Catégorie : Space optronics

In this paper, we will explain how the electronic components and the image sensors for our star trackers are selected, in order to propose the best performance/lifetime/price trade-off, while offering resistance to radiation.

The lead time and the ability to deliver satellite equipment, including star trackers, has now come down to just a few weeks, driven by the changing economic constraints of NewSpace. In a context such as this, how do we propose high-quality products meeting the requirements in such a short period of time?

In 2019, SODERN was the world’s first equipment manufacturer to produce and market a reliable, compact, standardized, off-the-shelf star tracker. It was initially intended for the OneWeb constellation, but in fact revolutionized the NewSpace market. The need for small, high-performance and accessible star trackers with a short delivery lead time, rapidly expanded to include all manufacturers of 6U to 500kg satellites.

The design of Auriga™ took account of 4 fundamental criteria: compactness, robustness across the entire celestial vault, the ability to produce several thousand items a year, and resistance to radiation, thus guaranteeing mission lifetimes of up to 10 years in LEO and 15 years in GEO.

When initial design work began on the Auriga™ star tracker, SODERN made its ability to deliver 2,000 trackers a year the focus of its strategy. To do this, right from the product design stage, it had to define its industrialization process, choosing the most robust and agile supply chain possible. The company thus made the decision not to use components from Hi-Rel foundries, but to upscreen automotive grade components, although with no compromise on reliability.

This decision guarantees that customers have access to a competitive product based on a supply chain that is familiar with high volumes and short lead times.

How? For more than 60 years now, SODERN, Société d’Etudes et de Réalisations Nucléaires, has developed unique in-house skills in the study and analysis of radiation phenomena, with a team of recognized experts, notably physicists with expertise in fundamental interactions and elementary particles. This also makes SODERN a world-class supplier of neutron sources.

These core skills have enabled us to take part in the design of iconic space missions in extreme radiation environments, with demanding customers. Prime examples are missions to the environment of Jupiter, namely Juice (specialized navigation cameras and Hydra star trackers) and Europa Clipper (Hydra star trackers with radiation hardening modifications). This expertise helped us determine that 35-krad tolerant electronics are ideal for customers whose LEO, MEO, GEO missions do not generally exceed 15 years.

The image sensor and all the electronic components used in the Auriga™ star tracker are upscreened. They undergo a rigorous selection, notably by means of systematic high-temperature burn-in stress test, and electrical characterizations across the equipment’s entire operating temperature range. Components failing the screening criteria are rejected, and will not be used for production. This selection process guarantees the superior reliability of the equipment produced. In the same way, all the procured component batches are subjected to radiation and environmental tests, ensuring their build quality and their ability to withstand an ionizing dose level of 35 krad.

If we look a little more closely, concerning a mission lifetime of 15 years, the primary radiation phenomenon which reduces performance – and therefore potentially the lifetime of the mission – tends to be displacement damage caused by protons. The effect is to impair the detector’s performance by degrading its signal-to-noise ratio, regardless of the detector’s tolerance to total ionizing dose.

 

The key was thus to develop proprietary image pre-processing algorithms associated with locally sourced electronics to compensate for this damage. Another solution, which is far more costly in terms of power consumption, would have been to cool down the image sensor, an option that was ruled out by SODERN. Next, the choice of an image sensor with small pixels and compact photodiodes, unlike most of the star trackers from the competition, was crucial. This is also because the smaller the photodiodes, the lower the detector’s sensitivity to proton-induced displacement damage.

In short, the level of tolerance to the ionizing dose, often expressed in krad in the datasheets, or the use of a space grade foundry, do not in guarantee by themselves the overall resistance to radiation effects. For most missions lasting less than 15 years, the limiting factor with the greatest impact will be proton-induced displacement damage. A high-reliability detector capable of tolerating 35 krad will therefore, in most cases, be a better option than a detector able to withstand 100 krad but with lower proton resistance and without appropriate and powerful image pre-processing algorithms.

Since 2019 and building on these compromises, more than 1,250 satellites have been equipped with SODERN star trackers, racking up more than 30 million flight hours with 100% mission success. Backed by its supply chain and its technological advances, SODERN delivers an average of 400 Auriga™ star trackers around the world every year (excluding constellations), with a lead time of less than 1 month.

