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.
Spaceopal and the European GNSS Agency (GSA, the future EUSPA, the European Union Agency for the Space Programme) have signed a contract for the development of an innovative reference algorithm and user terminal for the Galileo High-Accuracy Service (HAS).
Spaceopal is the prime contractor for Galileo’s operational services.
Spaceopal is an equal-share joint venture between Telespazio, a Leonardo (67%) and Thales (33%) company, and DLR Gesellschaft für Raumfahrtanwendungen (GFR) mbH. Spaceopal will develop the solution with the support of its shareholders DLR-GfR and Telespazio, and partners such as ANavS GmbH, the DLR IKN, IABG mbH and Iguassu Software Systems.
The project, awarded within the “Galileo Reference High Accuracy Service User Algorithm and User Terminal” Call, will develop the reference algorithm for HAS, which will be made publicly available and will be used for its validation. The user terminals at a high technology readiness level provided to GSA will serve as a blueprint and further facilitate the adoption of the European GNSS.
Spaceopal will develop the solution in the next 12 months, followed by a 6-month period of providing engineering support to the GSA for testing activities, training and demonstrating the performance of Galileo HAS.
Leveraging on the experience of the NAVCAST precise positioning services, on the commitment of Spaceopal’s shareholders and on the skills of its industrial partners, Spaceopal will build a close-to-market solution for the validation of the Galileo HAS service.
“This contract is a substantial milestone in Spaceopal’s path to innovation excellence and confirms our commitment to support the GNSS services of the future. We are delighted to be trusted by the European GNSS Agency to develop this service further facilitating the adoption of the European GNSS, that will provide an unmatched accuracy for the HAS users,” said Sebastian Fedeli, Spaceopal’s sales and procurement director.
Responsibility for in-depth troubleshooting and problem resolution of the GSC Ground Infrastructure has been transferred from a European GNSS Agency (GSA)-held European GNSS Service Centre (GSC) infrastructure contract to Spaceopal and its core team member DLR GfR, responsible in the Galileo Service Operator (GSOp) industrial organization also for L2/L3 maintenance activity. This contract extends for 10 years.
The transfer occurred after Spaceopal successfully passed the Maintenance Handover Review (MHOR) for the Level 2 and 3 Maintenance of the GSC in Torrejón de Ardoz, outside Madrid, Spain.
“Taking over this responsibility will allow us to react much quicker to anomalies in a more flexible way, directly improving operations and the service that the European GNSS Agency (GSA) provides to the Galileo end users,” said Christian Hessmann, Engineering Manager at Spaceopal.
The GSC services can be accessed by Galileo users via the GSC web portal.
Spaceopal is a joint venture between DLR Gesellschaft für Raumfahrtanwendungen (GfR) mbH, a full subsidiary of the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR), and the Italian firm Telespazio S.p.A. Both parties contribute their respective Galileo Control Centers in Oberpfaffenhofen and Fucino.
Since July 2017, Spaceopal GmbH has operated the Galileo satellite fleet under the GSOp contract and will thus ensure the provision of the Galileo services to the worldwide community.
The GSC provides the single interface between the Galileo system and the users of the Galileo Open Service (OS), and the Galileo Commercial Service (CS) for the provision of specific services beyond the Galileo Signal-In-Space (SIS) transmitted by the operational satellites. The GSC acts as an active means to engage in “in”- and “out” bound activities and is conceived as a centre of expertise, knowledge sharing, custom performance assessment, information dissemination and support to the provision of value-added services enabled by the Galileo OS and CS core services.
The GSC is located in a fully secured environment in Madrid, Spain, within the National Institute of Aerospace Technologies (INTA) facilities at Torrejón de Ardoz, overseen by the Spanish Ministry of Defence.
Spaceopal has launched NAVCAST, a GNSS precise point positioning (PPP) service featuring high-accuracy positioning enhancement for end users worldwide. NAVCAST aims to actively support and to accelerate widespread adoption of Galileo.
NAVCAST provides Galileo and GPS real time orbit and clock corrections based on an algorithm RETICLE (REal-TIme CLock Estimation), developed by the German Aerospace Centre (DLR e.V.).
Galileo and GPS observations, from more than 100 receivers of the worldwide IGS network, are used to estimate the current corrections which are broadcast to registered users relaying on the standard NTRIP protocol.
NAVCAST corrections improve the user error down to the centimeter level, making it attractive for a large number of applications, the company said.
Users can appraise the accuracy levels and convergence times achievable using NAVCAST (Galileo + GPS) corrections combined with a precise point positioning (PPP) engine, on the Spaceopal website. The underlying PPP engine (dual-frequency, ionosphere-free observations) estimates the local troposphere delays and fixes the carrier-phase integer ambiguities.
NAVCAST can be considered as proof of concept and Spaceopal’s contribution to high-accuracy GNSS services. NAVCAST corrections, which are broadcast over the Internet, could be in future via satellite constellation (such as MEO satellites).
From November 2010 until end of June 2017, Spaceopal was the prime contractor responsible for Galileo operations under the Galileo Full Operational Capability (FOC) Operations Framework contract, the company said. Spaceopal GmbH will continue to operate the Galileo satellite fleet under the Galileo Service Operator (GSOp) contract. Spaceopal is actively supporting the completion of the system to expand the services up to full operational capability by 2020.
