Conspiracy theorists and others of a paranoid disposition, beware: the number of satellites capable of tracking your location is set to double by the end of the decade, thanks to the launch of Galileo.
Europe’s answer to the US military’s GPS navigation system, Galileo is designed to provide highly accurate and guaranteed positioning services under civilian control.
Work has begun on building the system’s first test satellites, and international interest in the programme is growing. The Galileo Joint Undertaking, the joint EU-ESA body, announced recently that China has become a partner, and has agreed to invest e200m (£140m), making it the country’s largest scientific project with foreign partners.
But despite these positives the political and financial problems that have beset the project since its inception continue to threaten its progress.
Galileo, due to begin operation in 2009, will have dual frequencies, unlike GPS, allowing it to transmit navigation messages on two signals. This will increase its integrity and take its accuracy to 1m for some services and 4-5m for others, compared to GPS’s accuracy of 10-20m or less in built-up areas.
It will allow the system, a constellation of 30 satellites with 27 operational and three active spares, to be used for safety-critical services such as running trains, guiding cars and landing aircraft. Galileo will be inter-operable with GPS and, with double the number of satellites from which to take a position, will also make it possible to provide accurate locations in cities, where high-rise buildings can obscure signals from low on the horizon.
But none of this will be possible if Galileo is unable to transmit signals. So ESA will be launching a test satellite at the end of 2005 into the constellation’s planned orbit, to secure the frequencies allocated to the system by the International Telecommunications Union. Two such test satellites are being built, to guard against the threat of delays to one of the spacecraft during development or a craft being destroyed on launch.
The UK’s Surrey Satellite Technology is building the first of the two Galileo System Test Bed satellites, GSTB-V2-A. The company’s engineers next week begin integrating all the satellite’s sub-systems together. Once the satellite is complete, next year, it will be sent to ESA’s European Space Research and Technology Centre (ESTEC) at Noordwijk in the Netherlands for environmental tests, before being shipped to Baikonour in Russia ready for launch.
Once in orbit, the spacecraft will demonstrate some of the technologies to be used by the final Galileo satellites, including the antenna, and the first European-built rubidium clock, which uses the oscillation of atoms to measure time with extreme accuracy. This is crucial in satellite navigation, where positions are determined by the time it takes a signal broadcast by the satellite to reach a receiver.
The satellite will also be used to test the system’s signal generators, which will allow ESA to experiment with the new signal structures to be used on Galileo, said John Paffett, senior programme engineering manager at Surrey Satellite Technology.
‘There has been an ongoing debate between Europe and the US over the inter-operability of the Galileo and GPS signals, so this will allow some tests to be done on interference between the two, and to investigate how well the Galileo signals work,’ he said.
Finally, the test satellite will also be used to gather important information on the environment at Galileo’s intended orbit in the ‘Van Allen’ belt, 23,616km above the Earth. Although this is a similar orbit to that used by GPS, there are few satellites in this region, and the environmental radiation they are exposed to is harsh. This will degrade the performance of the satellites over time, so GSTB-V2-A will carry instruments – including the Qinetiq-built Merlin space weather monitor – to measure the radiation and provide continuous data on the danger to on-board equipment.
‘The environment drives the cost of the system. You have to design sub-systems that are going to survive for long periods of time in a harsh environment, so getting that information fed into the main programme is critical,’ said Paffett.
The second test satellite, GSTB-V2-B, is being built by the Galileo Industries consortium, which includes the UK and German arms of EADS Astrium as well as France’s Alcatel Space and Thales, and Italy’s Alenia Spazio.
In the UK, EADS Astrium is responsible for the navigation payload on the satellite and its ground control unit. These, along with the sub-systems being built elsewhere in Europe, will be delivered to the consortium’s facility in Rome in January for an integration readiness review.
The spacecraft will then be fitted together, before undergoing three months of testing from July to ensure it is ready for launch in December, according to Richard Peckham, head of business development for navigation at EADS Astrium.
Galileo Industries’ satellite was originally expected to carry an even more advanced clock than the rubidium device, known as a hydrogen maser. Based on the same principle as the rubidium – of forcing atoms to jump from one energy state to another to create an extremely stable microwave signal – the maser has a stability better than one nanosecond per day, and should be the most advanced clock ever sent into space.
But the clock is being provided by ESA, and there is a significant risk it will not be ready for the launch date, said Peckham. ‘We would certainly see that as one of the riskiest technology developments. It’s not a showstopper if it doesn’t happen, but in Europe we’re looking to advance the technology. Galileo is an opportunity to do things better than GPS,’ he said.
<b>All the wrong signals</b>
Galileo may be a technological success, but EU infighting has already chequered its progress and now a severe cash shortfall threatens to force cost-cutting. Helen Knight assesses the likelihood of a smooth launch.
ESA will decide in around August next year which of the two satellites will be launched into Galileo’s orbit. The space agency originally planned to build just one test satellite, but a delay of almost a year – caused by a disagreement between Germany and Italy over who would lead the project – meant that the Galileo frequencies were in danger of expiring.