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Catégorie : Space optronics

“June 12, 2024 – Sodern is pleased to announce a new version of its daytime star tracker solution at the Eurosatory Global Event for Defense and Security, to be held from June 17 to 21, 2024 in Paris-Nord Villepinte.

After several years of research and development, Sodern has developed an endo-atmospheric star tracker which, combined with an inertial unit, offers a new solution for on-board positioning.

This high-performance system operating during the day and at night is sovereign, cannot be jammed or decoyed and has the advantage of emitting no waves which could make the carrier detectable.

This solution, presented for the first time at the Paris Air Show in 2023, has since then been optimized for ground applications.

Fabien Robert, Head of Development and Commercial Operations, explains: “We are continuing to improve and develop our daytime star tracker solution to adapt it to a wide range of land, sea or airborne carriers. This solution has a number of advantages which lie in its increasing compactness making it suitable for a large number of uses. The current context means that we are regularly identifying new types of applications. We are on track to propose a commercial product in 2025.”

With the previous version being specifically designed for airborne applications, it naturally operated above the clouds. This improvement offers a major advantage for all applications operating at ground level.

The daytime star tracker is now agile and can detect stars in complete daylight, even in cloudy weather. The tracker can now be swiveled and automatically points at the best field to locate the stars.

Further progress in performance now enables positioning to within a hundred meters to be envisaged.

Most positioning systems today have the drawback of being extremely vulnerable, because they use technology based on satellite radio-navigation signals (GPS, Galileo, etc.). These positioning services may not only be unavailable, but can easily be jammed or decoyed and generate false data, erroneously indicating that the subject is positioned elsewhere. Sodern proposes an all-new reliable and attack-proof technology contributing to secure and autonomous navigation for all types of civil or military airborne or maritime carriers.

Nicolas Dekyvere, Product Manager for the Arquus company, says: “The huge interest for our vehicles is the possibility of identifying their position in real-time, while being immune to jamming. The system is also compact and consumes little, which makes it easier to install. Knowing the exact position of the vehicle, even in a jammed environment, is increasingly demanded by our customers, not only for navigation, but also for beyond-line-of-sight (BLOS) missile firing or artillery fire direction.”

Apart from the positioning application, this system also proposes a native capability for directing any instrument requiring precise pointing to within a few arc seconds, which opens up other potential uses.

The equipment is then suitable for any application looking to refine its sighting or heading data by measuring its alignment with the stars, including in the daytime.

Sodern will be present at the Eurosatory exhibition, Hall 6 – stand D119.

Arquus will be in Hall 5A – stand F79.

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Catégorie : Space optronics

“On 21 May 2024, Sodern is pleased to announce the launch of the Auriga™ Gyro solution, an Auriga™ star tracker merging gyro data. Sodern has developed a new version of the Auriga™ software library. It now includes the option of using data from any gyro to provide continuous attitude data even in difficult kinematic conditions.

The Auriga™ star tracker is today’s reference on the New Space market, with more than 1,200 optical heads (OHs) in flight, which have cumulated more than 27 million hours* of failure-free operation.

This star tracker is integrated with advanced high-tech components, perfectly optimized for smallsats of less than 500kg and New Space projects. With its standardized components, the Auriga™ star tracker is specially designed to meet cost-reduction goals while maintaining an excellent level of flight-proven technical performance and reliability.

Fabien Robert, VP Business Development & Sales, states: “Auriga™ Gyro augments our satellite equipment range, using the proven technology of the Auriga™ star tracker. We have been marketing Auriga™ since 2019 and have more than 53 satisfied customers. However, owing to the diversity of orbits and the duration of launcher and OTV missions, our customers asked us with finding a solution to make attitude control more robust to the problem of the tracker being blinded by the Sun, or inertial unit drift.

The purpose of our Auriga™ Gyro solution is therefore to provide our customers with precise, continuous information for an optimal ADCS. This solution will meet the needs of conventional and agile missions such as Earth observation and the IoT, but will also be of use for new launchers, long lasting missions and/or multi-orbital launches requiring optimal attitude control throughout the mission. We are receiving a growing number of requests to equip this type of launcher and are committed to making our expertise and know-how available to our customers.”

