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High-performance Space IMU
Astrix NS-IMU
What is a Space-Grade IMU and Why Is FOG Technology Essential?
Definition and core function of space measurement units
Space navigation starts with reliable inertial data. As spacecraft become increasingly autonomous, they require accurate and continuous motion measurements to perform complex operations such as orbital maneuvers, rendezvous and docking, and planetary exploration.
An Inertial Measurement Unit (IMU) combines gyroscopes and accelerometers to provide the inertial data required by Guidance, Navigation and Control (GNC) systems for precise trajectory and motion estimation, even when external navigation references are unavailable
Benefits of ITAR-free Fiber-Optic Gyroscope (FOG) technology
Discover the first ITAR-free Space IMU. The Astrix NS-IMU is a compact, radiation-tolerant Inertial Measurement Unit combining Exail's Fiber-Optic Gyroscope technology with high-accuracy accelerometers.
Built on Exail's proven Fiber-Optic Gyroscope expertise and derived from the Astrix NS architecture, it brings proven inertial technology into a new-generation IMU designed for demanding New Space missions. It provides precise measurements of angular motion and linear acceleration for advanced Guidance, Navigation and Control (GNC) systems.
Compact, radiation-tolerant and optimized for low SWaP requirements, the Astrix NS-IMU delivers high-end inertial performance for the next generation of space missions, from orbital maneuvers and docking to planetary exploration and Entry, Descent and Landing (EDL).
Developed through the EURISA Horizon 2020 programme
The Astrix NS-IMU originates from the EURISA project, funded by the European Union's Horizon 2020 research and innovation programme. The project aimed to develop a European high-performance, ITAR-free inertial measurement solution dedicated to the growing needs of New Space missions. Through this programme, the Astrix NS-IMU was successfully developed and matured to Technology Readiness Level 6 (TRL 6).
Since then, Exail has continued the qualification roadmap with the support of the European Space Agency (ESA), advancing the Astrix NS-IMU towards Technology Readiness Level 9 (TRL 9) for operational space missions
HIGH-PERFORMANCE INERTIAL SOLUTION for space missions
The Astrix NS-IMU is designed to support spacecraft requiring accurate and reliable motion estimation throughout their mission lifetime.
Key features
Developed without ITAR restrictions, the Astrix NS-IMU enables easier international integration and supports global space mission deployment.
Designed for serial production, the Astrix NS-IMU supports short lead times and high production volumes to meet the growing demand of New Space programs.
Building on the Astrix NS architecture, the Astrix NS-IMU benefits from Exail's experience in developing high-performance space inertial solutions. It brings this technological heritage into a new-generation IMU designed for the evolving needs of New Space missions.
Designed for harsh space environments, the Astrix NS-IMU supports long-duration missions while maintaining high inertial performance
With compact dimensions, low mass and low power consumption, the Astrix NS-IMU is optimized for New Space platforms where size, weight and power constraints are critical.
Leveraging Exail's proven Fiber-Optic Gyroscope technology, with in-house manufacturing of both optical fiber and accelerometers, the Astrix NS-IMU provides a complete inertial measurement solution with low noise, excellent bias stability and long-term reliability.
Enabling autonomous space operations
Orbital maneuvers
The Astrix NS-IMU supports precise maneuver execution and post-maneuver performance assessment by providing reliable motion measurements to the spacecraft GNC system.
Autonomous docking
The Astrix NS-IMU provides stable inertial data required for autonomous guidance systems during critical spacecraft proximity operations.
Rover navigation
The Astrix NS-IMU provides accurate dead-reckoning capabilities by measuring vehicle motion when external navigation references (eg: GNSS) are unavailable.
Entry, Descent and Landing (EDL)
During atmospheric entry, descent and landing, the Astrix NS-IMU supports accurate trajectory estimation when external navigation signals cannot be used.
Delta-V monitoring
The Astrix NS-IMU provides precise inertial measurements to support propulsion performance analysis and maneuver validation.
Technical specifications
 Astrix NS-IMU |
|
|---|---|
|
ARW |
0.005 °/√h |
|
Bias stability over 1h (steady temperature) |
0.005∘/h |
|
Bias stability end of life (all effects included) |
0.2 °/h |
|
Measurement Range (full performances) |
60∘/s qualified (higher on demand) |
|
Scale factor stability after @ 3σ (all effect included) |
< 200 ppm |
|
Scale factor linearity @ 3σ |
200 ppm |
|
Mass / Volume |
< 1.95 kg / 130 x 130 x 117 mm |
|
Power Consumption |
< 15W |
|
Start-up Time |
< 1 s for relevant data access |
| Datasheet |
Why choose a Fiber-Optic Space IMU?
Space missions require inertial sensors capable of maintaining high accuracy, stability and reliability throughout demanding operational environments. Fiber-Optic Gyroscope (FOG) technology provides the performance and robustness required for long-duration and safety-critical missions.
