Status date

The project aims to develop and to qualify a new version of the PROP module that is used in the Spacebus4000 platform for telecom satellite. The PROP module implements the electronic for the control and the monitoring of the propulsion valves. The re-designed module is named PROPA and takes advantage of the experience gathered on the SB4000 satellites to simplify the requirements and to reduce the manufacturing costs.

The objectives of the PROPA development are:

  1. To reduce the manufacturing costs by 15% in comparison to the PROP module.
  2. To be compliant with the requirements for both the Alphabus and the SB4000 platforms.

PROPA board and PFDIU packaging concepts:

click for larger image
click for larger image


click for larger image


The key issues solved by the project are:

  1. Simplify the valve command and monitoring electronic without degrading the reliability of the propulsion sub-system.
  2. Optimize the command of the ABM valves: a novel design using a power switch is used to reduce the number and the complexity of the DC-DC converters used to control these valves.
  3. Optimize the manufacturability and the testability of the module.

The PROPA will improve the competitiveness of the Spacebus4000 platform. The PROPA module is pin compatible with the PROP module. The qualified on-board software developed using the PROP module will be re-used to control and to monitor the PROPA.

The PROPA is compliant with the requirements of the new Alphabus platform developed by the European space industry for large satellites.

  1. ABM 400N engine : Commanding and Monitoring ABM valves:
    • 2 drivers ( 1 for PROB_N, 1 for PROB_R),
    • 1 FU and 1 OX coils in serial configuration in front of each driver.
  2. 10N thrusters : Commanding and Monitoring bistable valves (BSV):
    • up to 16 + 4 bistable valves requiring 2 pulsed ON/OFF commands each,
    • 42V and 50V compatibility (chosen by external wire strap),
    • up to 16 + 4 status acquisition.
  3. 10N thrusters : Commanding and Monitoring monostable valves (MSV) :
    • up to 16 monostable valves,
    • 42V and 50V compatibility (chosen by external wire strap),
    • up to 8 MSV simultaneous command,
    • 100 commands 16 bits words with a 1 ms resolution every 100 ms.
  4. 10N thrusters : Arming/Venting:
    • permanent command of 4 MSV out of 16,
    • programmable MSV selection.
  5. 10N thrusters : Thrusters On Time (TOT) alarm:
    • up to 8 MSV control out of 16,
    • programmable MSV selection, using the BBC,
    • programmable integration time from 0 to 64 s
    • programmable threshold from 0 to 64 s.
  6. 10N thrusters : Thrusters History :
    • 16 MSV control,
    • 100 ms integration time, 1 ms resolution.
  7. Standard Pressure Transducers: Conditioning up to 9 Standard Pressure Transducers:
    • a.conditioning of up to 9 analogue signals.
  8. High Accuracy Pressure Transducers: Frequency meter
    • up to 3N + 3R HAPT interfacing,
    • for each HAPT, 2 simultaneous square waves frequency signals measures,
    • use of external high accuracy clock (1 Hz).
  9. Miscellaneous: Inhibiting via umbilical
    • dry contact,
    • Miscellaneous: Bus Brick Connection,
    • use of the standard BBC component (RD1).
  10. Miscellaneous: Cross strapping and failure propagation protection:
    • cold redundancy for all functions except for commanding and monitoring of ABM valves and for the HAPT interfaces
  11. Miscellaneous: Providing power supplies
    • 9 outputs (one active at a time) Standard Pressure Transducers,
    • 1N + 1R outputs for 3N + 3R High Accuracy Pressure Transducers.
  12. Miscellaneous: Configuring the PROB
    • ON/OFF of the PROB,
    • power status.

The development activities are:

  • Design, development and documentation of the PROPA module;
  • Manufacturing, electrical, thermal and mechanical validation tests of an EM model;
  • Development of the test equipment (HW and SW) for the PROPA module;
  • Qualification of the PROPA module in the PFDIU EQM6.

All activities are completed

Current status

All activities are completed.

  1. Qualification of the PROPA EQM was completed on 17.07.08,
  2. Qualification of the PFDIU EQM6, including the PROPA EQM, was completed on 14.01.2009,
  3. First flight-qualified PROPA was delivered to Alphabus/Inmarsat XL program on 12.01.2009.