On April 26, the European Union Court of Justice dismissed a complaint from OHB System regarding a contract awarded to Thales and Airbus to supply satellites for the Galileo program, reported Reuters. OHB System supplied most of Galileo’s operating satellites.
In 2021, the European Commission rejected OHB System’s bid to supply the next-generation Galileo satellites and selected Airbus Defense and Space and Thales Alenia Space Italia. This follows a 2018 tender by the European Space Agency for next-generation Galileo satellites.
OHB System requested the European Commission and the ESA suspend the tender after its former chief operating officer was hired by Airbus and to exclude Airbus from the tender. This was rejected in January 2021.
The European Space Agency (ESA) and the One Sea Association — a non-profit global alliance of commercial manufacturers, integrators and operators of maritime technology, digital solutions, and automated and autonomous systems — are partnering to promote the development of space-enabled services that aim to support the maritime sector’s transition to autonomous shipping.
This partnership will combine expertise in the maritime sector and in autonomous shipping from One Sea with technical competence and mandate through the Business Applications and Space Solutions program from ESA to support the development and demonstration of space solutions in addressing user needs.
The European Space Agency (ESA) Academy is requesting university students to apply for the pilot edition of the Navigation Training Course. The course will take place June 26-30 at ESA Academy’s Training and Learning Facility in ESEC-Galaxia, Belgium.
With a specific focus on Galileo, the ESA Academy course aims to provide university students with an introduction to satellite navigation. Designed by ESA experts that developed the Galileo space and ground segment, this training course will offer students fundamental knowledge of Galileo’s architecture, tools, services and functionalities.
The training course will include lectures and hands-on exercises with a tour of Galileo in-orbit test facilities in ESEC, which provides an essential part of the current Galileo ground segment.
Upon completion of the training course, students will be evaluated and will receive a certificate of participation and course transcript, allowing them to request ECTS credits from their respective universities.
For more information and application requirements, visit the ESA website.
GMV has been selected by the European Space Agency (ESA) and the European Union Agency for the Space Programme (EUSPA) to develop the Galileo second-generation system test bed (G2STB). The G2STB will provide ESA with a key system verification and validation facility in support of its role as Galileo system development prime, enabling a wide range of Galileo system monitoring, troubleshooting, prototyping and experimentation activities.
GMV will deliver four G2STB versions over five years. Among these modules, the G2 high accuracy service (HAS) data generator and monitor aims to improve the Galileo HAS that was declared operational in January.
Other early capabilities of the G2STB include an upgraded orbit determination and time synchronization facility — capable of processing inter-satellite link data, a time service monitoring module, an integrity support message generator, a signal authentication service, an authentication validation module, an emergency warning service module, an ISL simulator and a G2G message composer.
The G2STB project aims for a smooth transition from the Galileo first-generation to the second-generation, building onto the G1G legacy system tools. The G2STB is one of the key infrastructure elements that ESA is developing for the correct functioning of the Galileo second-generation satellites.
The G2STB will eventually replace and upgrade the capabilities of the two first-generation facilities, the Galileo system evaluation equipment and the time and geodetic validation facility (TGVF-X). The latter, developed and operated by GMV over the last decade, has played a key role in monitoring the Galileo signals and system validation activities during the Galileo exploitation phase. The TGVF-X is also contributing to the early validation of new capabilities and elements being rolled out in recent and upcoming Galileo System updates.
In parallel to the development phase, the G2STB will help upgrade the network of Galileo experimental sensor stations to process new signals and capabilities to ensure the availability of a G2-capable, worldwide, multi-constellation network of receivers and bit-grabbers — independent from the operational Galileo sensor stations.
The Navigation Support Office at the Mission Control Centre of the European Space Operations Center (ESOC) has been tasked with providing independent precise orbit determination for European space missions. ESOC, which is based in Darmstadt, Germany, is a part of the of the European Space Agency (ESA). ESA aims to use high-quality signals from Galileo alongside GPS to sharpen the orbital positioning levels for future space missions.
The Navigation Support Office has used the positive results of the Copernicus Sentinel-6 mission — one of the first missions to fly a joint Galileo-GPS capable receiver, which improved positioning capabilities — to prove to ESA mission teams that future missions can harness the power of Galileo to improve positioning accuracy.