Sodern has developed a new version of the Auriga™ software library, which controls the OHs. This library now includes the option of using the angular velocity supplied by any available gyro on-board the satellite.

Auriga™ Gyro is particularly useful for satellites on agile missions such as Earth observation or space surveillance. Auriga™ Gyro could also fit launchers with long-lasting missions.

By coupling the Auriga™ star tracker with a gyro, the kinematic robustness, in other words the ability to withstand rapid rotations, is considerably improved, including the gyro’s velocity in the processing carried out by the star tracker.

Moreover, merging data from the star tracker with that from the gyro, enables the coupled equipment to continuously supply an attitude, even when the star tracker is unavailable (blinding, satellite maneuver).

This new software version also includes algorithms to rapidly return to tracking mode after experiencing blinding or after a satellite maneuver, without having to go through an acquisition mode (lost-in-space mode).

If the gyro measurement is unavailable, the star tracker continues to work without interruption.

The solution also has an algorithm for in-flight estimation and correction of errors, notably on the gyro (bias, scale factor, inter-axis misalignment). This allows more precise correction of the errors than on the ground and offers optimal performance.

Coupling with a simple tactical grade gyro (ARW = 0.15°/√h) enables the robustness of AurigaTM to be significantly improved:

The Auriga™ Gyro solution will be on the market as of July 2024.

The development of Auriga™ Gyro was supported by the French space agency CNES under the Pegase program (generic program for improvements to Satcom and platform equipment) and by the program « Plan de Relance France ».”

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Catégorie : Space optronics

“November 08, 2023 – Sodern is pleased to announce the launch of the Auricam range of compact space cameras suitable for all orbits (LEO, MEO, GEO), at reduced cost and deliverable within a few weeks of order. The versatile Auricam cameras have been designed to cover a wide range of missions, such as space surveillance and protection, ensuring the continuity and security of operations, in-orbit or rendezvous services, navigation and scientific exploration. The Auricam range includes two launch models offering two fields of view: Auricam D35 and Auricam D80.

Auricam draws on over fifty years of Sodern experience in space equipment development. Most recently, Sodern developed the navigation cameras for the European JUICE (NASA) and Earth Return Orbiter (NASA/ESA) missions. The latter, used for the mission to return Martian samples to Earth, is capable of detecting a twenty-centimeter capsule close to the Martian atmosphere at a distance of over 3,000 km.

Auricam cameras benefit from Sodern’s optoelectronic expertise and extensive resources. The Auricam range thus achieves a high level of performance in detecting debris, small satellites or rocket bodies up to magnitudes 6 to 8, while delivering excellent image quality thanks to a 4-million-pixel CMOS sensor.

Auricam cameras are available in two models to meet all operational needs.

A representative digital twin model will complete the offer to facilitate integration by satellite prime contractors. This model is based on a simulation tool developed by Sodern, and validated in flight for more than 10 years now on star tracker and camera projects.

 

The design of Auricam cameras has been specially developed to offer reduced size and weight, without compromising on robustness and performance. While being resistant to radiative environments, the mass of the Auricam D35 is only 420g for a volume of 71 x 59 x 140 mm3; and 450g and a volume of 71 x 59 x 150 mm3 for the D80. Power consumption is also optimized, at less than 2 watts.

Auricam cameras are equipped with standardized, off-the-shelf, tried-and-tested components to ensure optimum reliability combined with rapid delivery. Thus, our highly industrialized manufacturing process guarantees delivery within three to four months, depending on the options chosen.

“When in 2019, with Auriga™, we launched the first space star tracker designed for high-volume production, we were betting on the fact that space would become a major issue requiring ever shorter time-to-market in a context of increased competitiveness.

4 years later, strengthened by the confirmation of what is today a reality: we are launching a range of high-performance cameras that builds on the foundations of what has made Auriga™ so successful; the same mechanical interfaces, the same communication interfaces and, above all, the same reliability and off-the-shelf availability.

Our mission is to enable our customers to succeed in their missions, by providing high-quality, reliable equipment in the shortest possible time-frame,” says Fabien Robert, Vice-President Development & Sales.

The Auricam range is qualified for a lifetime of 15 years in geostationary orbit.

