A new network paradigm for the On-Board Reference Architecture (OSRA-Net)

Contractor(s): TAS (FR), GMV (ES), SPACEBEL (BE), bright ascension (UK)

ESA Budget: 400kE

YoC: 2017

Background and justification

The SAVOIR functional reference architecture is defining the different architectural elements of the on-board systems and their functions. The exchange of information required to support the execution of these functions need to be characterized in order to perform architectural trade-offs early in the development process.

Objective(s)

• Study the possibility to extend the OSRA concepts to new units of the SAVOIR reference architecture with a particular focus on the communication aspects.
• Analyze and characterize all the communications between all units to support the different functions.
• Specify the communication requirements of a spacecraft:

The seven classes of communication:

• Class 1: Low frequency, small / medium data size, non time critical
• Class 2: Medium frequency, Medium data size, time critical, medium QoS
• Class 3: Medium frequency, Medium data size, time critical, high QoS
• Class 4: Low frequency, Big data size, non time critical, low QoS
• Class 5: High frequency, Medium data size, time critical, medium QoS
• Class 6: Medium frequency, Big data size, time critical, medium QoS
• Class 7: Medium frequency, Small data size, time critical, low jitter, high QoS

Achievements and status

• The inputs provided to the SAVOIR Working Group will be used to produce a Requirement Document covering the communication in spacecrafts to be published in 2018.
• The prototype supported the verification of most of the requirements through an implementation of an AFDX-like and light protocol over SpaceWire.

Benefits

The identification of communication needs early in the development process shall allow to identify the best implementation solutions. The consideration of future use in spacecrafts (e.g. navigation by camera) shall provide requirements to developer of new communication links and protocols.

Next steps

A follow-on TRP activity called “OSRA ION” has been defined in the Avionics roadmap with the objective to reach TRL 4. This activity aims at developing a tool able to support the trade-off of spacecraft’s communication system.