Missions in the works
Proba-3 is a precision formation flying mission that aims to launch in 2024. The mission consists of two small satellites launched together that will separate to fly in tandem to prepare for future multi-satellite missions flying as one virtual structure. This mission will require millimeter-scale positioning precision and use a variety of positioning methods, including optical, radio and laser links and GNSS such as Galileo.
The ESA-supported Lunar Pathfinder will be launched into lunar orbit in 2024 with the intent of using it as a communication satellite for future moon missions. The spacecraft will incorporate a specially designed GPS- and Galileo-capable receiver that aims to demonstrate the feasibility of positioning fixes from 400,000 km away.
The future of Galileo
Galileo serves Europe and the world with accurate and reliable navigation services as well as a catalyst for future space missions — making it a critical aspect of both everyday life and the enhancement of accurate navigation. The constellation will continue to grow with 10 more Galileo first-generation satellites planned for launch in the next few years. Second-generation Galileo satellites with enhanced capabilities are being built for testing and qualification at ESA’s European Space Technology and Research Centre as well.
An artist’s impression of a Moon exploration scenario. (Image: ESA)
As there are several missions to the moon planned within the next decade, space agencies have started to consider how to keep time on the moon. To address time concerns, the LunaNet architecture, designed for lunar communications and navigation services, was introduced at the ESTEC technology center of the European Space Agency (ESA) in the Netherlands in November 2022.
“LunaNet is a framework of mutually agreed-upon standards, protocols and interface requirements allowing future lunar missions to work together, conceptually similar to what we did on Earth for joint use of GPS and Galileo,” said Javier Ventura-Trav
eset, ESA’s Moonlight navigation manager, coordinating ESA contributions to LunaNet. “Now, in the lunar context, we have the opportunity to agree on our interoperability approach from the very beginning, before the systems are actually implemented.”
“During this meeting at ESTEC, we agreed on the importance and urgency of defining a common lunar reference time, which is internationally accepted and towards which all lunar system and users may refer,” said Pietro Giordano, ESA navigation system engineer. “A joint international effort is now being launched towards achieving this.”
Each mission to the moon has operated on its own timescale from Earth. Deep space antennas have been used to keep onboard chronometers synchronized with terrestrial time at the same time to facilitate two-way communications. ESA stated that this way of working will not be sustainable in the coming lunar environment.
Time to think about time
Should a single organization be responsible for setting and maintaining lunar time? Also, should lunar time be set on an independent basis on the moon or kept synchronized with Earth? And what about time on other planets?
“Of course, the agreed time system will also have to be practical for astronauts,” said Bernhard Hufenbach, a member of the Moonlight Management Team from ESA’s Directorate of Human and Robotic Exploration. “This will be quite a challenge on a planetary surface where in the equatorial region each day is 29.5 Earth days long, including freezing fortnight-long lunar nights, with the whole of Earth just a small blue circle in the dark sky. However, having established a working time system for the moon, we can go on to do the same for other planetary destinations.”
To efficiently collaborate, the international community will have to settle on a common “selenocentric reference frame,” similar to the role played on Earth by the International Terrestrial Reference Frame, allowing the consistent measurement of precise distances between points across the planet.
The European Space Agency (ESA), in collaboration with the Joint Research Centre of the European Commission, are hosting this year’s ESA/JRC International Summer School on GNSS with the Swedish Space Agency in July in Kiruna, Sweden. The course will include an overview of satellite navigation from the theoretical basis of GNSS, their signals, and processing by receivers and more.
Elements of this year’s program will include details of low-Earth-orbit positioning, navigation and timing, navigation on the Moon, and Galileo’s Open Service Navigation Message Authentication. Exercises will include receiving signals from Galileo and other GNSS.
Participants will also learn about business aspects, intellectual property rights, and the future of satellite navigation systems, including Galileo second-generation.
Some of the world’s leading satnav and space experts will be giving lectures. Lecturers include Paul Verhoef, former director of navigation for ESA, and Jean-Jacques Dordain, former director general. The course will be opened by Anna Rathsman, Director General of the Swedish National Space Agency; Javier Benedicto, Director of Navigation at the European Space Agency; and Georgios Giannopoulos, head of the Technologies for Space, Security and Connectivity Unit at the Joint Research Centre of the European Commission.
