Remote Terminal Units Hero


Flexible and modular interface units for LEO, MEO, GEO and deep space satellites.

Flexible Remote Terminal Units

Remote Terminal Units (RTU) are applied as part of the satellites data handling system to extend the capabilities and the interfaces of the On-Board Computer. Terma’s RTU system provides a wide range of capabilities for monitoring, controlling, and powering of satellite equipment including sensors, thermistor, Attitude and Orbit Control System (AOCS) equipment and heaters.

Maximum flexibility during spacecraft integration

Customized Remote Terminal Units concept

In-house test and manufacturing facilities

Remote Terminal Unit Terma Space
For all mission types

Modular and flexible unit design

Terma's RTU system enables fast assembly of units of "any" size. Units can be assembled of off-the-shelf and custom-made modules as needed, and the customer can through configuration commands and tables modified the unit's operation. All unit configurations can as standard be manufactured to support any main bus range from 20V to 100V.
Terma RTU In Use DLR Heinrich Hertz Satellite in OHB, Bremen integration
Simplified satellite architecture

Distributed RTU system

Terma’s RTU system are designed as a small formfactor unit to support small and large satellites. For smaller satellites a single unit is typically able to provide the needed interfaces, while larger satellite may have several RTUs distributed throughout the satellite. The distributed unit architecture offers a number of benefits compared to a traditional single RTU, easier and more flexible satellite integration, simpler harness routing, lower harness mass and easier adaption to the satellite requirements.
Galileo Constellation ESA P. Carril ESA - P. Carril
For all environments

Mechanical, Thermal, and Radiation Endurance

Mechanical design of the assembled units is robust to sustain vibration and shock levels generates by most of the world’s launchers. A direct module thermal contact area to satellite structure ensures thermal segregation and proper temperature balance in the unit during all electrical load combinations. The electrical design provides full performance after 15 years in Geostationary Orbit.

RTU Modules

Terma have currently ten different off-the-shelf modules which provides a wide range of functionalities including: High Power Commanding, High accuracy signal and temperature acquisition, Serial data interfaces, Reaction wheel control and monitoring, Magnetorquer driving, Flow control valve, latch valve and ball valve driving, Voltage supply distribution, and Heater power distribution.

Core Module (CMH and CMS)

The CMH/S module acts as an RTU core module, connecting to various interface types through a MIL-STD-1553 Bus and a local Command/Telemetry bus distributed by a backplane module. It facilitates commandable functions and telemetry readings from connected interfaces. The CMH variant offers High-Power Commands, while the CMS version provides Serial Data Interfaces (SDI) with RS422 transceiver interfaces.

Heater Distribution Module (HDM)

The HDM interface facilitates power distribution to spacecraft heaters, functioning as a slave module to an upstream core module via a local Command/Telemetry bus. It is specifically designed to channel power from the spacecraft's main bus, regulated or unregulated, to resistive loads like heaters.

Attitude Control Module  (ACM and ACMB)

The ACM interface controls spacecraft attitude functions like reaction wheels and magnetic torquers as a slave module to an upstream core via a Command/Telemetry bus. It supports on/off switching through High-Power Commands and provides telemetry readings and status updates.

Orbit Control Module (OCML and OCMR)

The OCM interface acts as a slave module to an upstream core, controlling spacecraft orbit functions such as latch valves and flow control drives via a local Command/Telemetry bus. This module efficiently handles essential telemetry readings and orbit control operations.

Telemetry Acquisition Module (TAM)

The TAM module serves as an interface for monitoring spacecraft housekeeping signals and relaying telemetry data, acting as a slave module connected to an upstream core module via a local Command/Telemetry bus. Designed to integrate seamlessly with classical spacecraft sensors, it supports the on-board data handling system in managing essential spacecraft operations.

Case study

Terma has delivered more than 40 flight model RTUs for along range of missions, including H2Sat, Electra, LUXEOSys (NAOS), HERA, and CO2M.


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Søren Pedersen SPDS

Director, Sales and Business Development

Søren Pedersen