New on the scene

Four OHB satellites reinforce the Galileo constellation

OHB Redaktionsteam
Published on
by OHB Redaktionsteam, OHB SE

Tara, Samuel, Anna and Ellen have been at their workplaces for half a year now; they have fit in well with the team and training has run according to plan. At the end of January, they were declared ready for service in space. On 11 February 2019, it was time for duty. Since then, the four satellites have been part of the operational constellation of the European satellite navigation system Galileo, with their signals available to all receivers on Earth.

These four Galileo FOC* satellites have been supplied by Bremen-based satellite manufacturer OHB System AG as part of the second contract. They reinforce the satellite constellation and make the Galileo European satellite navigation system even more effective.

The Galileo satellites** operate in space at an altitude of around 23,000 kilometers, providing people in Europe and around the world with a wide range of useful navigation applications. At the same time, Europe is no longer dependent on other global satellite navigation systems such as GPS or Glonass. From 2020 onward, replacement satellites that are also engineered by OHB will be added to the Galileo constellation.

“It is something very special to realise that, not least of all due to OHB satellites, millions of people in Europe and all over the world can now receive more accurate navigation data, rescue services can be deployed more quickly and commerce and industry can rely on the time stamps provided by the satellite system. With navigation services, the benefits of space technology can be perceived directly by most people in their everyday lives,” says Dr Wolfgang Paetsch, a member of OHB System AG’s management board, who is responsible for navigation, Earth observation and science.

Step by step towards the completed system

Europe’s own global satellite navigation system Galileo provides various positioning, navigation and time determination services. The final configuration consists of 24 satellites arranged on three orbital planes plus reserve satellites (spares) and a worldwide network of ground stations. “The satellites will then provide full geographical coverage accompanied by a further improvement in positioning nominal accuracy and speed. As it is, Galileo already provides the most accurate positioning compared to other systems. These are levels of accuracy that we could only dream of ten years ago,” says Dr Wolfgang Paetsch. “By interconnecting different signals from several constellations, it will be possible to further enhance positioning accuracy and speed in the future.”

The first services were made available in December 2016. Each new satellite integrated in the satellite constellation makes the system more stable and faster. In addition to GPS and Glonass, more recent smartphones also pick up the Galileo open navigation service offered to the general public. Galileo’s public regulated service is tailored to institutional users such as public authorities, the police or the fire brigade. The search and rescue service enables emergency signals to be located accurately and reliably, ensuring the swifter arrival of the rescue team at the scene of emergency which could mean a matter of life or death.

Navigation satellites made by OHB

OHB System AG won three tender rounds and was commissioned by the European Space Agency ESA to develop, build and test a total of 34 Galileo satellites, of which 22 are currently in orbit. “All the satellites placed in orbit to date proved their full functionality in space before we handed them over to the operator. On the one hand, this confirms our satellite design and, on the other hand, it testifies to our expertise in satellite manufacture,” says Dr Paetsch. As the producer of the satellite platforms and the system prime for the satellite design, OHB is responsible for integrating and verifying the satellites as well as supporting the launch preparations and in-orbit verification.

“We maintain close contact with the companies that launch our satellites into space, test them and gradually place them in regular operation. Obviously, we monitor which satellites are active and provide support, if necessary,” explains Dr Manuel Czech who, in his capacity as Galileo project manager, oversaw the realization of twelve satellites, including the four new ones in the constellation.

All navigation satellites ordered from OHB so far are identical in construction. “At launch, each satellite is roughly the same size as the old telephone booths and has a mass of around 750 kilograms,” explains Dr Czech. “After unfolding in orbit, the solar panels have a span of 15 meters and generate nearly 2 kW of power.”

Upon completion, the satellites must prove in a series of tests lasting several months that they are fit for deployment in space. Only then are they transported in special containers to the launch site in Kourou, French Guiana, where they undergo further thorough testing before being launched. “I was present at all the launches, either in one of the control centers in Darmstadt or Toulouse or as a moderator at the launch event at OHB and also during the last three launches in Kourou. Each time it is invariably a very special event from any perspective!” says Dr Czech. “Today, the entire OHB team and I are particularly pleased about this outstanding achievement and the successful cooperation at European level!”

OHB ramping up series production again

ESA also opted for OHB System AG’s expertise in the third tender, ordering a dozen satellites in 2017. “Satellite integration on our proven production islands was restarted in December 2018. We now want to start producing one satellite every five weeks,” explains Dr Kristian Pauly. As the project manager with many years of broad experience, he is overseeing the completion of these twelve satellites. A senior satellite systems engineer at OHB from 2009 to 2015, he played a leading role in the development of the Galileo FOC satellites.

Now, Dr Pauly can be found regularly in the Galileo integration hall in Bremen again: “Similar to automotive production, our satellites pass along production islands and take shape piece by piece. All steps are well documented, with the product and quality assurance staff vigilantly watching over every satellite. This will not change with the 34th satellite either,” adds Dr Pauly. The entire team can leverage the wealth of experience that has been gained from the production of 22 satellites in the past. “Experience is particularly important in aerospace engineering as well and especially in series production,” says the 46-year-old aerospace engineer.

Next launch scheduled for 2020

According to Dr Pauly, the first two of his satellites should be ready for launch in autumn 2020. “By this time, the other ten satellites will also have reached varying stages of completion. We will then be completing two more satellites every three months.” 

OHB think tank: What should the next generation of satellites be capable of?

Looking forward, OHB intends to continue making a significant contribution to the Galileo system. Consequently, OHB has been thinking about sustainable new-generation satellites for a long time. “We understand what the European Space Agency ESA wants to achieve with the new generation and are technically well positioned for this. Obviously, the wealth of experience that we have gained from earlier contracts will be incorporated in our design and, of course, also in the proposal that we submit to ESA,” says Dr Czech.

“With the new generation, the focus will be on improving signals and services. This is exactly what users benefit from. At the same time, we will be concentrating, of course, on enhancing cost-optimized operations and improving signal security. We have many good ideas and want to convince with clever concepts,” adds Dr Pauly.

*) The FOC (full operational capability) phase of the Galileo program is being funded by the European Union. The European Commission and the European Space Agency ESA have signed a contract under which ESA acts as the development and sourcing agency on behalf of the Commission. The views expressed here do not necessarily constitute the positions of the European Union and ESA. Galileo is a registered trademark of the EU.

** The current constellation consists of IOV (in-orbit validation) and FOC (full operational capability) satellites.