The course is limited to 50 participants on a first-come, first-served basis and is open to graduate students, Ph.D. and postdoctoral researchers, as well as young engineers and academics working within industry or agencies, aged 38 or younger.
The summer school will take place July 17-28 in Kiruna, Sweden. Register before April 14 for a reduced early fee. For more information and to register, click here.
The European Space Agency (ESA) is in search of European companies interested in taking part in the in-orbit demonstration of a low-Earth-orbit (LEO) satellite navigation constellation utilizing novel frequencies and capabilities.
Those interested in participating are encouraged to attend ESA’s LEO-PNT Industry Day on March 7 at the ESTEC technical center in the Netherlands. The LEO-PNT Industry Day will give an overview of the project to companies, research institutions and ESA delegates from Member States.
A detailed invitation will be issued soon, covering all aspects of the LEO-PNT Orbit Demonstrator, including the space and ground segments, operations, launchers, the test user segment, experimentation, and segment demonstration.
Registration by Feb. 27 is required. To learn more, visit atpi.eventsair.com.
LEO satellites would supplement the existing Galileo constellation. (Image: ESA)
One Galileo satellite has been reconfigured to emit a new signal component optimized to serve low-end receiver devices and internet of things (IoT) applications. According to the European Space Agency (ESA), GSAT0202, in elliptical orbit, was reconfigured in January to transmit the new signal, also known as the G1 E5 Quasi Pilot.
The G1 E5 Quasi Pilot in the E5 band lies along a narrow part of the overall Galileo signal, intended to enable streamlined positioning fixes requiring less calculation — without affecting the E1 and E6 signal bands, on which Galileo also transmits. The initial receiver test showed that the signal component has the potential to reduce the signal acquisition time by a factor of three compared to the current GPS L5 or Galileo E5a signals.
Image: ESA
Once GSAT0202 was reconfigured, signal measurements were collected using the high-gain antenna installations from the Galileo in-orbit test facility, which confirmed the stability of the augmented signal. After G1 E5 Quasi Pilot was broadcast, it was successfully acquired and tracked by a set of receivers.
Airbus Defense and Space, Thales Alenia Space Italy, the European Union Agency for the Space Programme (EUSPA), the European Commission, and Spaceopal supported this test.
The other elliptical Galileo satellite, GSAT0201, will also be reconfigured after further testing. Selected chipset manufacturers will be involved in the testing under supervision of EUSPA. The test results will be evaluated at the Galileo Programme level, to eventually introduce G1 E5 Quasi Pilot into the constellation.
It was 2018. Representatives from the European Space Agency were visiting Google headquarters in Mountainview, California.
Under discussion was Europe’s plans to introduce a high accuracy and authentication service to their Galileo satellite navigation system. Galileo would broadcast precise point positioning corrections on the E6-B band and provide users decimeter-level accuracy. They would also be including a navigation authentication message enabling receivers to distinguish genuine messages from deceptive ones sent by spoofers.
Wouldn’t Google like to incorporate these capabilities in future versions of Android phones?
The answer from Google Distinguished Engineer, Frank van Diggelen, was a resounding “yes.”
Technologically Possible
Van Diggelen also had another thought. It should be possible to deliver precise positioning corrections and authentication data via the internet. This could allow phones with an internet connection to access the services as well. With an app, older smartphones would be able to take advantage of the services, and it wouldn’t be necessary to add new hardware to new phone designs.
The next logical step was to establish an internet-based high accuracy and authentication service for the United States’ GPS. Unlike the newer European Galileo and Chinese Beidou systems, GPS satellites don’t have the ability to transmit data to improve accuracy and authenticate signals.
Yet a couple of process challenges in the United States could make establishing such a service difficult and might prevent its creation entirely.
Data collection and use not yet an official program
The first is related to the way in which the U.S. collects and handles real-time tracking data of the Global Navigation Satellite Systems (GNSS) — GPS, GLONASS, Galileo, and BeiDou — to derive corrections needed for a high accuracy service.
