload of the On-Board Computer software and the deployment of both solar panels, placing the satellite in Sun Acquisition Mode.

On Monday 9th January, the on-board atomic clocks and signal generating systems were checked by the SSTL Mission Control Centre and found to be performing nominally. An ESA team then travelled to the Chilbolten groundstation in the UK to prepare to analyse the first Galileo signals to be transmitted from the GIOVE-A satellite.

The different modes of Galileo signals will now be generated sequentially using the GIOVE-A first payload chain to perform the frequency filing activities. Once these frequency filing activities are completed (expected by the end of January 2006), the payload commissioning will resume with the checkout of the second and third payload chains, assumed to be performed by mid-February 2006. Additional measurement campaigns will then be carried out to assess the Medium Earth Orbit (altitude of 24,000 kilometres) radiation environment, characterise the performance of on-board clocks and perform signal-in-space experimentations.

The 660 kg GIOVE-A satellite, built by SSTL for ESA in just 30 months and 28M Euros, has three mission objectives. First, it secures use of the frequencies allocated by the International Telecommunications Union (ITU) for the Galileo system. Second, it demonstrates critical technologies for the navigation payload of future operational Galileo satellites. Third, it is characterising the radiation environment of the orbits planned for the eventual full Galileo constellation.

GIOVE-A carries two small European rubidium atomic clocks, each with a stability of 10 nanoseconds per day, and two signal generation units, one able to generate a simple Galileo signal and the other a more representative Galileo signal. These two signals are broadcast through an L-band phased-array antenna designed to cover all of the visible Earth under the satellite. Two instruments monitor the types of radiation to which the satellite is exposed during its two year mission. The Galileo signals broadcast by GIOVE-A are being carefully analysed by ground stations to make sure they satisfy the criteria of the ITU filings.

SSTL website