Radiation Tolerant Propulsion Controller

VACCO’s Propulsion System Controller is optimized for SmallSats and CubeSats and is a fully integrated controller including several driver types for many configurations of valves, heaters and pressure transducers.

The controller can be used with a blowdown system or a pressure regulated system. It comes pre-installed with a pressure regulation algorithm which allows a normally closed valve to regulate pressure. This allows an elegant yet effective way for pressure regulation of green mono-propellants, hydrazine, cold gas or other systems.

This radiation tolerant controller heavily leverages components with flight heritage and TID and SEE testing to provide a robust controller package. The aluminum housing can easily be customized to provide additional radiation shielding. Flight heritage exists with NanoACE in LEO and two MarCO units flown by Mars. Flight proven from LEO (NanoACE) to Mars (MarCO) and beyond.

Existing Design Features

  • 20 valve drivers with automatic stepdown current
  • 12 Heater Drivers
  • 8 Thermistors & 8 Thermocouples
  • Closed loop temperature control
  • 3 pressure sensors inputs
  • 2 closed loop pressure controlers
  • Auxiliary analog inputs
  • 9 to 13V or 24-33V input
  • RS-422, full duplex data interface
  • Telemetry transmitted at 10 Hz
  • 10Hz command rate
  • Firing command response within 5ms
  • Firing time resolution to 1ms
  • Passed Radiation testing at 22 kRAD and 200 MeV protons (tested without shielding)
  • Built-in radiation sensors: 0-2kRAD and 0-13kRAD LEO and two MarCO units flown by Mars. Radiation test heritage includes 22kRAD TID and high energy 200 MeV proton SEE tests.


  • Flight and simulator boards available
  • Hot-cold and hot-warm redundancy
  • Emulators for ground testing
  • Custom operating voltages
  • Flight equivalent units for radiation testing
  • Custom designs for extra valves, heaters, thermistor, PTs, etc.

pdf-iconRadiation Tolerant Propulsion Controller Datasheet

Operating Parameters

Standby power <5W
Operating temperature rage - 30°C to +70°C
Storage temperature range - 40°C to +85°C
Operating voltage option 1 9 to 13V
Operating voltage option 2. 24 to 32V
Data interface RS-422, full duplex
Maximum fire duration 30 minutes
Fire time resolution 1ms
Maximum output current 6 Amps
Performance characteristics are based on customer requirements. As such, they are not representative of component capabilities or limitations.

Example Controller Block Diagram

PowerPoint Presentation

Example Flow Diagram

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