NASA’s Jet Propulsion Laboratory (JPL) operates NASA’s Global GNSS Network (GGN) of more than 60 stations around the globe, which provide their tracking data to JPL’s Global Differential GPS (GDGPS) System. The GDGPS System also has access to real-time tracking data from hundreds of additional sites, all of which track GPS and other GNSS. This allows the GDGPS System to generate precise corrections for the navigation messages of GPS and other GNSS. It also enables real time decimeter-level accuracy for positioning applications anywhere in the world. These corrections are provided to some government agencies and commercial entities on a reimbursable basis.
NASA’s GDGPS capabilities are not part of a formal, official government program, though. Rather they have grown organically as part of JPL’s efforts to push boundaries in scientific and engineering applications of GNSS, and its ability to take on work paid for by other agencies. Thus, GDGPS efforts lack a sufficient and established government funding line, formal programmatic tasking, and other structures and procedures needed to ensure its long-term viability as a government-provided service.
NASA and JPL officials recognized this and in 2020 established a working group to advise on how they should go forward. The following year that working group made several recommendations to NASA and the PNTAB. Among them were to establish a consistent level of NASA funding, create a Level-1 capabilities document for GDGPS, and start discussions towards an interagency memorandum of understanding (MOU) for long-term government funding.
At the same time, a PNTAB task force investigated the GDGPS activity and made recommendations to the PNTAB. They included: that NASA/JPL document GDGPS capabilities, including architecture, facilities, functions and products; that a stable government funding line for GDGPS be established; that a security review of GDGPS be undertaken; and to maintain GDGPS entrepreneurial aspects in pursuing multi-agency usage of its services.
Civil GPS rarely needs addressed
The second challenge to establishing high accuracy and authentication service for GPS appears to be the lack of an identified agent or mechanism within the federal government to do so.
Europe’s Galileo is a civilian system established and operated to support economic activity and development. The U.S’s GPS is run by the military.
First created to “put five bombs in the same hole,” it was built and run for years by the U.S. Air Force and is now the responsibility of the U.S. Space Force. Its primary mission is support of military missions and almost all funding comes through the Department of Defense (DOD).
Yet, indisputably, 99% of GPS users are not in the military and the system has become essential to most technologies and nearly every facet of the U.S. economy.
Official government policy has long recognized this, at least at the strategic level. Presidential policies issued in 2004 and in 2021 provided for improvements in functionality for civil users – as long as they were required by and entirely funded by a civil agency.
At a more tactical level, though, attempts to fund civil requirements have always faced great difficulty and rarely succeeded.* Mandates in presidential directives for civil signal monitoring, interference detection and mitigation, increased resilience, alternative PNT, and responsible use have all faced uphill battles and received little funding.
According to former senior government officials, this difficulty stems from civil GPS use being caught in a bureaucratic “Catch-22.”
On the one hand, executive branch policy dictates that funding for GPS capabilities and applications benefiting civil users must flow through the Department of Transportation (DOT). On the other, within government programming and budgeting circles, GPS is seen as an expensive military capability funded through the DOD. Requests for GPS and PNT-related funding through DOT are more difficult to explain and are easier to deny.
Compounding this difficulty is the lack of a clear and empowered national leader to advocate for a comprehensive and national approach to GPS and PNT issues and overcome bureaucratic snags.
As a result, the path forward for adopting the recommendation for a GPS high accuracy and resilience service is, at best, unclear.
Yet many on the President’s advisory board and in government are hopeful. “Establishing a high accuracy and resilience service for GPS is the right thing to do” said one. “We have all the pieces to make this happen. We just need to bring them together.”
And as one of the board members commented at the recent meeting, if the U.S. doesn’t do this “It stinks.”
Image: Slide from the National PNT Advisory Board Meeting in November 2022
*The exception to difficulties funding civil GPS-related capabilities is the Federal Aviation Administration’s Wide Area Augmentation System. It was established as the result of heavy lobbying by the airline industry, which continues to give it strong support.
In 2022, the Galileo GNSS continued to provide the world’s most precise satellite navigation information, to a user base that stands at more than 3.5 billion worldwide. Furthermore, provided services continue to improve and expand, with plans for high-accuracy positioning and signal authentication now reaching fruition.
