Power Distribution System Electronics

The SACI, PAPI, and LASI boards provide a complete spacecraft power distribution system solution. The SACI Board provides a solar array and battery interface complete with battery charge control and telemetry feedback capability. The PAPI/LASI and McLASI boards are general purpose switching cards which are controlled via the SACI. Multiple PAPI/LASI/McLASI boards may be combined to increase the system capabilities.

The SACI, McLASI, and PAPI/LASI are designed to be compatible with a 3U form factor and provide interfaces for a 3U cPCI backplane. In such a setup, the SACI and PAPI/LASI may be used as part of an Integrated Avionics Unit – combining C&DH and EPS functions in one compact assembly.

SACI™ Boards

Typical SACI Features

• Charge Control & Solar Array Interface Card
• 14 Solar Array String Inputs @ 6.9 A (derated)
• 12/14 Array Strings Switched
• Software Battery Charging with HW Backup
• Autonomous Charging of Dead Battery
• Switch Command & Telemetry Interface
• Controls up to 3 LASI Cards
• Solar Array / Battery / Load Current Telemetry
• Battery Voltage Telemetry
• 8 PRT Sensor Interfaces
• 3 Low Voltage Switched Outputs @ 5 V, +/-15 V
• 20 A Total Throughput Current
• RS-422 Interface
• Dimensions:
  • 112 mm x 218 mm x 36 mm
  • Mass: <0.32 kg

Program Heritage

• TacSat-2, XSS-11, AMS (Gen 1 SACI)
• STP-SIV, Angels, Aquila, LADEE (Gen 2 SACI)

SACI, McLASI, and PAPI/LASI are inteded to be used in an integrated avionics unit. In such a system, a SACI is used together with a custom backplane that also acts as a cPCI backplane. Multiple Boards may be used to provide up to 69 switched outputs. Any cPCI boards such as a CPU and MOAB may be added in the same system to provide a complete spacecraft C&DH and EPS avionics unit.

PAPI™ / LASI™ Boards

Typical PAPI/LASI Features

• 5 Arm/On/Off Outputs @ 6.9 A each (derated)
• 10 On/Off Outputs @ 6.9 A each (derated)
• 2 Arm/On/Off Outputs @ 1.2 A each (derated)
• 6 On/Off Outputs @ 1.2 A each (derated)
• 15 A Throughput Current
• Bus Voltage Telemetry
• Total Card Current Telemetry
• Switch Status Telemetry
• Dimensions:
  • 3U Form Factor
  • Mass: <0.22 kg

Program Heritage

• TacSat-2, XSS-11, AMS, STP-SIV,
• Angels, Aquila, LADEE

McLASI™ Boards

Typical McLASI Features

• 4 On/Off Outputs @ 15 A each (derated)
• 3 Torque Rod Power Outputs (H-Bridge)
• Valve and/or Motor Driver Circuitry
• 20 A Throughput Current
• Bus Voltage Telemetry
• Total Card Current Telemetry
• Switch Status Telemetry
• Dimensions:
  • 3U Form Factor
  • Mass: <0.20 kg

Program Heritage

• TacSat-2, Aquila, STP-SIV