Status date

Design, development and industrialisation of a Payload Interface Unit (PLIU). The PLIU is the equipment that acts as an interface between the satellite central computer and the telecommunication payload for all types of TM/TC lines as well as heater interfaces.

It is Thales Alenia Space España's strategy to profit from this investment and these developments to address future opportunities in the potential markets listed below:

  • MSS LEO constellations: Globalstar, O3B, Iridium
  • Navigation MEO constellations: Galileo
  • Small satellites (~500-800Kg) optimized for low cost/high production

The project deals with the tasks needed to upgrade the reference PLIU product. The upgrading made it valid for O3B constellation satellites application attacking three main axes:

  1. Functional improvement: TAS España enlarged significantly PLIU capability to handle/provide several types of TM/TC interfaces. It permitted both meeting O3B payload specific needs and ensuring the reutilization of the new equipment in future programs with just few adaptations.
  2. Implementation improvement: This improvement has been done in two main sub-axis: One, the growth of the quantity of interfaces in the PLIU means higher occupied surface by the associated electronic using existing hybrids instead of discrete parts, and secondly, to mitigate the obsolescence of the ATMEL MG2RT technology with the implementation of a FPGA instead of ASIC.
  3. Industrialisation of the product improvement: The stringent pressure for cost reduction obliged us to advance further in the industrialisation efforts with respect to the reference design taking also into account lessons being learnt in the realisation of the GB2 project. This task comprised the optimisation of both manufacturing and testing activities.

In summary, the proposed ARTES 4 activity intended to support O3B PLIU resulting contract by the realisation of these objectives and the development of a truly reference product for future opportunities.

The qualification of the ARTES4 PLIU EQM was focused on the new design based on FPGA and a complete qualification campaign was done in the different environmental fields as shown in the next picture.

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The challenges have been related to the implementation improvement based on hybridisation and digital control module redesign.

Hybridisation of two main circuitries as follows:

  1. Hybridisation of command generation circuitry: The MOSFET matrix considered to build up the command generation interface is suitable to hybridisation using existing devices.
  2. Hybridisation of heaters Control and Power Block circuitry: An existing hybrid from International Rectifier has been used as switch for the heater lines. The utilisation of these hybrids allows as well the reduction of the number of parts and optimising production costs.

Digital control module redesign was implemented in an FPGA that is the key part hosting all the intelligence of the equipment. The FPGA solution is the selected one taking into account the high Non Recurrent costs associated with the manufacturing of a new ASIC, and the cost, risk and scheduling advantages that this kind of parts present against ASIC solutions.


Over the last years, Thales Alenia Space España has also won several contracts for the supply of Data Handling units for a number of Earth observation satellites. These Data Handling units, which are the interface between the platform bus and the observation payload, benefit from the technical developments achieved in the frame of this ARTES project.

The replacement of the above-mentioned telecom and navigation satellite constellations (e.g. Globalstar, Iridium, O3b and Galileo) is expected in the long-term, as the lifetime of these satellites ranges from 10 to 15 years. In the short and mid-term, a significant volume of Earth observation programs is expected.


The PLIU is in charge of the interface between the Satellite Platform and the payload units. Its functions are:

  • To provide ANA, ML16, HLC and LLC Commands to payload equipments.
  • To acquire the telemetry data from the payload equipment.
  • To provide the ON/OFF function for the Payload Heaters.
  • To receive commands/ send telemetry words from/to the platform by means of redounded 1553B Bus interfaces.

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The Project Plan is composed of the following axes to be developed:

  1. Upgrade of the PLIU electrical design,
  2. Upgrade of the PLIU EGSE design
  3. Tools designed for the PLIU development
  4. Qualification of mounting processes
  5. Qualification of ARTES4 PLIU EQM

The ARTES4 PLIU EQM Qualification Test Sequence was the following one:

  • Initial Functional Tests,
  • Vibration Tests,
  • Post-vibration Functional Tests,
  • EMC Tests,
  • Post-EMC Functional Tests,
  • Shock Tests,
  • Post-Shock Functional Tests,
  • Thermal Vacuum Tests,
  • Final Functional Tests, and
  • Physical Measurements.

According to MIL STD 1553 Electrical Validation and Production test plan optimization, Initial and Final Functional Tests included the MIL-STD-1553 Electrical Test (buses A and B), which were performed semi automatically.

Current status

The results of the ARTES4 PLIU work are the following:

  1. Upgrade of the PLIU electrical design has been done
  2. Upgrade of the PLIU EGSE design has been done
  3. Tools designed for the PLIU development have been done
  4. Qualification of new mounting processes has been done
  5. Qualification of ARTES4 PLIU EQM has been done

Regarding the commercial accomplishments, Thales Alenia Space España was awarded the contract for the development of the PLIU for a constellation program, which was one of the two main targets. In addition, we have been awarded the contracts for the development of the Data Handling units for some Earth observation programs.