Hydra Star Tracker
Sodern
World-reference high-performance modular star tracker in three variants (Baseline, Access, Custom), 2.8 arcsec XY accuracy, 18-year GEO lifetime. Flown on NASA Europa Clipper, Lucy, GOES, ESA JUICE.
Technical specifications
- Cross-axis accuracy (XY)
- 2.8 arcsec (1σ)
- Field of view
- 16° × 16°
- Limiting magnitude
- Visual magnitude 6
- Design lifetime (GEO)
- 18 years
- Variants
- Hydra-Access (off-the-shelf, 8-week delivery), Hydra-Baseline (up to 4 optical heads), Hydra-Custom (mission-specific)
- Flight heritage
- NASA Europa Clipper, NASA Lucy, NASA GOES, ESA JUICE, NASA SphereX, NASA InSight, geostationary telecom platforms
About
The Hydra is Sodern’s flagship modular star tracker family, widely recognised as the world reference for high-performance attitude determination in demanding institutional and commercial satellite missions. Available in three variants: Hydra-Access (catalogue off-the-shelf with 8-week delivery), Hydra-Baseline (centralised or standalone, up to 4 optical heads for full-sky coverage), and Hydra-Custom (bespoke, radiation-hardened for the most demanding environments including deep space).
Hydra achieves 2.8 arcsec (1σ) cross-axis accuracy with a 16-degree-square field of view, magnitude threshold down to visual magnitude 6, and an 18-year GEO design lifetime. The modular architecture allows scalable redundancy: optical heads and processing electronics can be combined in various configurations, and the design supports both centralised electronics units (CEU) serving multiple heads and fully autonomous standalone heads.
Flight heritage includes NASA Europa Clipper (Hydra Custom, hardened for Jupiter’s extreme radiation environment), NASA Lucy asteroid mission, NASA GOES geostationary weather satellites, ESA JUICE (Hydra for navigation during Jupiter moon flybys), NASA SphereX all-sky survey, and many geostationary commercial telecom platforms. The Hydra has accumulated thousands of spacecraft-years of on-orbit heritage.
Documentation
No public datasheet yet — request the datasheet / ICD from the supplier.
