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MLO – Master Local Oscillator Project

BySpaceForest
3D rendering of the Master Local Oscillator (MLO) device, showcasing its compact design and advanced engineering.
Master Local Oscillator (MLO) — cutting-edge satellite signal source technology by SpaceForest.
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On May 14, 2019, at the ESA ESTEC headquarters, we reached a significant milestone. The team successfully completed a key phase in the development of the Dual Redundant Medium Power Master Signal Source, also known as the Master Local Oscillator (MLO).

Aerial view of the ESA ESTEC campus, showcasing modern architecture and green spaces, the European Space Agency's main technology and research center.
ESA ESTEC Campus — Europe’s leading space technology and research hub.

What is the Master Local Oscillator (MLO)?

The MLO device is a modern redundant medium-power satellite signal source used in space communication systems. It builds upon a proven predecessor — a local oscillator operating at 8.6 GHz, integrated with a hybrid downconverter. This earlier solution was developed by RUAG Space AB and successfully implemented in satellite systems.

The new MLO serves a similar function but comes with expanded capabilities. Its primary role is to provide a stable, redundant reference signal, which is critical for satellites operating in geostationary orbit (GEO).

3D visualization of the Master Local Oscillator (MLO) developed by SpaceForest, shown as a compact, modular RF device with precision components.
Master Local Oscillator (MLO) – a state-of-the-art redundant satellite signal source designed for long-term operation in GEO orbit.

Next Step: Achieving Technology Readiness Level 7 by the End of 2019

Following a successful Critical Design Review (CDR), the MLO project has entered its final development phase. The team aims to reach Technology Readiness Level 7 (TRL7) by December 2019. Testing and qualification are being conducted using a fully qualified engineering model (EQM).

Durability and Reliability in Space

The MLO is designed to operate for more than 15 years in GEO orbit. Its construction ensures high reliability and continuous operation, which is essential for telecommunication satellites, navigation systems, and other space applications.

Why is a Redundant Signal Source So Important?

Modern satellites employ redundant local oscillators to guarantee uninterrupted communication system performance. If one unit fails, the backup immediately takes over signal provision, minimizing the risk of service interruption.

Summary

The Master Local Oscillator project represents a major step forward in space technology development. After a successful CDR, the team is well on track to achieve TRL7, confirming the device’s readiness to perform under real orbital 

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images source: https://www.allardarchitecture.com/projects/estec-campus/