Netzer VLS Absolute Encoder – Precise Position Measurement in LEO Space Systems

The growing number of satellite missions and the rapid development of the New Space sector are creating increasing demand for precise and reliable position sensors. This is particularly true for systems operating in Low Earth Orbit (LEO), where components must function in extreme environmental conditions. One solution designed for such applications is the VLS series hollow-shaft absolute encoder from Netzer Precision Position Sensors.

The VLS series consists of modern absolute encoders with an ultra-low profile and very high measurement accuracy, developed for space, aerospace, and the most demanding precision automation systems. The VLS encoder family is the only commercially off-the-shelf (COTS) encoder solution that has been proven in space. In Poland, these solutions are available through AMG Automatyka.

Why an absolute encoder is crucial in satellite systems

In modern satellites and orbital platforms, accurately determining the position of mechanical components is extremely important. This includes systems responsible for positioning solar panels, communication antenna mechanisms, and control systems for optical instruments.

Absolute encoders are used in such applications because they assign a unique digital value to every shaft position. This means that the control system instantly knows the current position of the mechanism—even after a temporary power loss.

In the space environment, this is a significant advantage. Unlike incremental encoders, an absolute encoder does not require a reference procedure or returning to a home position, which increases the reliability of the entire system during an orbital mission.

Resistance to Low Earth Orbit environmental conditions

Devices operating in Low Earth Orbit (LEO) must be prepared for extreme environmental conditions, including cosmic radiation, significant temperature fluctuations, and operation in vacuum.

The VLS series absolute encoders have been designed specifically to address these challenges. Their construction meets requirements related to resistance to total ionizing dose (TID) radiation and single event effects (SEE). The materials used feature low outgassing properties, which is essential in a vacuum environment.

Additionally, the encoders are equipped with a special conformal parylene coating that reduces the risk of so-called tin whisker formation and improves operational reliability during long-duration space missions.

The devices can operate within a wide temperature range from –40°C to +105°C (optionally from –55°C to +125°C). Their design has also undergone rigorous testing for vibration, shock resistance, and other environmental stress screening (ESS) conditions.

VLS hollow-shaft encoder – compact design for modern satellites

The VLS series consists of hollow-shaft absolute encoders, meaning the devices feature a central through-hole. This design allows a drive shaft, wiring, or structural elements to pass through the center, significantly simplifying integration in compact satellite systems.

In space projects, component mass and dimensions are also extremely important. The VLS hollow-shaft encoder features an exceptionally flat design—with a height of less than 7 mm—and very low weight (the smallest encoder in the series weighs just 8 grams). As a result, it can be used in lightweight satellite platforms, including nanosatellites and microsatellites.

The key technical parameters of the VLS series include:

• measurement accuracy up to ±0.006°
• resolution up to 23 bits
• very low current consumption – below 100 mA
• SSI and BiSS-C communication interfaces
• hollow-shaft design simplifying mechanical integration
• high durability – MTBF up to 15 years

Thanks to these parameters, VLS absolute encoders can operate in applications requiring both the highest precision and high reliability.

Applications of VLS absolute encoders in Space systems

Thanks to their high precision, low weight, and environmental resistance, the Netzer VLS encoder family is already used in advanced photonics and space communication programs. These include Acquisition, Pointing & Tracking (APT) systems, Optical Inter-Satellite Links (OISL), Free-Space Optical communication (FSO), Deep Space Optical Communication (DSOC), and Inter-Satellite Links (ISL).

In these applications, VLS encoders provide precise and stable position feedback that enables accurate pointing, rapid signal acquisition, and reliable long-term tracking of objects.

Netzer encoders in the AMG Automatyka portfolio

The VLS series hollow-shaft absolute encoders represent a modern solution for projects requiring maximum reliability.

AMG Automatyka is a distributor of Netzer Precision Position Sensors solutions in Poland and supports customers in selecting appropriate sensors for advanced industrial, research, and space applications.