The European Union Agency for the Space Programme (EUSPA) and the European Space Agency (ESA) continue to enjoy an effective collaboration on the many development, deployment, and evolution activities of the Galileo Programme — each according to their respective responsibilities for service provision and system development with the European Commission (EC) acting as the program manager.
Ranging accuracy performance from January to September 2022.Positioning-related MPLS from January to October 2022.
New Services Launched in 2022
Excellent Performance
Service delivery operations and maintenance of operational systems are managed by EUSPA, which supervises many contracts that carry out the day-to-day activities from dedicated control and monitoring centers throughout Europe. In 2022, Galileo timing, navigation, and SAR/Galileo services were delivered with excellent performances that continue to exceed the formal declarations for minimum performance levels (MPL), which were increased in January, both in terms of absolute accuracy and overall service availability. The entry into service of two additional satellites in May and August, have further consolidated the overall service availability to end users.
Galileo FOC Batch 3 satellite under testing.
Expansion of Service Portfolio
The service provision teams have been able to focus on improvements to, and expansion of, the service portfolio.
The I/NAV improvement will positively impact end users by enabling a faster time to first fix, and updates to the data validity status flags will lead to better protection of users against expired navigation data. These changes are implemented in updates of the onboard software of the satellites being rolled out across the constellation. At present, seven operational satellites have been successfully updated; the complete software upgrade campaign is planned to be completed this summer.
Galileo’s new High Accuracy Service will provide free precise point positioning (PPP) corrections, in the Galileo E6-B data component and by terrestrial means, for Galileo and GPS (single and multi-frequency) to achieve real-time user position improved by up to 10 times. The infrastructure to support an initial service (Phase 1) is nearing completion, and the formal declaration of the service capabilities is planned for early this year.
To provide users with a method of authenticating the received Galileo signals, especially the satellites ephemerides and the Galileo timing parameters, the new Open ServiceNavigation Message Authentication (OSNMA) service enables a receiver to confirm that a navigation message originated from the EU Galileo infrastructure. Many application areas are expected to benefit from this capability, including smart tachographs, telematics and logistics, UAVs, location-based services, and timing services. Having successfully demonstrated the technology behind the service in 2022, including a public observation phase, the roll-out of the Initial Service is planned to take place by the end of the year.
A fourth Medium Earth Orbit Local User Terminal (MEOLUT) in La Réunion will extend the SAR/Galileo Forward Link Service Coverage Area over the Indian Ocean as part of the SAR/Galileo full operational capability (FOC) declaration expected in the first quarter of 2023. The Cospas-Sarsat commissioning of this new station was completed in September 2022, and operational data is already being distributed to Cospas-Sarsat.
Reference documents for the above services can be found at the EUSPA European GNSS Service Centre website, including technical notes, interface control documents and service declaration documents.
SAR/Galileo-related metrics from January to October 2022.Extension of the SAR/Galileo Forward Link Service Coverage Area over the Indian Ocean.
FOC Infrastructure Development Nears Completion
Satellite Production
The production of the third batch of Galileo FOC satellites advanced further in 2022 with the completion of the environmental tests and the system compatibility test campaigns at the European Space Agency Test Centre in Noordwijk, The Netherlands. After 10 years of successful testing, on Oct.18, 2022, the last Galileo FOC satellite (flight model number 34) left the test center to return to the premises of the satellite manufacturer, OHB Systems, in Germany. Testing of the remaining 10 satellites has confirmed that they have been correctly built and will perform well in orbit. The acceptance review of the last couple of satellites will take place this summer.
At the beginning of 2023, the plan is to start in-orbit testing of a quasi-pilot signal on the E5 frequency using the Galileo GSAT201/202 satellites in elliptical orbit. The provision of a signal offering coarse acquisition in Galileo E5-A/GPS L5 can be a distinguishing feature for Galileo with respect to all other constellations to further improve the capability to acquire the E5 signal at low complexity. Following in-orbit testing, the strategy for roll-out of this capability will be assessed with the involvement of receiver manufacturers.