From left: Ruy Pinto, chief information officer, deputy chief technology officer of SES; André Bauerhin, COO, Spaceopal; Nicole Robinson, SVP Global Government at SES Networks; Etienne Schneider, Luxembourg Deputy Prime Minister, Minister of the Economy. (Photo: SES)
SES will provide a series of services for the Galileo European navigation system under a long-term agreement with Spaceopal, a joint venture between Telespazio and DLR GfR mbH. According to SES, the contract is part of the Galileo Service Operator framework agreement between Spaceopal and the European Global Navigation Satellite System Agency.
Under the agreement, SES will provide Spaceopal with services to support the maintenance and operations of the Galileo Global Navigation Satellite System. Further, SES will be responsible for in-orbit measurements for the Galileo satellite constellation and provide VSAT managed services to Telespazio for the Galileo Data Dissemination Network.
“We are delighted to extend our partnership with SES in the framework of the Galileo Service Operator contract with the European Global Navigation Satellite Systems Agency,” said André Bauerhin, COO of Spaceopal. “SES’s previous success with the Galileo project in delivering and managing services for both in-orbit testing and the Galileo Data Dissemination Network has made SES the clear choice for this operational contract.”
SES also looks forward to the partnership.
“We are proud that we can continue to draw on the experience that we have accumulated while working on Galileo over the years, and continue to be part of the team in ensuring the reliability of the GNSS system and accommodating its shifting demands in the next decade,” said Nicole Robinson, SVP Global Government at SES Networks.
Previously, SES has provided infrastructure and services for the Galileo program, as well as ground stations and in-orbit testing during the In-Orbit Validation Phase.
Flight Operations Director Hervé Côme celebrating success finding the satellites. Photo: Galileo Control Centre
On September 27, the first two Galileo Full Operational Capability (FOC) satellites were handed over from the European Space Agency’s Space Operations Centre (ESOC) in Darmstadt, Germany, to the Galileo Control Centre, Oberpfaffenhofen, which will care for them pending a final decision on their use.
The satellites, launched on August 22, are in excellent health and working normally. However, a launcher problem left the pair in the wrong orbit, with higher apogee, lower perigee and an incorrect inclination compared to the planned circular orbit.
According to a release by the European Space Agency, the orbit presented a sudden and unexpected — though not untrained for — challenge to the team at ESOC responsible for the launch and early orbit phase. For months before each Galileo launch, a joint team of mission operations experts from ESA and France’s CNES space agency train intensively for this critical period, which typically lasts about eight days, from separation until handover to Oberpfaffenhofen.
“After launch, we quickly discovered that one of each satellite’s pair of solar wings had not deployed correctly,” said Liviu Stefanov, Spacecraft Operations manager. “At the same time, difficulties in receiving radio signals — indicated by unusually low power and instability — alerted us to the fact that the orbits could be incorrect. Basically, the ground stations were pointing to where we expected the satellites to be, and they weren’t there, so we weren’t getting good signals.”
The joint ESA–CNES Galileo operations team in the Main Control Room at ESA’s Space Operations Center, August 28. (Photo credit: R. Solaz).
Engineers determined within four hours the approximate actual orbit and then generated new commands to point the ground antennas to establish robust radio links. Working around the clock, and with assistance from the Galileo project engineers and the satellite builder, the teams then started to look at how to free the solar arrays. “Each undeployed wing had to be treated as a separate problem,” said Flight Operations Director Hervé Côme.
“Each satellite had to be maneuvered separately into an orientation where the undeployed panel was facing the Sun because we realized that one cause was linked to the low temperature of the release mechanism. It all required developing, validating and rehearsing new flight operation procedures on the fly.”
It took three days to release the trapped solar wing of the first satellite, and then two days later the second Galileo’s stuck array was also freed. The satellites have since been brought into full operation, as the teams in Darmstadt were tasked to retain control for five weeks — four weeks longer than planned.
“This was very demanding on the ESA and CNES personnel, and on the ESOC operations team in particular, but the strong bonds developed through months of joint training enabled them to perform very well,” Liviu said.
Possible uses of the two satellites are now being studied, and a future mission scenario will be decided at a later date.
While the process of handing over the satellites to the Galileo Control Centre (where they are operated by teams from a private company, spaceopal GmbH), had been practiced in the past, this was the first time it was done with FOC satellites in orbit. The delicate process involves transferring responsibility for commands and telemetry, and beginning the satellites’ secure mode of operation by the teams at Oberpfaffenhofen. The handover ran very smoothly over the last weekend in September.
“By the end of the Saturday, the first satellite was fully handed over, while the second handover took place on Sunday,” said Richard Lumb, ESA’s Galileo Mission director.
“I am extremely proud of the entire Mission Control Team and the way they handled a dramatic and very critical situation resulting from multiple, independent anomalies,” said Paolo Ferri, ESA’s head of Mission Operations. “After launch, the joint team managed to maintain control of the satellites under extremely difficult conditions, rapidly stabilized them, and determined the actual orbit. The accuracy and professionalism of the subsequent handover activities also showed that the joint team at ESOC and the spaceopal team at the Galileo Control Centre are very well tuned for this procedure, which will become increasingly frequent with future launches.”
