STRIVING CIU Constellation Interface Unit (CIU) - STRIVING Maiden In-orbit Demonstration/Validation Mission

  • Status
    Completed
  • Status date
    2024-08-16
  • Activity Code
    4G.028
Objectives

The objective of the STRIVING cIU in-orbit validation/demonstration project was to gain flight heritage for the Beyond Gravity Finland Automotive/COTS component based Interface Electronics circuits. 

The cIU electronics circuits are used in Beyond Gravity Constellation Onboard Computer (cOBC) and constellation Remote Terminal Unit (cRTU) products Power Drive and Analog IO board (PDIO Board).

Challenges

The main technical challenge was the spacecraft payload interface power supply voltage range incompatibility. 

The spacecraft is supplying 18V-25.2V operation voltage to payload and cIU was designed to 22V-38V operation voltage range. The cIU DCDC converter redesign was required.

Benefits

The Constellation On Board Computer (cOBC) is a complete subsystem entirely based on commercial components to enable high performance and short lead times at an affordable price, still delivering the high reliability Beyond Gravity is well known for.  cOBC is Beyond Gravity off-the-shelf type standard product, and therefore cOBC can be offered at affordable price level also for non-constellation type small customers. 

The cOBC provides a host of functions including on-board processing, GNSS receiver, ground communication and both platform and payload interfaces. 

The cOBC Power, Drive and Analog IO Interface (PDIO) board technologies are in the scope this project.
The PDIO board will be also re-used in Beyond Gravity cRTU product.

Features

The PDIO board for the cOBC and cRTU offer many common analogue interfaces to support magnetorquers, analogue acquisitions, thermistors, secondary power supplies, and stepper motors including SADE. The solution is entirely based on COTS technology while providing a highly reliable solution.

System Architecture

cOBC/PDIO is based on Automotive/COTS components. All components are TID tested to >30 RAD level by Beyond Gravity team. Design is latchup free, and components are SEE tested.  

The product is highly integrated, providing spacecraft avionics and key interfaces in a single unit. 

The PDIO Key features

  • Off-the-shelf solution available at short lead times and an attractive price point

  • Fast and easy integration into the cOBC, at the quantity needed, using backplane-less solution

  • Highly configurable in software 

  • Support for both redundant and single string solutions

  • Manufacturing highly automated and optimized for large quantities.

PDIO key functions: 

  • DCDC Converter

  • CAN bus TM/TC protocol

  • Automotive grade, dual core lock step 

  • Pulse Matrix Command outputs

  • Secondary Voltages

  • Stepper Motor drive for SADM and antenna mechanisms

  • Magnetorquer drive interface

  • Analog and Digital signal acquisition interface.

 

Plan

The key tasks:

  • System design related to cIU interfacing with Spacecraft payload interface. 

  • The cIU health telemetry data collection SW implementation

  • Additional load and stimuli board design and MAIT

  • PFM and FM board MAIT

  • cIU interoperability testing against the spacecraft payload interface simulator.

  • The cIU health telemetry data analysis after the IOD mission

Current status

The project was completed without in-orbit demonstration due the cancellation of SITAEL’s STRIVING maiden in-orbit demonstration/validation mission. However, applicable cOBC/PDIO Flight Model deliveries are ongoing. Flight heritage for the product will be achieved on upcoming customer missions.