New SAR Galileo MEOLUT facility in Réunion island.
Access to Space
The discontinuation of Soyuz launch services from the Kourou Space Centre in French Guiana, because of the Russia-Ukraine conflict, has caused delays in the two Galileo launches that had been planned for 2022. The Launch 12 campaign had to be interrupted and in March 2022 the FM25 and 26 satellites were put in storage at the Kourou launch base, then returned to Europe in November.
Ariane 6 is the baseline launcher for Galileo satellites to ensure European independent access to space. The remaining Batch 3 satellites will be launched with the Ariane 62 launcher vehicle, the two strap-on solid booster variants of Ariane 6, now undergoing the final stages of development led by prime contractor Ariane Group. Ariane 6’s maiden flight is scheduled to take place in the fourth quarter of 2023.
Ground Segment
An upgrade of the ground control segment, in charge of command and control of the satellite constellation, is being developed by the industrial consortium led by GMV. The upgrades will address resolution of hardware and software obsolescence including cyber security, operability improvements, and a security monitoring overlay.
With the planned increase in the number of satellites in orbit, an additional telemetry tracking and control facility (TTCF) is being deployed in Kourou leading to seven operational TTCF stations in early 2023.
The ground mission segment, in charge of navigation control, is undergoing a complete technological refresh, including hardware/software virtualization performed by an industrial consortium led by Thales France. This upgrade will provide additional robustness, including a system extended contingency mode resilient to outages lasting up to seven days and a new state-of-the-art cyber security monitoring system. It will also provide ranging authentication through encrypted codes on the E6-C signal component for the implementation of the Commercial Authentication Service. Global coverage will be further increased with the introduction of two Galileo sensor stations in Wallis (Pacific Ocean) and Bonaire (Caribbean Sea), for a total of 15 sites around the globe.
OSNMA-related metrics from January to October 2022.
G2G Development Started
Galileo’s second generation (G2G) will introduce many innovative technologies to offer unprecedented precision, robustness, and flexibility.
2022 was a key year for the evolution of G2G activities with the fast development cycles of the first batch of G2 satellites, beginning development of the associated G2G in orbit validation (IOV) ground segment and system test beds, and the consolidation of the G2G final system capabilities — including the coordination of the mission/service roadmaps with the EC, EUSPA, and the EU Member States delegates.
Ariane 62 launcher.
G2G Satellite Manufacturing
From the satellite development point of view, the two parallel contracts to develop and manufacture each of the six G2G batch one (G2SB1) satellites are progressing in a fast development environment, with the first hardware units ready for integration and testing.
Following the completion of preliminary design review, these two contracts (for six satellites each) are preparing for unit-level validation/testing, which will lead to the critical design review.
These satellites will provide the following key innovations:
Reconfigurable fully digital navigation payload
Point-to-point connection between satellites by inter-satellite-link for command and control, and ranging functionalities
Electric propulsion for orbit-raising capabilities
Advanced jamming and spoofing protection mechanisms to safeguard.
The Galileo signals will improve with:
On-board authentication capabilities
Increased ground-to-space data rate
Improved time reference (number of clocks and advanced clock monitoring functions).
G2G IOV Procurements
2022 was also the year in which two key events took place with respect to G2G in-orbit validation (IOV) ground segment and system test bed procurements:
Finalization of the procurement cycle, now in the final evaluation/award phase, to be kicked off in the first quarter of this year
Confirmation of the IOV design through different coordinated actions with the EC and EUSPA, including the G2 system preliminary design review.
The contracts will provide Europe with the following capabilities:
G2SB1 satellite launch and early orbit phase, in-orbit testing and enhanced legacy services provision
G2 new capabilities in-orbit validation, including prototyping and validation of all the novel technologies that can exploit the full capabilities of the G2SB1 satellites.