So the space agency had to order two units to prevent a failure of one unit putting the entire programme in jeopardy, said Peckham. ‘When the project was conceived securing the frequencies, although important, was only number three on ESA’s list of mission objectives, after proving the payload for European-designed and sourced equipment and characterising the medium-Earth orbit.
‘But because of this long delay it became possible that we wouldn’t get a satellite launched in time to secure the frequencies. ‘Plus there are others out there, notably China which is next in line, who have filed for the same frequencies and want to transmit navigation signals,’ he said.
Surrey Satellite Technology came forward with a design that could be used to build a spacecraft quickly. This would ensure that ESA could at least have a basic satellite ready in time to secure the frequency (although it is limited in the payload it can carry). But even so, building an extra satellite immediately added an extra e60m (£42m) to the project, which was already e140m (£97m) over-budget. This was a result of additional security requirements attached to the programme in December 2002, and running two parallel building projects has meant further expenditure, ESA admits.
The shortfall means there is not enough money left in the pot to spend on the next stage of the project, the In-Orbit Validation (IOV) phase. This is when four operational satellites are due to be built by Galileo Industries and launched in 2006, in a bid to validate the basic space and ground segments of the system. Creating a mini-constellation of satellites will allow ESA’s engineers to carry out more sophisticated experiments, including position fixing, which cannot be done with just one spacecraft.
The technology demonstration phase is effectively the risk-mitigation stage for the entire programme, before the Galileo concessionaire â€” to be chosen next month from three bidding consortia led by EADS, Eutelsat and Finmeccanica – begins deployment and operation of the final system.
Franco Bonacina, spokesman for ESA, said the space agency has e600m (£417m) left to spend on the IOV phase, but needs another e300m (£209m) to complete the programme. ‘Our analysis shows that’s the figure that would make it go,’ he said.
The space agency hopes to have a clearer picture by the end of the month, he said. ‘More money is needed from the member states, and of course industry will have to commit to a fixed price figure, but that is certainly within their scope. So the two things together should bring us to a solution.’
By mid-December ESA must finalise the budgets for all its 2005 programmes, so the two sides must reach an agreement by then, he said.
However, while Galileo Industries agrees more money is needed to complete the IOV phase, the two sides remain some way apart on just how much extra funding is required, said Dr Michael Healy, director of earth observation, navigation and science at EADS Astrium. ‘We’re quite a bit above that [the e300m], and quite honestly we’ve always been above that,’ he said.
Galileo Industries submitted its initial proposal to ESA in mid-October, which put the cost of the IOV phase at e1.1bn (£0.7m) – around 25 per cent higher than ESA’s estimate. This proposal was the first round in a negotiation process of around a month with ESA, with the consortium’s final bid expected on 12 November.
‘ESA wants to get full transparency on cost and to understand the cost in detail, and they want to work with us to find savings. They will potentially come back to us and de-scope the work, and we have a list of potential areas for cost savings,’ said Healy.
One such possibility would be buying in the US atomic clocks used on the GPS satellites, rather than investing in more costly European-built technology. However, this would mean Europe once again becoming reliant on US technology, in direct opposition to one of Galileo’s founding aims.
Costs could also be reduced by altering the system’s signal structure. In its existing form this is required to have a level of flexibility, to allow it to continue to be tweaked as necessary. But flexibility costs money, as it requires more advanced software and processors.
Finally, the IOV phase could be reduced from three satellites to four, while ESA has also asked the consortium to investigate the possibility of using its GSTB-V2-B test satellite in place of one of the IOV spacecraft, assuming Surrey Satellite’s spacecraft is chosen for the test bed launch.
Although Galileo Industries’ spacecraft is the more sophisticated of the two, it would still involve a compromise, said Healy. ‘It has no search-and-rescue payload, no C-Band receiver, and the signals it is broadcasting are those defined one or two years ago. There have not been drastic changes to the signals since, but the changes were obviously worth making or they wouldn’t have been made,’ he said.
The danger of slimming down the development stage, industry claims, is that it would reduce the amount of risk that can be taken out of the programme before the full deployment phase begins. This stage is to be funded on a private finance initiative basis, with one third coming from public funds and two-thirds from private investors. The greater the risks involved in the deployment phase, the more difficult it may be to secure investors.
Even if ESA and the consortium opt for one or two of the cost-cutting measures, Healy believes e900m (£626m) is still an unrealistic target. ‘I am a little worried about the cost. There has been quite a big difference in opinion [for some time] between Galileo Industries and ESA over what the cost will be – and that gap hasn’t converged,’ he said.
The recent agreement with China will help to make up some of the funding shortfall, as the deal includes e60m (£42m) to be made available through in-kind equipment contributions during the IOV phase.
But despite this, and however much money can be saved from the programme through cost cutting, ESA will have to go back to the EU member states and request more funding for the programme. To those involved, including Surrey Satellite’s John Paffett, this raises the depressing prospect of a return to the interminable arguments between project partners that caused such expensive delays in 2002-3.
‘If ESA is unable to reduce the cost of the IOV phase and has to go cap in hand back to the delegates and ask for another several hundred million euros I can see the same thing happening again,’ he said.