The development of this camera has benefited from support from CNES as part of the Investment in the Future Plan (PIA) launched by the French government.”

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Catégorie : Space optronics

The Hydra Access tracker is the latest addition to the well-known Hydra range of high-end star trackers. Offering exceptional quality and resilience, Hydra trackers have been flown on major institutional and scientific missions for several countries, as well as on telecommunication and observation satellites in all orbits for 12 years.

Hydra Access is a standardized and simplified version of the Hydra-CP high-end star tracker in terms of testing, integration and reviews. In exactly the same way as Hydra-CP, it is composed of an optical head which integrates the image pre-processing.
Hydra Access trackers are mass-produced using new industrial production methods, and are designed, manufactured and tested to improve productivity throughout the manufacturing chain in order to optimize production costs.
This off-the-shelf batch manufacturing process enables Hydra Access to offer a high-end tracker with low lead-time at an affordable price. Hydra Access thus meets the needs of Newspace companies wishing to upgrade their product range with more precise attitude control. It also meets the expectations of traditional players seeking greater profitability for their space programs.

Discover Hydra Access star tracker in video

Hydra Access benefits from the same technical capabilities and reliability as the Hydra CP high-end trackers, inherited from over fifty years of Sodern experience in developing advanced space equipment. Hydra Access is designed to meet the most demanding accuracy and robustness requirements. Using the HAS-2 CMOS sensor and proven star detection algorithms, it offers an acquisition time of less than 2 seconds and an attitude retrieval accuracy of approximately 1 arcsec.

In addition, Hydra Access has a thermoelectric sensor cooling system that can be activated on demand, according to the needs of the mission. Hydra Access also benefits from an embedded star catalog, a library of algorithms and advanced software.
“We designed Hydra Access with the aim of offering a tracker with exceptional and recognized performance, that is immediately available and at a lower price. I am convinced that Hydra Access will become the new standard in the high-end star tracker market, offering an ideal alternative for budget constrained missions”, explains Fabien Robert, Sales & Marketing Director.

Hydra Access is designed with hardened, radiation-resistant lenses and is available with a 26° protective baffle.

The design of Hydra Access benefits from the in-flight experience of Hydra optical heads, representing over 5 million hours of fault-free operation since 2012. More than 300 Hydra trackers are currently in flight. Hydra Access also offers a lifetime of more than 18 years in geostationary orbit (GEO)*.

* With Peltier activation.

Catégorie : Space optronics

Our star tracker for NASA’s Europa Clipper mission has been delivered to NASA’s Jet Propulsion Laboratory.
The star tracker, one of the most challenging ever designed by Sodern, will be critical to determine the spacecraft’s orientation while traveling from Earth to Jupiter.

“It gave me goose bumps to be a few feet away from the star tracker and think about its role in ensuring the success of this daring mission.” “The moment I saw it, I realized even more that our spacecraft is becoming a reality”

Discover it: https://europa.nasa.gov/news/43/mission-dispatch-tracking-the-stars/

Sodern is always proud to contribute to NASA’s and ESA’s missions to help mankind learn more about our solar system.

Next stop : Jupiter !

(c) NASA

Catégorie : Space optronics

In late 90’s, Sodern developed an Autonomous star tracker line based on a 1k x 1k CCD: the SED16, 26, & 36 family. The flight qualification of the SED16 was achieved on the SPOT5 satellite in May 2002. More than 200 SEDx6 units have been launched and have accumulated more than 12,750,000 operating hours by the end of 2021.

With the last units to be delivered in 2022 and 2023, we will reach a total number of 292 star trackers.

GEO: 96 SEDx6’s in flight.
LEO: 101 SEDx6’s in flight.

 

Some notable missions flying a SEDx6 star tracker include the following:

  • Earth observation missions

SPOT5: A French civil Earth observation satellite for remote detection
Pleiades: A constellation of 4 Earth observation satellites manufactured by Airbus Defense and Space for high resolution, commercial imagery.

  • Transport missions

Cygnus: Manufactured by Northrop Grumman, the Cygnus also services the international space station.

  • Deep space

Earth’s Moon: Japan’s “Selene”: 1st lunar mission for Sodern
Venus: Japan’s « Planet C » mission
Ceres: NASA Dawn mission