Eleven contracts will be issued to manage in synchrony all the G1 and G2 assets for the coming years:
G2 IOV ground control segment (G2 GCS) for satellites monitoring and control
G2 IOV ground mission segment/secured facility (G2 GMS-GSF) for the production, dissemination and monitoring of all enhanced legacy services and the dissemination of new G2 advanced capabilities for validation
G2 IOV security monitoring (G2 SECMON), for the cyber/security monitoring of the system
G2 filling device (G2 FD), to ensure proper initialization of system assets
G2 system test bed (G2STB), to generate and monitor new G2 capabilities for validation of the G2G mission/services
G2 PRS test bed (G2PRSTB), similar to G2 system test bed but focused on advanced PRS capabilities for validation purposes
G2 security chain (G2SC), a test bed to ensure proper satellite-ground segment qualification before launch
Four system engineering support contracts (G2 SETA), where the main GNSS technical experts from different industries in Europe provide their support to ESA and EUSPA in their different fields of expertise.
These contracts are complemented by a significant set of system research and development and test tools, such as test user receivers and radio frequency constellation simulators.
G2G batch number one (G2SB1) satellites.
Galileo Second Generation System PDR
The Galileo Programme is not only focusing on short-term G2G development activities, but also looking forward to the future in terms of the consolidation and definition of G2G final operation capabilities. During the second half of 2022, more than 200 public representatives from the EC, EUSPA, ESA and Member States held countless meetings in the frame of the G2G system preliminary design review, which concluded in early December 2022.
As part of this review, the long-term implementation (G2G in orbit capability, or IOC, and final operational capability, or FOC) was reviewed and an agreement was reached on future steps. The evolution of Galileo capabilities will not only provide better services through advanced technical solutions, but will also ensure continuity of service and enhanced backward compatibility for first-generation legacy users.
Conclusions
The efforts of ESA and EUSPA continue with the aim of providing users continuous and stable services and evolving space and ground infrastructure to maintain Galileo competitiveness with the other global navigation satellite systems.
For analogous updates on the other three GNSS constellations, please see:
New PNT satellites will operate in low Earth orbit (LEO). (Image: ESA)
News from the European Space Agency (ESA)
Satellite navigation is headed closer to users. ESA’s Navigation Directorate is planning an in-orbit demonstration with new navigation satellites that will orbit just a few hundred kilometers in space, supplementing Europe’s 23,222-km-distant Galileo satellites.
Operating added-value signals, these novel low-Earth-orbit (LEO) positioning, navigation and timing (PNT) satellites will investigate a new multi-layer satnav system-of-systems approach to deliver seamless PNT services that are much more accurate, robust and available everywhere.
Global in coverage, free for everyone to use, GNSS such as Europe’s Galileo have already transformed our society, and due to their sheer omnipresence their influence continues to grow. In 2021, the population of satnav receivers reached 6.5 billion around the world, and the sector is projected to maintain a 10% annual growth rate in the years ahead. But in various respects the standard GNSS approach is nearing the limits of optimum performance — to get even better, added ingredients are becoming essential.
“Satellite navigation has enabled a vast range of applications in recent years, but this very success is inspiring still more demanding user needs for the coming decade,” said Lionel Ries, head of ESA’s GNSS Evolutions R&D team, overseeing the agency’s LEO-PNT studies.
“For use cases such as autonomous vehicles, ships or drones, robotics, smart cities or the industrial internet of things for control of factory systems, the positioning requirements are growing from the current meter-scale to centimeter scale or even more precise, based on continuously reliable signals that are available anywhere, anytime — even indoors —while able to overcome interference or jamming.
“Up until now we have relied for positioning on the classical solution of GNSS such as Galileo, located in medium Earth orbit and based on L-band signals. Standard GNSS alone is not going to be able to fulfil all these future user demands. Instead Europe needs to seize the opportunity to investigate the potential of the kind of LEO constellations that are already on the way in the global market to enable new kinds of PNT services.”
Simply by virtue of physics, with less of a distance to cover down to Earth, the signals from these LEO-PNT satellites can be more powerful, able to overcome interference and reach places where today’s satnav signals cannot reach.
Additionally, by adopting novel navigation techniques and a wider range of signal bands the satellites can address particular user needs: for instance at lower orbits the satellites themselves move more rapidly relative to Earth’s surface — think of the International Space Station at 400 km that orbits the Earth every 90 minutes — which offers possible advantage in the time needed to reach very accurate positions. Also some bands could offer greater penetration in difficult environments while other bands could offer higher robustness and precision.
