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A high-performance, modular star tracker

Available with several fields of view to match mission profiles and architectures. From the best price-performance balance with Hydra Access to solutions tailored to customer requirements with Hydra Custom.

An autonomous tracking system

With its multi-head architecture, Hydra offers enhanced robustness, precision, and ease of use through autonomous operation.

Flight-proven since 2012

More than 245 Hydra units launched, and over ten million hours in operation.

Software

The software can be implemented either in the Hydra electronic unit (EU) or on the satellite’s onboard computer (OBC). The software library is available for various OBCs.

Electronic unit

Two versions: Hydra Baseline and Hydra TC (‘Two Channels’, featuring a fully redundant electronic unit). Centralized processing version also available.

Optical head and baffle

Fast acquisition and tracking precision of a few arcseconds with a CMOS detector; 26° sun exclusion angle; available with or without a thermoelectric cooler.

Main features

Robustness in acquisition and tracking≤6 deg/s | ≤8 deg/s
Precision XY2.8 arcsec
Lifetime in orbit10 years in LEO | 18 years in GEO

Our products

Hydra - Access

Hydra - Access

  • Most affordable version of the Hydra range
  • Batch manufacturing & off-the-shelf - 8-week delivery time
  • Standard test plan includes vibration testing, thermal vacuum testing, and calibration
  • No electronic unit, centralized processing by the software embedded in the OBC
  • Up to 3 Hydra optical heads
Hydra - Baseline

Hydra - Baseline

  • Best-in-class, highly modular star tracker
  • Centralized or stand-alone version
  • Three electronic unit versions available: LEO, GEO (with enhanced radiation shielding), and TC "Two Channels" (with hot or cold electronic redundancy in a single unit)
  • One or two electronic units for redundancy
  • From 1 to 4 optical heads / from 1 to 2 electronic units
Hydra - Custom

Hydra - Custom

  • Custom development, carried out for the JUICE & EUROPA CLIPPER missions, for example
  • Possibility of improving robustness with additional shielding and hardware or software adaptations
  • Low-power version available with Hydra-M (Minimum Power)
  • Possibility of additional studies and specific support throughout the mission's lifespan

Options

Testing facilities and support

  • Training with our experts to become knowledgeable on Sodern star tracker and ground support equipment, on site or remotely ;
  • Mission-specific radiation and performance assessments ;
  • Technical support for software integration ;
  • Engineering model ;
  • Star tracker numerical performance model ;
  • Static or dynamic optical ground support equipment ;
  • Electrical ground support equipment for H/W in the loop testing.

Management and reviews

Dedicated project management and manufacturing teams!
Several levels of management and reviews are proposed according to statement of work:

  • Standard or customised management.

Options available

In addition to the broad choice of configurations available in the HYDRA line-up:
• EEE parts level 1 or level 2 ;
• With or without Thermo-Electric Cooler ;
• Alignment cube orientations ;
• Software options are available to enhance performances, please contact us for more informations.

Examples of Hydra missions

Mission NASA Europa Clipper

EXPLORATION2024
NASA mission dedicated to the study of Europa, one of Jupiter's moons. Hydra star tracker is on board , custom-designed to withstand Jupiter's high-radiation environment.

Mission NASA JPL SphereX

EXPLORATION2025
Sodern is contributing to NASA JPL's SphereX mission with Hydra star tracker, delivered to BAE Systems. SphereX will collect data on more than 450 million galaxies to explore the origins of the universe.

Mission NASA Lucy

EXPLORATION2016
NASA's Lucy spacecraft's goal, equipped with Hydra star tracker, is to study Jupiter's Trojan asteroids.

Missions NASA Goes S-R-U

METEOROLOGIE2016
Geostationary meteorological satellites equipped with Hydra star trackers. The mission provides information on Earth's atmosphere and ocean masses for the U.S. National Weather Service.

Mission DirecTV-15

TELECOMMUNICATIONS2015
Equipped with our Hydra star tracker, the DirecTV-15 satellite is a geostationary communication satellite. It provides telecommunications services to the continental United States, Hawaii, Puerto Rico, and Alaska.
All our products undergo Space Qualification, involving stringent testing under extreme conditions to ensure robustness and high performances

Our Other Ranges

Auriga™

A compact, off-the-shelf star tracker, ideal for constellations and small satellites
The Auriga™ star tracker is a true showcase of advanced technology, perfectly optimized for the smallsat market under 500kg and New Space projects from 6U upward.
Auriga™

Horus

Single box star tracker
Horus is an autonomous and robust star tracker that leverages innovative technologies to deliver high performances and competitiveness in applications requiring a single field of view. Horus has notably been selected for use on telecommunications platforms developed by leading satellite manufacturers.
Horus
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