Compared with other solutions, Fiber-Optic Gyroscope technology provides:
Very low drift over time enables accurate navigation and trajectory estimation throughout the mission lifetime.
Low noise and excellent bias stability provide precise inertial data for advanced Guidance, Navigation and Control (GNC) systems.
The passive optical design of FOG technology ensures robust operation and long-term durability in demanding space environments.
Stable performance across operating conditions supports precise spacecraft maneuvering and autonomous navigation.
Fiber-Optic technology is well suited for missions requiring reliable performance in radiation environments, from LEO to deep-space applications.
Leading the Market in Space Navigation: How Astrix Compares
As space missions transition toward mega-constellations, in-orbit servicing, and autonomous exploration, selecting the right navigation payload requires balancing performance with SWaP (Size, Weight, and Power) efficiency. While the inherent benefits of Fiber-Optic Gyroscope (FOG) technology make it a top-tier choice for modern spacecraft, evaluating how it compares to alternative market technologies highlights why the Astrix architecture excels:
FOG vs. Mechanical Gyroscopes
Legacy mechanical systems rely on moving parts subject to physical wear and high power consumption. FOG is entirely solid-state, providing unlimited operational lifespan, zero maintenance, and high resistance to launch vibrations.
FOG vs. Ring Laser Gyroscopes (RLG)
RLGs offer high accuracy but require complex gas-discharge cavities, high voltage, and mechanical dithering mechanisms. FOG delivers equal or superior stability in a lighter, passive, and more power-efficient optical format.
FOG vs. MEMS Navigation sensors
While MEMS offer a minimal footprint, they struggle with severe thermal drift, high noise, and long-term instability. Astrix FOG technology provides orders-of-magnitude lower Angular Random Walk and strict bias repeatability for mission-critical pointing.
Frequently Asked Questions about Space IMUs and Astrix NS-IMU
A gyroscope measures angular velocity only, while an IMU combines gyroscopes and accelerometers to measure both rotational and linear motion. This enables complete inertial navigation and trajectory estimation.
An IMU provides continuous navigation data when external references such as GNSS, optical navigation or ground-based tracking are unavailable or insufficient.
Fiber-Optic Gyroscope technology offers superior long-term stability and lower drift, making it better suited for demanding space missions requiring high navigation accuracy.
The Astrix NS-IMU is derived from the Astrix NS architecture and benefits from Exail's long-standing expertise in Fiber-Optic Gyroscope technology for space applications.
A space-grade imu (or inertial measurement unit) is an advanced navigation system designed to calculate precise acceleration, velocity, position, and heading in space environments without relying on earth-based sensors or GPS signals. Unlike standard commercial or MEMS IMUs, space-qualified units are built around high- accuracy gyroscope and accelerometers technologies—such as a fiber-optic fog sensor—to deliver exceptional bias stability, low noise, and minimal drift error over extended time periods. Engineered to withstand harsh radiation, wide temperature variations, and intense motion, a space sensor provides an uninterrupted reference and essential data for long-term orbital missions.
In orbit and deep-space missions, a space-grade imu provides real-time motion and rotation rate tracking to guide the vehicle during critical maneuvers. The inertial measurement unit processes high-frequency data from its internal gyroscopes and accelerometers to detect micro-vibrations, maintain precise attitude control, and monitor velocity changes across every axis. This continuous feed of acceleration and angular rate information enables autonomous satellite positioning, precise delta-v monitoring during orbital adjustments, and reliable rover navigation or planetary entry, descent, and landing (EDL).
Designing a space-qualified imu requires balancing extreme mechanical robustness with high accuracy and long-term stability. Key engineering challenges include maintaining strict bias stability, minimizing internal noise, and preventing scale factor errors when subjected to cosmic radiation, vacuum, and extreme thermal cycling. Furthermore, engineers must optimize power consumption, physical weight, and spatial footprint within a tight window of operation, ensuring the gyroscopes and accelerometers deliver maximum performance and a reliable output without calibration drift throughout years of operation in space.
Recent advancements in space inertial navigation focus on integrating high-precision fiber-optic fog technology and next-generation mems architectures to achieve unprecedented performance in compact form factors. Flagship initiatives like the European EURISA Horizon 2020 programme have accelerated the development of ITAR-free, space-grade imus tailored for satellite constellations, autonomous docking, and planetary exploration. These innovations enable continuous position and heading tracking over a wide operating range, offering reliable data for future lunar landers, orbital transfer vehicles, and deep-space exploration missions.
The space IMU market is driven by specialized aerospace suppliers offering space-qualified inertial systems based on mechanical, MEMS, Ring Laser (RLG), and Fiber-Optic Gyroscope (FOG) technologies. As a leading European provider, Exail advances space-grade navigation through 100% ITAR-free FOG architectures. The industry’s technological growth is supported by European research initiatives—such as the EURISA Horizon 2020 programme—and commercial space partnerships, prioritizing maximum accuracy, reliability, and export independence for satellite and spacecraft missions.
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