Mega-constellations of hundreds or even thousands of low-orbiting satellites offer a means of acquiring continuous coverage for telecommunications services or Earth observation. (Image: ESA)
The purpose of ESA’s plan to perform an in-orbit demonstration of low Earth orbiting satnav satellites is precisely to consolidate the types of signals, enabling technologies and their potential for future services.
The plan is to build and fly an initial mini-constellation of at least half a dozen satellites to test capabilities and key technologies, as well as demonstrating signals and frequency bands for use by a follow-on operational constellation, in the same way that Europe’s GIOVE test satellites paved the way for Galileo. Success will place European industry in pole positions for follow-on commercial undertakings, as well as planned institutional programs.
“Each individual satellite would be comparatively small, below 70 kg in mass, compared to a 700 kg current Galileo operational satellite,” added Roberto Prieto-Cerdeira, Galileo Second Generation satellite payload manager and LEO-PNT project preparation manager as part of ESA’s FutureNAV program.
“They can be comparatively more streamlined because they can benefit from other means to calculate the accurate time without extremely precise atomic clocks on board — including relayed signals from the Galileo satellites above them. These satellites would also be built on a rapid batch production basis to save time and cost — we are targeting three years at the most from signing the contracts to the first satellites in orbit, the same kind of timescale achieved by GIOVE-A in the early 2000s.”
A vision of the future shows layered satellite navigation stretching from Earth to the Moon. (Image: ESA)
“It is ESA’s ambition to ensure Europe maintains a world-class space industry, and navigation today forms the single largest downstream space sector, worth about €150 billion annually and growing at the rate of 10% per year,” said ESA Director of Navigation Javier Benedicto-Ruiz. “Standing still is not an option; instead we need to explore new technical avenues to spur European competitiveness and commercialization.”
An operational version of the LEO-PNT constellation would represent a whole new layer for PNT delivery, combined with traditional GNSS as well as 5G/6G-based positioning on the ground, and fused with data from sensors in the user terminals.
Interest from industry
ESA has been researching core elements of the LEO-PNT concept since 2016. Now, with numerous low Earth orbit constellations already taking shape around the globe, the time is right to move from basic research to in-orbit demonstration.
Interest from European industry in the LEO-PNT project has been very high, shown by a recent Request for Information where ESA presented details of how companies and institutions might participate and a large number of companies registered and presented possible concepts and contributions.
Forward to FutureNAV
LEO-PNT is supported through the ESA Directorate of Navigation’s FutureNAV programme, which also includes the GENESIS satellite to measure the shape of Earth more accurately than ever before while also boosting the positioning performance of satnav satellites. The FutureNAV programme, which includes both GENESIS and the LEO-PNT initiative, is up for decision at ESA’s next Ministerial Conference, taking place in Paris on Nov. 22-23. Read the fact sheet here.
Until now, all navigation satellites have flown in medium-Earth orbit – up at 23,222 km in the case of Galileo, which delivers meter-level accuracy. At such altitudes the satellites move slowly across the sky, helping ensure global availability of satellite navigation signals, albeit at relatively low power.
ESA’s LEO PNT constellation would move to a “multilayer system of systems” approach, with medium-Earth orbit signals supplemented by those from LEO satellites at altitudes of less than 2,000 km — along with additional inputs from terrestrial PNT systems and user-based sensors, made up of approximately a dozen satellites, helping European companies move forward at a time when worldwide commercial interest is high in LEO constellations of all kinds, especially for telecommunications and PNT.
The satellites themselves can be stripped down compared to current navigation satellites, because they would essentially be relaying satnav signals from MEO. This is a key point because there will need to be many more satellites to ensure global coverage — because the lower the orbit the faster each individual satellite will pass across the sky. This fact also opens the way to a more agile “New Space” approach to satellite construction for European firms, with smaller payloads and simplified operations from the ground.
Their signals will be much stronger (potentially able to penetrate indoors), and transmitted on novel frequencies, which – along with the new geometries made possible by LEO satellites – should enhance overall service resilience. LEO PNT will also deliver faster position fixes and enable rapid two-way authentication checks. And overall signal availability will be boosted enormously, especially in high-latitude and polar regions.
